V. Symbol for vanadium. hydrogen and chlorine both have a valence of 1,

oxygen a valence of 2, and nitrogen 3, the valence-

balancing principle gives the formulas HCl, H

vacancy. (1) A defect in a crystal due to the

,Cl

O, NCl

, and N

, which indicate the rela-

absence of an atom in the lattice.

tive numbers of atoms of these elements in com-

See hole. (2) The absence of one or more electrons in

pounds that they form with each other. In inorganic

the outer shell of an atom.

compounds it is necessary to assign either a positive

or negative value to each valence number, so that

vacuole. Membrane-bound fluid-filled space

valence balancing will give a zero sum by algebraic

within a cell. In most plant cells, there is a single

addition. Negative numbers are called polar valence

large vacuole filling most of the cell’s volume.

numbers (–1 and –2). The valence of chlorine may

Some bacterial cells contain gas vacuoles.

be −1, +1, +3, +5, or +7, depending on the type of

compound in which it occurs. In organic chemistry

vacuum deposition. The process of coating a

only nonpolar valence numbers are used.

base material by evaporating a metal under high

See chemical bonding; oxidation; oxidation number;

vacuum and condensing it on the surface of the

coordination number.

material to be coated, which is usually another metal

or a plastic. Aluminum is most commonly used for

this purpose. The coatings obtained range in

valence electrons. The electrons in the outer-

thickness from 0.01 to as many as 3 mils. A vacuum

most shell of an atom determining chemical prop-

of about one-millionth atmosphere is necessary. The

erties.

process is used for jewelry, electronic components,

decorative plastics, etc. Thermally evaporated met-

valentinite. (antimony trioxide [ortho-rhom-

als and dielectric coatings can be effectively applied

bic]; white antimony).

to glass by this method. It is also called vacuum

CAS: 1309-64-4. Sb

coating and vacuum metallizing.

Properties: White or gray mineral, sometimes pale

red, white streak and adamantine or silky luster. D

vacuum distillation. Distillation at a pressure

5.57–5.76, Mohs hardness 2–3.

below atmospheric but not so low that it would be

Occurrence: Algeria, the former Yugoslavia, Italy,

classed as molecular distillation. Since lowering the

Germany.

pressure also lowers the boiling point, vacuum dis-

Use: Ore of antimony.

tillation is useful for distilling high-boiling and heat-

sensitive materials such as heavy distillates in petro-

leum, fatty acids, vitamins, etc.

valepotriate.

CAS: 18296-44-1. mf: C

Hazard: A poison.

vacuum forming. See thermoforming (2).

val. Abbreviation for value.

valeral. See valeraldehyde.

valacidin.

n-valeraldehyde. (valeric aldehyde; valeral;

CAS: 3930-19-6. C

amyl aldehyde; pentanal).

Properties: Brown to red solid. Soluble in polar

CAS: 110-62-3. CH

(CH

)

CHO.

solvents and alkaline solutions; insoluble in most

Properties: Colorless liquid. D 0.8095 (20/4C), fp

nonpolar solvents and acid solutions.

−91C, bp 102–103C, refr index 1.3944 (20C), flash

Use: Antibiotic (used as a preservative for biological

p 54F (12.2C) (CC). Slightly soluble in water; solu-

specimens); embalming fluids.

ble in alcohol and ether.

Derivation: Oxidation of amyl alcohol, also by the

“Valclene” [Du Pont]. TM for clear fluoro-

Oxo process.

carbon formulations with slight ethereal odor. Non-

Hazard: Flammable, dangerous fire risk. TLV: 50

flammable.

ppm.

Use: Dry-cleaning fluids.

Use: Flavoring, rubber accelerators.

See isovaleraldehyde.

valence. A whole number that represents or de-

notes the combining power of one element with

another. By balancing these integral valence num-

valeranone.

bers in a given compound, the relative proportions CAS: 55528-90-0. mf: C

of the elements present can be accounted for. If Hazard: A poison.

1309

1310VALERENAL

valerenal. oils, and as solvent for adhesives, insecticides, and

CAS: 4176-16-3. mf: C

O. lacquers.

Hazard: A poison.

valine. (␣-aminoisovaleric acid).

CAS: (

D-) 72-18-4. (CH

)

CHCH(NH

)COOH. An

valerenic acid.

essential amino acid.

CAS: 3569-10-6. mf: C

Properties: White, crystalline solid. Soluble in wa-

Hazard: A poison.

ter; verghtly soluble in alcohol; insoluble in ether;

shows the following optical isomers: (

DL-valine) Mp

valerianic acid. See valeric acid.

298C with decomposition. (

D-valine (natural iso-

mer): Mp 315C with decomposition. (

L-valine) Mp

valerian oil.

293C with decomposition.

Properties: Yellowish or brownish liquid; penetrat-

Derivation: Hydrolysis of proteins, synthesized by

ing odor. D 0.903–0.960, refr index 1.486 (20C).

the reaction of ammonia with ␣-chloroisovaleric

Soluble in alcohol, ether, chloroform, acetone, ben-

acid. Available commercially as

D-, L-, or DL-valine.

zene, and carbon disulfide. Combustible. Chief con-

Use: Dietary supplement, culture media, biochemical

stituents: Pinene, camphene, borneol, and esters of

and nutritional investigations.

borneol and valeric acid.

Derivation: Distilled from roots and rhizome of Va-

“Valium” [Hoffmann-La Roche]. TM for

leriana officinalis.

diazepam.

Use: Tobacco perfume, industrial odorant, flavors.

valone. (2-isovaleryl-1,3-indanedione).

valeric acid. (valerianic acid; n-pentanoic

Properties: Yellow, crystalline solid. Mp 68C. Insol-

acid).

uble in water; soluble in common organic solvents.

CAS: 109-52-4. CH

(CH

)

COOH.

A blood anticoagulant.

Properties: Colorless liquid; penetrating odor and

Hazard: Toxic by ingestion.

taste. D 0.9394 (20/4C), bp 185.4C, refr index

Use: Pesticide, rodenticide.

1.4081 (20C), vap press 0.08 mm Hg (20C), fp

−34C, flash p 205F (96C) (OC). Soluble in water,

vanadic acid. (1) meta-HVO

, (2) ortho-H

alcohol and ether. Undergoes reactions typical of

(3) pyro-H

. These acids apparently do not exist

normal monobasic organic acids. Combustible.

in the pure state but are represented in the various

Derivation: With other C

acids by distillation from

alkali and other metal vanadates. Ordinarily, vanad-

valerian, by oxidation of n-amyl alcohol, numerous

ic acid implies vanadium pentoxide (vanadic acid

essential oils.

anhydride).

Grade: Technical, reagent.

Hazard: Toxic by ingestion, strong irritant to skin

vanadic acid anhydride. See vanadium

and tissue.

pentoxide.

Use: Intermediate for flavors and perfumes, ester-

type lubricants, plasticizers, pharmaceuticals, vinyl

vanadic(II) acid, trisodium salt. See sodi-

stabilizers.

um orthovanadate.

See isovaleric acid.

vanadic sulfate. See vanadyl sulfate.

valeric aldehyde. See n-valeraldehyde.

vanadic sulfide. See vanadium sulfide.

␥-valerolactone.

CAS: 108-29-2.

vanadinite. Pb

Cl(VO

). A natural chlorovana-

date of lead.

Properties: Ruby-red, orange-red, brown, yellow

solid; resinous to adamantine luster. Mohs hardness

3, d 6.7–7.1. Soluble in strong nitric acid.

Occurrence: New Mexico, Arizona, Africa, Scot-

Properties: Colorless liquid. D 1.0518 (25/25C), bp

land, the former U.S.S.R..

205–206.5C, crystallizing point −37C, flash p 205F

Use: Ore of vanadium and lead.

(96C) (COC), refr index 1.4301 (25C), surface ten-

sion 30 dynes/cm (25C), viscosity 2.18 cP (25C), pH

(anhydrous) 7.0 (pH of 10 solution in distilled water

vanadium.

4.2). Miscible with water and most organic solvents, CAS: 7440-62-2. V. Metallic element having atom-

resins, waxes, etc.; slightly miscible with zein, bees- ic number 23, group VB of the periodic table, aw

wax, petrolatum; immiscible with anhydrous glyc- 50.9414, valences of 2, 3, 4, 5; two natural isotopes.

erin, glue, casein, arabic gum, and soybean protein. Properties: Silvery-white ductile solid. D 6.11, mp

Combustible. 1900C, bp 3000C. Insoluble in water; resistant to

Use: Dye baths (coupling agent), brake fluids, cutting corrosion, but soluble in nitric, hydrofluoric, and

1311 VANADIUM PENTOXIDE

concentrated sulfuric acids; attacked by alkali,

vanadium hexacarbonyl. V(CO)

forming water-soluble vanadates. Acts as either a Properties: Blue-green powder. Sublimes easily at

metal or a nonmetal and forms a variety of complex 50C (15 mm Hg), paramagnetic, decomposes with-

compounds. out melting at 60–70C.

Source: Not found native; principal ores are patron- Hazard: Strong irritant to tissue; store under inert

ite, roscoelite, carnotite and vanadinite. Also from gas.

phosphate rock (Idaho, Montana, Arkansas). Use: Chemical intermediate, production of plating

Occurrence: Colorado, Utah, New Mexico, Arizo- compounds and fuel additives.

na, Mexico, and Peru.

Derivation: (1) Calcium reduction of vanadium

vanadium hexacarbonyl, sodium salt.

pentoxide yields 99.8+% pure ductile vanadium; (2)

(bisdiglymesodium hexacarbonyl vanadate).

aluminum, cerium, etc. reduction produces a less

Na(C

)

V(CO)

. A convenient though incom-

pure product; (3) solvent extraction of petroleum ash

plete name for the complex compound.

or ferrophosphorus slag from phosphorus produc-

Properties: Yellow solid. Mp 173–176C (with de-

tion; (4) electrolytic refining using a molten salt

composition). Soluble in water, alcohol, and ether;

electrolyte containing vanadium chloride.

slightly soluble in hydrocarbons; relatively inert to

Grade: 99.99% pure (electrolytic process), single

air but is stored and shipped under nitrogen.

crystals.

Hazard: Strong irritant to tissue.

Use: Target material for X rays, manufacture of alloy

Use: Source of vanadium hexacarbonyl by treatment

steels, vanadium compounds, especially catalyst for

with phosphoric acid under special conditions.

sulfuric acid and synthetic rubber.

See ferrovanadium.

vanadium nitride. VN.

Properties: Black solid. D 6.13, mp 2320C. Insolu-

ble in water; slightly soluble in aqua regia.

vanadium acetylacetonate.

Use: Refractory.

Properties: Blue to blue-green crystals. Decomposes

before melting.

vanadium oxydichloride. See vanadyl chlo-

Derivation: Reaction of vanadyl sulfate with acetyl-

ride.

acetone and sodium carbonate.

Use: Catalyst.

vanadium oxytrichloride.

CAS: 7727-18-6. VOCl

vanadium carbide. VC.

Properties: Lemon-yellow liquid. D 1.811 (32C), fp

Properties: Crystal. Mohs hardness 2800 kg/sq mm,

−78.9C, bp 125–127C, nonionizing solvent. Dis-

d 5.77, mp 2800C, bp 3900C, resistivity 150 micro-

solves most nonmetals; dissolves and/or reacts with

ohm-cm (room temperature).

many organic compounds; hydrolyzes in moisture.

Use: Alloys for cutting tools, steel additive.

Hazard: Strong irritant to tissue.

Use: Catalyst in olefin polymerization (ethylenepro-

vanadium dichloride. (vanadous chloride).

pylene rubber) organovanadium synthesis.

CAS: 10213-09-9. VCl

Properties: Apple-green hexagonal plates. D 3.23

vanadium pentoxide. (vanadic acid anhy-

(18C). Soluble in alcohol and ether; decomposes in

dride).

hot water.

CAS: 1314-62-1. V

Derivation: From vanadium trichloride by heating in

Properties: Yellow to red crystalline powder. D

atmosphere of nitrogen.

3.357 (18C), mp 690C, bp (decomposes) 1750C.

Method of purification: Sublimation in nitrogen.

Soluble in acids and alkalies; slightly soluble in

Grade: CP.

water.

Hazard: Strong irritant to tissue.

Derivation: (1) Alkali or acid extraction from vana-

Use: Strong reducing agent, purification of hydrogen

dium minerals. (2) By igniting ammonium metava-

chloride from arsenic.

nadate. (3) From concentrated ferrophosphorus slag

by roasting with sodium chloride, leaching with

vanadium disulfide. V

water and purification by solvent extraction fol-

Properties: Solid. D 4.20, mp (decomposes). Solu-

lowed by precipitation and heating.

ble in hot sulfuric or nitric acids; insoluble in al-

Method of purification: Alkali solution, precipita-

kalies.

tion as ammonium metavanadate and ignition to

Use: Solid lubricant, electrode in lithium-based bat-

teries (experimental).

Grade: Commercial air-dried, commercial fused, CP

air-dried, CP fused.

vanadium ethylate. (C

V. Hazard: Toxic by inhalation. TLV: 0.05 mg(V

Properties: Dark-reddish-brown solid. m

; not classifiable as a human carcinogen.

Derivation: Reaction of vanadium chloride with so- Use: Catalyst for oxidation of sulfur dioxide in sulfu-

dium ethylate. ric acid manufacture, ferrovanadium, catalyst for

Use: Polymerization catalyst. many organic reactions, ceramic coloring material,

1312VANADIUM SESQUIOXIDE

vanadium salts, inhibiting UV transmission in glass, Hazard: Irritant.

photographic developer, dyeing textiles. Use: Catalyst for conversion of ethylene to ethanol.

See contact process.

vanadous chloride. See vanadium dichlo-

vanadium sesquioxide. See vanadium tri- ride.

oxide.

vanadyl chloride. (vanadium oxydichloride;

vanadyl dichloride; divanadyl tetrachloride).

vanadium sulfate. See vanadyl sulfate.

CAS: 10213-09-9. V

•5H

Properties: Green, deliquescent crystal. Usual tech-

vanadium sulfide. (vanadium pentasulfide;

nical product is a dark-green, syrupy mass 76–82%

vanadic sulfide). V

pure, or a solution. Slowly decomposed by water;

Properties: Black-green powder. D 3.0, decomposes

soluble in water, alcohol, and acetic acid; may react

on heating. Soluble in acids, alkali-metal sulfides

violently with potassium.

and alkalies; insoluble in water.

Grade: Technical.

Derivation: Action of hydrogen sulfide on vanadium

Hazard: Irritant.

chloride solution.

Use: Mordanting textiles.

Hazard: Toxic by inhalation (especially to animals).

Use: Vanadium compounds.

vanadyl sulfate. (vanadic sulfate; vanadium

sulfate).

vanadium tetrachloride.

CAS: 27774-13-6. VOSO

•2H

CAS: 7632-51-1. VCl

Properties: Blue crystals. Soluble in water.

Properties: Red liquid. D 1.816 (20C), fp −28C, bp

Derivation: Reduction of cold solution of concentra-

154C. Decomposes slowly to vanadium trichloride

ted sulfuric acid and vanadium pentoxide by sulfur

and chlorine below 63C. Soluble in absolute alcohol

dioxide gas.

and ether. Nonflammable.

Hazard: Irritant.

Derivation: Chlorination of ferrovanadium.

Use: Mordant, catalyst, aniline black preparation,

Method of purification: Distillation and fraction-

reducing agent, colorant in glasses and ceramics.

ation.

Hazard: Toxic by ingestion, inhalation, and skin

“Vanaquat” [Evans Vanodine]. TM for a

absorption. Open containers only in dry, oxygen-

cleaner and disinfectant for food processing equip-

free atmosphere or inert gas; wear goggles and pro-

ment.

tective clothing; corrosive to tissue.

Use: Preparation of vanadium trichloride, vanadium

dichloride, and organovanadium compounds.

“Vanason” [Evans Vanodine]. TM for a

tank sanitizer for dairy farm equipment.

vanadium tetraoxide. V

Properties: Blue-black powder. D 4.339, mp 1967C.

vancomycin hydrochloride.

Insoluble in water; soluble in alkalies and acids. Properties: Tan to brown powder; odorless; bitter

Derivation: (1) From vanadium pentoxide by oxalic taste. Soluble in water; moderately soluble in dilute

acid reduction. (2) From vanadium pentoxide by methanol; insoluble in higher alcohols, acetone,

carbon reduction. ether.

Hazard: Toxic and irritating. Derivation: Produced by Streptomyces orientalis

Use: Catalyst at high temperature. from Indonesian and Indian soil.

Grade: USP.

Use: Medicine (antibiotic).

vanadium trichloride.

CAS: 7718-98-1. VCl

Properties: Pink, deliquescent crystals. D 3.0 (18C),

“Vancote 2K” [Vanderbilt]. TM for a water-

decomposes on heating. Soluble in absolute alcohol borne epoxy fast dry shop primer.

and ether; decomposes in water.

Derivation: From vanadium tetrachloride boiling

van der Waals forces. (London dispersion

under reflux condenser.

force). Weak attractive forces acting between mole-

Hazard: Irritant.

cules. They are somewhat weaker than hydrogen

Use: Preparation of vanadium dichloride and organo-

bonds and far weaker than interatomic valences.

vanadium compounds.

They are involved in the van der Waals equation of

state for gases, which compensates for the actual

vanadium trioxide. (vanadium sesquioxide). volume of the molecules and the forces acting be-

CAS: 1314-34-7. V

. tween them. “Information regarding the numerical

Properties: Black crystals. D 4.87 (18C), mp 1970C. values of van der Waals forces is mostly semiempir-

Soluble in alkalies and hydrogen fluoride; slightly ical, derived with the aid of theory from an analysis

soluble in water. of chemical or physical data. Attempts to calculate

Derivation: From vanadium pentoxide by either hy- the forces from first principles have had a measure

drogen or carbon reduction. of success only for the simplest systems, such as

1313 “VARONIC”

H−H, He−He and a few others. When judging the pounds to three-dimensional and asymmetrical mo-

difficulties of such calculations, one must bear in lecular structure. This led to the development of

mind that the energies sought are of the same order stereochemistry. He was educated at the Universi-

of magnitude as those in the best atomic energy ties of Paris and Utrecht, where he received a doctor-

calculations.” (Henry Margenau). ate in 1874. He was a professor at Amsterdam,

See hydrogen bond; chemical bonding. Leipzig, and Berlin.

Van Dyke brown. (Cassel brown; Cologne

“Vapona” [Shell]. TM for an insecticide that

brown; Cologne earth; ulmin brown). A natural-

contains more than 93% 2,2-dichlorovinyl dimethyl

ly occurring pigment.

phosphate and less than 7% active, related com-

Derivation: Indefinite mixture of iron oxide and or-

pounds.

ganic matter. Obtained from bog-earth, peat depo-

See DDVP.

sits, or ochers that contain bituminous matter.

Hazard: As for dichlorovos.

Use: Pigment for artists’ colors and stains.

vapor. An air dispersion of molecules of a sub-

Van Dyke red. A brownish-red pigment con-

stance that is liquid or solid in its normal state, i.e., at

sisting of copper ferrocyanide; sometimes used to

standard temperature and pressure. Examples are

refer to red varieties of ferric oxide.

water vapor and benzene vapor. Vapors of organic

Use: Pigment.

liquids are also loosely called fumes.

See iron oxide red.

See evaporation; gas.

vanillin. (3-methoxy-4-hydroxybenzaldehyde;

vapor density. Weight of a vapor per unit vol-

vanillic aldehyde).

ume at any given temperature and pressure.

CAS: 121-33-5. (CH

O)(OH)C

CHO. The meth-

yl ether of protocatechuic aldehyde.

vapor-phase chromatography. See gas

Properties: White, crystalline needles; sweetish

chromatography.

smell. D 1.056, mp 81–83C, bp 285C. Soluble in 125

parts water, in 20 parts glycerol, and in 2 parts 95%

vapor pressure. (vap press; vap p; v.p.).

alcohol; soluble in chloroform and ether. Combus-

The pressure (often expressed in millimeters of mer-

tible.

cury, mm Hg) characteristic at any given tempera-

Derivation: (1) By extraction from the vanilla bean,

ture of a vapor in equilibrium with its liquid or solid

(2) from lignin contained in sulfite waste pulp li-

form.

quor.

Method of purification: Crystallization.

vapor tension. See vapor pressure.

Grade: Technical, USP, FCC.

Use: Perfumes, flavoring, pharmaceuticals, laborato-

varnish. (1) An organic protective coating similar

ry reagent, source of L-dopa.

to a paint except that it does not contain a colorant. It

may be composed of a vegetable oil (linseed, tung,

van Leeuwenhoek, Anton. (1632–1723). A

etc.) and solvent or of a synthetic or natural resin and

native of Holland, van Leeuwenhoek was a profes-

solvent. In the first case the formation of the film is

sional lens grinder. He developed the compound

due to polymerization of the oil and in the second to

optical microscope, which had been invented in

evaporation of the solvent. “Long-oil” varnishes

1590, to a point where he was able to obtain magnifi-

such as spar varnish have a high proportion of drying

cations up to 275 times. He was the first to observe

oil; “short-oil” types have a lower proportion, i.e.,

bacteria, spermatozoa, and other unicellular ani-

furniture varnishes. Spirit varnishes contain such

mals, which he described to the Royal Society of

solvents as methanol, toluene, ketones, etc. and of-

London.

ten also thinners such as naphtha or other light hy-

See optical microscope.

drocarbon. Flammable. (2) A hard, tightly adherent

deposit on the metal surfaces of automobile engines

“Vansil” [Vanderbilt]. TM for a calcium me-

resulting from resinous oxidation products of gaso-

talsillicate filler mineral.

line and lubricating oils.

Van Slyke determination. Treatment of pri-

varnish remover. See paint remover.

mary aliphatic amines and ␣-amino acids with ni-

trous acid and volumetric determination of evolved

nitrogen.

“Varonic” [Crompton & Knowles]. TM for

ethoxylated primary amines. 2- to 30-mole adducts

van’t Hoff, Jacobus H. (1852–1911). A of primary fatty amines based on coco, soya, tallow,

Dutch chemist who received the first Nobel Prize for and oleic acid.

chemistry in 1901. A father of physical chemistry, Properties: Oil and water soluble.

he did research on decomposition and formation of Use: In textile industry and other emulsifier applica-

double salts. He related optically active carbon com- tions.

1314VARRENTRAPP REACTION

Varrentrapp reaction. Cleavage of oleic acid vegetable black. In general, any form of more

into palmitic and acetic acids by heating with molten or less pure carbon produced by incomplete com-

potassium hydroxide. The procedure has been ex- bustion or destructive distillation of vegetable mat-

tended to olefinic acids in general. ter, wood, vines, wine lees.

vasopressin. (␤-hypophamine; antidiuretic

vegetable dye. A colorant derived from a vege-

hormone). One of the hormones secreted by the table source, i.e., logwood, indigo, madder, etc.

posterior lobe of the pituitary gland. It causes in

blood pressure and an increase in water retention by

vegetable gum. See dextrin.

the kidney. Vasopressin is an octapeptide consisting

of eight amino acids.

vegetable oil. An oil extracted from the seeds,

Derivation: Synthetic, or from the posterior lobe of

fruit, or nuts of plants and generally considered to be

the pituitary of food animals.

a mixture of glycerides (e.g., cottonseed, linseed,

Grade: USP as an aqueous solution for injection.

corn, coconut, babassu, olive, tung, peanut, perilla,

Use: Medicine (antidiuretic).

oiticica, etc.). Many types are edible. Being plant-

derived products, vegetable oils are a form of bio-

vasopressin, 8-l-arginine-. See arginine va-

mass. Some are reported to be convertible to liquid

sopressin.

fuels by passing them over zeolite catalysts.

Use: Paints (as drying oils), shortenings, salad dress-

vat dye. A class of water-insoluble dyes that can

ings, margarine, soaps, rubber softeners, dietary

be easily reduced, i.e., vatted to a water-soluble and

supplements, pesticide carriers.

usually colorless leuco form in which they can readi-

ly impregnate fibers. Subsequent oxidation then

vegetable tanning. The tanning of leather by

produces the insoluble colored form that is remark-

plant extracts.

ably fast to washing, light, and chemicals. Examples

See tannic acid; tanning; wattle bark; quebracho.

are indigo (CI 73000) and Indanthrene Blue BFP (CI

69825). The reducing agents are usually an alkaline

vehicle. A term used in paint technology to indi-

solution of sodium hydrosulfite (Na

). Oxida-

cate the liquid portion of a paint, composed of drying

tion is by air, perborate, dichromate, etc.

oil or resin, solvent, and thinner, in which the solid

Use: For cotton, wool, and cellulose acetate.

components are dissolved or dispersed.

See paint.

vat printing assistant. A mixture of gums and

reducing and wetting agents used to carry the dye in

Venetian red. A high-grade ferric oxide pig-

printing fabrics with vat dyes. They assist in secur-

ment of a pure red hue. It is obtained either native as

ing penetration of the fabric and in converting the

a variety of hematite red or more often artificially by

dyes from a semileuco to a leuco state.

calcining copperas (ferrous sulfate) in the presence

of lime. The composition ranges from 15 to 40%

“Vatsol” [Cytec]. TM for a series of wetting

ferric oxide and from 60 to 80% calcium sulfate. The

agents made in several different grades and types:

40% ferric oxide is the “pure” grade and has a d 3.45.

OS, sodium isopropyl naphthalene sulfonic acid;

Grade: 20–40% ferric oxide.

OT, sodium dioctyl sulfosuccinate.

See iron oxide red.

vatting The process of solubilizing vat dyes in an

venturi. A type of flowmeter used for liquids or

aqueous solution of caustic soda and sodium hydro-

fine particulates. It is a tube like device having

sulfite.

broad, flaring ends and a narrow central portion, or

throat; this so constricts the passage of the fluid that

Vauquelin’s salt. (Pd(NH

)

)Cl

•PdCl

its rate of flow increases while the pressure de-

compound obtained by treating palladium chloride

creases. The difference in pressure thus created is a

with ammonia.

measure of the flow. Venturis are used in scrubbers,

liquid and solid conveying systems, pipelines, and

aircraft instrument control, as well as in numerous

VC. Abbreviation for vinyl chloride or vinylidene

chemical process techniques such as hydrogenation,

chloride.

chlorination, and oxidation. The hydrogenation

technology involves hydrogen entrainment by rapid

vector. (1) In biochemistry, an animal (insect,

flow of a liquid catalyst through the venturi nozzle.

rodent, etc.) that carries or transports infectious mi-

croorganisms. Typical vectors are rats and mosqui-

toes. (2) A DNA molecule known to replicate auton-

veratraldehyde. (vertraldehyde; 3,4-dime-

omously in a host cell, to which a segment of DNA thoxybenzaldehyde).

may be spliced to allow its replication. The current CAS: 120-14-9. (CH

CHO.

types are plasmids, cosmids, YAC’s or a temperate- Properties: Mp 42–45C, bp 281C, flash p 235F

phage DNA. (112C), mw 166.18.

1315 “V-G-B”

veratric acid. (3,4-dimethoxybenzoic acid). Use: In latex paint formulations.

CAS: 93-07-2. (CH

COOH.

Properties: Mw 182.18, mp 179–82C.

“Versa Guma” [Cargill]. TM for a xantham

gum specialty ingredient.

Use: In food formulation in a broad range of pH and

veratrole. (1,2-dimethoxybenzene; pyrocate-

temperatures.

chol dimethyl ether).

CAS: 91-16-7. C

(OCH

)

Properties: Colorless crystals or liquid. Mp 21–22C,

“Versamag” [Morton]. See “Novogel”.

bp 206–207C, d 1.084 (25/25C). Soluble in alcohol

and ether; slightly soluble in water.

“Versene” [Ashland].

Derivation: Treatment of catechol in methanol with

CAS: 62-33-9. TM for calcium disodium EDTA

dimethyl sulfate and caustic.

chelating agent.

Use: Medicine (antiseptic).

Use: Pharmaceuticals, foods, and biological applica-

tions to control oxidation, and chelate metal ions.

veratrum alkaloid. One of a group of alkaloids

used in medicine to relieve hypertension. They in-

“Versene Fe-3 Specific” [Dow]. TM for an

clude Veratrum viride (American hellebore).

iron specialty chelating agent; active ingredient is

Hazard: May have severe side effects.

sodium dihydroxyethylglycine; available as straw-

See alkaloid.

colored liquid or white powder.

verdigris. See copper acetate, basic.

“Versenex” 80 [Dow]. TM for pentasodium

salt of diethylenetriaminepentaacetic acid.

vermiculite. Hydrated magnesium-iron-alumi-

num silicate capable of expanding 6–20 times when

“Versenol” 120 [Dow]. TM for the trisodium

heated to 1093C. The platelets exhibit an active

salt of N-hydroxyethylethylenediaminetriacetic

curling movement when heated, hence the name.

acid (C

Occurrence: Montana, North Carolina, South Caro-

Use: Organic chelating agent.

lina, Wyoming, Colorado, South Africa.

Properties: Platelet-type crystalline structure. High

verxite. (exfoliated hydrobiotite).

porosity, high void volume to surface area ratio, low

Properties: Thermally expanded (exfoliated) mag-

density, large range of particle size. Insoluble in

nesium-iron-aluminum silicate having a minimum

water and organic solvents; soluble in hot concentra-

of 98% purity and a bulk d of 5–7 lb/cu ft. Expansion

ted sulfuric acid. Water vapor adsorption capacity of

occurs by heating at 793C. Spongelike structure that

expanded vermiculite less than 1%, liquid adsorp-

absorbs liquids and permits reexpansion after com-

tion dependent on conditions and particle size,

pression to 70–80% of the original heat-expanded

ranges 200–500%. Noncombustible.

volume.

Grade: Unexpanded (ore concentrate), expanded

Use: Poultry feed in quantities less than 5% as a

(also called exfoliated), flake, activated.

nonnutritive bulking agent, pelleting or anti-caking

Use: Lightweight concrete aggregate, insulation,

agent and nutrient carrier in dog and ruminant feeds.

sound conditioning, fireproofing, plaster, soil condi-

For dog feeds the maximum permitted is 1.5%. La-

tioner, additive for fertilizers, seed bed for plants,

beling must state content when in excess of 1%.

refractory, lubricant, oil-well drilling mud. Filler in

See vermiculite.

rubber, paint, plastics. Wallpaper printing, removal

of strontium-90 from milk, absorption of oil spills

“Vespel” [Du Pont]. TM for fabricated parts,

on seawater, animal feed additive, packing, carrier

based on polyimide resin and diamond abrasive

for insecticides, catalyst and catalyst support, litter

wheels formulated with a high-temperature polyim-

for hatcheries, adsorbent.

ide binder.

See verxite.

vetiver oil. An essential oil with violetlike odor,

vermifuge. An agent used in veterinary medicine

strongly dextrorotatory.

to eliminate intestinal worms; an anthelmintic.

Use: Perfumery and fragrances.

vermilion, natural. See cinnabar.

“Vexar” [Du Pont]. TM for both low and

high-density polyethylene and polypropylene plas-

vernolepin. A sesquiterpene dilactone extracted

tic netting. Available in a wide variety of forms and

from leaves of an African plant Veronia hymenole-

colors for use in packaging.

pis.

Use: Biochemical research (inhibits tumor growth in

“V-G-B” [Uniroyal]. TM for reaction product

rats and reversibly retards plant growth).

of acetaldehyde and aniline.

Properties: Brown resinous powder. D 1.152, mp

“Versaflex” [Grace]. TM for polymer emul- 60–80C. Soluble in acetone, benzene, and ethylene

sion. dichloride; insoluble in water and gasoline.

1316“VIAGRA”

Use: Rubber antioxidant.

“Vikane” [Dow]. TM for sulfuryl fluoride.

“Viagra” [Pfizer]. (sildenafil citrate).

Vilsmeier-Haack reaction. Formulation of

CAS: 171599-83-0. mf: C

S•C

activated aromatic or heterocyclic compounds with

Use: A treatment for male erectile dysfunction.

disubstituted formamides and phosphorus oxychlo-

ride.

“Vibrathane” [Great Lakes/Asia Pacific].

TM for a liquid castable, urethane prepolymer.

vinal fiber. Generic name for a manufactured

fiber in which the fiber-forming substance is any

long-chain synthetic polymer composed of at least

“Vibrin” [Uniroyal]. TM for resin composi-

50% by weight of vinyl alcohol units, −CH

O−,

tions of polyesters and cross-linking monomers that

and in which the total of the vinyl alcohol units and

when catalyzed, will polymerize to infusible solid

any one or more of the various acetal units is at least

resins without evolving water or other by-products.

85% by weight of the fiber (Federal Trade Commis-

Use: Molding, laminating, impregnating, casting, au-

sion). It has good chemical resistance, low affinity

tomotive and aircraft structural parts, wall panels,

for water, good resistance to mildew and fungi.

table tops, coating for paper, boat hulls, chemically

Combustible.

inert tanks, large-diameter pipe.

Use: Fishing nets, stockings, gloves, hats, rainwear,

swimsuits.

vic-. Prefix meaning vicinal.

vinegar.

vicariance. Speciation which occurs as a result of

Properties: Brownish or colorless liquid. Dilute

the separation and subsequent isolation of portions

aqueous solution containing 4–8% acetic acid, de-

of an original population.

pending on source. Legal minimum is 4%. Also

contains low percentages of alcohols and mineral

vicinal. (vic-). Neighboring or adjoining posi-

salts. Nonflammable.

tions on a carbon ring or chain; the term is used in

Derivation: (1) Bacterial fermentation of apple ci-

naming derivatives with substituting groups in such

der, wine, or other fruit juice. (2) Fermentation of

locations in a structural formula or molecule. For

malt or barley. The fermenting agent is usually a

example, vicinal locations in the molecule shown

mold, e.g., Mycoderma aceti, generally known as

are occupied by the hydrogen atoms and the hydrox-

“mother.” Either type can be distilled to remove

yl groups:

color and other impurities and is then called white

vinegar.

Use: Mayonnaise, salad dressings, pickled foods,

preservative, medicine (antifungal agent), latex

coagulant.

“Vinoflex” [BASF]. TM for vinyl chloride

Victoria blue. (CI 44045). C

•HCl.

homo- and copolymers.

Properties: Bronze colored, crystalline powder. Sol-

uble in hot water, alcohol, or ether.

“Vinsol” [Aqualon]. TM for a series of low-

Derivation: Michler’s ketone is condensed with phe-

cost, dark, brittle, thermoplastic resins; ruby-red by

nyl-␣-naphthylamine.

transmitted light, dark-brown by reflected light.

Use: Dyeing silk, wool, and cotton; biological stain;

Available in solid form, flakes, fine powder, and

dye intermediate for complex acid pigment toners.

aqueous dispersion.

Use: Adhesives, asphalt emulsions, electrical insula-

Victoria green. See malachite green.

tion, inks, plastics.

“Victory” [Baker Petrolite]. TM for a plastic

vinyl. See vinyl compound.

grade of petroleum microcrystalline wax.

vinyl acetate.

vicuna. A soft, wool-like fiber obtained from a

CAS: 108-05-4. CH

COOCH:CH

. Raw material

South American animal similar to the llama.

for polyvinyl resins.

Use: Specialty high-grade coats, sweaters, etc. Com-

Properties: Colorless liquid stabilized with either

bustible.

hydroquinone or diphenylamine inhibitors. The hy-

droquinone stabilized material can be polymerized

vidarabine. Generic name for ara-A.

without redistillation. The DPA-stabilized material

must be distilled before polymerization. D 0.9345

“Vigofac 6” [Pfizer]. TM for an unidentified (20/20C), fp −100.2C, bp 73C, refr index 1.3941,

growth factor for addition to animal feeds. Derived bulk d 7.79 lb/gal, flash p 30F (−1.1C) (TOC), aut-

from dried streptomyces fermentation solubles. oign temp 800F (426.6C). Soluble in most organic

1317 VINYLCYCLOHEXENE

solvents including chlorinated solvents; insoluble in Use: Synthesis, copolymerization.

water.

Derivation: (1) Vapor-phase reaction of ethylene,

vinyl butyrate.

acetic acid, and oxygen, with a palladium catalyst.

CAS: 123-20-6. CH

:CHOOCC

(2) Vapor-phase reaction of acetylene, acetic acid,

Properties: Liquid. D 0.9022 (20/20C), bp 116.7C,

and oxygen, with zinc acetate catalyst. (3) From

fp −86.8C, flash p 68F (20C) (OC). Very slightly

synthesis gas. soluble in water.

Grade: Technical. Hazard: Flammable, dangerous fire risk.

Hazard: Flammable, dangerous fire risk. Flammable Use: Polymers, emulsion paints.

limits in air 2.6–13.4%. Toxic by inhalation and

ingestion. TLV: 10 ppm, STEL: 15 ppm; animal

n-vinylcarbazole. C

NHC:CH

carcinogen.

Properties: Liquid. Combustible.

Use: Polyvinyl acetate, polyvinyl alcohol, polyvinyl

Derivation: From acetylene and carbazole.

butyral, and polyvinyl chloride-acetate resins, used

Use: Polymerizes to form heat-resistant and insulat-

particularly in latex paints, paper coating, adhesives,

ing resins somewhat similar to mica in dielectric

textile finishing, safety glass interlayers. A vinyl

properties.

acetate-ethylene copolymer is available for special-

See polyvinyl carbazole.

ty products.

See polyvinyl acetal; polyvinyl acetate; polyvinyl

vinyl cetyl ether. See cetyl vinyl ether.

alcohol; polyvinyl chloride-acetate.

vinyl chloride. (VC; chloroethene; chloroe-

vinylacetonitrile. See allyl cyanide.

thylene).

CAS: 75-01-4. CH

:CHCl. The most important vi-

vinylacetylene. C

or H

C:CHC:CH. The di-

nyl monomer.

mer of acetylene, formed by passing it into a solution

Properties: Compressed gas, easily liquefied, ethe-

of cuprous and ammonium chlorides in hydrochlo-

real odor, usually handled as liquid. Phenol is added

ric acid.

as a polymerization inhibitor. D 0.9121 (liquid at 20/

Properties: Colorless gas or liquid. D 0.6867 (20C),

20C), bp −13.9C, fp −159.7C, vap press 2300 mm

bp 5C. Combustible.

Hg (20C), flash p −108F (−77C), autoign temp 882F

Use: Intermediate in manufacture of neoprene and for

(472C). Slightly soluble in water; soluble in alcohol

various organic syntheses.

and ether.

See divinyl acetylene.

Derivation: (1) Dehydrochlorination of ethylene di-

chloride; (2) reaction of acetylene and hydrogen

vinyl acrylate. See ethenyl 2-propenoate. chloride, either as liquids or gases.

Grade: Technical, pure 99.9%.

Hazard: Explosive limits in air 4–22% by volume.

vinyl alcohol. (ethenol). CH

:CH

O. Unstable

An extremely toxic and hazardous material by all

liquid; isolated only in the form of its esters or the

avenues of exposure. A carcinogen. TLV: TWA 5

polymer, polyvinyl alcohol.

ppm. Use in aerosol sprays prohibited.

Use: Polyvinyl chloride and copolymers, organic

vinylation. The formation of a vinyl derivative

synthesis, adhesives for plastics.

by reaction with acetylene. Thus vinylation of alco-

hols yields vinyl ethers such as vinyl ethyl ether,

vinyl-2-chloroethyl ether.

CAS: 110-75-8. CH

:CHOCH

Cl.

Properties: Liquid. D 1.0498 (20C), bp 109.1C, fp

vinyl bromide.

−69.7C, flash p 80F (26.6C) (OC). Very slightly

CAS: 593-60-2. CH

CHBr.

soluble in water.

Properties: Gas. Fp −138C, bp 15.6C, d 1.51.

Hazard: Flammable, dangerous fire risk.

Hazard: A carcinogen. TLV: 5 ppm; suspected hu-

man carcinogen.

vinyl compound. A compound having the vinyl

Use: Flame-retarding agent for acrylic fibers.

grouping (CH

==CH−), specifically vinyl chloride,

vinyl acetate, and similar esters but also referring

vinyl-n-butyl ether. (n-butyl vinyl ether;

more generally to compounds such as styrene

BVE).

CH==CH

, methyl methacrylate CH

==C(CH

)

CAS: 111-34-2. CH

:CHOC

COOCH

, and acrylonitrile CH

==CHCN. The vinyl

Properties: Liquid. D 0.7803 (20C), bp 94.1C, fp

compounds are highly reactive, polymerize easily,

−113C, refr index 1.3997, flash p 15F (−9.4C) (OC),

and the basis of a number of important plastics.

bulk d 7.45 lb/gal (20C). Slightly soluble in water;

soluble in alcohol and ether.

vinyl cyanide. See acrylonitrile.

Derivation: Reaction of acetylene with n-butyl al-

cohol.

Grade: Technical (98%).

vinylcyclohexene. (1-vinylcyclohexene-3; 4-

Hazard: Flammable, dangerous fire risk. vinylcyclohexene-1; cyclohexenylethylene).

1318VINYLCYCLOHEXENE

CAS: 100-40-3. CH

:CHCHCH

CH:CHCH

.A vinyl ethyl ether. (ethyl vinyl ether; EVE).

butadiene dimer.

CAS: 109-92-2. CH

:CHOC

Properties: Liquid. D 0.8303 (20/4C), fp −108.9C,

Properties: Colorless liquid. Extremely reactive, can

bp 128C, refr index 1.464 (20C), flash p 70F (21.2C)

be polymerized in liquid or vapor phase. D 0.754

(TOC), autoign temp 517F (269C). Temperatures

(20/20C), bulk d 6.28 lb/gal (20C), fp −115.0C,

above 80F (26.6C) and prolonged exposure to oxy-

viscosity 0.22 cP (20C), refr index 1.3739, flash p

gen-containing gases should be avoided because

−50F (−46C), autoign temp 395F (201.6C). Slightly

these conditions lead to discoloration and gum for-

soluble in water (0.9% by weight). Commercial ma-

mation.

terial contains inhibitor to prevent premature poly-

Grade: Technical 95%, pure 99%, research.

merization. Often stored underground to minimize

Hazard: TLV: 0.1 ppm (skin); Animal Carcinogen.

vapor losses.

Flammable, dangerous fire risk. Narcotic in high

Derivation: Reaction of acetylene with ethanol.

concentration.

Grade: Technical.

Use: Polymers, organic synthesis.

Hazard: Highly flammable, severe fire and explo-

sion risk, explosive limits in air 1.7–28%.

Use: Copolymerization, intermediate.

vinylcyclohexene dioxide. (vinylcyclohexane

dioxide).

vinyl ethyl ether polymer. See 5-(3 or 6-

CAS: 106-87-6.

oxo-1-cyclohexen-1-yl)-5-ethylbarbituric acid.

❘

vinyl-2-ethylhexoate.

Properties: Colorless liquid. D 1.098 (20/20C), bp

CAS: 94-04-2. CH

==CHOOCCH(C

227C, refr index 1.4782 (20C), viscosity 7.77 cP

Properties: Liquid. D 0.8751 (20/20C), bp 185.2C,

(20C), flash p 230F (110C). Combustible.

fp −90C, flash p 165F (73.9C) (OC). Insoluble in

Hazard: Toxic by ingestion and skin absorption,

water. Combustible.

strong irritant to skin and tissue. TLV: 0.1 ppm;

Use: Polymers, emulsion paints.

animal carcinogen.

Use: Polymers, organic synthesis.

vinyl-2-ethylhexyl ether.

CAS: 103-44-6. CH

==CHOCH

CH(C

vinylcyclohexene monoxide. (vinylcyclo-

Properties: Liquid. D 0.8102 (20/20C), bp 177.7C,

hexane monoxide). CH

:CHC

fp −100C, flash p 135F (57.2C) (OC), autoign temp

Properties: Liquid. D 0.9598 (20/20C), bp 169C, fp

395F (201.6C). Insoluble in water. Combustible.

−100C, flash p 136F (57.8C), viscosity 1.69 cP

Hazard: Moderate fire and explosion risk.

(20C). Very slightly soluble in water. Combustible.

Use: Intermediate for pharmaceuticals, insecticides,

Hazard: Moderate fire risk. Irritant.

adhesives, viscosity index improver.

Use: Polymers, organic synthesis.

2-vinyl-5-ethylpyridine.

vinyl ether. (divinyl ether; divinyl oxide).

(CH

==CH)C

N(C

CAS: 109-93-3. CH

:CHOCH:CH

Properties: Liquid. D 0.9449 (20/20C), bp 138C

Properties: Colorless liquid; characteristic odor. D

(100 mm Hg), vap press 0.1 mm Hg (20C), fp

0.769, bp 39C, refr index 1.3989 (20C), flash p −22F

−50.9C, flash p 200F (93.3C) (COC). Insoluble in

(−30C), autoign temp 680F (360C). Slightly soluble

water. Combustible.

in water; miscible with alcohol, acetone, chloro-

Use: Copolymer, synthesis.

form, and ether. Must be protected from light.

Derivation: Treatment of dichloroethyl ether with

vinyl fluoride. (fluoroethylene).

alkali.

CAS: 75-02-5. CH

==CHF.

Grade: NF (contains 96–97% vinyl ether, remainder

Properties: Colorless gas. Bp −72C. Insoluble in

dehydrated alcohol).

water; soluble in alcohol and ether.

Hazard: Flammable, severe fire and explosion risk;

Hazard: Flammable, dangerous fire and explosion

explosive limits in air 1.7–27%. Toxic by inhalation,

risk. Toxic by inhalation. TLV: 2.6 mg(F)/m

overexposure may be fatal.

Use: Monomer.

Use: Copolymer with 3–5% polyvinyl chloride for

See polyvinyl fluoride.

plastic products such as clear plastic bottles; medi-

cine (anesthetic, for brief operations only).

vinylheptacyclotetrasiloxane.

CAS: 3763-39-1. mf: C

vinyl-␤-ethoxyethyl sulfide.

Hazard: Low toxicity by ingestion. A severe skin

:CHSCH

irritant.

Properties: Colorless liquid; pungent, camphorlike

odor. D 0.9532 (15C), bp 65C (8 mm Hg).

vinylidene chloride. (VC).

Use: Organic synthesis.

CAS: 75-35-4. CH

==CCl

Properties: Colorless liquid. Fp −122.53C, bp 37C,

vinylethylene. See butadiene. flash p 14F (−10C) (OC), autoign temp 856F

1319

-VINYL

(457C), readily polymerizes. Insoluble in water.

vinyl methyl ether. (methyl vinyl ether; me-

Commercial product contains small proportion of

thoxyethylene; MVE).

inhibitor.

CAS: 107-25-5. CH

==CHOCH

Hazard: Flammable, dangerous fire risk, explosive

Properties: Colorless compressed gas, or colorless

limits in air 5.6−11.4%. Toxic by inhalation. TLV: 5

liquid. D 0.7500 (20/20C), bp 6.0C, vap press 1052

ppm; STEL 20 ppm; animal carcinogen.

mm Hg (20C), flash p −60F (−51C), fp −121.6C.

Use: Copolymerized with vinyl chloride or acryloni-

Slightly soluble in water; soluble in alcohol and

trile to form various kinds of saran. Other copoly-

ether; easily polymerized. Commercial material

mers are also made. Adhesives; component of syn-

contains a small proportion of polymerization inhib-

thetic fibers.

itor.

See saran.

Derivation: Catalytic reaction of acetylene and

methanol.

Grade: Technical (95% min), pure.

vinylidene chloride-butyl acrylate

Hazard: Highly flammable, severe fire and explo-

copolymer.

sion risk, explosive limits in air 2.6–39%.

CAS: 9011-09-0. mf: (C

•C

)

Use: Copolymers used in coatings and lacquers;

Hazard: Low toxicity by ingestion.

modifier for alkyl, polystyrene, and ionomer resins;

plasticizer for nitrocellulose and adhesives.

vinylidene fluoride. (1,1-difluoroethylene).

See polyvinyl methyl ether.

CAS: 75-38-7. H

C==CF

. A monomer.

Properties: Colorless gas; faint ethereal odor. Bp

vinyl methyl ketone. (3-buten-2-one; methyl

−83C (1 atm), fp −144C (1 atm), d (liquid) 0.617

vinyl ketone).

(24C). Slightly soluble in water; soluble in alcohol

CAS: 78-94-4. CH

COCH==CH

and ether.

Properties: Colorless liquid. D 0.8636 (20/4C), bp

Derivation: Interaction of hydrogen with dichlorodi-

80C, flash p 20F (−6.6C) (CC). Soluble in water and

fluoroethane.

alcohols.

Grade: 99% min purity.

Hazard: Flammable, dangerous fire risk. Skin and

Hazard: Flammable, dangerous fire risk, explosive

eye irritant.

limits in air 5.5–21%. Toxic by inhalation. TLV: 2.5

Use: Monomer for vinyl resins, component of ionom-

mg(F)/m

er resins, intermediate in steroid and vitamin A syn-

Use: Polymers and copolymers, chemical intermedi-

thesis, alkylating agent.

ate.

See polyvinylidene fluoride.

2-(vinyloxy)ethyl nitrate. See ethylene gly-

col mononitrate vinyl ether.

vinylidene resin. (polyvinylidene resin). A

polymer in which the unit structure is (−H

CCX2−),

vinyl plastics. See polyvinyl resins.

in which X is usually chlorine, fluorine, or cyanide

radical. Examples are saran and “Vitron” A.

vinyl propionate. CH

==CHOOCC

Properties: Liquid. D 0.9173 (20/20C), bp 95.0C, fp

vinyl isobutyl ether. (isobutyl vinyl ether;

−81.1C, flash p 34F (1.1C) (OC). Almost insoluble

IVE).

in water.

CAS: 109-53-5. CH

==CHOCH

CH(CH

)

Hazard: Flammable, dangerous fire risk.

Properties: Colorless liquid. D 0.7706 (20/20C), bp

Use: Polymers, emulsion paints.

83.3C, vap press 68 mm Hg (20C), fp −132C, refr

index 1.3938, flash p 15F (−9.4C) (OC). Very slight-

vinylpyridine. C

NCH==CH

ly soluble in water; soluble in alcohol and ether;

Properties: Colorless liquid. Boils with resinifica-

easily polymerized.

tion at 159C, d 0.9746 (20C), refr index 1.5509

Derivation: Catalytic union of acetylene and isobu-

(20C). Dissolves in water to extent of 2.5%; water

tyl alcohol.

dissolves in it to 15%; soluble in dilute acids, hydro-

Method of purification: Washing with water, drying

carbons, alcohols, ketones, esters. Commercial ma-

in the presence of alkali, and distillation from metal-

terial contains inhibitor. Combustible.

lic sodium.

Hazard: Irritant to skin and eyes.

Grade: Technical.

Use: Elastomers and pharmaceuticals. Latex used as

Hazard: Flammable, dangerous fire risk.

tire cord binder (41% solids). The latex is copoly-

Use: Polymer and copolymers used in surgical adhe-

merized with butadiene-styrene.

sives, coatings, and lacquers; modifier for alkyd and

polystyrene resins; plasticizer for nitrocellulose and

n-vinyl-2-pyrrolidone.

other plastics; chemical intermediate.

CAS: 88-12-0.

vinylmagnesium chloride. CH

==CHMgCl.

Usually supplied dissolved in tetrahydrofuran. CH

==CHN

❘

CO.

Use: Grignard reagent. Properties: Colorless liquid. Bp 148C (100 mm Hg),

13201-VINYL-2-PYRROLIDONE

mp 13.5C, flash p 209F (98.3C) (COC), d 1.04. weight of vinyl chloride units, −CH

CHCl− (Federal

Combustible. Trade Commission). It has good resistance to chem-

Derivation: From acetylene and formaldehyde by icals, bacteria, moths; unaffected by water and sun-

high-pressure synthesis. light; low softening point. Tenacity 3.1 g/denier,

Hazard: Irritant and narcotic. difficult to ignite, self-extinguishing.

Use: Polyvinylpyrrolidone, organic synthesis.

See polyvinyl chloride.

1-vinyl-2-pyrrolidone crosslinked insoluble

vioform. (iodochloroxyquinoline). Odorless,

polymer. See polyvinylpolypyrrolidone.

nonirritant, sterilizable substitute for iodoform.

vinyl stabilizer. A substance added to vinyl

violanthrone. See dibenzanthrone.

chloride resins during compounding, to retard the

rate of deterioration caused by formation of hydro-

Violet #1. An FD&C color used for meat grad-

gen chloride. Many combine readily with hydrogen

ing, cosmetics, beverages, etc. It is a triphenylmeth-

chloride but do not otherwise interfere with the

ane dye banned by the FDA in 1973 because of

properties and uses of the final product. Amines,

carcinogenic risk.

basic oxides, and metallic soaps are commonly used.

violet gentian. See methyl violet.

vinyl stearate. CH

(CH

)

COOCH==CH

Properties: White waxy solid. Mp 28–30C, bp 175C

viomycin. An antibiotic produced by Streptomy-

(3 mm Hg), d 0.9037 (20/20C), refr index

ces puniceus. Unique among antibiotics in that it is

1.4355–1.4362 (55C), iodine no. 80–82. Insoluble

more active against acid-fast organisms than against

in water and alcohol; moderately soluble in ketones

other groups. Mycobacteria are most sensitive to

and vegetable oils; soluble in most hydrocarbon and

viomycin, and the antibiotic is active against strains

chlorinated solvents. Combustible.

of Mycobacterium tuberculosis, which are resistant

Use: Plasticizer (copolymerizer), lubricant.

to other antibiotics. Available commercially as sul-

fate.

vinylstyrene. See divinyl benzene.

viosterol. Irradiated ergosterol.

vinyl toluene. (methyl styrene).

CAS: 25013-15-4. CH

==CHC

“Vipex 19” [Crowley]. TM for a specialty

Properties: Colorless liquid. Fp −76.8C, bp

formulated high viscosity oil.

170–171C, d 0.890 (25/25C), bulk d 7.41 lb/gal, refr

Use: In asphalt pavement emulsified rejuvenation.

index 1.534 (34C), flash p 130F (54.4C) (CC), aut-

oign temp 921F (494C). Very slightly soluble in

viral vector. A viral DNA altered so that it can

water; soluble in methanol, ether. Combustible.

act as a vector for recombinant DNA.

Hazard: Moderate fire risk. TLV: 50 ppm; STEL

100 ppm; not classifiable as a human carcinogen.

viridogrisein. See etamycin.

Use: Solvent, intermediate.

virion. A single virus particle.

vinyl trichloride. See 1,1,2-trichloroethane.

Virtanen, Arrturi I. (1895–1973). A Finnish

vinyltrichlorosilane.

biochemist who won the Nobel Prize in 1945. His

CAS: 75-94-5. CH

CHSiCl

work was primarily concerned with research in nu-

Properties: Colorless or pale-yellow liquid. Bp

trition and agriculture. He made important discov-

90.6C, d 1.265 (25/25C), refr index 1.432 (20C),

eries regarding prevention of fodder spoilage and

flash p 16F (−8.89C). Readily hydrolyzed with lib-

bacterial fermentation as well as nitrogen metabo-

eration of hydrogen chloride; polymerizes easily;

lism in plants. His Ph.D. was awarded at the Univer-

soluble in most organic solvents; reacts with al-

sity of Helsinki and followed by an illustrious career

cohol.

that included awards throughout Scandanavia.

Derivation: Reaction of acetylene and trichlorosi-

lane (peroxide catalyst), reaction of trichlorosilane

virus. An infectious agent composed almost en-

with vinyl chloride.

tirely of protein and nucleic acids (nucleoprotein).

Grade: Technical.

Viruses can reproduce only within living cells and

Hazard: High by ingestion and inhalation, strong

are so small that they can be resolved only with an

irritant to tissue. Flammable, dangerous fire risk.

electron microscope. Since they pass through filters

Use: Intermediate for silicones, coupling agent in

that retain bacteria, they are often called filterable

adhesives and bonds.

viruses. Tobacco mosaic was the first virus to be

crystallized and isolated (Dr. W. M. Stanley, 1935);

vinyon. Generic name for a manufactured fiber in it contains some 2000 protein molecules in a se-

which the fiber-forming substance is any long-chain quence of 158 amino acids (mw 40,000,000). Bushy

synthetic polymer composed of at least 85% by stunt virus found in tomato plants has a molecular

1321 VITAMIN

weight of 7,600,000. First synthesis of a virus was shear. A liquid has a viscosity of one poise if a force

reported in 1967. of 1 dyne/square centimeter causes two parallel liq-

Viruses differ from organisms in that they are only uid surfaces one square centimeter in area and one

half alive; they lack metabolism, are unable to uti- centimeter apart to move past one another at a veloc-

lize oxygen, to synthesize macromolecules, to grow, ity of 1 cm/second. One poise equals 100 centi-

or to die. They are parasites, relying on a living host poises. Viscosity in centipoises divided by the liquid

cell. They account for many diseases, including density at the same temperature gives kinematic

mumps, measles, scarlet fever, smallpox, influenza, viscosity in centistokes (cs). One hundred centi-

and possibly the common cold. Their shapes are stokes equal one stoke. To determine kinematic vis-

similar to those of bacteria (rods, spheres, fila- cosity, the time is measured for an exact quantity of

ments). They have the ability to mutate; they are also liquid to flow by gravity through a standard capil-

antigenic and thus initiate formation of antibodies. lary.

Some act as bacteriophages. A direct relation be- Water is the primary viscosity standard with an

tween virus and cancer has been shown, the DNA of accepted viscosity at 20C of 0.010019 poise. Hydro-

the virus becoming irreversibly bound to the DNA carbon liquids such as hexane are less viscous. Mo-

of the affected cells. See bacteria; deoxyribonu- lasses may have a viscosity of several hundred centi-

cleic acid. stokes, while for a very heavy lubrication oil the

viscosity may be 100 centistokes. There are many

empirical methods for measuring viscosity. See

viscometer. (viscosimeter). A device for mea-

Saybolt Universal Viscosity; viscometer.

suring the viscosity of a liquid. The types most

widely used are the Engler, Saybolt, and Redwood,

which indicate viscosity by the rate of flow of the

viscosity index improver. A lubricating-oil

test liquid through an orifice of standard diameter or additive that has the effect of increasing the viscosi-

the flow rate of a metal ball through a column of the ty of the oil in such a way that it is greater at high

liquid; other types utilize the speed of a rotating temperature than at low temperature. Agents used

spindle or vane immersed in the test liquid. The for this purpose are polymers of alkyl esters of meth-

liquids commonly measured are lubricating oils and acrylic acid, polyisobutylenes, etc.

the like; heavier (non-Newtonian) liquids such as

paints and paper coatings require more complex

viscosity, kinematic. See viscosity.

devices, e.g., Brookfield and Krebs-Stormer.

See viscosity.

“Vistac A” [AKZO]. TM for a series of syn-

thetic hydrocarbon polymers.

viscose process. The best-known process for

Use: Rubber-base adhesives and cements; latex and

making regenerated cellulose (rayon) by converting

asphalt emulsions.

cellulose to the soluble xanthate, which can be spun

into fibers and then reconverted to cellulose by treat-

visual purple. See rhodopsin.

ment with acid. Wood pulp is steeped with 17–20%

caustic soda; the resulting alkali cellulose is pressed

vitamin. Any of a number of complex organic

to remove excess liquor and the soluble ␤- and ␥-

compounds, present in natural products or made

cellulose, and then shredded and aged. It is then

synthetically, which are essential in small propor-

treated with carbon disulfide and sodium hydroxide

tions in the diet of animals and humans. Some are fat

to form an orange, viscous solution of cellulose

soluble (A, D, K); others are water soluble (B com-

xanthate. After filtration and deaeration, this solu-

plex, C). Their precursors are called provitamins. A

tion (viscose) is forced through minute spinnerette

normal diet usually contains sufficient vitamins for

openings (or long slit dies in the case of cellophane)

health, although older people, the ill, young, or in-

into a bath containing sulfuric acid and various salts

firm may require different standards. Their usual use

such as sodium and zinc sulfate. The salts cause the

in medicine is restricted to correction of specific

viscose to gel immediately, forming a fiber or film of

metabolic deficiencies. Some authorities believe

sufficient strength to permit it to be drawn through

that habitual intake of standard vitamin preparations

the bath under tension. At the same time the sulfuric

readily available on the market is of little if any

acid decomposes the xanthate, converting the fibers

nutritional benefit. The following list of cross-refer-

to cellulose, in which form they are washed and

ences will serve to locate technical information

dried.

about the various vitamin entries in this book:

See rayon; cellophane.

Vitamin A. See carotene; cryptoxanthin; reti-

nol; 3-dehydroretinol; provitamin.

viscosification. Increasing the viscosity of a

Vitamin B. See vitamin B complex; thiamine;

liquid.

riboflavin; niacin; panthothenic acid; biotin; cy-

anocobalamin; pyridoxine; folic acid; inositol.

viscosimeter. See viscometer.

Vitamin C. See ascorbic acid.

Vitamin D. See ergosterol; ergocalciferol; cho-

viscosity. The internal resistance to flow exhib- lecalciferol.

ited by a fluid; the ratio of shearing stress to rate of Vitamin E. See tocopherol.

1322VITAMIN A

Vitamin K. See phytonadione; menadione; their glassy appearances. Sulfuric acid was called oil

phthiocol. of vitriol. Derived from vitrum (glass).

Vmax. The maximum velocity of an enzymatic

vitamin A

, anhydrous. See all-trans

-anhy-

reaction when the binding site is saturated with sub-

droretinol.

strate.

vitamin B complex. A group of closely in-

VM&P naphtha. See naphtha (la).

terrelated vitamins found in rice bran, yeast, wheat

germ, etc., originally thought to be one substance.

VOC. See volatile organic compound.

Studies carried out by R. J. Williams and associates

later revealed the astonishing complexity of this

voids. Empty spaces of molecular dimensions oc-

group. He states as follows: “The physiological ac-

curring between closely packed solid particles, as in

tivity originally observed was due to the additive

powder metallurgy. Their presence permits barriers

effect of a considerable number of substances, each

made by powder metallurgy techniques to act as

one of which is of itself essential. If and when the

diffusion membranes for separation of uranium iso-

designations B

, etc., are used, they have an

topes in the gaseous diffusion process.

entirely different meaning from the parallel use of

See diffusion, gaseous.

or K

and K

because in the case of the D

and K vitamins one form can replace another. In the

Voight amination. Amination of benzoins with

case of the B vitamins each form is a distinctly

amines in the presence of phosphorus pentoxide or

different substance with different functions, and

hydrochloric acid.

each member of the family is separately indispens-

able. No one B vitamin can replace any other.”

“Volan” [Du Pont]. (methacrylatochromic

chloride). TM for bonding agent.

vitamin B

tripalmitate. See pyridoxine

Use: Applied to glass fibers used in reinforced plastic

tripalmitate.

laminates to improve adhesion between glass and

resin.

vitamin E acetate. See d

-␣-tocopheryl ace-

tate.

volatile organic compound. (VOC). Any

hydrocarbon, except methane and ethane, with va-

vitexin. See 8-␤-d-glucopyranosyl-apigenin.

por pressure equal to or greater than 0.1 mm Hg.

“Viton” [Du Pont]. TM for a series of fluoroe-

volatility. The tendency of a solid or liquid mate-

lastomers based on the copolymer of vinylidene

rial to pass into the vapor state at a given tempera-

fluoride and hexafluoropropylene with the repeating

ture. Specifically the vapor pressure of a component

structure possibly −CF

−CH

−CF

−CF(CF

)−.

divided by its mole fraction in the liquid or solid.

Properties: White transparent solid. D 1.72–1.86.

Resistant to corrosive liquids and chemicals up to

Volhard-Erdmann cyclization. Synthesis of

315C. Useful continuous service at 204–232C. Re-

alkyl and aryl thiophenes by cyclization of disodium

sistant to ozone, weather, flame, oils, fuels, lubri-

succinate or other 1,4-difunctional compounds (␥-

cants, many solvents; radiation resistance good.

oxo acids, 1,4-diketones, chloroacetyl-substituted

Nonflammable.

esters) with phosphorus heptasulfide.

Use: Gaskets, seals, diaphragms, tubing, aerospace

and automotive components, high-vacuum equip-

Volhard’s solution. A solution of potassium

ment, low-temperature and radiation equipment.

thiocyanate.

Use: Analytical chemistry.

vitreous. Descriptive of a material having the

appearance and properties of a glass, i.e., a hard,

voltaic cell. Two conductive metals of different

amorphous, brittle structure, as in porcelain enamel.

potentials, in contact with an electrolyte, which gen-

See vitrification; glass.

erate an electric current. The original voltaic cell

was composed of silver and zinc, with brine-mois-

vitreous enamel. See porcelain enamel.

tened paper as electrolyte. Semisolid pastes are now

used; electrodes may be lead, nickel, zinc, or cadmi-

vitrification. The process of converting a sili-

um.

ceous material into an amorphous, glassy form by

See solar cell.

melting and cooling. As applied to radioactive waste

disposal, it refers to incorporation of the waste in

volumetric analysis. See titration.

glassy materials for permanent storage.

Von Baeyer, Adolf. (1835–1917). A German

vitriol. An obsolete term once used to refer to a chemist who received the Nobel Prize for chemistry

number of sulfates (lead, copper, zinc) because of in 1905. His work concerned organic dyes and hy-

1323 “VYCOR” BRAND

droaromatic compounds. He was educated in Berlin Inorganic accelerators and metallic oxides (usually

zinc) are essential for satisfactory cure. Organic

under the direction of Bunsen and Kekule. He was a

accelerators, introduced in the early 1920s, notably

professor in Strasbourg and Munich. Von Baeyer

shortened vulcanization time.

made many discoveries, including barbituric acid

Three factors affect the properties of a vulcanizate:

and the molecular structure of indigo.

(1) the percentage of sulfur and accelerator used, (2)

the temperature, and (3) the time of cure. Sulfur is

Von Braun reaction. The reaction between

usually from 1 to 3%; with strong acceleration the

phosphorous pentahalide and an N-substituted benz-

time can be as short as three minutes at high temper-

amide to give an alkylene dihalide and benzonitrile.

ature (150C). Vulcanization can also occur at room

temperature with specific formulations (self-curing

von Richter reaction. Carboxylation of sub-

cements).

stituted aromatic nitro compounds with ethanolic

Vulcanization was discovered in 1846 by Charles

potassium cyanide at 120-270C, the carboxyl group

Goodyear in the U.S. and simultaneously by

entering a position ortho to that previously occupied

Thomas Hancock in England. Its overall effect is to

by the eliminated nitro group.

convert rubber hydrocarbon from a soft, tacky, ther-

moplastic to a strong, temperature-stable thermoset

von Richter synthesis. Formation of cinno-

having unique elastic modulus and yield properties.

line derivatives by diazotization of o-aminoarylpro-

See rubber; rubber, synthetic.

piolic acids or o-aminoarylacetylenes followed by

hydration and cyclization. The method is applicable

to preparation of cinnolines substituted in the benze-

“Vulcosal” [Dow]. TM for the industrial grade

noid ring.

of salicylic acid.

Use: Stabilizer and retarder of vulcanization.

“Voranate” [Dow]. TM for a series of urethane

intermediates that are the reaction products of poly-

“Vulklor” [Uniroyal]. TM for tetrachloro-p-

ols and isocyanates. They are adducts or quasiprepo-

benzoquinone.

lymers to be used in combination with “Voranol”

Use: Vulcanizing agent.

products to obtain rigid urethane foams.

“Vultex.” TM for a vulcanized rubber or synthet-

“Vorane” [Dow]. TM for a group of polyure-

ic rubber latex.

thane chemicals, raw materials for polyurethane

Use: Health care workers’ gloves, drug sundries,

elastomers, coatings, and foams.

dipped products, adhesives.

“Voranol” [Dow]. TM for a series of polyols

“Vybar” [Baker Petrolite]. TM for a grade of

used as intermediates in urethane elastomers, coat-

petroleum microcrystalline wax.

ings, and flexible and rigid foams.

Use: Hardening and upgrading paraffins, coatings,

polishes, adhesives, cosmetics, color dispersants,

VPC. Abbreviation for vapor-phase chromatog-

paper coatings, lubricants, floor wax, ski wax inks,

raphy.

ozone barriers for elastomers, and anticaking treat-

See gas chromatography.

ments.

“VPM” [Du Pont]. TM for a solution contain-

“Vycel P” [Crowley]. TM for a polyester mod-

ing 32.7% sodium methyldithiocarbamate used as a

ifier.

soil fumigant.

Use: Improves impact resistance.

vulcanization. A physicochemical change re-

sulting from cross-linking of the unsaturated hydro-

“Vycor” Brand Glass No. 7900 [Corning].

carbon chain of polyisoprene (rubber) with sulfur, TM for a glass made by a process in which an

usually with application of heat. The precise mecha- article fabricated by conventional methods is chemi-

nism that produces the network structure of the cally leached to remove substantially all of the in-

cross-linked molecules is still not completely gredients except silica. When fired at high tempera-

known. Sulfur is also used with unsaturated types of tures a transparent glass of high softening point and

synthetic rubbers; some types require use of perox- extremely low expansion coefficient is produced.

ides, metallic oxides, chlorinated quinones, or nitro- Properties: Softening point 1500C, temp limit in

benzenes. Natural rubber can be vulcanized with service 900C, linear coefficient of expansion per

selenium, organic peroxides, and quinone deriva- degree C

0.0000008, d 2.18, refr index 1.458 (a

tives but these have limited industrial use; high-en- similar glass, No. 7910, will transmit over 60%

ergy radiation curing is an important innovation. radiation at 254 millimicrons in a 2-mm section).

Vulcanization can be effected with sulfur alone in Use: Laboratory and industrial glassware, including

high percentage, but the time required is too long to beakers, crucibles, flasks, dishes, tubes, cylinders,

be economical and the properties obtained are poor. containers, flat glass rods.