P. Symbol for phosphorus. polyethylene film aluminum cans (beer, soft

(textiles) drinks)

ceramic jars (cos-

p-. (p-). Abbreviation for para-.

metic creams)

steel cylinders

PA. Abbreviation for phthalic anhydride and for

(gases)

polyamide.

Pa. Symbol for protactinium.

packing. (1) A collar or gasket used to seal me-

chanical devices to prevent leakage of oil or water;

Paal-Knorr pyrrole synthesis. Formation of

often made of specially compounded rubber or a

pyrroles by heating 1,4-dicarbonyl compounds with

flexible plastic. (2) The operation of placing solid

ammonia or primary amines in a sealed tube.

materials or objects in shipping containers in such a

way as to secure maximum space economy and

Paar turbidimeter. A visual-extinction device

freedom from damage by vibration or impact. Barri-

for measurement of solution turbidity. The length of

ers of paperboard, foamed plastic, or glass fiber are

the column of liquid suspension is adjusted until the

widely used. (3) An inert material used in distillation

light filament can no longer be seen.

columns to baffle the downward flow of countercur-

See nephelometry.

rent liquid; it may be glass fiber or beads, metal

tubes called Raschig rings, metal chains, or specially

PABA. Abbreviation for p-aminobenzoic acid.

shaped devices of various kinds (saddles, helices,

rings, etc.).

PABA sodium. See sodium-p-aminobenzoate.

See tower, distillation.

PAC. See P1-derived artificial chromosome.

paclitaxel. (taxol; 5-␤,20-epoxy-1,2-␣,4,7-

␤,10-␤,13-␣-hexahydroxy-tax-11-en-9-one 4,10-

“Pace” [Olin]. TM for water-treatment chemi-

diacetate 2-benzoate 13-ester with (2r,3s)-n-ben-

cals and particularly chlorinated organic com-

zoyl-3-phenylisoserine). C

pounds.

CAS: 33069-62-4.

Use: Swimming-pool chlorination.

packaging. The operation of placing materials in

suitable containers or protective covering for pur-

poses of storage, distribution, and sale. Some pack-

ages act merely as containers, but others protect

perishable materials (especially foodstuffs) from

environmental damage, contamination, and biologi-

cal deterioration; in this respect the critical factor is

exclusion of moisture vapor, bacteria, and oxygen.

Some packages perform both functions simulta-

neously. Common packaging materials are:

(for nonperishable (for perishable products)

products)

Properties: Needles from aq methanol. Mw 853.99,

wooden boxes, glass bottles

mp 213–216C (decomp). Extracted from the bark of

kegs, barrels

Pacific yew tree, Taxus brevifolia.

fiber drums “tin” cans

Use: Treatment of ovarian cancer.

glass bottles (per- plastic film

See taxol.

fumes,

pharmaceuticals) cellophane (tobacco)

paclobutrazol. See trimmit.

polyvinyl chloride polypropylene

bottles

(detergents) polyvinylidene chloride

padan. [S,S

′

(2-dimethylaminotrimethyl-

aluminum tubes (to- polyethylene enebisthiocarbamate)].

othpaste) CAS: 15263-52-2. C

Cl.

paperboard cartons paraffin-coated paper and Hazard: Toxic by ingestion.

board Use: Insecticide.

939

940PAHA

PAHA. See p-aminohippuric acid. “Palacet” [BASF]. TM for a series of organic

pigments used for dyeing and printing on acetate,

nylon, and polyester fibers.

paint. A uniformly dispersed mixture having a

viscosity ranging from a thin liquid to a semisolid

“Palatin” [BASF]. TM for metallized acid

paste and consisting of (1) a drying oil, synthetic

dyestuffs approaching the fastness of chrome colors.

resin, or other film-forming component, called the

binder; (2) a solvent or thinner; and (3) an organic or

palindrome. Biology: A segment of duplex

inorganic pigment. The binder and the solvent are

DNA in which the base sequences of the two strands

collectively called the vehicle. Paints are used (1) to

is the same from each end of the strands.

protect a surface from corrosion, oxidation, or other

type of deterioration, and (2) to provide decorative

palconic acid. An alkali-soluble extract of red-

effects.

wood bark dust. A mixture of partially methylated

Hazard: Flammable, dangerous fire risk (except wa-

phenolic acids.

ter based). Toxic if vapors are inhaled over a long

period. The lead content of household paints is limit-

palladium.

ed to 0.5%.

CAS: 7440-05-3. Pd. Metallic element of atomic

See paint; emulsion; vehicle; protective coating; anti-

number 46, aw 106.4, valences of 2, 3, 4, group VIII

fouling paint.

of the periodic table; there are 6 stable isotopes.

Properties: Silver-white, ductile metal that does not

paint, emulsion. (latex paint). A paint com-

tarnish in air. It is the least noble (most reactive) of

posed of two dispersions: (1) dry powders (colo-

the platinum group. Absorbs up to 800 times its own

rants, fillers, extenders) and (2) resin. The former is

volume of hydrogen. Attacked by hot, concentrated

obtained by milling the dry ingredients into water.

nitric acid and boiling sulfuric acid, soluble in aqua

The resin dispersion is either a latex formed by

regia and fused alkalies, insoluble in organic acids,

emulsion polymerization or a resin in emulsion

good electrical conductor. D 12.0, mp 1554C, bp

form. The two dispersions are blended to produce an

2800C, Mohs hardness 4.8, Brinell 61, Vickers

emulsion paint. Surfactants and protective colloids

(annealed) 41. Noncombustible, except as dust.

are necessary to stabilize the product. Emulsion

Occurrence: Siberia, Ural Mountains (the former

paints are characterized by the fact that the binder is

U.S.S.R.), Ontario, South Africa.

in a water-dispersed form, whereas in a solvent paint

Derivation: In ores with platinum, gold, copper, etc.

it is in soluble form. The principal latex paints are

Concentrated ores are dissolved in aqua regia; after

styrene-butadiene, polyvinyl acetate, and acrylic

gold and platinum are removed by chemical treat-

resins. Percentage composition may be 25–30% dry

ment, palladium is precipitated by ammonia, fol-

ingredients, 40% latex, and 20–30% water, plus

lowed by hydrochloric acid. After further purifica-

stabilizers. The unique properties of emulsion paints

tion treatment, ignition yields palladium metal.

are ease of application, absence of disagreeable

Available forms: Wire, leaf, powder, single crystals.

odor, and nonflammability. They can be used on

Grade: CP (99.99%), technical (99.0%).

both interior and exterior surfaces.

Use: Alloys for electrical relays and switching sys-

tems in telecommunication equipment, catalyst for

paint, inorganic. A potassium silicate−based,

reforming cracked petroleum fractions and hydro-

corrosion-resistant coating designed for use on

genation, metallizing ceramics, “white” gold in jew-

bridges and other metalwork subject to marine envi-

elry, resistance wires, hydrogen valves (in hydrogen

ronments.

separation equipment), aircraft spark plugs, protec-

tive coatings.

paint, metallic. A paint in which the primary

palladium chloride. (palladous chloride; pal-

pigment is a finely divided metal dispersed in the

ladium dichloride).

vehicle. Most common is aluminum paint, but other

CAS: 7647-10-1. (1) PdCl

. (2) PdCl

•2H

metals are also used.

Properties: Dark brown, deliquescent powder or

crystals. (1) D 4.0 (18C), mp 675C (decomposes).

paint remover. (varnish remover). A mixture

Soluble in water, hydrochloric acid, alcohol, and

in liquid or paste form containing volatile solvents

acetone.

and nonvolatile components that retard evaporation

Derivation: By solution of palladium in aqua regia

of the solvent, thereby prolonging its action. Typical

and evaporation.

solvents are methanol, denatured ethanol, meth-

Grade: Technical, reagent.

ylene chloride, toluene, benzene, and ethyl acetate.

Use: Analytical chemistry, “electroless” coatings for

Paraffin is often used as the retarder. Caustic remov-

metals, photography, leak detection in gas lines,

ers contain sodium phosphate, sodium silicate, caus-

indelible inks, catalyst.

tic soda, or the like.

palladium diacetate.

paint, water-based.

See paint, emulsion. CAS: 3375-31-3. (CH

COO)

Pd.

941 PALMITOYL CHLORIDE

Properties: Reddish-brown, crystalline solid. De-

palladous sodium chloride. See palladium

composes at 200C. Insoluble in water and alcohols; sodium chloride.

soluble in acetone, chloroform, acetonitrile.

Derivation: Reaction of palladium nitrate or palladi-

pallet. A low platform of wood or metal used for

um sponge with glacial acetic acid.

transportation or temporary storage of materials or

Use: Catalyst for organic reactions.

semifinished products, it stands on supports that are

high enough to permit handling by forklift trucks.

palladium iodide. (palladous iodide). PdI

palmarosa oil. (geranium oil, Turkish).

Properties: Black powder. D 6.003 (18C). Soluble in

CAS: 8014-19-5. A light-yellow essential oil con-

a solution of potassium iodide; insoluble in alcohol,

sisting chiefly of geraniol; optically active.

water, and ether; decomposes at 350C.

Use: Source of geraniol; perfumes and flavors.

palladium monoxide. See palladium oxide.

palm butter. See palm oil.

palladium nitrate. (palladous nitrate).

“Palmetto” [Olin]. TM for agricultural dusting

Pd(NO

)

sulfur.

Properties: Brown salt, deliquescent, decomposed

Use: Insecticide and fungicide.

by heat. Soluble in water with turbidity; soluble in

dilute nitric acid.

palmitamide.

Hazard: Oxidizing agent, may react with organic

Properties: Semisynthetic compound derived from

materials.

palm oil.

Use: Analytical reagent, catalyst.

Use: Food additive; packaging material release

agent.

palladium oxide. (palladium monoxide).

PdO.

palmitic acid. (hexadecanoic acid; cetylic

Properties: Black-green or amber solid. D 8.70

acid).

(20C), mp 750C (decomposes). Soluble in dilute

CAS: 57-10-3. CH

(CH

)

COOH. A saturated fatty

acids.

acid, it occurs in natural fats and oils, tall oil, and

Derivation: Careful ignition of the nitrate or pro-

most commercial-grade stearic acid.

longed heating of the finely divided metal at 800C.

Properties: White crystals. D 0.8414 (80/4C), mp

Use: Reduction catalyst in organic synthesis.

62.9, bp 351.5C, 271.5C (100 mm Hg), 139.0C (1

mm Hg), refr index 1.4309 (70C). Soluble in hot

palladium potassium chloride. (palladous

alcohol and ether; insoluble in water. Combustible.

potassium chloride; potassium palladium chlo-

Derivation: From spermaceti by saponification and

ride). PdCl

•2KCl.

from palm oil, hydrolysis of natural fats.

Properties: Reddish-brown crystals. D 2.67, mp

Method of purification: Crystallization.

524C. Soluble in water; slightly soluble in hot al-

Grade: Technical, 99.8%, FCC.

cohol.

Use: Manufacture of metallic palmitates, soaps, lu-

Use: Reagent for carbon monoxide determination.

bricating oils, waterproofing, food-grade additives.

palmitic acid amide. See palmitamide.

palladium sodium chloride. (palladous so-

dium chloride; sodium palladium chloride).

palmitic acid cetyl ester. See cetin.

NaPdCl

•3H

Properties: Brown salt. Hygroscopic, soluble in al-

palmitin. See tripalmitin.

cohol and water.

Use: Analysis (testing for carbon monoxide, ethyl-

palmitoleic acid. (cis-9-hexadecenoic acid).

ene, illuminating gas, iodine).

(CH

)

CH:CH(CH

)

COOH. An unsaturated

fatty acid found in nearly every fat, especially in

“Palladon” [LaMotte]. TM for p-nitrosodime-

marine oils (15–20%).

thylaniline used in the colorimetric determination of

Properties: Colorless liquid. Mp 1.0C, bp 140–141C

palladium and platinum.

(5 mm Hg). Insoluble in water; soluble in alcohol

and ether. Combustible.

palladous chloride. See palladium chloride.

Grade: Purified product 99%.

Use: Organic synthesis, chromatographic standard.

palladous iodide. See palladium iodide.

palmitoyl chloride. (hexadecanoyl chloride;

palladous nitrate. See palladium nitrate.

palmityl chloride, so-called). CH

(CH

)

COCl.

Properties: Colorless liquid. Mp 11–12C, bp 194.5C

palladous potassium chloride. See palladi- (17 mm Hg). Soluble in ether, decomposes in water

um potassium chloride. or alcohol.

942PALMITYL ALCOHOL

palmityl alcohol. See cetyl alcohol. pancreatin. A mixture of enzymes, principally

pancreatic amylase, trypsin, and pancreatic lipase.

Obtained from the pancreas of hog or ox.

palmityltrimethylammonium chloride.

Properties: Cream-colored amorphous powder;

See hexadecyltrimethylammonium chloride.

characteristic odor. Acts upon starch and proteins.

Soluble in water; insoluble in alcohol. It changes

palm kernel oil (unhydrogenated).

protein into proteoses and derived substances, and

Properties: From the kernal of the fruit of the oil

starch into dextrins and sugars. Its greatest activity is

palm Elaeis guineensis. A fatty solid; characteristic

in neutral or slightly alkaline media.

sweet nutty flavor.

Derivation: Pancreas gland is extracted by macerat-

Use: Food additive.

ing with chloroform, water, dilute boric acid, glycer-

ol, or alcohol; filtered; and evaporated.

palm nut cake. (palm cake). The cakes

Grade: NF.

formed in the press when the palm nut kernels are

Use: Preparation of so-called predigested protein nu-

expressed to obtain the oil. Contains various useful

trients, in bating compounds of leather; to remove

constituents, such as unexpressed oil, carbohy-

starch and protein sizings from textiles.

drates, proteins, and salts. Typical analysis: proteins

30.4%, fats 8.4%, fiber 41.0%, water 9.5%, ash

Paneth technique. Method demonstrating the

10.6%.

existence of free radicals (e.g., methyl) or atoms,

Use: Cattle-food, fertilizer ingredient.

which is based on the removal of a metallic “mirror”

by a stream of gas containing the radicals. The reac-

palm oil.

tion products can be collected and assayed.

Properties: Yellow-brown, buttery, edible solid at

room temperature. D 0.952, mp 30C, iodine number

13.5, saponification number 247.6. Soluble in alco-

“Pano-drench” [Morton]. TM for a liquid

hol, ether, chloroform, carbon disulfide. Combus- soil-treatment concentrate containing 0.6% cya-

tible. no(methylmercuri)-guanidine.

Occurrence: Oil palms are native to several coun- Hazard: Toxic by ingestion.

tries in central Africa and are extensively cultivated

in Malaysia, which is its chief commercial source. It

“Pan-o-lite” [Solutia]. TM for monobasic cal-

is also produced in Indonesia.

cium phosphate.

Use: Soap manufacture, pharmacy, food shortening,

Use: Food chemical used in waffle, pancake, and

cutting-tool lubricant, hot-dipped tin coating, terne

cake mixes.

plating, cosmetics, softener in rubber processing,

cotton-goods finishing, substitute for tallow as

pantethine.

mold-release agent.

CAS: 16816-67-4. C

. The disulfide form

of N-pantothenylthioethanolamine. Lactobacilus

palm oil (unhydrogenated).

bulgaricus growth factor (LBF). A fragment of

Properties: From the pulp of the fruit of the oil palm

coenzyme A, a pantothenic acid derivative.

Elaeis guineensis. A deep orange-red fatty semisol-

Use: Biochemical research.

id @ 21−27°; characteristic sweet nutty flavor.

Use: Food additive.

panthenol. USAN for pantothenol.

2-PAM. Abbreviation for 2-pyridine aldoxime

methiodide.

pantocaine. (4-butylaminobenzoic-␤-dimethyl-

aminoethyl ester hydrochloride).

“Pamak” [Aqualon]. TM for various tall oil