Note.—The values for the properties in this table are based upon maximum and minimum figures submitted to Modern Plastics by a number of manufacturers of each type of material. Differences in test procedures and sizes of test specimens may lead to erroneous conclusions in some cases if direct comparisons are attempted. Special grades of materials are often available which excel in one particular property.

Source: Modern Plastics, vol. 15, No. 2, opp. p. 120. October 1937.

Table 22.—Synthetic resins and other plastics: Specific gravity, specific volume, and resistance to other substances

Type Specific gravity Specific volume Water absorption, immersion 24 hours1 Effect of weak acids Effect of strong acids Effect of weak alkalies Effect of strong alkalies Effect of organic solvents
Cubic inches
per pound
Synthetic resins:
Tar-acid—Formaldehyde:
Molded, wood flour filler 1.34-1.52 20.7-18.2 0.2-0.6 None to slight. Varies2 Slight to marked Decomposes None.3
Molded, mineral filler 1.70-2.09 16.4-13.3 0.01-0.3 do. do.2 do. do. Do.3
Molded, fabric filler 1.37-1.40 20.2-19.8 1.0-1.3 do. do.2 do. do. Do.3
Laminated, paper base 1.34-1.55 20.7-17.8 0.5-9.0 do. do.2 do. do. Do.3
Laminated, fabric base 1.34-1.55 20.7-17.8 0.5-9.0 do. do.2 do. do. Do.3
Laminated, asbestos cloth base 1.6-1.65 17.3-16.8 0.5 do. do.2 do. do. Do.3
Cast 1.27-1.32 21.8-20.0 0.01-0.5 do. do. do. Do.
Tar-acid—Furfural:
Wood flour filler 1.3-1.4 21.3-19.8 0.2-0.6 do. do.2 do. do. Do.
Mineral filler 1.6-2.0 17.3-13.9 0.01-0.15 do. do.2 do. do. Do.
Fabric filler 1.3-1.4 21.3-19.8 0.8-1.4 do. do.2 do. do. Do.
Urea—Formaldehyde 1.48-1.50 18.7-16.5 1-2 do. Decomposed or surface attacked. do. do. Do.
Vinyl, unfilled 1.34-1.36 20.7-20.4 0.05-0.15 Resistant Resistant Resistant Resistant (4).
Vinyl, filled 1.35-2.5 20.5-11.1 0.2-4.0 Dependent on filler. Dependent on filler. Dependent on filler. Dependent on filler. (4).
Acrylate 1.18 23.3 0.3 None Oxidizing acids attack surface. None Slight (5).
Polystyrene 1.05-1.07 26.3-25.8 0 do. None do. None Widely soluble.
Other plastics:
Shellac compound 1.1-2.7 25.2-10.3 Deteriorates Deteriorates Deteriorates Deteriorates Attacked by some.
Cold molded:
Nonrefractory 1.98-2.0 14.0-13.9 1.5 Slight Decomposes Decomposes Decomposes Do.
Refractory 2.2 12.6 0.5-15 Decomposes do. None None None.
Rubber compounds:
Chlorinated rubber 1.5 18.5 0.1-0.3 Resistant Resistant Resistant Resistant Soluble in aromatic hydrocarbons.
Modified isomerized rubber 1.06 26.1 0.02 do. do. do. do. Attacked by some.
Hard rubber 1.12-1.8 24.7-15.4 0.02 do. Attacked by oxidizing acids. do. do. Do.
Casein 1.35 20.5 3-7 do. Decomposes Softens Decomposes Resistant.
Cellulose compounds:
Ethyl cellulose 1.14 24.3 61.25 Slight Decomposes None None. Widely soluble.
Cellulose acetate sheet 1.27-1.37 21.8-20.2 1.5-3.0 do do Slight Decomposes (7).
Cellulose acetate molding 1.27-1.63 21.8-17.0 1.4-2.8 do do do do (7).
Cellulose nitrate 1.35-1.60 20.5-17.3 1.0-3.0 do do do do (7).

1 ASTM D48-33.

2 Decomposed by oxidizing acids; reducing and organic acids no effect.

3 On bleed-proof materials.

4 Resists alcohols, aliphatic hydrocarbons, and oils. Soluble in ketones and esters; swells in aromatic hydrocarbons.

5 Soluble in ketones, esters, and aromatic hydrocarbons.

6 48 hours.

7 Soluble in ketones and esters; softened by alcohols; little affected by hydrocarbons.

Note.—The values for the properties in this table are based upon maximum and minimum figures submitted to Modern Plastics by a number of manufacturers of each type of material. Differences in test procedure and sizes of test specimens may lead to erroneous conclusions in some cases if direct comparisons are attempted. Special grades of materials are often available which excel in one particular property.

Source: Modern Plastics, vol. 15, No. 2, opp. p. 120. October 1937.