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Effect of structure on the glass temperature of polyamides
Author(s) -
Temin Samuel C.
Publication year - 1965
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1965.070090209
Subject(s) - polyamide , piperazine , polymer chemistry , hexamethylenediamine , isophthalic acid , alicyclic compound , materials science , diamine , side chain , phenylene , polyester , polymer , chemistry , organic chemistry , composite material , terephthalic acid
A penetrometer method, for which validity was demonstrated, was utilized for measuring the glass temperatures of several polyamides. Adipic acid, sebacic acid, and hexamethylenediamine were used as representatives of linear aliphatic components of the nylons. Isophthalic acid, diphenic acid, and m ‐xylylenediamine were employed to provide examples with phenyl rings in the polymeric chain. Piperazine was used to assay the effect of a rigid alicyclic ring. To provide bulky side groups, 9,9‐bis(2′‐carboxyethyl)fluorene and 9,9‐bis(3′‐aminopropyl)fluorene were utilized. Several new nylon salts and polyamides were prepared. The results illustrate the contribution of chain stiffness and side chain bulkiness to the glass temperature, T g . Assuming, as did Rybnikar, a T g of −65°C. for nylon 66 and other linear aliphatic polyamides, the elevation caused by inclusion of a m ‐phenylene group in the chain was shown to be about 165°C. The piperazine ring had an effect at least equivalent to that of the m ‐phenylene group. A single bulky side group elevated the glass temperature by about 185°C. over the value for linear aliphatic polyamides, the same increment observed in the cases of polyesters and addition polymers. A second bulky group made a smaller incremental addition to T g . Thus, a value of T g well below room temperature for linear aliphatic polyamides was found consistent with the present results.