Thermal Degradation and Electrical Properties of Random and Block Piperazine Copolyamides
作者:
S.D. Bruck,
A.A. Levi,
期刊:
Journal of Macromolecular Science: Part A - Chemistry
(Taylor Available online 1967)
卷期:
Volume 1,
issue 6
页码: 1095-1110
ISSN:0022-233X
年代: 1967
DOI:10.1080/10601326708053760
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
The thermal degradation of random and block copolymers of terephthaloyltrans-2,5-dimethylpiperazine/isophthaloyltrans-2,5-dimethylpiperazine were investigated in terms of rates, activation energies, degradation products, and electrical properties. The rates of degradation and the nature of the volatile degradation products indicate that both random and block copolymers follow a nearly random free-radical type of cleavage in vacuum with activation energies between 59 and 61 kcal/mole. In the temperature range 390=440°C, the block copolymers are significantly more stable in a vacuum (the rates of degradation are two to four times slower) than the random copolymers. In contrast to the random copolymers, the block copolymers showed only slight frequency dependence of their dielectric constants and dissipation factors between 0.1 and 100 kcps.
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