This review-paper shows that usually chemical stress relaxation is generally approximated by Maxwellian decay for hydrocarbon rubber vulcanizates. However, according to later more careful experiments, the chemical relaxation was found not to be necessarily expressed by Maxwellian decay, but by the modified relaxation curve of q//m(t) equals at plus b multiplied by (times) exp(ct) instead of q//m(t) equals at. The diffusion effects are very important in the degradation of rubber vulcanizates. For the degradation of rubber vulcanizates at high temperatures in air in the steady state of diffusion, the rate of scission, q//a//v was found to be expressed by a different equation. For a perfect rubber network having the crosslinking density n(0), the following relationship is obtained as well-known, f(0) equals n(0)RT( alpha minus alpha ** minus **2). For a degraded one, f(t) equals n(t)RT( alpha minus alpha ** minus **2) is obtained. For extremely degraded rubber vulcanizates, however, the improved equation was found to be applicable instead of the above equation.
|ジャーナル||Journal of Polymer Engineering|
|出版ステータス||Published - 1983 1 1|
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