摘要
从 Avrami等关于结晶相转变的严格微分公式和准静态假设条件出发 ,导得了一种可表征体系冷却收缩应力对聚合物结晶影响的动力学处理方法。采用该方法对 PP及 3种不同分子量的 HDPE的研究结果表明 ,聚合物熔体冷却过程中的收缩应力具有促进结晶的作用 ,可引起体系晶体生长指数 n、生长速率常数 k和结晶度的显著增大 ;试样 k值随冷却速率 a的变化率 (Δk/ Δa)
According to Avrami′s rigorous mathematical derivative equation and quasi static conditions, a kinetic method which can characterize the effects of cooling shrinkage stress on crystallization behavior has been derived. The crystallization kinetic behaviors of PP and three kinds of HDPE with various mo1ecular weights have been investigated by this method. The results show that the cooling shrinkage stress of these polymer melts can accelerate themselves crystallization and lead to the obvious increase of the crystallization growth index n and the growth rate constant k . It was found that there is a good consistency between the changing rate of k over the cooling rate a (Δ k /Δ a ) and the Charpy impact strength of the polymers.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2001年第4期149-152,156,共5页
Polymer Materials Science & Engineering
