摘要
用DSC研究了粘均分子量((?)_η)和冷却速率(q)对PET熔体非等温结晶动力学参数、结晶峰高(h_(peak))和结晶热焓(△H_c)的影响。实验结果表明,Avrami指数都在3.0±0.5范围内;Avrami常数随增大((?)_η)而逐渐减小,随q增大而显著增大。q的变化影响结晶峰的峰温(T_(Peak)),也影响h_(Peak));用h_(Peak)对T_(Peak)作图,发现((?)_η)从8,000到29,000的h_(Peak)在162～170℃的温度范围内出现最大值;在T_(Peak)为177℃,有下述定量关系 ㏒ h_(Peak)=1.15×10~2((?)_η)^(-1/2)-2.04。而△H_ζ不仅依赖于((?)_η),还依赖于q。
The influence of molecular weight (η) and cooling rate (q) on the Avrami exponent(n) and constant (z) , △Hc and the peak height (hpeak) of the non-isothermal crystallization of fractionated PET from the melt has been studied by DSC. All values of n were within the range of 3.0 ± 0.5, but Z decreased with the increasing of Mη, and increased with the raising of q. Raising q, the temperature of crystallization peak (Tpeak) decreased, and hpeak changed. Through plotting hpeak vs.Tpeak, it was found that the maximum hpeak located between 162 and 170℃ of Tpeak for PET with Mη ranging 8,000 to 29,800. At 177℃ of Tpeak, the following quantitative relationship was found between hpeak and Mη,log hpeak = 1.15×102Mη-1/2.04.△Hc depends on Mη as well as q.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
1989年第5期57-61,共5页
Polymer Materials Science & Engineering
