阶梯等温结晶法处理后聚丙烯的熔融行为及其影响因素  

Melting Behavior of Polypropylene After Stepwise Isothermal Crystallization and Factors Affecting the Behavior

作　　者：郭梅芳[1] 宋文波[2] 盛建方[2] 侯莉萍[2] 李前树[1] 

机构地区：[1]北京理工大学理学院,北京100081 [2]中国石油化工股份有限公司北京化工研究院,北京100013

出　　处：《石油化工》2005年第10期994-997,共4页Petrochemical Technology

基　　金：国家重点基础研究发展规划项目(G1999064800-07)

摘　　要：采用差示扫描量热法分析了聚丙烯经阶梯等温结晶法处理后的熔融行为,考察了相对分子质量、等规度及共聚单体对聚丙烯熔融行为的影响,并采用Thom son-G ibbs方程计算了所形成结晶的片晶厚度分布。实验结果表明,均聚等规聚丙烯经阶梯等温结晶法处理后的熔融曲线有4个典型的熔融峰;高相对分子质量或高等规度的聚丙烯含有更多较长的丙烯序列,形成更多较厚的片晶;随聚丙烯相对分子质量的增加或等规度的提高,高温区间熔融峰的相对峰面积明显增加;而共聚单体的插入会明显降低熔融温度范围,使部分高温区间的熔融峰消失。Melting behavior of polypropylene （PP） after stepwise isothermal crystallization （ SIC ） and factors affecting the behavior, namely relative molecular mass, isotacticity and comonomer of PP, were studied by differential scanning calorimeter （DSC）. Lamella thickness and crystalline propylene sequence distribution were calculated by using Thomson -Gibbs equation and relative peak area of melting peaks. Four typical melting peaks on melting curves of homopolypropylene samples were observed. Peak temperature for each melting peak increased along with relative molecular mass of PP. PP with higher relative molecular mass or higher isotacticity had longer crystallizable propylene sequence and formed thicker larnella. Relative peak area of melting peaks at higher temperature increased along with isotacticity or relative molecular mass of PP. Due to insertion of ethylene comonomer in PP backbone, melting temperature range lowered and some melting peaks at high temperature disappeared.

关 键 词：聚丙烯 差示扫描量热法 阶梯等温结晶 相对分子质量 等规度 共聚单体 熔融行为 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]