均聚与无规共聚聚丙烯β结晶行为研究  

β-crystallization Behaviors of Homo-polypropylene and Random Co-polypropylene

作　　者：张凤波[1] 王艳芳[1] 黄强[1] 李荣波[1] 刘晓舟[1] 吴林美[1] 陈商涛[1] 姜凯[1] 

机构地区：[1]中国石油天然气股份有限公司石油化工研究院,北京100195

出　　处：《中国塑料》2013年第7期25-32,共8页China Plastics

摘　　要：使用差示扫描量热仪,广角X射线衍射仪和偏光显微镜对比研究了熔体流动速率接近的均聚和无规共聚聚丙烯添加成核剂前后结晶行为的变化情况。结果表明,熔体冷却速率对均聚聚丙烯中β晶的形成影响较大:较低的冷却速率利于体系中β晶的形成;随着降温速率的增加,体系中β晶含量逐渐降低;在相同的结晶条件下,均聚聚丙烯更易形成β晶;在无规共聚聚丙烯中,β晶的含量也随降温速率的变化而改变,但由于β晶含量较低,变化较小;添加成核剂之后,均聚聚丙烯和无规共聚聚丙烯的结晶温度和结晶活化能均升高,β晶的含量和结晶度都大幅提高;但β晶含量随熔体冷却速率的变化较小;并且与共聚聚丙烯相比较,均聚聚丙烯中β晶的含量和结晶度均要高于前者。The crystallization behavior of homo-polypropylene and random co-polypropylene with and without nucleating agent was investigated comparatively using differential scanning calorimetry （DSC）, wide-angle X-ray diffraction （WAXD）, and polarized optical microscopy （PLM）. The experimental results indicated that the faster the cooling rate of melted polypropylene, the greater the content of β-polypropylene, which was more obvious for homo-polypropylene than random co-polypropylene. Meanwhile, it was found that the homo-polypropylene with lower melting flow rate was more likely to form β-form crystallites. In the presence of β-nucleating agent, both homo- and random co-polypropylene possessed a greater number of spherulites, higher crystallization temperature, crystallization activation energy, the content of β-polypropylene and crystallinity, compared with their neat counterparts. However, the influence of cooling rates on the content of β-polypropylene was reduced for both homo- and random co-polypropylene with addition of nucleating agents. At the same cooling rates and content of β-nucleating agent, the homo- polypropylene always had higher crystallinity and larger content of β-polypropylene than those of random co-polypropylene.

关 键 词：均聚聚丙烯 无规共聚聚丙烯 Β成核剂 结晶 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]