冷却速率对β成核剂改性PP结晶行为的影响  

Influence of cooling rate on crystallization behavior of β-nucleated PP

作　　者：陆秋欢[1] 陶红[1] 

机构地区：[1]中国石化上海石油化工股份有限公司塑料事业部,上海200540

出　　处：《合成树脂及塑料》2006年第4期35-38,共4页China Synthetic Resin and Plastics

摘　　要：利用差示扫描量热仪研究了冷却速率对β成核剂改性聚丙烯(PP)结晶行为的影响。冷却速率越慢,高温停留时间越长,则PP中β晶型含量越高,PP的冲击强度越高。冷却速率为5℃/min时,PP中β晶型质量分数达86.12%;冷却速率为20℃/min时,β晶型质量分数为72.04%;而当试样以极快速冷却时,β晶型含量为0。β晶型PP的结晶速率慢于α晶型PP,只有在较高的温度范围内等温结晶时,β晶型PP的结晶速率才快于α晶型PP。因此,一般加工工艺条件下β晶型含量较少。The influence of cooling rate on crystallization behavior of β-nucleated polypropylene （β-PP） was studied with differential scanning calorimeter. The result indicates that the lower the cooling rate, the longer the residence time at high temperature; the higher the content of β-form in PP, the higher the impact strength of PP. The content of B-form in PP amounts to 86.12% at cooling rate of 5 ℃/min and 72.04% at 20℃/min. When the specimen is cooled at an extreme high cooling rate, the content of β-form reduces to nil. The crystallization rate of β-form usually is lower than α-form, however, when the isothermal crystallization process occurs in a higher temperature range, the crystallization rate of β-form is higher than α-form. Therefore, the content of β-form in PP is comparatively lower under the conventional processing conditions.

关 键 词：聚丙烯 Β成核剂 冷却速率 结晶 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]