庚二酸类成核剂对等规聚丙烯β晶结晶行为的影响

Effect of Pimelic Acid-Based Nucleators on Crystallization Behavior of β Crystalline Form in Isotactic Polypropylene

研究了结晶温度(100～140℃)对添加庚二酸钠、庚二酸锌、庚二酸钙、庚二酸钡成核剂的等规聚丙烯中β晶结晶行为的影响。发现庚二酸钠、庚二酸锌、庚二酸钙和庚二酸钡是有效的β晶型成核剂,随着结晶温度的提高,成核改性聚丙烯的β晶型含量持续增大,并在130℃时达到最大值,结晶温度在130℃～140℃之间,成核改性的聚丙烯发生明显的β→α晶型转变。β晶型成核效率由大到小的顺序为:庚二酸钙>庚二酸钡>庚二酸锌>庚二酸钠,庚二酸钙是最佳β晶型成核剂。

The nucleation behavior of sodium pimelate, zinc pimelate, calcium pimelate, and barium pimelate in polypropylene at various temperatures was studied. All the pimelates generated β form crystals, the content of which increased with increasing crystallization tempearature up to 130 ℃. Above 130 ℃, the β→α transition occurred. The order in the efficiency of β nucleation was calcium pimelate 〉 barium pimelate 〉 zinc pimelate 〉 sodium pimelate.