取代芳基杂环磷酸金属盐类成核剂在等规聚丙烯中的成核效应

Nucleation efficiency of substituted aromatic heterocyclic phosphoric acid metal salts as nucleators for isotactic polypropylene

采用DSC考察了2,2′亚甲基双(4,6二叔丁基苯基)磷酸的不同金属盐在等规聚丙烯中的成核效应,并研究了这些成核剂对等规聚丙烯力学性能和光学性能的影响.结果表明,一价的取代芳基杂环磷酸金属盐如钠盐、锂盐、钾盐具有很好的成核效果,添加0.2%(质量)的钠盐、锂盐或钾盐,可使聚丙烯的结晶峰温度分别提高13.5、13.6℃和15.0℃,结晶度提高5%左右,结晶速率显著提高;同时可使聚丙烯的拉伸强度提高10%左右,弯曲模量提高30%左右,雾度降低40%左右.而二价的钙盐、镁盐、锌盐和三价的铝盐的成核效果不明显.同时非等温结晶动力学研究表明一价的钠盐、锂盐和钾盐的加入可使聚丙烯的结晶方式发生明显的改变.

Nucleation efficiency of 2, 2＇-methylene-bis （4, 6-di-tert-butylphenyl） phosphoric acid metal salts as the nucleators for isotactic polypropylene （ipp） were investigated with differential scanning calorimeter （DSC）, their effects on mechanical and optical properties of iPP were also studied. The results showed that monovalent metal salts of substituted aromatic heterocyclic phosphoric acid such as sodium salt, lithium salt and potassium salt had good nucleation efficiency. With 0.2% （mass） of sodium salt, lithium salt and potassium salt blended with iPP, the crystallization peak temperature of PP could be increased by 13.5℃, 13.6℃ and 15. 0℃, respectively, the mass fraction of crystallinity of iPP could be increased by about 5%, and crystallization rate was enhanced increasingly. Meanwhile the tensile strength and flexural modulus of iPP could be increased by about 10% and 30%, respectively, and the haze value of iPP could be decreased by about 40%. But bivalent and trivalent metal salts of the phosphoric acid had little effect on properties of iPP. Furthermore the studies on non-isothermal crystallization kinetics of iPP showed that the addition of sodium salt, lithium salt and potassium salt could change the crystallization growth pattern of iPP.