α和β-成核作用硅灰石对聚丙烯结晶行为的共同作用

Combined Effect of Compound Wollastonite withαandβ-Nucleating Effect on Crystallization of Polypropylene

α/β复合成核剂改性聚丙烯(PP)已有研究,但α和β-成核作用无机粒子填充PP的结晶行为有待探索。文中通过制备α和β-成核作用硅灰石填充PP复合材料,考察了硅灰石所具有α和β-成核作用和成核效率对PP结晶行为、熔融特性和β-晶含量的影响及规律。结果表明,当2种硅灰石成核效率相差较大时,具有较高成核效率的硅灰石在PP成核结晶过程中发挥主导作用;而当2种硅灰石成核效率相近时,α和β-成核作用硅灰石之间存在竞争成核作用,最终形成β-晶含量由两者的质量比决定。

Althoughα/βcompound nucleating agents modified polypropylene(PP)has been studied in the past few years,the crystallization of PP filled with compound inorganic particles with a andβ-nucleating effect remains to be explored.In our work,compound wollastonite with a andβ-nucleating effect filled PP composites were prepared.The influence of a andβ-nucleating effect and nucleation efficiency of wollastonite on the crystallization behavior,melting characteristics,as well as the relative content ofβ-phase were systematically investigated.The results indicate that if the nucleation efficiency of two kinds of wollastonite exist great difference,wollastonite with higher nucleation efficiency plays a dominant role during the nucleation and crystallization process of PP.However,when wollastonite with different nucleating effect has similar nucleation efficiency,the competitive nucleation between two kinds of wollastonite occurs.As a result,the final relative content ofβ-phase is determined by the mass ratio of wollatonite with different nucleating effect.