可控流变PP的制备

Preparation of controlled-rheology PP

以抗冲共聚聚丙烯（PP）作为基础树脂，采用可控流变技术制备了不同流动性能的可控流变聚丙烯（CRPP）．研究了CRPP与基础树脂性能之间的关系以及CRPP的链结构、结晶行为、相态结构和流变行为。结果表明：高流动CRPP的性能与基础树脂的性能关系密切；可控流变技术难以获得高拉伸断裂应变和高冲击强度的高流动CRPP；降解剂用量为700μg/g时，CRPP的重均分子量从2．270×10^5降至1．351×10^5，相对分子质量分布从6．49降至4．71：高流动CRPP的相态结构与基础树脂明显不同。

Various controlled-rheology polypropylene（CRPP） resins with different melt flow rates were prepared from copolymerized impact polypropylene（PP） via controlled rheology process. The relationship between properties of CRPP and basic PP was studied, and the molecular structure, crystallization, morphology and theological behavior of CRPP were also explored. The results show that the properties of CRPP are closely related to that of the basic resin. It is difficult to obtain CRPP with high tensile strain at break and Izod impact strength through controlled rheology process. When the dosage of degradant is 700 μg/g, the relative molecular mass and its distribution of CRPP decrease from 2.270×10^5, 6.49 to 1.351×10^5, 4.71, respectively. The morphology of CRPP is remarkably distinguished from the basic resin.