Probing into the pristine basic morphology of high impact polypropylene particles
Probing into the pristine basic morphology of high impact polypropylene particles
复制标题
高抗冲聚丙烯颗粒原始基本形貌的探讨
DOI：
10.1016/j.polymer.2009.07.042
复制
发表时间：
2009-09-10
期刊：
影响因子：
4.6
通讯作者：
Wang, Dujin
中科院分区：
文献类型：
--
作者：
Zhou, Yong;Niu, Hui;Wang, Dujin
本文主要利用透射电子显微镜（TEM）技术，包括普通TEM和先进的透射电子显微层析（TEM）技术，研究了在工业MgCl_2/TiCl_4 Ziegler-Natta催化剂上进行的丙烯（P）均聚和乙烯（E）/丙烯共聚合制备的高抗冲聚丙烯（hiPP）粒子的原始基本形态。结果表明，整个hiPP粒子的基本结构单元是亚微米级的PP（聚丙烯）球和纳米级的EP（乙烯-共聚-丙烯）液滴。EP橡胶（EPR）微区是由EP液滴凝聚而成。连续形成的EP液滴从内到外填充预成型PP骨架内部的微孔和大孔，从而提供不同尺寸的EPR域。考虑到这两种基本结构单元，提出了描述hiPP粒子多种结构的新的四元结构模型。从这些发现中，有人建议，以获得具有优异的刚度/韧性平衡的性能的hiPP聚合物，这是至关重要的控制第一阶段的丙烯均聚，同时合理设计的催化剂结构，以实现所需的EPR分散体形态，决定hiPP性能。(C)2009爱思唯尔有限公司保留所有权利。
In this paper, the pristine basic morphology of high impact polypropylene (hiPP) particles prepared with an industrial MgCl2/TiCl4 Ziegler-Natta catalyst undergoing sequentially occurred propylene (P) homopolymerization and ethylene (E)/propylene copolymerization has been probed mainly using transmission electron microscopy (TEM) techniques including plain TEM and the advanced transmission electron microtomography (TEMT). It is revealed that the basic structure units comprising a whole hiPP particle are the submicron PP (polypropylene) globule and nano-sized EP (ethylene-co-propylene) droplet. EP rubber (EPR) domain is formed by the agglomeration of EP droplets. Continually formed EP droplets turn to fill, from inside out, the micro- and macro-pores inside the preformed PP skeleton, affording different-sized EPR domains. Taking the two basic structure units into account, new quaternary structure model describing the manifold structures of hiPP particles has been proposed. From these findings, it is suggested that, to gain hiPP polymers with excellent stiffness/toughness-balanced properties, it is crucial to control the first-staged propylene homopolymerization alongside a rational design of the catalyst architecture to accomplish desired EPR dispersion morphologies that dictate hiPP properties. (C) 2009 Elsevier Ltd. All rights reserved.