具有特定拓扑结构的聚烯烃高分子的合成

具有特定拓扑结构的聚合物合成一直是高分子合成化学领域的一个重要研究内容，设计和合成具有特定拓扑结构的聚烯烃高分子更是进一步发掘聚烯烃这一量大面广的通用高分子材料的性能、开拓其新的应用领域的重要手段。在催化剂和聚合方法的研究取得重要进展的基础上，近年来国际上在合成不同拓扑结构（包括嵌段、接枝、梳型和星型）的聚烯烃高分子研究方面发展也较快，所合成的部分高分子亦显示出独特的功能性。本文首先综述不同拓扑结构聚烯烃高分子合成的研究现状，然后结合近期化学所在此领域的研究进展，提出独特的以苯乙烯封端反应性聚烯烃为模块构建拓扑结构聚烯烃的新思路。     

Development of a catalytic cracking process for converting waste plastics to petrochemicals

The catalytic degradation of polyolefin using H-gallosilicates was examined using a bench-scale reactor (0.8kg/h) with semicontinuous feeding and the following plastics: (1) low-density polyethylene (LDPE) pellets; (2) linear low-density polyethylene (L-LDPE) pellets; (3) high-density polyethylene (HDPE) pellets; (4) polypropylene (PP) pellets; (5) polyolefin obtained from pulverized industrial waste plastics. The yields of liquid compounds from these materials, which were aromatics in most cases, ranged from 55wt% to 68wt%. With an increase in the ratio of total reactant to catalyst, the liquid yield remained the same. Yields of benzene, toluene, and xylenes (BTXs) decreased rapidly to below 50wt% at a ratio of more than 30. Differences in this ratio for BTXs were always small and were independent of the material. Only about half of the gas product was propane with a fresh catalyst. When the experiments were repeated, propylene, isobutane, and isobutene were found to increase.     

聚丙烯／聚烯烃弹性体共混体系的结构-性能关联

聚丙烯是目前应用最广泛的通用塑料之一。为了克服聚丙烯脆性大的弱点，人们发展了多种方法来增韧聚丙烯，其中聚丙烯和聚烯烃弹性体共混是常用的改性聚丙烯的方法。本文介绍了聚丙烯／聚烯烃弹性体共混物相容性的研究方法和较为普遍接受的增韧理论，并对近年来国内外聚烯烃弹性体增韧聚丙烯的研究进展做了介绍。