Preparation and characterization of high MFR polypropylene and polypropylene/poly(ethylene-co-propylene) in-reactor alloys
Preparation and characterization of high MFR polypropylene and polypropylene/poly(ethylene-co-propylene) in-reactor alloys
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DOI：
10.1002/app.42984
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发表时间：
2016-02
影响因子：
3
通讯作者：
Biao Zhang;Zhisheng Fu;Zhiqiang Fan;P. Phiriyawirut;Sumate Charoenchaidet
中科院分区：
文献类型：
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作者：
Biao Zhang;Zhisheng Fu;Zhiqiang Fan;P. Phiriyawirut;Sumate Charoenchaidet
本工作以环己基甲基二甲氧基硅烷或双环戊基二甲氧基硅烷为外给电子体，采用球形氯化镁负载≈催化剂，合成了熔体流动速率为30g/10min的高熔体流动速率聚丙烯(HF-PP)和PP/聚(乙烯-丙烯-共聚)反应器内合金(HF-PP/EPR)。研究了De对HF-PP和HF-PP/EPR的聚合活性、链结构、力学性能和相形态的影响。加入CHMDMS使聚合物MFR随H2的变化比DCPDMS更敏感，生成的PP/EPR合金中含有更多的无规乙丙橡胶(r-EP)和嵌段乙丙橡胶(S-EP)。CHMDMS还可引起S-EP的形成，其阻滞性高于DCPDMS。在DCPDMS存在下制备的HF-PP/EPR合金的弯曲性能高于CHMDMS制备的HF-PP/EPR合金，但冲击强度低于CHMDMS。以CHMDMS和DCPDMS为增韧剂制备的合金对橡胶相的增韧效果基本相同，但DCPDMS可提高合金的硬度。©2015威利期刊公司J.应用。波兰姆。SCI。2016年，133,42984。
In this work, high melt flow rate (MFR) polypropylene (HF-PP) and polypropylene/poly(ethylene-co-propylene) in-reactor alloys (HF-PP/EPR) with MFR ≈ 30 g/10 min were synthesized by spherical MgCl2-supported Ziegler–Natta catalyst with cyclohexylmethyldimethoxysilane (CHMDMS) or dicyclopentyldimethoxysilane (DCPDMS) as external donor (De). The effects of De on polymerization activity, chain structure, mechanical properties, and phase morphology of HF-PP and HF-PP/EPR were studied. Adding CHMDMS caused more sensitive change of the polymers MFR with H2 than DCPDMS, and produced PP/EPR alloys containing more random ethylene-propylene copolymer (r-EP) and segmented ethylene-propylene copolymer (s-EP). CHMDMS also caused formation of s-EP with higher level of blockiness than DCPDMS. HF-PP/EPR alloy prepared in the presence of DCPDMS exhibited higher flexural properties but lower impact strength than that prepared with CHMDMS. Toughening efficiency of the rubber phase was nearly the same in the alloys prepared using CHMDMS or DCPDMS as De, but stiffness of the alloy can be improved by using DCPDMS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42984.