Brittle-ductile transition behavior of the polypropylene/ultra-high molecular weight polyethylene/olefin block copolymers ternary blends: Dispersion and interface design
Brittle-ductile transition behavior of the polypropylene/ultra-high molecular weight polyethylene/olefin block copolymers ternary blends: Dispersion and interface design
复制标题
聚丙烯/超高分子量聚乙烯/烯烃嵌段共聚物三元共混物的脆塑转变行为：分散和界面设计
DOI：
10.1016/j.polymer.2019.121819
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发表时间：
2019-11-07
期刊：
影响因子：
4.6
通讯作者：
Guo, Shaoyun
中科院分区：
文献类型：
--
作者：
Han, Shida;Zhang, Tianci;Guo, Shaoyun
超高分子量聚乙烯（UHMWPE）具有优异的抗冲击和抗裂性能，可用于增韧聚丙烯（PP）。不幸的是，它们之间的巨大粘度失配导致大的UHMWPE团聚体的形成和机械性能的劣化。本文分别采用凝胶母料共混法和烯烃嵌段共聚物法实现了PP/UHMWPE的均匀共混和增强界面相互作用。结果表明，在PP基体中形成了具有核壳结构的UHMWPE-OBC相，OBC作为UHMWPE核与PP基体之间的相容壳层，以亚微米级的尺寸分散在PP基体中。随着OBC用量的增加，PP/UHMWPE/OBC（G-P/U（20）-O）共混物的核壳结构逐渐改善，当OBC用量达到5份时，共混物发生脆韧转变。加入7 phr OBC和20 phr UHMWPE后，G-P/U（20）-O（7）共混物形成了完美的核壳结构，缺口冲击强度为55.47 kJ/m2，比G-P/U（20）的9.86 kJ/m2大得多，是纯PP的17.5倍。通过对核壳结构演变过程中的结晶行为和流变行为的研究，建立了核壳结构与性能的关系，揭示了核壳结构的脆韧转变和增韧机理。
Ultra-high molecular weight polyethylene (UHMWPE), which possesses outstanding impact and crack resistance, can be potentially used to toughen polypropylene (PP). Unfortunately, enormous viscosity mismatch between them leads to the formation of large UHMWPE agglomerates and the deterioration of mechanical properties. In this work, a kind of Gel masterbatch mixing (GMM) method and olefin block copolymers (OBC) were used to realize the intimate mixing of PP/UHMWPE and strengthened interface interaction, separately. The results showed that UHMWPE-OBC phases with core-shell structure were formed and dispersed in PP matrix in a submicron size, which OBC was as a compatible shell between UHMWPE core and PP matrix. As the amount of OBC in the PP/UHMWPE/OBC (G-P/U (20)-O) blends increased, the core-shell structure was gradually improved and the brittle-ductile transition occurred when the OBC content reached to 5phr. After adding 7phr OBC and 20phr UHMWPE, the perfect core-shell structure was formed in G-P/U(20)-O(7) blends and the notched Izod impact strength was 55.47 kJ/m(2), which was much higher than the 9.86 kJ/m(2) (G-P/U(20)) and about 17.5 times larger than Pure PP. Furthermore, crystallization and rheological behaviors were measured to reveal the evolution of core-shell structure and the microstructure-properties relationship was also established to reveal brittle-ductile transition and toughening mechanism.