Design of Supertoughened and Heat-Resistant PLLA/Elastomer Blends by Controlling the Distribution of Stereocomplex Crystallites and the Morphology
Design of Supertoughened and Heat-Resistant PLLA/Elastomer Blends by Controlling the Distribution of Stereocomplex Crystallites and the Morphology
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DOI：
10.1021/acs.macromol.8b02262
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发表时间：
2019-01
期刊：
影响因子：
5.5
通讯作者：
Baogou Wu;Qingtao Zeng;Deyu Niu;Weijun Yang;W. Dong;Mingqing Chen;P. Ma
中科院分区：
文献类型：
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作者：
Baogou Wu;Qingtao Zeng;Deyu Niu;Weijun Yang;W. Dong;Mingqing Chen;P. Ma
通过控制聚乳酸（PLLA）/弹性体共混物中立构复合物（sc）的分布和形态结构由海岛型向共连续型转变，制备了超韧耐热PLLA/弹性体共混物。为了控制sc的分布和相形态，首先将聚（d-丙交酯）（PDLA）与乙烯-乙酸乙烯酯-甲基丙烯酸缩水甘油酯弹性体（EVMG）共混以制备包含游离PDLA和EVMG-g-PDLA共聚物的EVMG/PDLA母料。在随后的色母与PLLA的熔融共混过程中，游离和接枝的PDLA将分别与PLLA在基体和界面上形成SC。因此，原位形成的sc微晶不仅增强了界面粘合力，而且增加了PLLA基质的熔体粘度和结晶速率。通过调节PDLA含量，可以调节sc微晶的数量，以获得可设计的性能和共连续的形态，从而大大改善PLLA的韧性;
Supertoughened and heat-resistant poly(l-lactide) (PLLA)/elastomer blends were prepared by controlling the distribution of stereocomplex (sc) crystallites and the morphological change from sea–island structure to cocontinuous-like structure. To control the distribution of sc and the phase morphology, poly(d-lactide) (PDLA) was first blended with ethylene–vinyl acetate–glycidyl methacrylate elastomer (EVMG) to prepare EVMG/PDLA masterbatch comprising both free PDLA and EVMG-g-PDLA copolymers. The free and grafted PDLA would collaborate with PLLA to form sc in the matrix and at the interface, respectively, during subsequent melt-blending of the masterbatch with PLLA. Consequently, the in situ formed sc crystallites not only enhanced the interfacial adhesion but also increased the melt viscosity and crystallization rate of the PLLA matrix. The sc crystallites amount can be tuned via PDLA content to achieve designable properties and cocontinuous-like morphology, leading to highly improved toughness of PLLA; e...