Improved mechanical and thermal properties of PLLA by solvent blending with PDLA-b-PEG-b-PDLA
Improved mechanical and thermal properties of PLLA by solvent blending with PDLA-b-PEG-b-PDLA
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通过与 PDLA-b-PEG-b-PDLA 溶剂混合改善 PLLA 的机械和热性能
DOI：
10.1016/j.polymdegradstab.2014.01.023
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发表时间：
2014-05-01
影响因子：
5.9
通讯作者：
Chen, Xuesi
中科院分区：
文献类型：
--
作者：
Liu, Yanlong;Shao, Jun;Chen, Xuesi
本文通过溶液浇铸法将两种类型的聚(D-丙交酯)-b-聚(乙二醇)-b-聚(D-丙交酯)(PDLA-b-PEG-b-PDLA)添加到PLLA基质中。通过广角X射线衍射(WAXD)、差示扫描量热法(DSC)、拉伸试验和热重分析仪(TGA)对所得薄膜进行了表征。结果表明，当共聚物的量超过30wt％时，这些共混物的耐热性可以得到改善，因为无论是从溶液还是从熔体，在该添加量下优先形成高熔点立体复合物。当添加 30 wt% 共聚物时，共混物的拉伸强度和断裂伸长率均得到提高，部分原因是对映体 PLA 之间的立体络合和 PEG 嵌段的增塑作用的协同效应。在370℃以上的温度下，共混物表现出比纯PLLA更高的热稳定性。这些结果表明PLLA的韧性和耐热性得到改善，这为PLA的应用提供了可能。 (C) 2014 Elsevier Ltd. 保留所有权利。
In this article, two types of poly (D-lactide)-b-poly (ethylene glycol)-b-poly (D-lactide) (PDLA-b-PEG-b-PDLA) were added into PLLA matrix by solution casting method. The obtained films were characterized by wide-angle X-ray diffractomery (WAXD), differential scanning calorimetry (DSC), tensile testing and thermal gravimetric analyzer (TGA). Results indicated that the heat resistance of these blends could be improved when the amount of copolymer exceeded 30 wt%, because the high melting point stereocomplex was preferentially formed at that addition amount, whenever from solutions or from melt. Both the tensile strength and elongation at break of the blends were enhanced when 30 wt% copolymer was added, which were partly caused by the synergistic effects of stereocomplexation between enantiomeric PLAs and plasticization of PEG blocks. The blends showed higher thermal stability than neat PLLA at temperature above 370 degrees C. These results showed that the toughness and heat resistance of PLLA were improved, which made the application of PLA probable. (C) 2014 Elsevier Ltd. All rights reserved.