• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>RSC Advances >Polymorphism of a high-molecular-weight racemic poly(L-lactide)/poly(D-lactide) blend: effect of melt blending with poly(methyl methacrylate)
【24h】

Polymorphism of a high-molecular-weight racemic poly(L-lactide)/poly(D-lactide) blend: effect of melt blending with poly(methyl methacrylate)

机译：高分子量外消旋聚（L-丙交酯）/聚（D-丙交酯）共混物的多态性：与聚甲基丙烯酸甲酯熔融共混的效果

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The effect of melt blending with poly(methyl methacrylate) (PMMA), a miscible polymer with polylactide (PLA), on the crystallization and melting behaviors and crystalline structure of high-molecular-weight poly(L-lactide)/poly(D-lactide) (PLLA/PDLA) blend was investigated by differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). Due to the decreased segmental mobility of PLA chains and the dilution effect of the introduced PMMA, the crystallization of PLA is hindered. The polymorphic crystallization of the PLLA/PDLA blend can be tailored by the amount of PMMA and dynamic and isothermal crystallization conditions. The formation of stereocomplex (sc) crystallites is favored for the blends containing PMMA lower than 50 wt% during cold crystallization. During isothermal melt crystallization, the formation of sc crystallites is always accompanied by the generation of homochiral (hc) crystallites at a crystallization temperature (T-c) ranging from 110 to 160 degrees C for neat PLLA/PDLA blend, while the crystallization window for exclusive sc crystallites is widened to 160 degrees C, 140-160 degrees C, and 110-150 degrees C for PLLA/PDLA blends containing 10, 25, and 50 wt% PMMA, respectively. Especially, the formation of sc crystallites can be enhanced over the entire T-c range of 110-160 degrees C when the PMMA content is lower than 25 wt%. The enhanced sc crystallite formation can be ascribed to the reduced crystallization competition resulting from highly restricted hc crystallization. With the PMMA content increasing to 75 wt%, the inhibition effect on the crystallization of PLA suppresses either hc or sc crystallization.
机译：与可与聚丙交酯（PLA）混溶的聚合物聚甲基丙烯酸甲酯（PMMA）熔融共混对高分子量聚（L-丙交酯）/聚（D-）的结晶和熔融行为及晶体结构的影响通过差示扫描量热法（DSC）和广角X射线衍射（WAXD）研究了丙交酯（PLLA / PDLA）混合物。由于PLA链的节段迁移率降低以及引入的PMMA的稀释作用，阻碍了PLA的结晶。 PLLA / PDLA共混物的多晶型结晶可通过PMMA的量以及动态和等温结晶条件进行调整。在冷结晶过程中，对于含有低于50 wt％的PMMA的共混物，形成立体络合物（sc）微晶是有利的。在等温熔融结晶过程中，纯PLLA / PDLA共混物在结晶温度（Tc）为110至160摄氏度时，sc晶体的形成总是伴随着同手性（hc）晶体的产生，而独家sc的结晶窗口对于分别包含10、25和50 wt％PMMA的PLLA / PDLA共混物，微晶分别增宽到160摄氏度，140-160摄氏度和110-150摄氏度。特别地，当PMMA含量低于25wt％时，可以在110-160℃的整个T-c范围内增强sc微晶的形成。增强的sc微晶形成可以归因于高度限制的hc结晶导致的结晶竞争降低。随着PMMA含量增加到75wt％，对PLA结晶的抑制作用抑制了hc或sc结晶。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号