Enhanced crystallization rate and mechanical properties of poly(L-lactic acid) by stereocomplexation with four-armed poly(ε-caprolactone)-block-poly(D-lactic acid)diblock copolymer
Enhanced crystallization rate and mechanical properties of poly(L-lactic acid) by stereocomplexation with four-armed poly(ε-caprolactone)-block-poly(D-lactic acid)diblock copolymer
复制标题
四臂聚(ε-己内酯)-嵌段-聚(D-乳酸)二嵌段共聚物立体络合提高聚(L-乳酸)的结晶速率和机械性能
DOI：
10.1002/pi.5352
复制
发表时间：
2017-06-01
影响因子：
3.2
通讯作者：
Gan, Zhihua
中科院分区：
文献类型：
--
作者：
Ning, Zhenbo;Liu, Junjie;Gan, Zhihua
为了提高聚L-乳酸(PLLA)的结晶速度和力学性能，用一系列四臂聚乳酸(4a-poly(epsilon-caprolactone)-block-poly(D-lactic-b-PDLA)共聚物进行了共混。结果表明，4a-PCL-b-PDLA共聚物的含量越高或PDLA嵌段越长，共混物的结晶速度越快，这是由于4a-PCL-b-PDLA共聚物的PLLA基质与PDLA嵌段之间形成了立体复合晶所致。同时，PDLA嵌段可以改善柔性PCL相和PLLA相之间的相容性，有利于提高力学性能。拉伸结果表明，10%4a-PCL5k-b-PDLA(5k)/PLLA共混物的断裂伸长率最大，约为72%，这是由于对映体间的立体络合作用、多臂结构和PCL嵌段的增塑共同作用的结果。结果表明，在PLLA共混物中控制4a-PCL-b-PDLA共聚物的组成和含量可以显著提高PLLA基质的结晶速度和力学性能。(三)2017年化学工业学会
Poly(L-lactic acid) (PLLA) was blendedwith a series of four-armed poly(epsilon-caprolactone)-block-poly(D-lactic acid) (4a-PCL-b-PDLA) copolymers in order to improve its crystallization rate and mechanical properties. It is found that a higher content of 4a-PCL-b-PDLA copolymer or longer PDLA block in the copolymer lead to faster crystallization of the blend, which is attributed to the formation of stereocomplex crystallites between PLLA matrix and PDLA blocks of the 4a-PCL-b-PDLA copolymers. Meanwhile, the PDLA block can improve the miscibility between flexible PCL phase and PLLA phase, which is beneficial for improving mechanical properties. The tensile results indicate that the 10% 4a-PCL5k-b-PDLA(5k)/PLLA blend has the largest elongation at break of about 72% because of the synergistic effects of stereocomplexation between enantiomeric PLAs, multi-arm structure and plasticization of PCL blocks. It is concluded that well-controlled composition and content of 4a-PCL-b-PDLA copolymer in PLLA blends can significantly improve the crystallization rate and mechanical properties of the PLLA matrix. (C) 2017 Society of Chemical Industry