多级拉伸挤出制备右旋聚乳酸/左旋聚乳酸复合材料的结构与性能  

Structure and Properties of D-Polylactide/L-Polylactide Composites Prepared by Multistage Tensile Extrusion

作　　者：朱一凡[1] 李姜[1] 郭少云[1] Yifan Zhu;Jiang Li;Shaoyun Guo(State Key Laboratory of Polymer Materials Engineering,Polymer Research Institute,Sichuan University,Chengdu 610065,China)

机构地区：[1]高分子材料工程国家重点实验室(四川大学)四川大学高分子研究所

出　　处：《高分子材料科学与工程》2019年第9期62-66,共5页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(51873112)

摘　　要：通过自主研发的多级拉伸挤出设备,将5%右旋聚乳酸(PDLA)/左旋聚乳酸(PLLA)立构复合共混样品及PLLA对比样进行挤出。通过差示扫描量热分析、二维广角X射线衍射、扫描电子显微镜、拉伸试验研究了多级拉伸挤出下立构晶(SC)对PLLA结晶性能、微观形貌及力学性能的影响。结果表明,立构晶能显著改善PLLA的结晶速度和结晶度,同时其在9个层倍增器下能进一步促进PLLA结晶。挤出样品的结晶度从6.8%提高到38%,并形成了取向的微晶网络结构。多级拉伸挤出制备的PDLA/PLLA复合材料相对于未加层倍增器挤出的PLLA材料,力学性能得到显著的提升,拉伸强度和断裂伸长率分别提高了15.8%和909.6%。The self-developed multi-stage stretch extrusion equipment was used to extrude 5% D-polylactide/L-polylactide(PDLA/PLLA) blends and PLLA samples. The effects of stereocomplex crystals(SC crystals) on the crystallinity, morphology and mechanical properties of PLLA under the multi-stage stretch extrusion were studied by differential scanning calorimetry, two-dimensional wide-angle X-ray diffraction, scanning electron microscopy and universal stretching machine. The results show that the SC crystals can significantly improve the crystallization rate and crystallinity of PLLA, while the SC crystals further promote PLLA crystallization under 9 layer multipliers(LEMs). The crystallinity of the extruded sample increases from 6.8% to 38% and formed an oriented micro-crystalline network structure. The mechanical properties of the PDLA/PLLA composites prepared by multi-stage stretch extrusion are significantly improved compared with the PLLA material extruded by 0 LEM. The tensile strength and elongation at break are increased by 15.8% and 909.6%, respectively.

关 键 词：聚乳酸 立构晶 结晶 取向 

分 类 号：TQ320.666[化学工程—合成树脂塑料工业]