中国塑料 ›› 2021, Vol. 35 ›› Issue (2): 77-83.DOI: 10.19491/j.issn.1001-9278.2021.02.013

• 加工与应用 • 上一篇    下一篇

PLA基复合材料高温拉伸诱导的宏微观变形

罗飞1,2, 郝凌奥1, 王腾飞1, 刘鸿鹏1, 党旭丹1, 王亚明2, 刘春太2, 宋彦1   

  1. 1.河南工程学院机械工程学院,郑州 451191
    2.郑州大学橡塑模具国家工程研究中心,郑州 450002
  • 收稿日期:2020-08-21 出版日期:2021-02-26 发布日期:2021-02-22
  • 基金资助:
    河南省高等学校重点科研项目(20B430002);河南工程学院博士培育基金(DKJ2019022)

High⁃temperature Stretching Induced Multi⁃structural Deformation of PLA⁃based Composites

LUO Fei1,2, HAO Lingao1, WANG Tengfei1, LIU Hongpeng1, DANG Xudan1, WANG Yaming2, LIU Chuntai2, SONG Yan1   

  1. 1.College of Mechanical Engineering,Henan Institute of Engineering,Zhengzhou 451191,China
    2.National Engineering Research Center for Advanced Polymer Processing Technology,Zhengzhou University,Zhengzhou 450002,China
  • Received:2020-08-21 Online:2021-02-26 Published:2021-02-22

摘要:

采用聚乳酸(PLA)和螺旋碳纳米管(HCNT)与不同质量分数的聚己二酸/对苯二甲酸丁二酯(PBAT)熔融机械共混造粒,并利用真空热压机在不同压力和保压时间下制备矩形样条。利用差示扫描量热仪(DSC)、林肯拉伸热台和广角X射线衍射仪对复合材料的玻璃化转变温度以及恒定拉伸速率下的宏微观变形进行了研究。结果表明,样品中分子取向会随着宏观变形的增加而增大,且取向演化速度逐渐增加。其中在PBAT含量最多和最少的2组样品中,分子取向演化速度随着PBAT含量的增加、保压时间的延长和热压压力的升高而加快。但在其余对照实验组中取向演化速率与压力和保压时间的依赖关系并不明显,显示了分散相PBAT、自由体积和HCNT对分子取向的协同影响。使用一种三元件黏弹模型拟合实验结果,分析发现低含量PBAT样品对保压时间更敏感,高含量PBAT样品对压力更敏感。

关键词: 聚乳酸, 螺旋碳纳米管, 分子取向, 黏弹模型, 宏微观变形

Abstract:

The PLA/coiled carbon nanotube (HCNT) composites were prepared through melt blending with different mass fractions of PBAT. A series of rectangular samples based on these composites were prepared through hot pressing under different pressures and packing time by using an automatic vacuum hot?pressing machine. Their glass transition temperature and multi?structural deformation at a constant stretching rate were investigated by DSC, Linkam stage and wide?angle X?ray diffraction measurement. The results indicated that the molecular orientation and the rate of orientation evolution increased with an increase in macro?deformation. For two samples with lower and higher contents of PBAT, the rate of orientation evolution increased with the increase of packing time and pressure. However, in the cases of other samples, the dependence of the rate of orientation evolution on pressure and time was not evident. This phenomenon implied there was a synergetic effect on the molecular orientation from the dispersed PBAT, free volume and HCNT. A three?element viscoelastic model was used to analyze the experimental data. The fitting results indicated that the sample with a lower content of PBAT was more sensitive to packing time, but the sample with a higher content of PBAT was more sensitive to pressure.

Key words: poly(lactic acid), helical carbon nanotube, molecular orientation, viscoelastic model, multi?structural deformation

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