中国塑料 ›› 2010, Vol. 24 ›› Issue (12): 30-35 .DOI: 10.19491/j.issn.1001-9278.2010.12.006

• 材料与性能 • 上一篇    下一篇

聚乳酸/可反应性纳米SiO2复合材料的等温结晶动力学

郭有钢 张予东 徐翔民 张普玉   

  1. 河南大学化学化工学院 ,精细化学与工程研究所 河南大学化学化工学院 ,精细化学与工程研究所 黄河水利职业技术学院 河南大学化学化工学院
  • 收稿日期:2010-08-06 修回日期:1900-01-01 出版日期:2010-12-26 发布日期:2010-12-26

Isothermal Crystallization Kinetics of PLLA/Reactable Nano-SiO2 Composites

Yougang GUO Yu-Dong Zhang Xiang-Min Xu Puyu ZHANG   

  • Received:2010-08-06 Revised:1900-01-01 Online:2010-12-26 Published:2010-12-26
  • Contact: Puyu ZHANG

摘要: 采用熔融共混法制备了聚乳酸/可反应性纳米二氧化硅(PLLA/RNS)复合材料。利用差示扫描量热仪研究了RNS对PLLA等温结晶行为的影响;用Avrami 方程研究了PLLA及其复合材料的等温结晶动力学。结果表明,加入RNS对PLLA结晶起到了异相成核作用,随着RNS含量的增加,PLLA的结晶速率(K)提高,半结晶时间(t1/2)减小,而Avrami指数(n)变化不大,说明RNS没有改变PLLA结晶的成核机理;利用Arrhenius方程和Lauritzen-Hoffman理论分别对PLLA及其复合材料的结晶活化能(ΔE)、成核参数(Kg)和折叠链端表面自由能(σe)进行计算后发现,复合材料的ΔE比纯聚乳酸的小,Kg 、σe略有增加。这表明加入RNS降低了复合材料的ΔE,从而有效地促进了PLLA基体的结晶。

关键词: 聚乳酸, 纳米二氧化硅, 复合材料, 等温结晶动力学

Abstract: PLLA/reactable nano-SiO2 (RNS) composites were prepared via melting blending. The isothermal crystallization behavior of PLLA and its composites was studied with differential scanning calorimetry(DSC) and the effect of RNS was explored. The crystallization Kinetics under isothermal conditions was described by using Avrami equation. It showed that RNS had the function of heterogeneous nucleation to PLLA matrix. With increasing RNS content, the crystallization rate K of PLLA matrix was increased and the half-time crystallization t1/2 decreased, while the Avrami exponent n had no significant change, which indicated that RNS hadn't changed the nucleation mechanism of PLLA. In addition, Arrhenius and Lauritzen-Hoffmann equations were employed to estimate the activation energy ΔE, the nucleation parameter Kg, and the end surface energies σe. It was found that the activation energy of the composites was smaller than that of the pure PLLA. The values of Kg and σe for the composites have increased slightly compared with pure PLLA.

Key words: poly(l-lactide), nano-SiO2, composite, isothermal crystallization kinetics

中图分类号: