中国塑料 ›› 2013, Vol. 27 ›› Issue (05): 49-55 .DOI: 10.19491/j.issn.1001-9278.2013.05.010

• 材料与性能 • 上一篇    下一篇

聚甲醛/可反应性纳米SiO2复合材料的等温结晶及热分解行为

张予东 郭莉萍 徐翔民 胡修池 张治军   

  1. 河南大学化学化工学院 河南大学特种功能材料教育部重点实验室 黄河水利职业技术学院机电工程系 黄河水利职业技术学院机电工程系 河南大学特种功能材料重点实验室
  • 收稿日期:2013-01-25 修回日期:1900-01-01 出版日期:2013-05-26 发布日期:2013-05-26

Isothermal Crystallization and Thermal Decomposition of Polyoxymethylene/Reactable Nanosilica Composites

  

  • Received:2013-01-25 Revised:1900-01-01 Online:2013-05-26 Published:2013-05-26

摘要: 采用熔融共混法制备了聚甲醛(POM)/可反应性纳米二氧化硅(RNS)复合材料。通过差示扫描量热仪研究了RNS对POM等温结晶行为的影响,利用热重分析仪研究了该材料的热分解变化,用Avrami 方程和HoffmanLaurititzen理论进行了分析。结果表明,RNS在POM结晶过程中起到了异相成核作用,结晶速率常数K增大,半结晶时间t1/2降低,表面自由能下降,Avrami指数n有所降低,说明RNS改变了POM的结晶和生长过程,RNS提高了POM复合材料的热稳定性,其中,添加5 % RNS的POM复合材料起始分解温度提高了32 ℃,用FOW法和Friedman法计算其分解过程的表观活化能均高于POM,这说明RNS与POM之间存在着较强的相互作用,RNS既是POM的成核剂又是热稳定剂。

关键词: 聚甲醛, 纳米二氧化硅, 等温结晶, 热分解

Abstract: Polyoxymethylene/reactable nanosilica composites were prepared via melt blending. The isothermal crystallization behavior of POM and its composites were studied with differential scanning calorimetry, and the effect of nanosilica was explored. The thermal decomposition was studied using thermogravimetric analysis. Avrami equation and HoffmanLaurititzen theory were used to analyze kinetics of isothermal crystallization of POM and its compositions. It showed that the reactable nanosilica (RNS) had a function of heterogeneous nucleation on the POM matrix, which enhanced the crystallization rate of POM, reduced the halftime for crystallization and the surface free energy of the developing crystals. The Avrami exponent n decreased, which indicated that RNS changed the crystallization and growth mechanism of POM. RNS improved the thermal stability and the onset temperate was improved 32 ℃ by 5 % RNS consents. The apparent activation energy of POM/RNS calculated using FOW and Friedman methods was higher than that of POM, which indicated that there must be some strong interaction between RNS and POM. RNS is both a nucleating agent and thermal stability agent of POM.

Key words: polyoxymethylene, nano-silica, isothermal crystallization, thermal decomposition

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