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Fried-man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。
Polyoxymethylene/reactable nano-silica composites were prepared via melt blending. The isother- mal 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 a- nalysis. Avrami equation and Hoffman-Laurititzen theory were used to analyze kinetics of isothermal crystalli- zation of POM and its compositions. It showed that the reactable nano-silica （RNS） had a function of hetero- geneous nucleation on the POM matrix, which ei^hanced the crystallization rate of POM, reduced the half- time for crystallization and the surface free energy of the developing crystals. The Avrami exponent n de- creased, which indicated that RNS changed the crystallization and growth mechanism of POiVL RNS improved the thermal stability and the onset temperate was improved 32 ~C by 5 G RNS consents. The apparent acti- vation 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 PO1V[ RNS is both a nucleating agent and thermal stability agent of PO1VL
出处
《中国塑料》
CAS
CSCD
北大核心
2013年第5期49-55,共7页
China Plastics
基金
河南省科技攻关重点项目(122102210245)
关键词
聚甲醛
纳米二氧化硅
等温结晶
热分解
polyoxymethylene nano-siliea isothermal crystallization thermal decomposition
