摘要:本文采用乙烯基三乙氧基硅烷 (A-151)对凹凸棒土(AT)进行表面接枝改性,得到表面改性凹土(OAT);再通过溶液接枝得到聚丙烯酸正丁酯包覆AT杂化粒子(BOAT);同时,通过叔丁基过氧化氢处理使凹凸棒土表面接枝过氧基团制得引发活性凹土(OOAT)。FTIR表明A-151、聚丙烯酸正丁酯(PBA)接枝包覆到AT表面上;通过熔融共混反应挤出法制备HDPE/OAT和HDPE/AT,溶液共混法制备HDPE/OOAT以及 HDPE/BOAT纳米杂化材料。Raman光谱表明改性后的凹凸棒土同HDPE发生了化学反应;力学性能测试发现AT能够使HDPE的拉伸强度提高16%和冲击强度提高44%;SEM分析结果表明,BOAT在HDPE基体中能够以棒晶为基本形态的均匀分散,PBA能有效解决AT和HDPE的界面问题。TG分析表明AT、OAT和BOAT分别使HDPE的分解温度提高了,其中HDPE/BOAT的分解温度升高至480℃;DSC研究了OAT对复合材料结晶行为的影响,结果AT的存在使HDPE的结晶度降低,结晶速率增大。
关键词:凹凸棒土;HDPE;A-151硅烷偶联剂;丙烯酸正丁酯(PBA);表面接枝改性
Abstract:In this paper, the attapulgite was modified with silane coupling agent VTES (A-151), poly(bultyl acrylate)(PBA) and ter-butyl hydroperoxide(TBHP).FTIR showed that A-151 and PBA were successfully grafted on the surface of attapulgite;The nanocomposites of HDPE/OAT were prepareded by solution blending method.,Raman showed that AT modified with A-151 was grafted to HDPE via chemical reactions. HDPE/AT and HDPEB/OAT nanocomposites were prepared by melt reaction blending extrusion. Mechanical properties test showed that HDPE’s tensile strength was increased by 16% and impact strength was increased by 44%.The result of SEM indicated that the modified attapugite were dispersed homogeneously in a form of needle structure in HDPE matrix since PBA grafted on AT acted as a compatilizer;the TG analysis shows that the OAT improved the heat resistance of the nanocomposites and the decomposition temperature of HDPE/BOAT was raised to 480℃;the crystallization behavior of HDPE/OAT was studied by DSC-the crystallization degrees was decreased and crystallization rate was increased with the existence of AT.
Key words:the attapulgite;HDPE;PBA;VTES;surface grafting modification