核/壳纳米复合粒子填充聚苯乙烯的流变行为  

MELT RHEOLOGY OF CORE-SHELL NANOPARTICLES FILLED POLYSTYRENE

作　　者：殷先泽 谭业强[1] 林雷 宋义虎[1] 郑强[1] 

机构地区：[1]浙江大学高分子合成与功能构造教育部重点实验室浙江大学高分子科学与工程学系,杭州310027

出　　处：《高分子学报》2012年第11期1335-1341,共7页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号51073136);中央高校基本科研业务费专项资金(基金号2011QNA4031)资助项目

摘　　要：采用细乳液聚合制备了以偶联剂改性纳米二氧化硅粒子(SiO2)为核、交联聚苯乙烯(PS)为壳的SiO2@PS复合纳米粒子(SCCSN).采用透射电子显微镜(TEM)、动态光散射(DLS)法考察了SCCSN的粒子形貌特征,发现SCCSN呈球形,粒径约90 nm,均匀分散;采用热失重(TG)、调制式差示扫描量热(MDSC)与动态力学分析(DMA)研究了SCCSN的结构特征,发现PS包覆率随交联剂含量增加而升高,且玻璃化转变温度(Tg)显著升高.交联壳层不仅能够将聚合物锚固在SiO2表面,屏蔽SiO2粒子与基体PS间相互作用,而且阻止PS壳层与基体PS分子链间的缠结.MDSC结果显示,SiO2与SCCSN填充可降低复合物Tg.动态流变结果表明,填充PS熔体非线性流变行为与PS分子链解缠结有关,SiO2与SCCSN均不影响填充熔体非线性流变机理.SCCSN的SiO2核对PS的增强效应略优于SiO2,且增强效应与壳层交联度有关.Shell crosslinked core-shell nanoparticles （SCCSN） with modified SiO2 as core and crosslinked polystyrene （PS） as shell were prepared via miniemulsion polymerization in the presence of silane modified nanosilica. The structure characterization of SCCSN was examined by transmission electron microscopy （ TEM ）, thermogravimetry （ TG）, dynamic light scattering （ DLS ）, modulated differential scanning calorimetry （MDSC） and dynamic mechanical analysis （DMA）. It was found SCCSN of about 90 nm in diameter was spherical and could uniformly disperse after surface grafting PS. In addition,the glass transition temperature of SCCSN obviously increased with increasing divinyl benzene amounts. The PS shell was crosslinked using divinyl benzene as crosslinker,which not only tightly anchors the shell on the nanoparticle surface,raises PS grafted ratio and prevents nanoparticles interaction, but also segregates the silica core from the matrix and avoids entanglement between the shell PS and the matrix macromolecules in SCCSN filled PS composites. MDSC analyses showed that both silica and SCCSN led to slight reduction in glass transition temperature of PS. Dynamic rheology showed both silica and SCCSN did not influence the mechanism responsible for the origin of rheological nonlinearity assigned to disentanglement of PS macromolecules in the matrix. The SiO2 core in SCCSN exhibited a reinforcement effect slightly stronger than that of bare SiO2 particles and the reinforcement was related to the crosslinking degree of the PS shell

关 键 词：核 壳粒子 细乳液聚合 增强 

分 类 号：TQ325.2[化学工程—合成树脂塑料工业]