无皂乳液聚合制备PMMA/MMT纳米复合材料的研究

Preparation of PMMA/MMT Nanocomposites by Soap-free Emulsion Polymerization

采用离子交换法,用溴化烯丙基三乙基铵对钠基蒙脱土进行改性制备了有机蒙脱土,再以甲基丙烯酸甲酯(MMA)为单体,过硫酸钾为引发剂,通过无皂乳液聚合制备聚甲基丙烯酸甲酯/蒙脱土(PMMA/MMT)纳米复合材料。采用傅里叶变换红外(FTIR)、X-射线衍射(XRD)和扫描电镜(SEM)等手段对有机蒙脱土和复合材料的结构进行表征。结果表明:溴化烯丙基三乙基铵成功插层到蒙脱土层间,层间距由1.32 nm增大到1.44 nm;FTIR和XRD测试结果表明不同蒙脱土含量的PMMA/MMT纳米复合材料均具有剥离型结构;SEM测试结果表明PMMA/MMT纳米复合粒子的粒径随蒙脱土含量的增加而减小。

Organo-montmorillonite was obtained by using aUyltriethylammonium bromide to modify sodium montmorillonite through cation exchanging reaction. Poly（methyl methacrylate）/montmorillonite （PMMA/MMT） nanocomposites were synthesized by soap-free emulsion polymerization using methyl methacrylate （MMA） as monomer and potassium persulfide as initiator. The structures of the organo-montmorillonite and nanocomposites were characterized with Fourier transform infrared spectroscopy （FTIR）, X-ray diffraction spectroscopy （XRD） and scanning electron microscopy （SEM）. The spacing increases from 1.32 nm to 1.44 nm after intercalation modification of MMT with the use of allyltdethylammonium bromide. FTIR and XRD results show that PMMA/ MMT nanocomposites with different MMT content have an exfoliated structure. SEM results show that the diameter of PMMA/MMT composite particles decreases with the increase of the MMT content.