纳米二氧化硅颗粒表面设计及其填充聚氯乙烯复合材料的性能

利用表面原位接枝聚合在纳米二氧化硅颗粒表面引入聚甲基丙烯酸甲酯(PMMA)高分子链段,用共混法制备了nano-SiO2/PVC复合材料,研究了不同界面特性时SiO2/PVC复合材料的力学性能.研究结果表明通过表面原位接枝聚合反应可以在纳米二氧化硅颗粒表面接枝聚甲基丙烯酸甲酯;表面接枝PMMA的nano-SiO2/PVC复合材料在力学和加工性能等方面都优于偶联剂处理和表面未处理样品.在纳米二氧化硅颗粒填充量为0%～8%(wt)时,复合材料的拉伸强度和冲击强度随着填充量的提高先上升后下降,并在4%～6%(wt)达到最大值.经PMMA表面接枝后SiO2/PVC具有更强的界面作用,偶联剂KH570处理的次之,表面未处理样品的最差.

Interface Design and Mechanical Properties of SiO2/PVC Nanocomposites

In order to improve the interfacial adhesion between the matrix and inorganic particles, the SiO2 nanoparticles were modified with polymethyl methacrylate (PMMA) and silicane couplant KH507 respectively, and then the SiO2/PVC composites were prepared via the melt blending method. The microstructure and mechanic properties of SiO2 nanoparticle filled PVC composites were investigated by FT-IR, TG, SEM, etc.. The FT-IR spectrums and TG curves show that the PMMA and KH570 have been grafted onto the surfaces of SiO2 particles, respectively. It is found that the PVC composites filled with SiO2 nanoparticle grafted by PMMA (SiO2-g-PMMA/PVC) have lower equilibrium torque, higher tensile and impact strength than that of PVC composites filled with KH570 or untreated SiO2 nanoparticles. The SiO2-g-PMMA /PVC nanocomposites with maximum tensile strength and single notched impacted strength can be obtained when their blended SiO2 nanoparticle contents are in 4%~6%(wt.). The SiO2-g-PMMA nanoparticles have bigger interfacial interaction with PVC matrix than that of KH570 treated SiO2 nanoparticles, and the KH570 treated SiO2 nanoparticles have bigger interfacial interaction than that of untreated SiO2 nanoparticles.