Preparation And Properties Of PP/PP-g-PS/Nano-SiO₂Composites

In this work, in order to improve dielectric, mechanical, and thermal properties of PP,we take less Modified Nano-silicon dioxide(Nano-SiO2) blend with PP to modify the properties of PP,.In the mean time, add PP-g-PS into system and to improve compatibility of Modified Nano-SiO2/PP blends so that may further improve dielectric, mechanical, and thermal properties property of PP. We will respectively discuss about the effect of PP-g-PS on the composites and effect of Modified Nano-SiO2on the composites. Through these discussions we want to find one of the best ratio among three components in system and try to find reason why can improve dielectric, mechanical, and thermal properties.We first prepared PP-g-PS copolymer and Modified Nano-SiO2, and we used FTIR, TGA, TEM to characterized the molecular structure of PP-g-PS and Modified Nano-SiO2, Through these testing, we found that the FTIR spectra of PP-g-PS showed some new peaks at1490cm-1,695cm-1,785cm-1, and at the range of the3000-3100cm-1, it can prove that the PS has been successfully grafted onto PP molecular chains. The FTIR spectra of Modified Nano-SiO2showed some new peaks at704cm-1,1449cm-1,1496cm-1. The TGA curve of Modified Nano-SiO2showed that in the400℃-450℃, the weight loss of Modified Nano-SiO2is best high, and from the TEM of Modified Nano-SiO2showed that the particle size of Modified Nano-SiO2is50nm.All of these can prove that the PS has been successfully covered onto Nano-SiO2molecular chains.The composites was prepared by melt blending method, And respectively discussed effect of PP-g-PS on dielectric, mechanical, and therm properties of composites and effect of Modified Nano-SiO2on dielectric and mechanical properties of composites. The results show that the maximum tensile strength of the composites can reach to23.674MPa, compare to pure PP, the tensile strength of the composites can improve47%; In the105-106Hz, the maximum dielectric constant can reach to3.1,it also can improve41%to compare to pure PP; The High voltage breakdown strength can reach to33.12kV/mm, it can improve24%to compare to pure PP; Morphologies and thermodynamic properties was characterized by SEM, DSC, The results show that the composites have highly thermodynamic propertie, and better than pure PP; when the same content of PP-g-PS in the composites, the content of Modified Nano-SiO2in the composites increases, the crystallization of the composites is rise, and in the same, it also can change polymorphs of the composites.