The Study On Structure And Performance Of Nano-SiO₂/PBT Composite

By the method of melt-blending, the composites of (nano-SiO₂, SiO₂ bundled nano-CaCO₃, magnesium salt whisker, montmorillonite)/PBT were prepared, and the properties were investigated under different nano-inorganic component. The result showed that the nano-SiO₂ was the first choice for modifying PBT for the good properties of nano-SiO₂/PBT composite.It was found that the best overall mechanical properties were obtained after adding the microcontent nano-SiO₂. the tensile strength, elongation at break, notch impact strength and flexural strength compared PBT were increased by 12%, 100%, 10 % and 5% respectively while the content nano-SiO₂ was 0.1 phr.The mechanism of PBT modified by the microcontent of nano-SiO₂ was discussed. The results of micromorphic study showed: the dispersion of nano-particle was well-proportioned in PBT by the size of nanometer while the content of nano-SiO₂ was 0.1phr. So the mechanics properties of PBT were improved under this content. The conglobation of nano-particle was increased while the content of nano-particle was increasingly added in PBT. The crystal temperature and crystallinities of PBT were enhanced, but the sizes of spherocrystal of PBT were reduced after adding the microcontent of nano-SiO₂, which was combined with the increase of mechanical properties of the system.The PBT/ABS/nano-SiO₂ and PBT/M-POE/nano-SiO₂ composites were processed, and the properties were compared with the PBT/ABS and PBT/M-POE composites respectively. The effect of blending method (one type method and masterbatch method) on the properties of the system was also studied. The result showed: the tensile and flexure mechanical properties of PBT/ABS/nano-SiO₂ composites by masterbath method were increased a little compared with the composites by one type method, but the notch impact strength was reduced. The notch impact strength was enhanced compared with the PBT in this system. In the PBT/M-POE/nano-SiO₂ system, the mechanical properties were reduced after adding the nano-SiO₂. the three phase system of PBT nano-composites were preliminary studied and needed further investigation.Moreover, the rhological characteristics of the composites were investigated. The result showed that the acrot orque and rinal torque of PBT/nano-SiO₂ were increased while the content of nano-SiO₂ was improved. The acrot torque of PBT/M-POE(or PBT/ABS) was increased as the nano-SiO₂ increasing adding, but the rinal torque was reduced.After studying the nano-composites of PBT, the proper inorganic components were found in modifying PBT. The modification mechanism was discussed and the effect of nano-SiO₂ on modified PBT was studied, preliminary investigation of dispersion properties and blending method was discussed in ternary system of PBT nano-composite. It is directed that the results to further investigate the nano-composites of PBT.