LAUSR

ABSTRACT Hyper-branched poly(styrene) (HPS) made from copolymerisation of styrene (St) and a branching monomer divinylbenzene (DVB) in the presence of a chain transfer agent n-dodecanethiol (C12SH) was grafted onto the surface of nano-SiO2 via emulsion polymerisation (donated as HPS-SiO2). A series of PS/HPS-SiO2 composites were obtained by the addition of prepared HPS-SiO2 into the pure PS. The structures and properties of the product were characterised by Fourier-transform infrared spectra (FT-IR), differential scanning calorimetry, thermogravimetric analysis and dynamic mechanical analysis (DMA). The results showed a strong interface interaction between HPS and nano-SiO2 indicating that the HPS has grafted onto the surface of nano-SiO2. The storage modulus, Young’s modulus, glass transition temperature (Tg) and thermal decomposition temperature of the composite were increased apparently by loading an appropriate amount of HPS-grafted SiO2.