Nanocomposites of high-impact polystyrene with unmodified nanosized TiO 2 and polystyrene-encapsulated MPTMS-modified nanosized TiO 2 : mechanical,thermal and morphological properties

Abstract

Polymer nanocomposites of high-impact polystyrene (HIPS) with either unmodified nanosized titanium dioxide (nTiO2) or polystyrene (PS)-encapsulated MPTMS-modified nTiO2 (PS-MPTMS-nTiO2) were prepared. The PS-MPTMS-nTiO2 was synthesised via in situ differential microemulsion polymerization. The PS-MPTMS-nTiO2 exhibited a core–shell morphology with diameter of 45.3 nm. The addition of unmodified nTiO2 to the HIPS caused a reduction in the impact strength, tensile strength, and elongation at break, but an increase in the Young's modulus. Meanwhile, the inclusion of the PS-MPTMS-nTiO2 was found to enhance the impact and tensile strength, Young's modulus and thermal stability of the nanocomposites, while the elongation at break was deteriorated compared to that of the pure HIPS. This was due to the PS shell that hindered the agglomeration of the nTiO2 particles, leading to a better dispersion of the PS-MPTMS-nTiO2 particles in the HIPS matrix. Moreover, the Tg of HIPS in all nanocomposites was slightly affected by the nanoparticles.