Hualun Cai1,2, Xiuju Zhang3, Kai Xu2, Huan Liu1,2, Jiangxun Su1,2, Xin Liu1,2, Zien Fu1,2, Ying Guo1,2, Mingcai Chen2
1Graduate School of the Chinese Academy of Sciences, Beijing 100049, China
2Guangdong Provincial Key Laboratory of Organic Polymer Materials for Electronics, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, P. O. Box 1122, Guangzhou 510650, China
3Department of Material Science and Engineering, Jinan University, Guangzhou 510632, China
Tóm tắt
AbstractOctaphenylsilsesquioxane (PH‐POSS) and octa(γ‐methacryloxypropyl)silsesquioxane (MA‐POSS) were successfully synthesized by hydrolytic condensation of phenyltrichlorosilane and γ‐methacryloxypropyltrimethoxysilane, and characterized by Fourier transform infrared (FT‐IR), 1H and 29Si nuclear magnetic resonance (NMR), and matrix‐assisted laser desorption/ionization‐time of flight (MALDI‐TOF) mass spectrum. Morphology, degradation behavior, thermal, and mechanical properties of hybrid composites were studied by transmission electron microscopy (TEM), polarized optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), surface contact angle (SCA), tensile, and impact testing. Domains of PH‐POSS and MA‐POSS dispersed in the matrix with a wide size distribution in a range of 0.1–0.5 µm, while PH‐POSS exhibited a preferential dispersion. Because of the possible homopolymerization of MA‐POSS during the melt blending, the glass transition temperature of polycarbonate (PC)/MA‐POSS composites remained nearly unchanged with respect to PC/PH‐POSS composites that showed a depression of Tg due to the plasticization effect. It is interesting to note that the incorporation of POSS retarded the degradation rates of PC composites and thus significantly improved the thermal stabilities. SiO fractions left during POSS degradations were a key factor governing the formation of a gel network layer on the exterior surface. This layer possessed more compact structures, higher thermal stabilities, and some thermal insulation. In addition, percentage residues at 700°C (C700) significantly increased from 10.8% to 15.8–22.1% in air. Fracture stress of two composites showed a slight improvement, and the impact strength of them decreased monotonically with the increase of POSS loading. Copyright © 2011 John Wiley & Sons, Ltd.
