Synthesis, characterization and thermal properties of inorganic-organic hybrid

Abstract

Poly (St-MAn-APTES)/silica hybrid materials were successfully prepared from styrene (St), maleic anhydride (MAn) and tetraethoxysilane (TEOS) in the presence of a coupling agent 3-aminopropyltriethoxysilane (APTES), by free- radical solution polymerization and in situ sol-gel process. The TEOS content varied from 0 to 25 wt%. Fourier transform infrared spectroscopy and 29 Si nuclear magnetic resonance spectroscopy were used to characterize the structure of the hybrids (condensed siloxane bonds designated as Q1, Q2, Q3, Q4, with 3-aminopropyltriethoxysilane having mono-, di-, tri, tetra-substituted siloxane bonds designated as T1, T2 and T3). The results revealed that Q3, Q4 and T3 were the major microstructure elements in forming a network structure. The hybrid materials were also characterized by the methods of solvent extraction, Transmission Electron Microscopy (TEM), differential scanning calorimetry (DSC) and thermogravi- metric analysis (TGA) for determining the gel contents, particle size and thermal performance. The results showed that gel contents in the hybrid materials were much higher, the SiO2 phase were well dispersed in the polymer matrix, silicon diox- ide existed at nanoscale in the composites, which had excellent thermal stability.