| dc.description.abstract | Homogeneous polystyrene and silica gel polymer hybrids were prepared by in-situ radical polymerization in sol-gel reaction mixture. Styrene monomer was introduced into a sol-gel reaction mixture of tetraethoxysilane (TEOS) and the polymerization was initiated by 2,2’’-azobisisobutyronitrile (AIBN) at 60℃, while sol-gel reaction of TEOS proceeded to form a silica gel.
This study was divided into two parts depended on the preparation of hybrids by using styrene monomer with or without purification.
In the part of the preparation of organic-inorganic hybrids by adding styrene monomer without purification, the main purpose were to confirm transparent hybrids could be prepared by this method or not and also to discuss the preparation conditions, the amount and concentration of acid, the amount of water, AIBN, TEOS and solvent. The results showed that the transparent hybrids were obtained even at adding small amount of water by using ethanol or CH3CN as solvent. The characterizations of the hybrids were determined by the results of GPC, DSC and TGA. The DSC curve of the transparent hybrids did not show any clear glass transition temperature. This lack of glass transition suggests that the polymer chains are uniformly distributed in the inorganic glass network. The porous silica obtained from the hybrids had high surface area and large pore volume and exhibited pore size 1.88 nm. These results indicate that polystyrene was dispersed at a nano-meter level in the silica gel matrix.
In the part of the preparation of organic-inorganic hybrids by adding styrene monomer with purification, the main purpose was to investigate the effect of the concentration of reactants, water and styrene, on the hybrids. The results indicated that the transparent hybrids were obtained by adding various amounts of water（[H2O] / [TEOS] = 4.35×10-2∼10）and styrene（St / TEOS = 0.184∼0.554）by in-situ radical polymerization in sol-gel reaction mixture. The characterizations and pore size of the hybrids were determined by the results of FTIR, DSC, TGA and ASAP. The TGA curves of the transparent hybrids show the higher heat-resistant of hybrids can be obtained by increase the amount of water and TEOS. The ratio of organic to inorganic parts was about 0.232 to 0.817. | en_US |