BLOCK COPOLYMER OF 2-METHYL-2-OXAZOLINE WITH SILICA-GEL - AN ORGANIC-INORGANIC HYBRID POLYMER

Ring-opening polymerization of 2-methyl-2-oxazoline followed by termination with 3-aminopropyltriethoxysilane produced poly(N-acetylethylenimine) (polyoxazoline) (POZO) having a terminal triethoxysilyl group. Triethoxysilyl-terminated telechelic POZO was also prepared by using bifunctional initiators. These silane coupling POZOs were subjected to reaction with silanol groups at the surface of silica gel to modify its surface hydrophilicity. Triethoxysilyl-terminated POZOs were also subjected to acid-catalyzed cohydrolysis polymerization with tetraethoxysilane by the so-called sol-gel method to produce a novel organic-inorganic hybrid polymer (block copolymer). The hybrid obtained was a homogeneous, transparent, glassy composite material, which showed more hydrophilicity in comparison with that of silica gel without POZO segments. On the other hand, a hybrid polymer consisting of poly(2-ethyl-2-oxazoline) and silica gel showed amphiphilic properties absorbing both water and organic solvents. Pyrolysis of these hybrids at 600-degrees-C produced silica having micro-pores.