Various silicon-containing polymers with Si(H)-CC units

Nine new kinds of thermosetting polymers with the Si(H)-C dropC unit were synthesized by dehydrogenative polycondensation reactions between hydrosilanes and diethynyl compounds in the presence of a magnesia catalyst. Phenylsilane, silane, vinylsilane, and n-octylsilane were used as the hydrosilanes, and 1,3-diethynylbenzene, 1,4-diethynylbenzene, 4,4 ' -diethynyldiphenyl ether, and 1,3-diethynyl-1,1,3, 3-tetramethyldisiloxane were used as the diethynyl compounds. All the polymers were thermosetting, highly heat-resistant, easily soluble in a solvent, and moldable. In particular, -Si(R)H-C dropC-C6H4-C dropC-(R = H or CH=CH2) showed high thermal stability; the temperature of 5% weight loss was greater than 800 degreesC, and the residue at 1000 degreesC was over 90%. The thermal stabilities of the polymers were attributed to the crosslinking reaction of the Si-H and C dropC bonds. (C) 2001 John Wiley & Sons, Inc.