POLYMERIC ORGANOSILICON SYSTEMS - XXIX - THERMAL-PROPERTIES OF POLY[(DISILANYLENE)OLIGOPHENYLENES]

Thermal properties of variously substituted poly[(disilanylene)oligoph enylenes], [((SiRR2SiRR2)-R-1-R-1)(p -C6H4)(m)](n) (R-1 = R-2 = Me, R- 1 = R-2 = Et, and R-1 = Ph, R-2 = Me, m = 1-4) were investigated. The thermogravimetric analysis of the polymers in the range of 20-1000 deg rees C showed rapid weight loss starting from about 400 degrees C. The total weight loss of the polymers at 1000 degrees C was calculated to be 54.5-75.5% based on the initial weight of the polymers. GC-MS anal ysis of the volatile products obtained from the pyrolysis of the polym ers with R-1 = R-2 = Me, m = 2 and R-1 = R-2 = Et, m = 1-4 at 500 degr ees C indicated the formation of silicon-containing oligomers arising from the Si-Si and Si-phenylene bond cleavage, mainly. The formation o f oligophenylenes, H(C6H4)(1)H (l = 1-4), was also observed in the pyr olysis of the polymers with m = 3 and 4. A model reaction for the poly mer degradation was also examined, using 1,2-diphenyltetramethyldisila ne. (C) 1998 Elsevier Science S.A. All rights reserved.