摘要: In an effort to provide a route to new viscoelastic high-temperature polymers with potential for development into broad use-temperature fuel-resistant sealants, an investigation of novel model alkarylenesiloxane polymers was under... 展开 In an effort to provide a route to new viscoelastic high-temperature polymers with potential for development into broad use-temperature fuel-resistant sealants, an investigation of novel model alkarylenesiloxane polymers was undertaken. A number of new linear and cyclic alkarylenesilanes were prepared in an unsuccessful attempt to obtain and polymerize previously unreported cyclodisiloxane monomers by ring-opening techniques. Several of the intermediates were used as monomers in alternate condensation polymerization reactions to yield low and moderate molecular weight polymers of the desired structure. One of the latter, poly(1,1,3,3-tetramethyl-disiloxanylene-m-xylylene), was obtained as a viscous, highly adherent semisolid with an intrinsic viscosity of 0.46 and a number average molecular weight of 39,000. Thermogravimetric analysis of this polymer in a nitrogen atmosphere indicated thermal stability superior to that of a hybrid fluorocarbon-silicone polymer under development as a candidate fuel tank sealant. (Author) 收起