Synthesis and Properties of Polymers Containing Silphenylene Moiety via Catalytic Cross-Dehydrocoupling Polymerization of 1,4-Bis(dimethylsilyl)benzene

Abstract

The catalytic cross-dehydrocoupling polymerization of 1,4-bis(dimethylsilyl)benzene with water, ammonia, disilanol, aliphatic and aromatic diols, and dicarboxylic acids was successfully conducted under mild conditions to afford silphenylene-containing polycarbosilazane, polycarbosiloxanes, poly(silyl ether)s, and poly(silyl ester)s. This efficient novel route allowed accessing various silphenylene-containing polymers with well-defined structures which were verified by NMR, IR, and SEC analyses. The influence of the structures of the constitutional units between silphenylene groups on the transition temperatures, crystallization behavior, thermal stability, solubility, and degradability of these polymers was also systematically investigated.

Synthesis and characterization of poly(silphenylenesiloxane)s containing functional side groups, a study to high-temperature elastomer

“…When preparing 1a, the reaction was controlled to proceed at around room temperature within a relatively short reaction time in order to minimize the unexpected disproportionation reaction of the silane derivatives, which is often observed in such reactions involving silanes containing at least one hydrido substituent [24 -26]. By using slightly excessive amount of water in the palladium-catalyzed dehydrocoupling polymerization of BSB with water [18,20,21], and followed with careful fractional precipitation, the prepolymer 4 with hydroxy terminal and narrow polydispersity ðM n ¼ 2840; PD ¼ 1:03Þ was obtained.…”

Precise Synthesis of Poly(silphenylenesiloxane)s with Epoxy Side Functional Groups by Tris(pentafluorophenyl)borane as a Catalyst

“…Lithium aluminum hydride (LAH) was purchased from Kanto Chemical Co. Inc. 1,4-diaminobenzene was obtained from Nacalai Co. Inc. 1,4-Bis(dimethylsilyl)benzene (BSB) and PTMPS were prepared according to the literatures. [17][18][19] Hexane, tetrahydrofuran (THF), methanol and diethyl ether were dried before use.…”

Synthesis of poly(methylphenylsiloxane) rich in syndiotacticity by Rh-catalysed stereoselective cross-dehydrocoupling polymerization of optically active 1,3-dimethyl-1,3-diphenyldisiloxane derivatives

“…The stereoselectivity (A difference in stereoisomer ratio between crude 7 and 7 puri®ed by silica gel column chromatography was not observed.) of the reaction catalysed by RhCl(PPh 3 3 were also examined under similar conditions, but they resulted in very low yield (RuCl 2 (PPh 3 ) 2 , 4 % yield and 83 % retention), or no product at all. If the nucleophlicity of (S)-6 was increased, higher yield of the product and stereoselectivity of the reaction would be accomplished under milder conditions.…”