Through the reactivity of the Si-H bond with B-OH groups with nickel power as the catalytic agent, phenyldi[(methyldiphenylethynyl) -silcon-oxygen]borane (B-MDPES) was prepared based on methyl-diphenylethynyl-silane (MDPES) and phenylboronic acid. Si-O-B unit was intruduced successfully into the molecular structure of silicon-containing arylacetylene polymers. We studied the curing mechanisms of B-MDPES resin and the heat resistance and thermo-oxidation properties of B-MDPES thermoset. The purpose of this research was to develop boron-containing arylacetylene polymers with improved heat resistance and thermo oxidation properties. TGA data showed that B-MDPES thermoset possessed outstanding high-temperature resistance in nitrogen and was sensitive to oxygen when heated to a temperature higher than 580 oC. Td5 in niten and air were 681.4 oC and 578.4 oC, the char yields at 900 oCwere of 91.7 % and 42.6 % in nitrogen and air respectively, higher clearly than that of MDPES thermoset . The thermal decomposition processes of B-MDPES thermoset in inert atmosphere were detected using Pyrolysis-Gas Chromatography -Mass. The thermal decomposition process was inferred from the decomposition products of the thermoset, including three parts of fragmentation processes. One part was the cleavage of the Si-C bond resulted in the formation of methyl group and phenyl-naphthyl group; the other part part was cleavage of the C-H bond in methyl group and phenyl-naphthyl group resulted in products of methine group and naphthyl group. Another was that the cleavage of C-C bond and B-C bond resulted in the formation of phenyl group. The thermal decomposition products are either a direct result of the degradation of thermoset or recombination or degradation of compounds formed during pyrolysis. From the gases evolved from the degradation of BPES thermoset, benzene, naphthalene and 1-phenyl-naphthalene were direct results of the degradation, toluene and ethylbenzene were the recombinations of phenyl group and methyl or ethyl group. Biphenyl was the recombination of two phenyl groups. Benzene was the main degradated compound, accounting for 49.27%.

Structure and properties of a high-temperature polymer containing boron and silicon

251st National Meeting (2016)

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