Structural Study of Silyl−Carborane Hybrid Diethynylbenzene−Silylene Polymers by High-Resolution Solid-State 11B, 13C, and 29Si NMR Spectroscopy

The structure of silyl-carborane (1,7-C2B10H10) hybrid diethynylbenzene-silylene polymers with thermal treatment over a wide range of temperatures has been characterized by using 11B MQ-MAS NMR, and 13C and 29Si CP-MAS NMR methods. From the experimental results, the following was found: (1) naphthalene rings form by diene reaction between the Ph−C≡C group and C≡C group at temperatures from 250 to 500 °C; (2) three-dimensional network forms by addition reaction between the vinyl group and C≡C group at curing temperatures from 250 to 350 °C and addition reaction between m-carborane group and the vinyl group and/or the C≡C group at curing temperatures from 250 to 350 °C; (3) the hybrid polymers are decomposed by oxidation at curing temperature of 500 °C; and (4) structural change of the m-carborane hybrid polymer leads to desirable modification of the oxygen index, heat deflection temperature, and flexural strength.