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Two polyborosiloxanes(PBSis) with char yield up to 74.13% at 800 °C were synthesized by the direct polycondensation of boric acid with phenyltrimethoxysilane in diglyme. The PBSis were characterized by gel permeation chromatography, IR spectroscopy as well as1H-,29Si- and11B-NMR. PBSi modified phenol-formaldehyde resins(PBSi/PFs) were prepared at different PBSi/PF mass ratios and were cured at 150 °C. The PBSi/PFs were characterized by IR spectroscopy, scanning electron microscopy, thermogravimetric analysis and tensile test. The results revealed that the cured PBSi/PFs had sea-island morphology and higher char yield than the common PF. PBSi/PF blend with PBSi/PF mass ratio of 0.4:1 had char yield up to 70.83% at 800 °C. The PBSi/PFs had tensile strength similar to PF. The ceramization of PBSi/PFs was also studied. The silicon boron oxycarbide(SiBOC) ceramics formed were characterized by IR spectroscopy and elemental analysis. This method provided a valuable way to prepare easily shapeable polymer blends as ceramic precursors.
Two polyborosiloxanes (PBSis) with char yield up to 74.13% at 800 ° C were synthesized by the direct polycondensation of boric acid with phenyltrimethoxysilane in diglyme. The PBSis were characterized by gel permeation chromatography, IR spectroscopy as well as 1H-, 29i- and 11B- NMR. PBSi modified phenol-formaldehyde resins (PBSi / PFs) were prepared at different PBSi / PF mass ratios and were cured at 150 ° C. The PBSi / PFs were characterized by IR spectroscopy, scanning electron microscopy, thermogravimetric analysis and tensile test. The results revealed that the cured PBSi / PFs had sea-island morphology and higher char yield than the common PF. PBSi / PF blend with PBSi / PF mass ratio of 0.4: 1 had char yield up to 70.83% at 800 ° C. PBSI / PFs had tensile similar to PF. The ceramization of PBSi / PFs was also studied. The silicon boron oxycarbide (SiBOC) ceramics was characterized by IR spectroscopy and elemental analysis. This method provides a valuable way to prepare easily sh apeable polymer blends as ceramic precursors.