Synthesis and effects of MDT silicone resin on PMPS-based ablative composites.

ABSTRACT A novel methylphenyl silicone resin, with M, D, and T units, was synthesized by cohydrolysis and cocondensation method from dimethyldimethoxysilane (Me₂Si(OMe)₂), phenyltrimethoxysilane (PhSi(OMe)₃), hexamethyldisiloxane, and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane in toluene/water mixture catalyzed by hydrochloric acid and trifluoromethanesulfonic acid. The vinyl end-capped MDT silicone resins were chosen for reinforcement filler to enhance the mechanical properties of silicone-based ablative composites. The effects of resins with various R/Si ratios, vinyl content, and loadings on mechanical properties of PMPS rubbers were investigated. It was revealed that on the premise of good fluidity and processing performance, MDT resin showed excellent reinforcing effect and thermal stability compared with silica. MDT reinforced ablative composite showed satisfactory mechanical and antiablative properties. The linear ablation rate was 0.01 mm/s, which maybe associated with high yield of charred residue in thermogravimetric analysis results. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41571. [ABSTRACT FROM AUTHOR]