Preparation and Pyrolysis of from Cross-linked Polymethylsilane via Hydrosilylation

Abstract

Pyrolysis products from p-diethynylbenzene-modified polymethylsilane was studied. Polymethylsilane (PMS) was modified by platinum-catalyzed hydrosilylation with p-diethynylbenzene at room temperature to form a brown-colored viscous liquid. The ceramic residues prepared via pyrolysis of modified PMS were characterized via infrared (IR) spectroscopy, solid-state ²⁹Si nuclear magnetic resonance spectroscopy with magic angle spinning technique (solid-state ²⁹Si MAS NMR) and X-ray diffraction (XRD). IR spectroscopy showed that mineralization process significantly proceeded in the temperature range from 600°C to 800°C. XRD analysis suggested that the crystallization of b-SiC occurred above 1200°C. Solid-state ²⁹Si MAS NMR suggested that a ceramic residue pyrolyzed at 1200°C was mainly composed of an SiC₄ environment.