Surface Characterization of Methylsilsesquioxane-Phenylsilsesquioxane Copolymers

Abstract

Mixtures of methyl-and phenyltrichlorosilanes have been hydrolyzed to obtain cross-linked polysiloxanes, often referred to as polysilsesquioxanes. Glassy or amorphous materials are obtained, depending on the reaction conditions used. Infrared spectroscopy, scanning electron microscopy, and gas chromatography have been employed to study the surface characteristics of these materials. The infusible solids that are obtained are thermally stable up to 400 °C. Surface areas for the materials range from 0.02 to 5 m2/g, depending on the reaction conditions. Swelling experiments show that the materials are very tightly cross-linked networks. The soft materials having surface areas around 5-10 m2/g are suitable as adsorbents for gas-solid chromatography.

Short silica fiber composites with simultaneous interpenetrating polymer networks constituted by siloxane and phenolic systems

“…Polysiloxanes are well‐known as high temperature resistant polymers suitable for several specialized applications such as insulators, adhesives and potting compounds. Among them, polymethylsilsesquioxane (PMSQ) with the empirical formula (CH 3 SiO 3/2 ) n has gained immense attention in recent years because of its inimitable structural architecture and unique properties compared to conventional organic macromolecules . Polymer networks based on PMSQ possess exceptional thermal and weather resistance, non‐toxicity and chemical stability because of the rugged siloxane (Si–O–Si) bond and polycyclic network structure.…”

Thermal degradation, mechanical behavior and Co60 gamma-irradiation induced effects of poly(methylphenylsiloxane)/phenylene-silica hybrid material

“…A suitable material is poly(methylphenylsiloxane) (PMPS), which can be obtained from the cohydrolysis and condensation of chlorosilanes mixture. 4 –6 This highly crosslinked resin possesses good resistance to high temperature and irradiation, as well as advanced electric insulation and weatherability. 6 –8 However, the flexibility in backbones restricted the thermal stability of conventional PMPS, because the polymer tends to suffer unzipping degradation 8 –10 at the linear segments.…”