Heat-Tretment Effect on Poly-Organo-Siloxane Spherical Particles Prepared in W/O Emulsion

抄録

Monodispersed micro poly-organo-siloxane spherical particles synthesized from methyltrimethoxysilane in W/O emulsion consisting of sorbitantrioleate (SPAN85),n-octane, and H₂O were heat treated from 100 to 600 °C in the air, and examined form SEM, DTA, NMR, FT-IR, and specific surface area measurements.The heating process is characterized as follows. Before the formation of the Si-O-Si linkage by elimination of CH₃ in Si-CH₃ near 410 °C, silica network in the particles consists of only T units and transformation of T² into T³, increasing and decreasing in specific surface area, and shrinkages of particles were observed up to 410 °C. On the other hand, after the Si-O-Si linkage formation, silica network consists of only Q units and the particles were thermally stable with almost constant diameter and specific surface area. The reason was also discussed.