Hierarchical porous ceramics developed by using a Si-based preceramic polymer

CERTUCHE ARENAS, C.S.; BOLAÑOS RIVERA, J.O. ; X. HUNG HUNG, Y.M.X; SANDOVAL, M.L.; TALOU, M.H.; CAMERUCCI, M. A.

Congreso; Pan American Ceramic Congress and Ferroelectrics Meeting of Americas (PACC-FMAs); 2022

Silicon-based preceramic polymers are an important type of precursors used in the processing of novel silicon-based ceramics. Different processing routes based on the consolidation of a hybridbody from the preceramic crosslinking reaction or the infiltration of a carbon-based template with the precursor, and then pyrolysis in controlled atmosphere, are proposed to develop hierarchicalporous ceramics with unique chemical compositions. In this work, a partially condensed polysilsesquioxane (MP-SSO) synthetized by sol-gel method from 3-methacryloxypropyl-trimethoxysilane was used as consolidating or infiltration agent of poplar templates. The MP-SSO was characterized by ATR-FTIR, 1H, 13C and 29Si NMR, DSC and rheological tests. Porous hybrid bodies were prepared by crosslinking (25°C, 72h; 10 vol% of TETA) of MP-SSO/sucrose/SiOC (preceramic/porogen/filler) mixtures (50/40/10 vol%) and calcining (300°C, 1h), and were characterized by porosity measuring and SEM. The templates were infiltrated at 50 bar, cured (135°C, 3h) and characterized by infiltration degree, porosity measuring, TGA, and SEM/EDS. All samples were pyrolyzed in N2(1000-1600°C, 2-4h) and characterized by porosity measuring, XRD, Leco, 29Si NMR, Raman and SEM/EDS. The materials shown high hierarchical porosity, SiC nanowires, Si3N4 crystals and SiOC amorphous phase, whose amounts and features depended on the processing conditions.