Process for obtaining a geopolymeric alumino-silicate and products thus obtained

摘要: The geopolymeric alumino silicates have been grouped in three families depending on the atomic ratio Si/Al which may be 1, 2 or 3. With most commonly used simplified notation, a distinction is made between poly(sialate) Mn(-Si-O-Al-O-)n (M)-PS; poly(sialate-siloxo) Mn(-Si-O-Al-O-Si-O-)n (M)-PSS; and poly(sialate-disiloxo) Mn(-Si-O-Al-O-Si-O-Si-O-)n (M)-PSDS. object of invention to describe process for obtaining geopolymer alkaline family (M)-PSDS with Si/Al=3. It consists reacting resin obtained from reactional mixture containing: a) an aqueous solution silicate molar SiO2:MnO equal SiO2:M2O 4.0:1 6.5:1 concentration over 60 % wt where initial viscosity at 20 °C 200 centipoises, then increases not exceed 500 centipoises before 5 hours °C; b) oxide (Si2O5,Al2O2) Al cation coordination (IV-V) as determined by MAS-NMR spectrum 27Al, said being such quantity that Al?2?O3:SiO2 1:5.5 1:6.5, letting cure. As against prior art, fact there no need add fillers prevent matrix cracking makes it possible keep very low develop its film-forming property, distinct advantage when fibres other granular materials are impregnated.