Polycondensation of Water Glass Sodium Silicates in the Presence of [B_nX_n]~(2-) (n = 10, 12; X = H, Cl) Boron Cluster Anions

摘要

It has been shown that two competing processes occur in a system of water glass (WG) silicates and [BnXn](2-)(n= 10, 12; X = H, Cl) boron cluster anions (WG/[An]) in the range 100-200 degrees C: the formation of a supramolecular structure due to cation-anion contacts of the silanol groups of the silicate with [An]'s att = 100 degrees C and the condensation of the silanol groups of the silicate, resulting in the formation of polysiloxane chains (t = 180 degrees C). The difference in temperature conditions between these processes leads to inhibition of the silicate condensation process. The detailed structure of the silicate component of the WG/[An] systems has been studied as a function of [An] content.