HYDROLYTIC POLYCONDENSATION OF AMINOALKYL TRIALKOXYSILANES AND THEIR COOLIGOMERIZATION WITH OCTAMETHYLCYCLOTETRASILOXANE

Hydrolysis of aminoalkyltrialkoxysilanes H(2)NR'Si(OR)(3) [where R is -C2H5 and R' is -(CH2)(3)-(compound I), -CH2(CH3)CH (compound II), or -(CH2)(6)(H)NCH2- (compound III), or R is -CH3 and R' is -(CH2)3- (com pound IV)] and cooligomerization of these aminoalkyltrialkoxysilanes w ith octamethylcyclotetrasiloxane D-4, catalyzed by KOH and ammonium po ly(dimethylsiloxane-alpha,omega-diolate) (TMAS), were studied. The act ivity of aminoalkyltrialkoxysilanes in hydrolysis varies in the series III > IV > II > I. Aminoalkyltrialkoxysilane increases the activity o f nucleophilic catalysts with respect to the siloxane bond of D-4. In the presence of KOH, the process involves deep scission of primary pro ducts from the reaction of aminoalkyltrialkoxysilane with D-4, affecte d by new aminoalkyltrialkoxysilane molecules, and the subsequent copol ymerization of these products with Dq In the presence of TMAS, the pre vailing process is telomerization, which occurs via the reaction of D- 4 with the primary product from the reaction of aminoalkoxysilane with D-4. The consumption rate of D-4 always obeyed a first-order equation with respect to the current D-4 concentration.