The reaction of catalytic dehydrocondensation of dihydroorganocyclotet
ra(hexa)siloxanes with dihydroxyorganocyclotetra(hexa)siloxanes in the
presence of platinochlorohydric acid and of anhydrous powder-like cau
stic potassium has been studied. Reaction order, activation energies a
nd dehydrocondensation rate constants were found. Thermogravimetric, t
hermomechanical and X-ray studies of the synthesized polymers were car
ried out. (C) 1998 Elsevier Science Ltd. All rights reserved.