TETRAMETHYLAMMONIUM 3-AMINOPROPYL DIMETHYLSILANOLATE - A NEW CATALYST FOR THE SYNTHESIS OF HIGH-PURITY, HIGH-MOLECULAR-WEIGHT ALPHA,OMEGA-BIS (AMINOPROPYL) POLYDIMETHYLSILOXANES

Tetramethylammonium 3-aminopropyl dimethylsilanolate, readily prepared from bis(3-aminopropyl) tetramethyldisiloxane and tetramethylammonium hydroxide pentahydrate, has been found to serve as a highly effective catalyst for the ring opening polymerization of cyclic siloxanes with an end blocker such as bis(3-aminopropyl) tetramethyldisiloxane to give aminopropyl terminated linear polydimethylsiloxanes. By following a novel two stage procedure, even high molecular weight (5,000-55,000 g/mol) silicone diamines were able to be prepared in a high state of purity; chain extension reactions of these diamines with diisocyanates gave a series of high molecular weight silicone polyureas with good elastomeric properties.