Novel Urea-Siloxane Polymers as Gelling Agents for Silicone Fluids

摘要

A series of polyureas were synthesized from amino terminated polydimethylsiloxane oligomers of different molecular weight and various diisocyanates. These polymers were characterized by nuclear magnetic resonance (NMR), infrared (IR) spectroscopy and size exclusion chromatography (SEC). The formation of hydrogen bonding of the urea segments was investigated by temperature dependent IR-spectroscopy. The gelation behavior in silicone fluids such as dimethylcyclosiloxanes was investigated. The influence of the structure of the hard and the soft segment on the gelation properties was evaluated.