| Abstract: | α,ω-Divinyl-terminated polydimethylsiloxane polymers with low polydispersivity were synthesized via anionic polymerization of hexamethylcyclotrisiloxane (D3). Five “monodisperse” polymers with different molecular weights were hydrosilylated with tetrakisdimethylsiloxysilane in the presence of platinum catalysts and inhibitors to form crosslinked networks. Control studies to determine the effect of platinum, silicon hydride, and heat were performed to verify that no redistribution occurred during hydrosilylation. The properties of these cured samples were characterized chemically by degradation with trifluoromethanesulfonic acid in the presence of hexamethyldisiloxane, infrared spectroscopy, and nuclear magnetic spectroscopy. Mechanical properties were studied by measurements of Shore A hardness, dynamic shear modulus, and tensile modulus. The relationship between the molecular weight of the vinyl polymer and the final properties of the cured networks was measured. © 1993 John Wiley & Sons, Inc. |
