Metal-free synthesis of alternating silylether–carbosilane copolymers using unsaturated ketones

Abstract

We report metal-free B(C₆F₅)₃-catalysed hydrosilylation polymerization for alternating silylether–carbosilane copolymers. The reaction was carried out at room temperature using bis(dimethylsilyl)benzene and cyclic and aliphatic unsaturated ketones. It was found that 1,4-conjugation on the unsaturated ketone monomers is important for undergoing hydrosilylation-based polymerization on both CO and CC groups. The obtained polymers were characterized by high molecular weight (M_w = 4.23 × 10⁴, PDI = 2.0), tunable T_g (ranging from −7 to 27 °C) and good thermal stability (above 280 °C). Hydrolysis of silylether linkages with an HCl catalyst was demonstrated, revealing an alternating arrangement, which was supported by monitoring the polymerization processes with ¹H NMR measurements.