Preparation and Properties of α‐Cyanoacryloyloxyethoxypropyl‐functionalized MQ Silicone Resin

Abstract

Abstractα‐Cyanoacryloyloxyethoxypropyl‐functionalized MQ resins were synthesized using commercially available hydrogen‐containing MQ silicone resin and 2‐(allyloxy)ethoxytrimethylsilane through a series of hydrosilylation, condensation and retro‐Diels‐Alder reactions. Under the conditions of room temperature and relative humidity of 60 %, the prepared silicone resins could be completely cured within 10 h without adding any promoters. When a small amount of N, N‐dimethyl‐p‐toluidinewas added as an accelerator, the curing time could be shortened to 3–5 s. Although grafted α‐cyanoacryloyloxyethoxypropyl groups on MQ resins reduced their thermal stabilities, the introduction of α‐cyanoacryloyloxyethoxypropyl groups destroyed the order of polysiloxane segments and eliminated the crystallization behavior of polysiloxane, which is beneficial to maintain structural stability of the functionalized polysiloxanes over a wide temperature range. The water contact angle of the cured product decreased from 102° to approximately75° when α‐cyanoacryloyloxyethoxypropyl groups were grafted to the polysiloxaneand thus changed the hydrophobicity of the polydimethylsiloxane materials to hydrophilicity. The novel α‐cyanoacryloyloxyethoxypropyl‐functionalized MQ resins not only maintain the inherent flexibility of polysiloxanes but also endow the silicone materials with the characteristics of fast cross‐linking.