Rapid, catalyst-free crosslinking of silicones using triazines

Abstract Silicone elastomers are a class of polymers that are typically cured with metal‐based catalysts. There is a need to reduce the presence of metals in polymers for both cost and environmental reasons. We describe the preparation of amino‐triazinyl silicone networks that are readily formed, without catalysts, from aminopropyl silicones and cyanuric chloride or, more practicably, a pre‐modified dichlorotriazinyl silicone (a masterbatch). The amine groups serve both as nucleophiles leading to crosslinks and to neutralize the HCl byproduct of the reaction. Elastomer properties, ranging from very soft gels to rigid elastomers, could be controlled simply by choice of the telechelic or pendant aminopropylsilicones that were added to the masterbatch. The presence of amines and ammonium ions in the products do not significantly affect the high stability of the elastomers toward hydrolytic or thermal oxidative stress.

Modulus data were collected 24 hr after elastomer formation on 3.5 mm thick samples using a MACH-1 micromechanical testing instrument (Biomomentum) equipped with a 0.5 mm hemispherical indenter using a Poisson ratio of 0.5.