The Synthesis of a Silicone With Tetrafunctional Epoxy Group and Its Application as Toughening Agent in Epoxy Resins

ABSTRACT In this work, tetraepoxy‐cyclohexaneethyl 2, 4, 6, 8‐tetramethylcyclotetrasioxane (TECCTS), with a tetrafunctional epoxy group, was prepared and utilized as a toughening agent in epoxy resin. In the synthesis, vinyl epoxycyclohexane was introduced into the epoxy resin via a hydrosilylation addition reaction using D 4 H, which is a cyclic structure formed by the SiOSi bond, as the main structure. A series of E51/TECCTS/D230 epoxy resins were prepared for performance testing. The successful synthesis of TECCTS was confirmed through the analysis of FT‐IR and NMR. Mechanical property tests demonstrated that as the incorporation of TECCTS increased, the tensile strength of the E51/TECCTS/D230 epoxy resin gradually decreased, while the elongation at break gradually increased. The elongation at break of TECCTS‐40 epoxy resin was found to be 164.56%, representing a substantial increase of 1342% in comparison to E51/D230 epoxy resin. The experimental findings demonstrated that TECCTS, due to its distinctive molecular structure and flexible chain segments, can effectively enhance the molecular chain mobility of modified resins, thereby efficiently toughening epoxy resins.