Inorganic–organic polymer networks derived from a cyclic siloxane tetrafunctional glycidyl ether resin

A tetrafunctional glycidyl ether cyclic siloxane epoxy resin (TGTS) has been synthesized, characterized and cured with four aromatic amine hardeners: 1,3-phenylenediamine (PDA), diethyltoluenediamine (DETDA), 4,4-diaminodiphenylmethane (DDM) and 1,3-bis(4-aminophenoxy)benzene (APB). Each of the cured networks produces transparent and homogeneous networks, although when TGTS is cured with DETDA, reduced compatibility led to lower epoxide consumption, a more heterogenous microstructure and deleterious effects upon properties. Reduced miscibility of DETDA significantly impacts the chemical structure and microstructure of the network, resulting in significant reductions in thermal and mechanical properties but higher UV-A transmission. The PDA-, APB- and DDM-cured networks conversely were more miscible and display properties typical of organic–inorganic hybrid networks, such as good mechanical properties at ambient and sub-ambient temperatures, comparatively high glass transition temperatures, improved resistance to oxidation and lower UV-A transmission. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.