Biobased epoxy reactive diluents prepared from monophenol derivatives: effect on viscosity and glass transition temperature of epoxy resins

Abstract

The use of reactive diluents is undeniably of paramount importance to develop epoxy resins which would meet more demanding and restrictive processes and applications in terms of viscosity and glass transition temperature.

Oligosiloxane-Based Epoxy Vitrimers: Adaptable Thermosetting Networks with Dual Dynamic Bonds

“…For example, the lower viscosity (8−12 mPa•s −1 ) of our disiloxane diepoxide (Si2) could be beneficial for fiber-reinforced composite manufacturing to better impregnate fibers with vacuum infiltration 17 compared to the common diepoxide cross-linker diglycidyl ether of bisphenol A, which has a viscosity of 11000−16000 mPa•s −1 . 20 To synthesize the networks, the siloxane diepoxide (Si2 or Si8) and the dicarboxylic acid components were mixed at a 1:1 stoichiometric ratio of acid/epoxide at 150 °C, at which time TBD was added and the resin was pour-cast into a preheated mold. These elevated temperatures were needed as a result of the high melting temperature of PDAA.…”

“…We expect the low intrinsic viscosity attained by the siloxane bonds to offer processing advantages and the dual dynamic bonds to impart unique self-healing behavior. For example, the lower viscosity (8–12 mPa·s –1 ) of our disiloxane diepoxide (Si2) could be beneficial for fiber-reinforced composite manufacturing to better impregnate fibers with vacuum infiltration compared to the common diepoxide cross-linker diglycidyl ether of bisphenol A, which has a viscosity of 11000–16000 mPa·s –1 …”