Modeling of thermo-physical properties for FRP composites under elevated and high temperature

A decomposition model for resin in glass fiber-reinforced polymer composites (GFRP) under elevated and high temperature was derived from chemical kinetics. Kinetic parameters were determined by four different methods using thermal gravimetric data at different heating rates or only one heating rate. Temperature-dependent mass transfer was obtained based on the decomposition model of resin. Considering that FRP composites are constituted by two phases – undecomposed and decomposed material – temperature-dependent thermal conductivity was obtained based on a series model and the specific heat capacity was obtained based on the Einstein model and mixture approach. The content of each phase was directly obtained from the decomposition model and mass transfer model. The effects of endothermic decomposition of the resin on the specific heat capacity and the shielding effect of evolving voids in the resin on thermal conductivity are dependent on the rate of decomposition. They were also described by the decomposition model; the effective specific heat capacity and thermal conductivity models were subsequently obtained. Each model was compared with experimental data or previous models, and good agreements were found.