Solid state bonding of graphite/thermoset composites via interchain transesterification reaction (ITR)

Abstract Thick section composite laminates are expensive and difficult to manufacture because of problems with porosity, large reaction exotherms from epoxies and residual strains. The copolyester thermosets described here can eliminate these problems. Through interchain transesterification reactions, individually cured prepreg plies of graphite reinforced copolyester can be bonded with each other in the solid state. ITR bonding is shown to produce well‐consolidated laminates with less than 2% void volume and mechanical properties comparable to those of current high‐end polymer matrix composites. DMA testing showed the glass transition to begin at 190°C for a 45% fiber volume fraction composite. Tensile testing of 55% fiber volume composites at room temperature showed modulus, strength and elongation to failure averages of 105.4 GPa, 1.02 GPa and 1.0% respectively.