Influence of a reactive diluent on curing kinetics, Internal Curing Process, and Mechanical Performance of Filament Wound Glass Fiber-Reinforced Epoxy Composite Pipes

Nowadays, glass reinforced epoxy (GRE) pipes are industrially manufactured by the filament winding process using internal heating technology. This study deals with the comprehensive evaluation of a strategy aimed to improve the plant productivity by means of physical experiments, mechanical tests, and numerical simulations of the curing process. The reactive system is composed by diglycidyl ether of bisphenol A (DGEBA), methyltetrahydrophtalic anhydride (MTHPA), and benzyltriethyl ammonium chloride (BTEAC) used as initiator. An increase in BTEAC concentration in system formulation leads to a reduction in curing times of GRE pipes. The processing problems associated with this increment are proposed to be solved by the incorporation of a reactive diluent (RD) together with the optimization of the curing cycle. The effects that different amounts of 1,4-butanedioldiglycidyl ether (DGEBD) added as RD exerts on system viscosity, copolymerization kinetics mechanism, curing process and properties of matrix, laminated composites and GRE pipes are deeply analyzed. Results demonstrate that if a 10 wt% RD is used, not only the strategy turns out to be feasible but also GRE pipes performance is improved. POLYM. ENG. SCI., 59:344-354, 2019. (c) 2018 Society of Plastics Engineers