Effects of Glass Fibers and Polypropylene/Glass Fiber Hybrid Fibers on the Kinetics and Mechanical Properties of Epoxy Composites

摘要

Curing reactions of diglycidyl ether of bisphenol F (DGEBP-F) and pre-catalyzed methyltetrahydrophthalic anhydride (MrnPA) with benzyl triethyl ammonium chlo- ride (BTEAC) were studied and effects of glass fibers evaluated. The influence on the kinetics of glass fibers and a hybrid blend of maleated polypropylene + glass fibers is studied. Isafuermal and dynamic kinetic parameters are detemlined by differential scanning calorimetry (DSC). Applicability of the autocatalytic model is investi- gated. The model serves well in the range of degrees of conversion between 25 and 800/0. At high conversion rates the diffusion control becomes apparent. Glass fibers accelerate the curing. shortening the time needed to reach the maximum reaction rate; this is reflected in lower activation energies for curing in comparison to the neat resin. The effects observed can be explained by a reaction between the amine group present on the fiber surfaces and the epoxy glycidyl groups. The result of both isothermal and non-isothermal curing of resin + glass fibers commingled with polypropylene are close to those for the neat resin. The reinforcement itlcreases the elastic modulus 12 times. the tensile strength 2 times. and the impact strength 285 times. The glass fibers + commingled polypropylene reinforcement provides comparable mechanical properties as glass fibers alone when normalized with respected to the density fraction of the fibers.