Volume shrinkages and mechanical properties of various fiber-reinforced hydroxyethyl methacrylate–polyurethane/unsaturated polyester composites

In this study, two kinds of hydroxyethyl methacrylate–polyurethane (HEMA–PU) were used as volume shrinkage modifiers, and several hydroxyethyl methacrylate–polyurethane modified unsaturated polyester (HEMA–PU/St./UP) resins crosslinked with styrene were synthesized and characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and in terms of their mechanical properties, including their tensile strengths and Izod impact energies. The properties of the HEMA–PU–modified St./UP and St./UP were compared for potential applications as matrices for glass fiber-, aramid fiber-, and UHMWPE fiber-reinforced composites. The effects of the HEMA–PU content and the type of polyol in the HEMA–PU resin matrices of the composites were investigated through testing of their mechanical properties, bulletproof testing, and observations of their morphologies.