Development of multifunctional composite materials based on thermoset polyester resin

Thermoset resins and composite materials produced using thermoset resins are flammable. For this reason, combustion properties of composite materials must comply with international standards. In this study, unsaturated polyester resin (UPR) was used as a thermoset matrix, glass fibers as reinforcement element, triethyl phosphate (TEP), diphenyl cresyl phosphate (DPK), aluminum hydroxide (ATH) were used as flame retardants. To prepare UPR, unsaturated polyester macromolecules were initially synthesized. The chain structures of macromolecules were investigated using nuclear magnetic resonance (1H-NMR) spectroscopy, and their number average molecular weights and weight average molecular weights were determined using gel permeation chromatography (GPC). UPR was prepared by blending macromolecules and styrene. Flame-retardant thermoset resins were prepared by blending TEP, DPK, and ATH. Thermoset resins were investigated by physical (density, viscosity, reactivity), chemical (FTIR), mechanical (DMA, flexural, hardness, tensile, impact, HDT), thermal (TGA, TGA-FTIR) and combustion (LOI, UL-94, CCT, smoke density) tests. Composites were produced by reinforcing UPR, UPR-T10-A10 (highly flame retadant) thermoset resins with glass fibres. The physical properties of the composites were examined using density tests, and their mechanical properties were assessed using DMA, hardness, flexural, and impact tests, while the burning properties were evaluated through LOI, UL-94, CCT, and smoke density tests. As a result of this study, multifunctional composite materials have been developed that exhibit combustion properties in compliance with the EN 45545-2 standard, possess high mechanical strength, feature antimicrobial surfaces, and are suitable for use in rail vehicles.