Research officer, National Research Council of Canada, Ottawa,
An accelerated weathering test (2 to 0.67 cycle) has been applied to glass-fiber reinforced polyester (GRP) to evaluate the effect of constituents on the surface durability of GRP. The nature and rate of induced surface degradation was assessed by scanning electron microscopy. For general-purpose GRP (GRP (GP)), replacement of chopped glass roving reinforcement with chopped glass mat reinforcement did not change the nature and rate of surface degradation. Incorporation of a glass surfacing veil, to provide a resin-rich surface layer, however, improved the durability of GRP (GP) to fiber pop out by 100%. Moreover, replacement of styrene with a styrene-methyl methacrylate cross-linking agent enhanced the resistance of GRP (GP) to fiber pop out, erosion, and surface microcracking an average of 70%. Substitution of an ultraviolet absorber Tinuvin P with Tinuvin 327 did not alter the durability of ethylene glycol-based GRP, while replacement of Tinuvin P with Tinuvin P/Tinuvin 144 in neopentyl glycol-based GRP improved the resistance to fiber pop out by 17% but decreased the durability to erosion and surface microcracking by 19 and 12%, respectively.
Paper ID: CTR10774J