Research officer, National Research Council of Canada, Division of Building Research, Ottawa, Ontario
An accelerated weathering test (2 to 0.67 cycle) has been applied to glass-fiber-reinforced polyester (GRP) to determine the effect on surface durability of modifiying the chemical composition of the resin matrix. The nature and rate of induced surface degradation were monitored by scanning electron microscopy. For GRP based on general purpose polyester resin (o-phthalic anhydride-propylene glycol-maleic anhydride-based) the nature of surface damage was not significantly influenced by chemical modification, although the time of initiation was altered. The average overall durability of GRP improved 60% by substitution of propylene glycol with neopentyl glycol, 30% by incorporation of a greater amount of maleic anhydride, and 20% by replacement of both anhydride and glycol with isophthalic acid and neopentyl glycol, respectively. By inference, replacement of anhydride with isophthalic acid reduced the durability of neopentyl glycol-based GRP by 40%.
Paper ID: CTR10867J