Gel coated fiber-reinforced composition of polyetherester, unsaturated polyester and vinyl monomer

A gel coated fiber-reinforced polymer comprising a fiber-reinforced composition and a gel coat wherein the fiber-reinforced composition is obtained by combining a curable thermoset resin composition with reinforcing fiber and curing the curable thermoset resin composition and wherein the curable thermoset resin composition comprises:

• (A) at least 5 wt % of an at least partially end-capped unsaturated polyetherester resin obtained by (1) reacting at least one polyrther, the polyether selected from the group consisting of polyether polyols, alkylene oxide-alkylene oxide copolymer, wherein the alkylene group of each alkylene oxide is different, or combinations thereof, and at least one ethylenically unsaturated anhydride or dicarboxylic acid in the presence of at least one catalyst effective to promote insertion of the anhydride or dicarboxylic acid into carbon-oxygen bonds of the polyether to produce unsaturated polyetherester resin polymer chains and (2) reacting the unsaturated polyetherester resin polymer chains with at least one end-capping compound to form the at least partially end-capped polyetherester resin, wherein the at least one-end capping compound comprises at least one compound having at least one epoxy group,
• (B) an unsaturated polyester resin having a ratio of the number average molecular weight to the average number of double bonds per polymer molecule in the range from about 200 to about 400, in an amount such that the weight ratio of polyester resin (B) to polyetherester resin (A) is in the range from about 10:90 to about 90:10;
• (C) about 10 to about 70 wt % of at least one vinyl monomer;
• and
• (D) a curing agent.