Abstract: A resin film with at least 50 wt % of at least one polymerisable vinyl ester prepolymer having at least two carbon-carbon unsaturated functional groups and a curing system, the prepolymer in a concentration of at least 10 wt %, based on the weight of the polymerisable resin, and has the structure R1n-R2-R1?m, wherein R1 and R1? are the same or different, n and m are each at least one and may be the same or different, and each of R1 and R1? includes a carbon-carbon unsaturation at a free end thereof remote from R2, and includes a residue of an epoxy resin, and wherein R2 is a polyfunctional chain extending linker between R1 and R1?, and is derived from a polyfunctional carboxylic acid having the structure R-Fnx, where Fn is a carboxylic acid functional group, x is at least 2, and R comprises an organic moiety having aliphatic, araliphatic, cycloaliphatic, heterocyclic and/or aromatic groups, containing any type and/or combination of saturated, unsaturated and/or aromatic carbon bonds, and wherein R may be unsu

Abstract: A resin film with at least 50 wt % of at least one polymerisable vinyl ester prepolymer having at least two carbon-carbon unsaturated functional groups and a curing system, the prepolymer in a concentration of at least 10 wt %, based on the weight of the polymerisable resin, and has the structure R1n-R2-R1?m, wherein R1 and R1? are the same or different, n and m are each at least one and may be the same or different, and each of R1 and R1? includes a carbon-carbon unsaturation at a free end thereof remote from R2, and includes a residue of an epoxy resin, and wherein R2 is a polyfunctional chain extending linker between R1 and R1?, and is derived from a polyfunctional carboxylic acid having the structure R-Fnx, where Fn is a carboxylic acid functional group, x is at least 2, and R comprises an organic moiety having aliphatic, araliphatic, cycloaliphatic, heterocyclic and/or aromatic groups, containing any type and/or combination of saturated, unsaturated and/or aromatic carbon bonds, and wherein R may be unsu

Abstract: A composite material layer, which is a curable resin which is in the form of a solid layer at 20° C., the composite material layer being a prepreg of at least one ply of fibrous reinforcement material at least partly impregnated by the curable resin or a film of the curable resin, wherein at least 50 wt % of the curable resin comprises at least one polymerisable vinyl ester prepolymer having at least two carbon-carbon unsaturated functional groups, the prepolymer being polymerisable by reaction of the unsaturated functional groups to form a cured resin, wherein the curable resin further is a free-radical curing system for polymerizing the polymerisable vinyl ester prepolymer.