A prepreg comprising a fibrous material contacting a polymerizable resin, at least 50 wt % of the polymerizable resin comprising at least one polymerizable monomer having at least two carbon-carbon unsaturated functional groups, the monomer being polymerizable by reaction of the unsaturated functional groups to form a cured resin, wherein the resin has a heat of polymerization of less than 230 KJ/kg to provide a maximum increase in temperature of the prepreg of 60° C. during polymerization under adiabatic conditions.