Sizing compositions, sized reinforcing products and methods for making reinforced thermoset composites

A combination of reactive fibers and a resin composition comprising:

• glass fibers sized with a sizing composition, wherein the glass fibers have not been treated with a silane compound;
• a polymerization catalyst;
• a polymerization initiator physically bonded to the glass fibers, wherein the polymerization initiator does not comprise a silane moiety;
• and
• the resin composition comprising one or more polymer reactants;
• wherein:
• the sizing composition comprises a solution,
• the sizing composition comprises water and a film former,
• the solution comprises the polymerization initiator,
• the reactive fibers comprise the film former in contact with the glass fibers and the polymerization initiator,
• the film former aids the physical bonding of the polymerization initiator to the glass fibers,
• the sizing composition excludes an emulsifying agent,
• the polymerization initiator is configured to initiate the polymerization of the one or more polymer reactants,
• the polymer reactants comprise thermosetting polymer reactants,
• the polymerization catalyst is configured to catalyze polymerization of a thermoset resin in the presence of the polymerization initiator,
• the polymerization catalyst comprises a metallic salt of a carboxylic acid, and
• the carboxylic acid is a C8 to C12 carboxylic acid.

A group of reactive fibers which can be incorporated into a polymer and fiber reinforced composite, the group of reactive fibers comprising:

• glass fibers sized with a sizing composition, wherein the glass fibers have not been treated with a silane compound;
• a polymerization initiator physically bonded to the glass fibers, wherein the polymerization initiator does not comprise a silane moiety;
• a polymerization catalyst;
• and
• a film former in contact with the glass fibers and the polymerization initiator, wherein:
• the sizing composition comprises a solution,
• the sizing composition comprises water,
• the solution comprises the polymerization initiator,
• the film former aids the physical bonding of the polymerization initiator to the glass fibers,
• the sizing composition excludes an emulsifying agent,
• the polymerization catalyst is configured to catalyze polymerization of a thermoset resin in the presence of the polymerization initiator,
• the film former is selected from the group consisting of a modified vinyl acetate copolymer in a surfactant system and an N-vinyl amide polymer, and
• the surfactant system is anionic, nonionic, or a combination of anionic and nonionic.