Abstract: The synthesis of liquid molding resins derived from plant oils that are capable of curing to high modulus thermosetting polymers and composites is described in this invention. The resins described resemble the unsaturated polyester, vinyl ester and epoxy resins presently used as the polymer matrix material in high performance glass, carbon, aramid and natural fiber reinforced composite materials. The resins disclosed herein are suitable for polymer and composite manufacture by Resin Transfer Molding (RTM), Reaction Injection Molding (RIM), Vacuum Assisted Resin Transfer Molding (VARTM), Seeman's Composite Resin Infusion Manufacturing Process (SCRIMP), Atmospheric Pressure Molding (APM), open mold casting, spray-up, Sheet Molding Compound (SMC) Bulk Molding Compound (BMC), filament winding, pultrusion, prepregs, lamination and compression molding.