Oxirane rings in epoxidized soybean oil were opened in reaction with monoethylene glycol and then fused with bisphenol A, hydroxylated soybean oil and a corn. low-moLmass epoxy resin in bulk. The polymeric products were filled with sepiolite (1 or 2% by mass) and crosslinked with a 4,4'-diphenylmethane diisocyanate. The composite materials produced were studied for static tensile, flexural and compression strength, impact resistance, hardness and resilience as well as for thermal stability and morphol. The addn. of sepiolite resulted in a decrease in mech. strength and thermal stability of the composites.