The paper presents the results of studies on the synthesis and mechanical properties of the fusion product of epoxidized soybean oil with bisphenol A, which are a part of the current research on environmentally friendly raw materials for the preparation and modification of modern polymeric materials. It has been shown that the use of 4,4’-methylene diphenyl diisocyanate in the cross-linking process of the fusion product in the presence of Dabco 33-LV and BYK-A530 or BYK-A525 gives hard materials with interesting mechanical properties.