Synthesis and Characterization of Epoxy Resin Modified with Polyurethane

Di-functional(PU-B) and tri-functional(PU-A and PU-D) polyurethane prepolymers were prepared from toluene diisocyanate(TDI) and polyether polyhydric alcohol(N-330 and PF-15).Through the graft reaction of the obtained polyurethane prepolymers with epoxy resins,and then cross-linking with dicyamine,a series of epoxy resins modified with polyurethane were synthesized.The effects of structures and dosages of epoxy resins and polyurethane prepolymers,as well as the dosages of thickening agent silica derivates on the adhesive properties of EPR-PU composite system were investigated in detail.The results indicated that the optimum composition of EPR-PU system is m(E-51)∶m(E-20)∶m(PU-D)∶m(PU-A)=3∶2∶0.06∶0.54,at which the mechanical strengths of the adhesive reach the highest level.