A novel epoxy resin toughening diluent (UE6M) containing epoxy polyurethane was synthesized by the coupling reaction of diphenyl-methane-diisocyanate(MDI) and domestic epoxy diluent 669. Different dosages of UE6M were added to pure epoxy resin(E51) to form epoxy blends

we recorded the viscosity changes of the blends with different content of UE6M

results showed that compared with pure epoxy resin(E51)

the epoxy resin toughening diluent(UE6M)had a dramatically dilution effect on epoxy resin(E51)

the viscosity of the mixed system with 30% and 40% UE6M were only 6.35% and 1.43%

respectively

of that of pure epoxy resin(E51). And then

the blends were cured with acetonitrile triethylenetetramine

we studied the effect of UE6M usages to the properties of the cured blends. Dynamic mechanical test and other mechanical test results confirmed the addition of UE6M to pure epoxy resin could induce toughening effect obviously: the tensile strengths of cured blends with 30% and 40% UE6M were 87.9% and 80.9% of that of the cured pure E51 epoxy resin

all exceed 60MPa! While the bending strength and modulus did not decrease significantly

the elongation at break was more than 8 times that of the cured epoxy resin

and the bending strain was more than 2 times that of the cured epoxy resin.