General unsaturated polyester resin (UPR) was synthetised by maleic anhydride

phthalic anhydride and 1

2-propylene glycol. While due to its highly crosslinked structure of rigid benzene ring after curing

it will cause the polymer with slow toughness

high brittleness

flammable and high shrinkage. C36 dimer fatty acid modified styrene polyester resin materials were prepared by using C36 dimer fatty acid

phthalic anhydride

maleic anhydride and 1

2-propylene glycol

styrene as the cross-linking agent

benzoyl peroxide as the initiator. The structure and surface morphology of tensile of resin were characterized by FT-IR and SEM. The study found that the DFA was introduced into the main chain of the resin

and the fracture mode changed from brittle fracture to ductile fracture. In this study

the effects of various mole fractions of DFA on the thermal stability

mechanical properties and solvent resistance of the resin were investigated by TG

DSC

tensile

bending

hardness and solvent resistance test. Study found that when the DFA content is 6% (mole fraction)

modified UPR materials contain the best comprehensive performance. The initial thermal decomposition temperature from 147℃ to 201℃

the glass transition temperature reduced from 146.6℃ to 120.7℃. The tensile strength

elongation at break

modulus of elasticity

Shore hardness and bending strength were 7.23

2.90

7.84

1.63 and 5.12 times that unmodified UPR material. And resistance to solvent loss rate were reduced by more than 70%. In conclusion

DFA can be used as a kind of efficient toughening agent

helps to improve the toughness of the styrene polyester resin

and to broaden the scope of application of styrene polyester resin.