Abstract: T-SAN and M-SAN resins were synthesized with tetra- and mono-functional initiators via high temperature continuous solution polymerization in toluene, respectively. With nearly the same molecular weight and molecular weight distribution, T-SAN possessed better thermal resistance and melt flow behavior. The two SANs were blended with a same ABS resin forming T-ABS and M-ABS resins. The T-ABS possessed the same tensile strength as M-ABS, but 17 % higher impact strength than M-ABS. The rubber particles in T-SAN were finer and more uniformly dispersed than in M-SAN. At whiten zone, more distinct deformation of the rubber particles in T-ABS was observed.

Key words: tetra-functional initiator, styrene-acrylonitrile copolymer, acrylonitrile -butadiene -styrene tripolymer