Viscoelastic behavior and impact strength were examined for model ABS
resins for various gel contents in dispersed polybutadiene particles a
nd also grafting degree. ABS resins with the gel content of 50% and 70
% showed an impact strength which increased with the grafting degree.
However, ABS resins with the gel content of 80% had a low value indepe
ndent of the grafting degree. Electron microscopic observation and H-1
spin-spin relaxation measurements suggested that a crosslinking react
ion was induced in the polybutadiene particle with the gel content of
80% by radicals due to an initiator for the graft reaction. GPC experi
ments also suggested that the polybutadiene particle with the gel cont
ent of 80% had more branches than other polybutadine particles had. Th
us, the crosslinking and the degree of branching influenced the viscoe
lastic behavior and impact strength effectively.