Influence of Cross-Link Structure on Impact Strength of ABS

Viscoelastic behavior and impact strength were examined for model ABS resins for various gel contents in dispersed polybutadiene particles and 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 independent of the grafting degree. Electron microscopic observation and 1H spin-pin relaxation measurements suggested that a crosslinking reaction was induced in the polybutadiene particle with the gel content of 80% by radicals due to an initiator for the graft reaction. GPC experiments also suggested that the polybutadiene particle with the gel content of 80% had more branches than other polybutadine particles had. Thus, the crosslinking and the degree of branching influenced the viscoelastic behavior and impact strength effectively.