QUANTITATIVE CHARACTERIZATION OF TOUGHENING MECHANISMS OF RUBBER-MODIFIED POLYMERS

The volume rubber of rubber modified polymers under creep at room temp erature were successfully used ta characterize the toughening mechanis ms of blends with brittle polymer matrices such as high Impact polysty rene. This approach cannot be applied to pseudo-ductile polymers such as polypropylene and polyamide, because they are ductile when stretche d at low speed at room temperature. Eased on the time-temperature equi valence principle, the volume change at low temperature is proposed to characterize quantitatively the toughening mechanisms of polymer blen ds with ductile matrices, which is illustrated by applying this approa ch to rubber modified polypropylene.