Correlating ultra-toughening of bio-based polyamide 410 with melt rheological and solid state relaxation dynamics by gelation rheology approach

摘要

The sol-gel or viscous-elastic transitions of the bio-based polyamide 410/POE-g-MA (polyethylene-co-octene copolymer grafted with maleic anhydride) blends have been systematically discussed in the framework of melt rheology as assessed on a parallel plate rheometer set-up in small amplitude oscillatory shear mode and solid state dynamic mechanical relaxation measurements. The viscous response dominated enhancement in elastic moduli of the blends that was characterized by the phase transitions across the composition range of 10-15 wt% of POE-g-MA. A direct correlation between the gel point (estimated from the cross-over of frequency-independent loss tangent curves) and the ultra-toughness (maximized to an extent of similar to 15-fold increase in notched Izod impact strength) could be established vis-a-vis its corroboration from the morphology of the impact-failed surfaces. The extent of maleic anhydride (-MA) content induced phase interaction with polyamide 410 via the formation of a polyamide-co-(polyoctene-co-ethylene) type copolymer linkage in solid-state and its subsequent impact on solid-state damping was analyzed. The study establishes qualitative correlation between ultra-toughening of polyamide 410 to that parameters based on relaxation dynamics measurements using melt rheology and solid-state dynamic responses conforming to the principles of gelation rheology.