physical and biodegradation properties of poly(l-lactide)-b-poly (ethylene glycol)-b-poly(l-lactide)/polypropylene blends for potential use as partially biodegradable plastics

This study investigates the thermal, morphological, mechanical, and biodegradation properties of blends comprising poly(l-lactide)-b-poly (ethylene glycol)-b-poly(l-lactide) triblock copolymer (plla-peg-plla) and polypropylene (pp) compared to the plla/pp blends. all the blends were prepared using a melt-blending technique. the ability to crystallize and the thermal stability of the plla-peg-plla were enhanced by blending pp, whereas these properties were not enhanced for the plla. the crystallinity of plla-peg-plla increased from 20.4% to 23.5-38.8%. the temperature at maximum decomposition rate (td,max) of plla end-blocks increased from 310 °c to 327-332 °c. the phase compatibility between the plla-peg-plla and pp was better than between the plla and pp, as indicated by the smaller size of dispersed pp particles in the plla-peg-plla matrix. the plla-peg-plla/pp blends showed greater flexibility, higher wettability, and faster biodegradation rates than the plla/pp blends. this suggests that these plla-peg-plla/pp blends may be used as flexible and partially biodegradable plastics.