Plasticized-starch/poly(ethylene oxide) blends prepared by extrusion.

Blends based on plasticized-wheat starch (as matrix or rich phase) and poly(ethylene oxide) (PEO) (as dispersed phase) were prepared by melt processing in a twin-screw extruder. The extrusion of the plasticized-starch is significantly facilitated by blending with PEO. Plasticized-starch and PEO are immiscible in the range of the investigated blend ratios (90/10-50/50). The phase inversion takes place when the PEO content is 50 wt.% in the blend. Both the thermal stability and the tensile properties of plasticized-starch are improved by blending with PEO. Also, a synergistic effect between plasticized-starch and PEO is noticed at 25-40 wt.% PEO content in the blend, the Young's modulus of the materials obtained being the highest and higher than both neat polymer components at those blending ratios.