Characterization of biodegradable polymers by inverse gas chromatography: IV, blends of amylopectin and poly (l-lactide-co-caprolactone-co-glycolide)

Abstract

The morphology changes, surface energy, crystallinity and the thermodynamics of blends of amylopectin (AP) and Poly (l-lactide-co-caprolactone-co-glycolide) (PLCG) were investigated at a range of 80–120°C using the IGC Method. The effect of various compositions of the blend on these quantities was explored. Twenty three solutes were selected having different chemical nature such as alkanes, acetates, ether and ketones, halogenated, and six-member ring families. They provided a variety of specific interactions with the blends’ surface. PLCG is amorphous while AP is crystalline at the experiment temperatures. Retention diagrams of AP–PLCG blends showed two regions, crystalline and amorphous. These two zones enabled the estimation of Tg and Tm of AP, PLCG and the blends. Interaction parameters showed strong interactions between solutes and PLCG as the values were close to zero. Polymer–polymer interaction parameters showed exothermic values for all solutes and all weight fractions of PLCG, indicating the compatibility of AP and PLCG. When AP was blended with 50%PLCG, the degree of crystallinity was significantly reduced that led to a depression in Tm and Tg. However, the surface energy of AP was not improved by the blending process.