Compatibility and characteristics of poly(butylene succinate) and propylene-co-ethylene copolymer blend

Propylene-co-ethylene elastomer resin (PER) has been blended into biodegradable poly(butylene succinate) copolymer (PBS) by a melt-blending process to develop a novel semi-biodegradable thermoplastic elastomer. The PBS/PER blends displayed good compatibility in the range 70/30 > PBS/PER > 30/70 according to analyses by DSC, DMA and the Couchman method. Although the PBS/PER blends displayed compatibility, SEM analyses of most of the PBS/PER blends revealed two-phase structures including sea-island and irregular fiber-shaped morphologies, except for PBS/PER (70/30). PBS/PER (60/40) and PBS/PER (50/50) display low tensile strength due to large sea-phase and irregular fiber-shaped morphologies, even though they have good compatibility. PBS/PER (70/30) apparently exhibited a single phase by SEM and showed the best compatibility by DSC and DMA. Furthermore, the tan 6, elongation and initial moduli of the PBS/PER blends were seen to increase with increasing PER content, indicating that the toughness and shock resistance of PBS are improved by incorporating PER into the composition. (C) 2009 Elsevier Ltd. All rights reserved.