Biodegradation of aliphatic polyester composites reinforced by abaca fiber

The composites of aliphatic polyesters (poly(E-caprolactone) (PCL), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly(butylene succinate) (PBS), and poly(lactic acid) (PLA)) with 10 wt.% untreated or acetic anhydride-treated (AA-) abaca fibers were prepared and their biodegradability was evaluated by the soil-burial test. In case of PCL composites, the presence of untreated abaca or AA-abaca did not pronouncedly affect the weight loss because PCL itself has a relatively high biodegradability. However, the addition of abaca fibers caused the acceleration of weight loss in case of PHBV and PBS composites. Especially, when untreated abaca was used, the PHBV and PBS composite specimens were crumbled within 3 months. This result is a marked contrast to the fact that neat PHBV and PBS specimens retain the original shape even after 6 months. Although no weight loss was observed for neat PLA and PLA/AA-abaca composite, the PLA/untreated abaca composite showed ca. 10% weight loss at 60 days, which was caused by the preferential degradation of the fiber. (C) 2004 Elsevier Ltd. All rights reserved.