Characterization and biodegradability of polyester bioplastic-based green renewable composites from agricultural residues

• Published in: Polymer degradation and stability Vol. 97; no. 1; pp. 64 - 71
• Main Author: Wu, Chin-San
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2012; Elsevier
• Subjects: Agricultural residues; Applied sciences; Azospirillum brasilense; bacteria; biodegradability; Biodegradation; Composite; composite materials; Composites; crosslinking; culture media; Exact sciences and technology; films (materials); Forms of application and semi-finished materials; mechanical properties; molecular weight; Oryza sativa; Poly(butylene succinate adipate); polyesters; Polymer industry, paints, wood; rice hulls; succinic acid; Technology of polymers; viscosity; Biodegradation; Poly(butylene succinate adipate); Agricultural residues; Composite; Biological properties; Acrylic acid copolymer; Graft copolymer; Biodegradability; Intrinsic viscosity; Mechanical properties; Experimental study; Rice by product; Composite material; Succinate copolymer; Ester copolymer; Morphology; Concentration effect; Reaction mechanism; Agricultural waste; Adipate copolymer; Rheological properties
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2011.10.012

The biodegradability, morphology, and mechanical properties of composite materials consisting of acrylic acid-grafted poly(butylene succinate adipate) (PBSA-g-AA) and agricultural residues (rice husk, RH) were evaluated. Composites containing acrylic acid-grafted PBSA (PBSA-g-AA/RH) exhibited noticeably superior mechanical properties compared with those of PBSA/RH due to greater compatibility with RH. The dispersion of RH in the PBSA-g-AA matrix was highly homogeneous as a result of ester formation, and the consequent creation of branched and cross-linked macromolecules, between the carboxyl groups of PBSA-g-AA and hydroxyl groups in RH. Each composite was subject to biodegradation tests in an Azospirillum brasilense BCRC 12270 liquid culture medium. The bacterium completely degraded both the PBSA and the PBSA-g-AA/RH composite films. Morphological observations indicated severe disruption of the film structure after 20–40 days of incubation. The PBSA-g-AA/RH (20 wt%) films were not only more biodegradable than those made of PBSA but also exhibited lower molecular weight and intrinsic viscosity, implying a strong connection between these characteristics and biodegradability.