Mechanical Property Characterization of Plasticized Sugar Beet Pulp and Poly(Lactic Acid) Green Composites Using Acoustic Emission and Confocal Microscopy

• Published in: Journal of polymers and the environment Vol. 16; no. 1; pp. 19 - 26
• Main Authors: Finkenstadt, V. L, Liu, C.-K, Cooke, P. H, Liu, L. S, Willett, J. L
• Format: Journal Article
• Language: English
• Published: Boston Boston : Springer US 2008; Springer US
• Subjects: acoustic emission; acoustic emissions; acoustic properties; biodegradable products; Chemistry; Chemistry and Materials Science; composite materials; composite polymers; confocal microscopy; elongation; Environmental Chemistry; Environmental Engineering/Biotechnology; extrusion; glycerol; Industrial Chemistry/Chemical Engineering; injection molding; lactic acid; low temperature; Materials Science; mechanical properties; Microscopy; Original Paper; plasticizers; plastticized sugar beet pulp; poly(lactic acid); Polymer Sciences; Q1; sorbitol; sugar beet pulp; tensile strength; Sugar beet pulp; Acoustic emission; Extrusion; Poly(lactic acid); Composite; Injection-molding
• ISSN: 1566-2543; 1572-8919; 1572-8900
• DOI: 10.1007/s10924-008-0085-8

Sorbitol and glycerol were used to plasticize sugar beet pulp-poly(lactic acid) green composites. The plasticizer was incorporated into sugar beet pulp (SBP) at 0%, 10%, 20%, 30% and 40% w/w at low temperature and shear and then compounded with poly(lactic acid) (PLA) using twin-screw extrusion and injection molding. The SBP:PLA ratio was maintained at 30:70. As expected, tensile strength decreased by 25% and the elongation increased. Acoustic emission (AE) showed correlated debonding and fracture mechanisms for up to 20% w/w plasticizer and uncorrelated debonding and fracture for 30-40% sorbitol and 30% glycerol content in SBP-PLA composites. All samples had a well dispersed SBP phase with some aggregation in the PLA matrix. However, at 40% glycerol plasticized SBP-PLA composites exhibited unique AE behavior and confocal microscopy revealed the plasticized SBP and PLA formed a co-continuous two phase system.