Tensile fracture behavior of a biodegradable polymer, poly(lactic acid)

• Published in: Polymer testing Vol. 25; no. 5; pp. 628 - 634
• Main Authors: Arakawa, Kazuo, Mada, Toshio, Park, Sang-Dae, Todo, Mitsugu
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2006; Elsevier
• Subjects: Applied sciences; Biodegradable polymer; Crack growth; Elastic energy; Exact sciences and technology; Fracture; Material testing; Mechanical properties; Physical properties; PLA; Polymer industry, paints, wood; Properties and testing; Technology of polymers; Testing and control; Fracture; Material testing; PLA; Biodegradable polymer; Elastic energy; Crack growth; Mechanical properties; Tensile property; Plastic deformation; Experimental study; Lactone polymer; Tension test; Lactic acid polymer; Precracked specimen; Aliphatic polymer; Kinetics; Measurement method; Fracture energy; Fracture mode
• ISSN: 0142-9418; 1873-2348
• DOI: 10.1016/j.polymertesting.2006.04.004

The stable and dynamic fracture behavior of a biodegradable polymer, poly(lactic acid) (PLA), was investigated using single-edge-cracked tensile specimens. To study the dynamic effect of brittle facture, the specimens were pin-loaded using a special jig that allowed them to split and fly off in the loaded direction after fracture. The non-elastic effect of viscoelastic and plastic deformations was also measured using an optical high-speed extensometer, which consisted of an optical fiber and a position-sensing detector (PSD). For the stable and dynamic fracture process, external work applied to the specimen and its fracture surface was partitioned into U s and U d, and A s and A d, respectively. The energy release rate, G s, for stable crack growth was determined using U s/ A s. The kinetic and non-elastic energies were measured and subtracted from U d to evaluate the fracture energy for the dynamic process, E f. The dynamic energy release rate, G f, was then determined as E f/ A d. G d was also obtained as U d/ A d to correlate with G s and G f, and the results are discussed.