The effect of high-pressure carbon dioxide treatment on the crystallization behavior and mechanical properties of poly( l-lactic acid)/poly(methyl methacrylate) blends

• Published in: Polymer (Guilford) Vol. 47; no. 11; pp. 3954 - 3960
• Main Authors: Hirota, Shin-ichi, Sato, Takatoshi, Tominaga, Yoichi, Asai, Shigeo, Sumita, Masao
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 17.05.2006; Elsevier
• Subjects: Applied sciences; Carbon dioxide; Crystallization; Exact sciences and technology; Mechanical properties; Organic polymers; Physicochemistry of polymers; Polymer blend; Properties and characterization; Polymer blend; Carbon dioxide; Crystallization; Crystal form; Polymer blends; Optically active polymer; Property composition relationship; Physical dressing; Mechanical properties; Methyl methacrylate polymer; Experimental study; Structure composition relationship; High pressure; Elongation at fracture; Lactic acid polymer; Supramolecular structure; Miscibility; Thermodynamic properties
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2006.03.069

The purpose of this study is to investigate the effect of carbon dioxide (CO 2) on the crystallization behavior and the mechanical properties of PLLA/PMMA blends with various weight fraction of PMMA. PLLA/PMMA blends can be crystallized even at a low temperature of 0 °C under high-pressure CO 2. The films treated with high-pressure CO 2 at 0 °C have about three times larger strain at break than that of the amorphous and cold-crystallized film. The size of spherulites in the CO 2 treated film is considered to be smaller than the wavelength of the visible light because of a good transparency. The improvement of the strain at break is attributed to the reduction of the stress concentration during the deformation.