Effect of dissolved carbon dioxide on the glass transition and crystallization of poly(lactic acid) as probed by ultrasonic measurements

• Published in: Journal of applied polymer science Vol. 112; no. 3; pp. 1345 - 1355
• Main Authors: Reignier, J, Tatibouët, J, Gendron, R
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 05-05-2009; Wiley
• Subjects: Applied sciences; biopolymers; blowing agents; Crystallization; Exact sciences and technology; glass transition; Organic polymers; Physicochemistry of polymers; Properties and characterization; Gas absorption; Carbon dioxide; Crystallinity; Experimental study; Lactone polymer; Glass transition temperature; Lactic acid polymer; blowing agents; Pressure effect; Aliphatic polymer; Concentration effect; crystallization; Kinetics; Measurement method; biopolymers; glass transition; Isothermal crystallization; Ultrasonic method
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.27896

The effects of dissolved carbon dioxide (CO₂) molecules on the glass-transition temperature as well as the crystallization kinetics of poly(lactic acid) have been investigated with a novel device that combines ultrasonic and volumetric measurements. Ultrasonic parameters such as the sound velocity are very sensitive to crystallization and can be used to monitor the crystallization kinetics. The glass-transition temperature has been found to decrease nonlinearly as the CO₂ concentration increases. The maximum in the crystallization rate has been found to increase with the addition of CO₂.