Management of moisture penetration and hydrolytic degradation of polylactide (PLA) is extremely important during the manufacturing, shipping, storage, and end-use of PLA products. Moisture transport, crystallization, and degradation in PLA have been measured through a variety of experimental techniques including size-exclusion chromatography differential scanning calorimetry and X-ray diffraction. Quartz crystal microbalance and dynamic vapor sorption experiments have also been used to measure moisture sorption isotherms in PLA films with varying crystallinity. A surprising result is that, within the accuracy of the experiments, crystalline and amorphous PLA films exhibit identical sorption isotherms.
Bibliographical noteFunding Information:
The research conducted for this project was supported by the National Research Initiative of the USDA Cooperative State Research, Education and Extension Service, grant no. 2004-35504-14636, which funded the research of Cairncross during his sabbatical in the BioBased Products Department at the University of Minnesota. The research was also supported by seed grant funding from the University of Minnesota, Initiative for Renewable Energy and the Environment (IREE) and by funding and samples from NatureWorks, LLC. Access to experimental facilities in the laboratories of Ted Labuza and Gary Reineccius in the Food Science and Nutrition Department at the University of Minnesota is gratefully acknowledged. Allan Smith and Fletcher Smith aided in this research by allowing access to the Masscal G1™ and their expertise in its use. Discussions with Marc Hillmyer (University of Minnesota, Chemistry Department) and Roger Ruan (University of Minnesota, Biosystems and Agricultural Engineering Department) were also helpful in this research.
- Bio-based polymers
- Biodegradable polymers
- Polylactic acid