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Crystallization kinetics study of poly(L‐lactic acid)/carbon nanotubes nanocomposites |
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| Authors: | Yeong‐Tarng Shieh Yawo‐Kuo Twu Chean‐Cheng Su Rong‐Hsien Lin Gin‐Lung Liu |
| Affiliation: | 1. Department of Chemical and Materials Engineering, National University of Kaohsiung, Kaohsiung 811, Taiwan;2. Department of Bioindustry Technology, Dayeh University, Dacun, Changhua 51591, Taiwan;3. Department of Chemical and Material Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan;4. Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Douliou, Yunlin 640, Taiwan |
| Abstract: | Effects of carbon nanotubes (CNT) on the isothermal crystallization kinetics of poly(L ‐lactic acid) (PLLA) were quantitatively investigated using the Avrami equation and the secondary nucleation theory of Lauritzen and Hoffman. CNT via grafting modification with PLLA could well disperse in the PLLA matrix and give significantly enhanced crystallization rate and crystallinity of PLLA as analyzed by differential scanning calorimetry and polarized optical microscopy. Analysis of isothermal crystallization kinetics using the Avrami equation demonstrated that CNT significantly enhanced the bulk crystallization of PLLA. Analysis of spherulite growth kinetics using the secondary nucleation theory of Lauritzen and Hoffman found that CNT could expand the temperature range of the crystallization regime III of PLLA. Values of the nucleation constant (Kg) in crystallization regimes III and II of PLLA both increased with increasing CNT contents. The Kg III/Kg II ratios were found to be close to the theoretical value 2 but were not clearly found to depend on the CNT contents. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 983–989, 2010 |
| Keywords: | carbon nanotubes crystallization kinetics crystallization differential scanning calorimetry (DSC) nanocomposites poly(L‐lactic acid) polyesters |