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Thermal Behavior of Poly(L-lactide) Having Low L-Isomer Content of 94% after Compressed CO2 Treatment

Lan, Qiaofeng; Yu, Jian; He, Jiasong; Maurer, Frans LU and Zhang, Jun (2010) In Macromolecules 43(20). p.8602-8609
Abstract
The effect of compressed CO2 treatment on the thermal behavior of poly(L-lactide) (PLLA) with low L-isomer content of 94% was studied by using differential scanning calorimetry (DSC) and temperature modulated DSC. It was shown that the treated samples displayed rich thermal transition signals during DSC heating, which is differ from the PLLA having high L-isomer content, including enthalpy relaxation, endothermic annealing, melting-recrystallization process, and cold crystallization. The results suggested that the crystalline phase obtained has less perfection and low crystallinity regardless of the treatment conditions because of the low crystallizability of the PLLA. This PLLA was induced to crystallize after treatment under CO2 at 2 MPa... (More)
The effect of compressed CO2 treatment on the thermal behavior of poly(L-lactide) (PLLA) with low L-isomer content of 94% was studied by using differential scanning calorimetry (DSC) and temperature modulated DSC. It was shown that the treated samples displayed rich thermal transition signals during DSC heating, which is differ from the PLLA having high L-isomer content, including enthalpy relaxation, endothermic annealing, melting-recrystallization process, and cold crystallization. The results suggested that the crystalline phase obtained has less perfection and low crystallinity regardless of the treatment conditions because of the low crystallizability of the PLLA. This PLLA was induced to crystallize after treatment under CO2 at 2 MPa and temperature >= 65 degrees C and at pressures of 4-16 MPa and temperatures as low as 0 degrees C. At 2 MPa, the alpha crystal form is formed predominantly in the crystallized samples. The results also indicated that the ELLA-CO2 system exhibited the property of retrograde vitrification. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Macromolecules
volume
43
issue
20
pages
8602 - 8609
publisher
The American Chemical Society
external identifiers
  • wos:000283289100036
  • scopus:77958161094
ISSN
0024-9297
DOI
10.1021/ma101473r
language
English
LU publication?
yes
id
53b857bd-66d1-4a42-b316-09a2557845c4 (old id 1720707)
date added to LUP
2010-12-09 12:43:36
date last changed
2018-05-29 12:01:32
@article{53b857bd-66d1-4a42-b316-09a2557845c4,
  abstract     = {The effect of compressed CO2 treatment on the thermal behavior of poly(L-lactide) (PLLA) with low L-isomer content of 94% was studied by using differential scanning calorimetry (DSC) and temperature modulated DSC. It was shown that the treated samples displayed rich thermal transition signals during DSC heating, which is differ from the PLLA having high L-isomer content, including enthalpy relaxation, endothermic annealing, melting-recrystallization process, and cold crystallization. The results suggested that the crystalline phase obtained has less perfection and low crystallinity regardless of the treatment conditions because of the low crystallizability of the PLLA. This PLLA was induced to crystallize after treatment under CO2 at 2 MPa and temperature >= 65 degrees C and at pressures of 4-16 MPa and temperatures as low as 0 degrees C. At 2 MPa, the alpha crystal form is formed predominantly in the crystallized samples. The results also indicated that the ELLA-CO2 system exhibited the property of retrograde vitrification.},
  author       = {Lan, Qiaofeng and Yu, Jian and He, Jiasong and Maurer, Frans and Zhang, Jun},
  issn         = {0024-9297},
  language     = {eng},
  number       = {20},
  pages        = {8602--8609},
  publisher    = {The American Chemical Society},
  series       = {Macromolecules},
  title        = {Thermal Behavior of Poly(L-lactide) Having Low L-Isomer Content of 94% after Compressed CO2 Treatment},
  url          = {http://dx.doi.org/10.1021/ma101473r},
  volume       = {43},
  year         = {2010},
}