Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization
The degradation of poly(lactic acid) (PLA) during thermal-mechanical processing was studied and the influence of processing conditions on degradation rate was determined by size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS). A two-parameter model accounting for both chain scission and recombination processes was used to describe the experimentally observed molar mass distribution. The degradation and recombination rate constants were determined for undried and dried PLA. It was highlighted that the effect of processing temperature (in the 170-210 °C range), processing time (until 30 min) and shear rate (rotor speed varying from 0 to 150 rpm) on molar mass reduction can be relatively well simulated insofar as self-heating related to the mechanical energy conversion into heat was taken into account. The influence of melt processing on the thermal behaviour of PLA was also investigated using temperature modulated differential scanning calorimetry (TMDSC). It was evidenced that the molar mass reduction affects the crystallizability of PLA. Cold crystallization temperature progressively decreases with decreasing molar mass and the metastable a' phase is formed in place of the stable ? phase. The a' phase can be partially converted into ? form during melting giving rise to a double-melting peak. The two peaks can be separated using reversing and non-reversing signals confirming that recrystallization of the a' form occurs.
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dig-cirad-fr-5755522022-04-15T09:45:38Z http://agritrop.cirad.fr/575552/ http://agritrop.cirad.fr/575552/ Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization. Le Marec Pierre Erwan, Ferry Laurent, Quantin Jean-Christophe, Bénézet Jean-Charles, Bonfils Frédéric, Guilbert Stéphane, Bergeret Anne. 2014. Polymer Degradation and Stability, 110 : 353-363.https://doi.org/10.1016/j.polymdegradstab.2014.10.003 <https://doi.org/10.1016/j.polymdegradstab.2014.10.003> Researchers Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization Le Marec, Pierre Erwan Ferry, Laurent Quantin, Jean-Christophe Bénézet, Jean-Charles Bonfils, Frédéric Guilbert, Stéphane Bergeret, Anne eng 2014 Polymer Degradation and Stability 000 - Autres thèmes U10 - Informatique, mathématiques et statistiques The degradation of poly(lactic acid) (PLA) during thermal-mechanical processing was studied and the influence of processing conditions on degradation rate was determined by size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS). A two-parameter model accounting for both chain scission and recombination processes was used to describe the experimentally observed molar mass distribution. The degradation and recombination rate constants were determined for undried and dried PLA. It was highlighted that the effect of processing temperature (in the 170-210 °C range), processing time (until 30 min) and shear rate (rotor speed varying from 0 to 150 rpm) on molar mass reduction can be relatively well simulated insofar as self-heating related to the mechanical energy conversion into heat was taken into account. The influence of melt processing on the thermal behaviour of PLA was also investigated using temperature modulated differential scanning calorimetry (TMDSC). It was evidenced that the molar mass reduction affects the crystallizability of PLA. Cold crystallization temperature progressively decreases with decreasing molar mass and the metastable a' phase is formed in place of the stable ? phase. The a' phase can be partially converted into ? form during melting giving rise to a double-melting peak. The two peaks can be separated using reversing and non-reversing signals confirming that recrystallization of the a' form occurs. article info:eu-repo/semantics/article Journal Article info:eu-repo/semantics/publishedVersion http://agritrop.cirad.fr/575552/1/document_575552.pdf application/pdf Cirad license info:eu-repo/semantics/restrictedAccess https://agritrop.cirad.fr/mention_legale.html https://doi.org/10.1016/j.polymdegradstab.2014.10.003 10.1016/j.polymdegradstab.2014.10.003 info:eu-repo/semantics/altIdentifier/doi/10.1016/j.polymdegradstab.2014.10.003 info:eu-repo/semantics/altIdentifier/purl/https://doi.org/10.1016/j.polymdegradstab.2014.10.003 |
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000 - Autres thèmes U10 - Informatique, mathématiques et statistiques 000 - Autres thèmes U10 - Informatique, mathématiques et statistiques Le Marec, Pierre Erwan Ferry, Laurent Quantin, Jean-Christophe Bénézet, Jean-Charles Bonfils, Frédéric Guilbert, Stéphane Bergeret, Anne Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization |
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The degradation of poly(lactic acid) (PLA) during thermal-mechanical processing was studied and the influence of processing conditions on degradation rate was determined by size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS). A two-parameter model accounting for both chain scission and recombination processes was used to describe the experimentally observed molar mass distribution. The degradation and recombination rate constants were determined for undried and dried PLA. It was highlighted that the effect of processing temperature (in the 170-210 °C range), processing time (until 30 min) and shear rate (rotor speed varying from 0 to 150 rpm) on molar mass reduction can be relatively well simulated insofar as self-heating related to the mechanical energy conversion into heat was taken into account. The influence of melt processing on the thermal behaviour of PLA was also investigated using temperature modulated differential scanning calorimetry (TMDSC). It was evidenced that the molar mass reduction affects the crystallizability of PLA. Cold crystallization temperature progressively decreases with decreasing molar mass and the metastable a' phase is formed in place of the stable ? phase. The a' phase can be partially converted into ? form during melting giving rise to a double-melting peak. The two peaks can be separated using reversing and non-reversing signals confirming that recrystallization of the a' form occurs. |
format |
article |
topic_facet |
000 - Autres thèmes U10 - Informatique, mathématiques et statistiques |
author |
Le Marec, Pierre Erwan Ferry, Laurent Quantin, Jean-Christophe Bénézet, Jean-Charles Bonfils, Frédéric Guilbert, Stéphane Bergeret, Anne |
author_facet |
Le Marec, Pierre Erwan Ferry, Laurent Quantin, Jean-Christophe Bénézet, Jean-Charles Bonfils, Frédéric Guilbert, Stéphane Bergeret, Anne |
author_sort |
Le Marec, Pierre Erwan |
title |
Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization |
title_short |
Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization |
title_full |
Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization |
title_fullStr |
Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization |
title_full_unstemmed |
Influence of melt processing conditions on poly(lactic acid) degradation: Molar mass distribution and crystallization |
title_sort |
influence of melt processing conditions on poly(lactic acid) degradation: molar mass distribution and crystallization |
url |
http://agritrop.cirad.fr/575552/ http://agritrop.cirad.fr/575552/1/document_575552.pdf |
work_keys_str_mv |
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1758024445985816576 |