Títol:
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Crystallization kinetics of chain extended poly(L-lactide)s having different molecular structures
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Autor/a:
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Yousefzade, Omid; Jeddi, Javad; Franco García, María Lourdes; Puiggalí Bellalta, Jordi; Garmabi, Hamid
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Altres autors:
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Química; Universitat Politècnica de Catalunya. PSEP - Polimers Sintètics: Estructura i Propietats. Polimers Biodegradables. |
Abstract:
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Poly(L-lactide)s (PLLAs) with different chain structures were prepared by reactive melt processing and using Joncryl ADR as chain extender. Results of gel permeation chromatography (GPC) revealed that chain extended PLLAs had high molecular weights and two differentiated molecular weight distributions. Linear rheology was sensitive to the obtained molecular structures and revealed as the increase on the amount of chain extender gradually led to a decrease of the loss factor in the whole frequency region and to an increase of melt viscosity and both storage and loss moduli. In addition, the entanglement density increased significantly with addition of chain extender and had a significant influence on crystallization kinetics. Correlation of molecular weight, viscosity and entanglements changed the crystallinity and crystallization kinetics of chain extended PLLAs in both isothermal and non-isothermal crystallizations. Specifically, samples prepared from 1 wt-% of Joncryl (PLLA1R) revealed the highest nucleation and the fastest crystallization rate. |
Matèries:
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-Àrees temàtiques de la UPC::Enginyeria dels materials -Àrees temàtiques de la UPC::Enginyeria química -Polylactic acid -Crystallization -Chain extended PLLA -Molecular structure -Rheological properties -Crystallization kinetics -Àcid polilàctic -Cristal·lització |
Drets:
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Tipus de document:
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Article - Versió presentada Article |
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