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Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)

The role of organic solvents in governing the crystallization and morphology of semi-crystalline poly-l-lactide (PLLA) sheets was systematically investigated. Three different organic solvents; ethyl acetate (EA), o-dichlorobenzene (ODCB), and nitrobenzene (NB), with a solubility parameter analogous...

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Autores principales: Udayakumar, Mahitha, Kollár, Mariann, Kristály, Ferenc, Leskó, Máté, Szabó, Tamás, Marossy, Kálmán, Tasnádi, Ildikó, Németh, Zoltán
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7284506/
https://www.ncbi.nlm.nih.gov/pubmed/32384750
http://dx.doi.org/10.3390/polym12051065
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author Udayakumar, Mahitha
Kollár, Mariann
Kristály, Ferenc
Leskó, Máté
Szabó, Tamás
Marossy, Kálmán
Tasnádi, Ildikó
Németh, Zoltán
author_facet Udayakumar, Mahitha
Kollár, Mariann
Kristály, Ferenc
Leskó, Máté
Szabó, Tamás
Marossy, Kálmán
Tasnádi, Ildikó
Németh, Zoltán
author_sort Udayakumar, Mahitha
collection PubMed
description The role of organic solvents in governing the crystallization and morphology of semi-crystalline poly-l-lactide (PLLA) sheets was systematically investigated. Three different organic solvents; ethyl acetate (EA), o-dichlorobenzene (ODCB), and nitrobenzene (NB), with a solubility parameter analogous to PLLA and with a high capability of swelling, were chosen. It has been witnessed that the degree of crystallization and crystal morphology depends highly on the degree of swelling and evaporation rate of the solvent. Besides, the temperature and time of treatment played a significant role in the crystallization of polymers. The effect of different solvents and curing times are reflected by the measured X-ray diffraction (XRD) peaks and the differences are best shown by the unit cell size. The largest variation is observed along the c-axis, indicating shorter bonds, thus, showing better conformation after NB and ODCB treatment. The percentage of crystallinity calculated using the classical relative crystallinity index of XRD shows closer values to those calculated with differential scanning calorimetry (DSC) data, but a huge variation is observed while using the LeBail deconvolution method. The strong birefringence of polarised optical micrograph (POM) and the crystal morphology of scanning electron micrograph (SEM) also evidenced the orientation of polymer crystallites and increased crystallinity after solvent-supported heat treatment.
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spelling pubmed-72845062020-06-19 Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide) Udayakumar, Mahitha Kollár, Mariann Kristály, Ferenc Leskó, Máté Szabó, Tamás Marossy, Kálmán Tasnádi, Ildikó Németh, Zoltán Polymers (Basel) Article The role of organic solvents in governing the crystallization and morphology of semi-crystalline poly-l-lactide (PLLA) sheets was systematically investigated. Three different organic solvents; ethyl acetate (EA), o-dichlorobenzene (ODCB), and nitrobenzene (NB), with a solubility parameter analogous to PLLA and with a high capability of swelling, were chosen. It has been witnessed that the degree of crystallization and crystal morphology depends highly on the degree of swelling and evaporation rate of the solvent. Besides, the temperature and time of treatment played a significant role in the crystallization of polymers. The effect of different solvents and curing times are reflected by the measured X-ray diffraction (XRD) peaks and the differences are best shown by the unit cell size. The largest variation is observed along the c-axis, indicating shorter bonds, thus, showing better conformation after NB and ODCB treatment. The percentage of crystallinity calculated using the classical relative crystallinity index of XRD shows closer values to those calculated with differential scanning calorimetry (DSC) data, but a huge variation is observed while using the LeBail deconvolution method. The strong birefringence of polarised optical micrograph (POM) and the crystal morphology of scanning electron micrograph (SEM) also evidenced the orientation of polymer crystallites and increased crystallinity after solvent-supported heat treatment. MDPI 2020-05-06 /pmc/articles/PMC7284506/ /pubmed/32384750 http://dx.doi.org/10.3390/polym12051065 Text en © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Udayakumar, Mahitha
Kollár, Mariann
Kristály, Ferenc
Leskó, Máté
Szabó, Tamás
Marossy, Kálmán
Tasnádi, Ildikó
Németh, Zoltán
Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)
title Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)
title_full Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)
title_fullStr Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)
title_full_unstemmed Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)
title_short Temperature and Time Dependence of the Solvent-Induced Crystallization of Poly(l-lactide)
title_sort temperature and time dependence of the solvent-induced crystallization of poly(l-lactide)
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7284506/
https://www.ncbi.nlm.nih.gov/pubmed/32384750
http://dx.doi.org/10.3390/polym12051065
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