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Article: Crystallization kinetics of poly(L-lactide)/carbonated hydroxyapatite nanocomposite microspheres

TitleCrystallization kinetics of poly(L-lactide)/carbonated hydroxyapatite nanocomposite microspheres
Authors
KeywordsBiomaterials
Carbonated hydroxyapatite
Crystallization
Nanocomposites
Poly(L-lactide)
Issue Date2009
PublisherJohn Wiley & Sons, Inc. The Journal's web site is located at http://www.interscience.wiley.com/jpages/0021-8995/
Citation
Journal Of Applied Polymer Science, 2009, v. 113 n. 6, p. 4100-4115 How to Cite?
AbstractMicrospheres consisting of carbonated hydroxyapatite (CHAp) nanoparticles and poly(L-lactide) (PLLA) have been fabricated for use in the construction of osetoconductive bone tissue engineering scaffolds by selective laser sintering (SLS). In SLS, PLLA polymer melts and crystallizes. It is therefore necessary to study the crystallization kinetics of PLLA/CHAp nanocomposites. The effects of 10 wt% CHAp nanoparticles on the isothermal and nonisothermal crystallization behavior of PLLA matrix were studied, using neat PLLA for comparisons. The Avrami equation was successfully applied for the analysis of isothermal crystallization kinetics. Using the Lauritzen-Hoffman theory, the transition temperature from, crystallization Regime II to Regime III was found to be around 12O0C for both neat PLLA and PLLA/CHAp nanocomposite. The combined Avrami-Ozawa equation was used to analyze the nonisothermal crystallization process, and it was found that the Ozawa exponent was equal to the Avrami exponent for neat PLLA and PLLA/CHAp nanocomposite, respectively. The effective activation energy as a function of the relative crystallinity and temperature for neat PLLA and PLLA/CHAp nanocomposite under the nonisothermal crystallization condition was obtained by using the Friedman differential isoconversion method. The Lauritzen-Hoffman parameters were also determined from the nonisothermal crystallization data by using the Vyazovkin-Sbirrazzuoli equation. CHAp nanoparticles in the composite acted as an efficient nucleating agent, enhancing the nucleation rate but at the same time reducing the spherulite growth rate. This investigation has provided significant insights into the crystallization behavior of PLLA/CHAp nanocomposites, and the results obtained are very useful for making good quality PLLA/CHAp scaffolds through SLS. © 2009 Wiley Periodicals, Inc.
Persistent Identifierhttp://hdl.handle.net/10722/129263
ISSN
2015 Impact Factor: 1.866
2015 SCImago Journal Rankings: 0.578
ISI Accession Number ID
Funding AgencyGrant Number
Hong Kong Research Grants CouncilHKU 7118/05E
Funding Information:

Contract grant sponsor: Hong Kong Research Grants Council (GRF research grant); contract grant number: HKU 7118/05E.

References
Grants

 

DC FieldValueLanguage
dc.contributor.authorZhou, WYen_HK
dc.contributor.authorDuan, Ben_HK
dc.contributor.authorWang, Men_HK
dc.contributor.authorCheung, WLen_HK
dc.date.accessioned2010-12-23T08:34:23Z-
dc.date.available2010-12-23T08:34:23Z-
dc.date.issued2009en_HK
dc.identifier.citationJournal Of Applied Polymer Science, 2009, v. 113 n. 6, p. 4100-4115en_HK
dc.identifier.issn0021-8995en_HK
dc.identifier.urihttp://hdl.handle.net/10722/129263-
dc.description.abstractMicrospheres consisting of carbonated hydroxyapatite (CHAp) nanoparticles and poly(L-lactide) (PLLA) have been fabricated for use in the construction of osetoconductive bone tissue engineering scaffolds by selective laser sintering (SLS). In SLS, PLLA polymer melts and crystallizes. It is therefore necessary to study the crystallization kinetics of PLLA/CHAp nanocomposites. The effects of 10 wt% CHAp nanoparticles on the isothermal and nonisothermal crystallization behavior of PLLA matrix were studied, using neat PLLA for comparisons. The Avrami equation was successfully applied for the analysis of isothermal crystallization kinetics. Using the Lauritzen-Hoffman theory, the transition temperature from, crystallization Regime II to Regime III was found to be around 12O0C for both neat PLLA and PLLA/CHAp nanocomposite. The combined Avrami-Ozawa equation was used to analyze the nonisothermal crystallization process, and it was found that the Ozawa exponent was equal to the Avrami exponent for neat PLLA and PLLA/CHAp nanocomposite, respectively. The effective activation energy as a function of the relative crystallinity and temperature for neat PLLA and PLLA/CHAp nanocomposite under the nonisothermal crystallization condition was obtained by using the Friedman differential isoconversion method. The Lauritzen-Hoffman parameters were also determined from the nonisothermal crystallization data by using the Vyazovkin-Sbirrazzuoli equation. CHAp nanoparticles in the composite acted as an efficient nucleating agent, enhancing the nucleation rate but at the same time reducing the spherulite growth rate. This investigation has provided significant insights into the crystallization behavior of PLLA/CHAp nanocomposites, and the results obtained are very useful for making good quality PLLA/CHAp scaffolds through SLS. © 2009 Wiley Periodicals, Inc.en_HK
dc.languageengen_US
dc.publisherJohn Wiley & Sons, Inc. The Journal's web site is located at http://www.interscience.wiley.com/jpages/0021-8995/en_HK
dc.relation.ispartofJournal of Applied Polymer Scienceen_HK
dc.rightsJournal of Applied Polymer Science. Copyright © John Wiley & Sons, Inc.-
dc.subjectBiomaterialsen_HK
dc.subjectCarbonated hydroxyapatiteen_HK
dc.subjectCrystallizationen_HK
dc.subjectNanocompositesen_HK
dc.subjectPoly(L-lactide)en_HK
dc.titleCrystallization kinetics of poly(L-lactide)/carbonated hydroxyapatite nanocomposite microspheresen_HK
dc.typeArticleen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0021-8995&volume=113&spage=4100&epage=4115&date=2009&atitle=Crystallization+kinetics+of+poly(L-Lactide)/carbonated+hydroxyapatite+nanocomposite+microspheres-
dc.identifier.emailWang, M:memwang@hku.hken_HK
dc.identifier.emailCheung, WL:wlcheung@hkucc.hku.hken_HK
dc.identifier.authorityWang, M=rp00185en_HK
dc.identifier.authorityCheung, WL=rp00103en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1002/app.30527en_HK
dc.identifier.scopuseid_2-s2.0-67649470591en_HK
dc.identifier.hkuros177507en_US
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-67649470591&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.volume113en_HK
dc.identifier.issue6en_HK
dc.identifier.spage4100en_HK
dc.identifier.epage4115en_HK
dc.identifier.isiWOS:000267994700081-
dc.publisher.placeUnited Statesen_HK
dc.relation.projectSelective Laser Sintering of Porous Biopolymer/Biocomposite Scaffolds for Bone Tissue Engineering-
dc.identifier.scopusauthoridZhou, WY=26636766600en_HK
dc.identifier.scopusauthoridDuan, B=7005042335en_HK
dc.identifier.scopusauthoridWang, M=15749714100en_HK
dc.identifier.scopusauthoridCheung, WL=7202743084en_HK

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