Preparation of nanocomposites of poly("-caprolactone) and multi-walled carbon nanotubes by ultrasound micro-molding. influence of nanotubes on melting and crystallization
Olmo, Cristian (Universitat Politècnica de Catalunya)
Amestoy, Hegoi (Universidad del País Vasco)
Casas, Maria Teresa (Universitat Politècnica de Catalunya)
Martínez, Juan Carlos (ALBA Laboratori de Llum de Sincrotró)
Franco García, María Lourdes (Universitat Politècnica de Catalunya)
Sarasua, José Ramón (Universidad del País Vasco)
Puiggalí, Jordi (Universitat Politècnica de Catalunya)

Date:	2017
Abstract:	Ultrasound micro-molding technology was successfully applied to prepare nanocomposites based on a poly(ε-caprolactone) (PCL) matrix and multi-walled carbon nanotubes (MWCNTs). Optimization of processing parameters (i. e. , amplitude, force and time) was crucial to obtain nanocomposites without any evidence of degradation, high material saving and short processing time (7-8 s). Good dispersion of nanotubes was achieved after processing previously formed solvent casting films. This dispersion was even partially detected in pieces directly obtained from powder mixtures of both components. Incorporation of MWCNTs had a remarkable influence on melting and crystallization processes, which were systematically studied by time resolved synchrotron experiments. Results indicated higher melting and crystallization temperatures for the nanocomposite, with temperature differences higher than 5 °C. Carbon nanotubes were effective nucleating agents and had an influence on crystallinity, crystallization rate and even on lamellar morphology, which was evaluated by analysis of the correlation function of small angle diffraction profiles. Crystallinity within lamellar stacks was lower for the solvent casting nanocomposite, but in this case lamellae underwent a thickening process during heating that accounted for the increase in the melting temperature. Crystallization from the melt rendered similar lamellar morphologies at the end of the process due to a lamellar insertion mechanism.
Grants:	Ministerio de Economía y Competitividad MAT2015-69547-R Ministerio de Economía y Competitividad MAT2015-69367-R Agència de Gestió d'Ajuts Universitaris i de Recerca 2014/SGR-188
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Carbon nanotubes ; Crystallization ; Micro-molding technology ; Morphological parameters ; Nanocomposites ; Synchrotron radiation ; Ultrasounds
Published in:	Polymers, Vol. 9, Issue 8 (August 2017) , art. 322, ISSN 2073-4360

DOI: 10.3390/polym9080322
PMID: 30970997

18 p, 6.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > The ALBA Synchrotron
Articles > Research articles
Articles > Published articles