abstract
The main purpose of this work was to widen the range of applications of the polyurethane foams (PUFs) obtained from renewable resources as higher added value materials by increasing their electrical and thermal conductivities and get a better insight of the parameters governing these properties. The increase of these properties is frequently achieved by filling PUFs with carbon nanofibers (CNFs), carbon nanotubes (CNTs) or graphene layers, however their cost limits their widespread use. In this work, an inexpensive procedure has been developed to prepare electrical conductive PUFs using castor oil (CO) as polyol and expanded graphite (EG). The chemical and structural characteristics of the ensuing composite foams have been evaluated, as well as their morphology and their mechanical, thermal and electrical properties. The DC electrical conductivity results have been fitted to Taherian model. EG loadings between 0.5 and 1.5% (w/w) caused a systematic increase of the thermal and electrical conductivities Moreover, in this fillers' loading range the remaining physical properties namely the glass transition temperature and the Young's modulus are appropriate for standard applications. (C) 2016 Elsevier Ltd. All rights reserved.
keywords
FREE FLAME-RETARDANT; EXPANDED GRAPHITE; CARBON NANOTUBES; NANOCOMPOSITES; BEHAVIOR; ENHANCEMENT; PERFORMANCE
subject category
Materials Science
authors
Gama, N; Costa, LC; Amaral, V; Ferreira, A; Barros-Timmons, A
our authors
Ana Margarida Madeira Viegas de Barros Timmons
Associate Professor
Artur Jorge Faria Ferreira
Professor Coordinator
Nuno Vasco da Costa Gama Batista de Melo
Junior Researcher
Vitor Brás Sequeira Amaral
Full professorGroups
G1 - Porous Materials and Nanosystems
G2 - Photonic, Electronic and Magnetic Materials
G4 - Renewable Materials and Circular Economy
Projects
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
acknowledgements
This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. Thermal Analysis Laboratory was funded by FEDER Funds through Programa Operacional Factores de Competitividade - COMPETE and by National Funds through FCT under the project REEQ/515/CTM/2005. L. C. Costa acknowledges FEDER by funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013. V. Amaral acknowledges project RECI/CTM-CER/0336/2012 co-financed by FEDER, QREN reference COMPETE: FCOMP-01-0124-FEDER-027465. The authors acknowledge CEMUP for the XPS analysis.