resumo
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.
palavras-chave
FREE FLAME-RETARDANT; EXPANDED GRAPHITE; CARBON NANOTUBES; NANOCOMPOSITES; BEHAVIOR; ENHANCEMENT; PERFORMANCE
categoria
Materials Science
autores
Gama, N; Costa, LC; Amaral, V; Ferreira, A; Barros-Timmons, A
nossos autores
Ana Margarida Madeira Viegas de Barros Timmons
Professor associado
Artur Jorge Faria Ferreira
Professor Coordenador
Nuno Vasco da Costa Gama Batista de Melo
Investigador Júnior
Vitor Brás Sequeira Amaral
Professor CatedráticoGrupos
G1 - Materiais Porosos e Nanossistemas
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G4 - Materiais Renováveis e Economia Circular
Projectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2013)
agradecimentos
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.