1. a Institute of Material Science and Technology (INTEMA), University of Mar del Plata, Juan B. Justo 4302, B7608FDQ, Mar del Plata, Argentina
2. b Institute of Material Science and Technology (INTEMA), University of Mar del Plata, Juan B. Justo 4302, B7608FDQ, Mar del Plata, Argentina
3. c Institute of Natural Fibres (INF), ul. Wojska Polskiego 71 b, 60-630 Poznán, Poland
4. d Polymer and Composite Material Group, INTECIN (UBA-CONICET), Engineering Faculty, University of Buenos Aires, Las Heras 2214, Buenos Aires 1127AAR, Argentina Received 29 September 2007; accepted 24 May 2009