1. Department of Mining-Metallurgy Engineering and Materials Science; POLYMAT, University of the Basque Country (UPV/EHU), School of Engineering; Alameda de Urquijo s/n. 48013 Bilbao Spain
2. Department of Polymer Science and Technology; POLYMAT, University of the Basque Country (UPV/EHU); M. de Lardizabal 3 20018 Donostia-San Sebastian Spain