title: The effect of the Nb2O5 dispersion on ethylene vinyl acetate to obtain ethylene vinyl acetate/Nb2O5 nanostructured materials.
abstract: This work investigated the effect of niobium pentoxide nanoparticles (Nb2O5) on the molecular organization of an ethylene vinyl acetate copolymer (EVA) matrix containing 28% vinyl acetate groups, according to their dispersion and distribution in the polymer matrix. Due to niobium pentoxide's characteristics and properties, it may interfere in the chemical and UV resistance, as well as in the EVA mechanical properties, increasing mechanical resistance. The EVA/Nb2O5 nanocomposite films, with Nb2O5 varying from 0.25 to 1% in relation to the total EVA mass, were prepared by solution casting. The Nb2O5 was well dispersed with the use of ultrasound. These films were mainly characterized by X-ray diffraction and low-field nuclear magnetic resonance through relaxometry, in order to obtain responses on the structural organization and molecular dynamic, respectively, and consequently to understand the effect of the nanoparticles on the EVA matrix. The results showed that the addition of Nb2O5 to the EVA matrix caused changes in its crystallinity and molecular mobility, due to the new interactions formed by the good dispersion of nanoparticles and also their distribution in the EVA matrix, changing the copolymer characteristics due to the formation of a new material.
authors.affiliation: Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, Bloco J, Cidade Universitária, Ilha do Fundão, CP 68525, Rio de Janeiro, RJ 219415-970, Brasil.
authors.forename: Ana Claudia S
authors.initials: AC
authors.lastname: Valentim
authors.forename: Maria Inês Bruno
authors.initials: MI
authors.lastname: Tavares
authors.forename: Emerson Oliveira
authors.initials: EO
authors.lastname: da Silva