A novel polymeric material, a poly(methylmethacrylate) (PMMA)/ethylene-co- vinylacetate (EVA) blend, is presented. The blend shows outstanding impact behaviour, at the same level as that of commercially-available ultra-tough PMMA. Moreover, transparency is retained with a transparent-to-opaque transition at about 50 degree C. The authors show the behaviour of the optical transmission as a function of the temperature, and measure some physical properties of this material. An attempt is made to correlate the thermo-optical behaviour to the variation, across the transition, of fundamental parameters, such as the melting of sub-included rubber particles, the refractive indices of PMMA and EVA, and the particular morphology of the blend. The latter is very interesting, as the rubber particles, by etching techniques, have been shown to be composed of sub-included PMMA domains, leading to a so-called multiple core-shell structure. (Author abstract) 9 Refs.
Bernini, U. Malinconico, M. Martuscelli, E. Mormile, P. Novellino, A. Russo, P. Volpe, M.G.