ULTRA-TOUGH SYNTHETIC GLASSES MADE BY REACTIVE BLENDING OF PMMA AND EVA RUBBERS - OPTOTHERMAL CHARACTERIZATION

A novel polymeric material, a poly(methylmethacrylate) (PMMA)/ethylene -co-vinylacetate (EVA) blend, is presented. The blend shows outstandin g impact behaviour, at the same level as that of commercially-availabl e ultra-tough PMMA. Moreover, transparency is retained with a transpar ent-to-opaque transition at about 50 degrees C. The authors show the b ehaviour 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, acros s the transition, of fundamental parameters, such as the melting of su b-included rubber particles, the refractive indices of PMMA and EVA, a nd the particular morphology of the blend. The latter is very interest ing, as the rubber particles, by etching techniques, have been shown t o be composed of sub-included PMMA domains, leading to a so-called mul tiple core-shell structure.