INVESTIGATION OF THE OPTOTHERMAL PROPERTIES OF A NEW POLYMERIC BLEND - POLYMETHYL-METHACRYLATE POLY(ETHYLENE-CO-VINYLACETATE)

A new polymeric blend, polymethyl methacylate-poly(ethylene-co-vinylacetate) (PMMA-EVA) has been produced recently in our laboratories. The optothermal characterization of PMMA-EVA was carried out by measuring the ultraviolet photoacoustic spectra of PMMA, EVA, and PMMA-EVA (25-degrees-C, 220-350 nm), of a PMMA-EVA blend (250-750 nm) at two temperatures (19-degrees-C and 65-degrees-C), and by measuring the scattering coefficient (at 514.5 nm) of PMMA-EVA versus the temperature in the range 38-86-degrees-C. Our measurements show that, in the explored thermal range, the blend undergoes a phase transition when its optical properties change drastically. The peculiar optical and thermal properties observed appear attractive for possible applications as temperature-controlled optical devices.