Light-scattering capacity of ethylene-vinyl acetate copolymers in polypropylene: Toward high haze and transmittance

摘要

Light-scattering materials were fabricated by the melt blending of polypropylene with an ethylene-vinyl acetate copolymer (EVA) to prevent the glare effect of light-emitting diodes. The results show that the light-scattering capacity was remarkably dependent on the phase morphologies of EVA. (1) When EVA was dispersed as spherical droplets, the transmittance and haze gradually increased with the enrichment of EVA, and the half-peak width of the light-scattering pattern reached a maximum when 30 wt % EVA was loaded. On the basis of the analysis of Mie scattering theory, the enlargement of scattering particles promoted light transmittance, and more incoming light was deflected at the arclike interfaces. This induced a distinct antiglare effect. (2) When scattering particles deformed and expanded vertically in the light-transmitting direction, the light-scattering capacity turned out to be weakened by further enrichment of the EVA phase. The planelike interfaces reduced the deflection of incoming light, and this led to decreases in the scattering angles. (c) 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42844.