Incorporation D'ophite Dans Un Copolymere Éthylene-Propylène: Influence Sur La Coloration Et Le Comportement Mecanique Des Composites

Plastics are generally reinforced and colored by using a combination of a natural filler or glass fiber and a synthetic coloring agent or pigment. Filler loading is usually comprised between 20 and 60%, while that of the coloring agent is often less than 3%. A natural mineral filler, named ophite, was incorporated into a PP-PE copolymer. This naturally colored filler is able to both color the polymer green and to reinforce it. The colorimetric properties obtained (CIELab space) highlights the importance of filler granulometry on the appearance of the filled polymer (tint, saturation, brightness) and the main influence of the submicronic fraction. The results also show the use which can be made of a physical model of diffusion to forecast how the tint of the filled specimens evolves. Moreover, the flexural modulus and the impact resistance obtained are comparable to those of common mineral fillers (talcs, micas, kaolins) in the same polymer matrix.