IMPROVEMENT OF IMPACT STRENGTH OF POLYPROPYLENE FILLED WITH LATEX COATED KAOLIN

The addition of kaolin in polypropylene homopolymer (PP) leads to a de crease in impact properties. This is due to the lack of adhesion betwe en the PP and the filler. An interesting way of improving adhesion bet ween the two components is to coat the mineral filler in a latex. The efficiency of the coating operation depend on the chemical nature of t he coating agent (i.e, the latex) and the coating conditions. The coat ing conditions were evaluated by measuring the electrokinetic potentia ls of the kaolin and latex particles. The different analytical techniq ues used proved the fixation of the latex onto the kaolin. The results of mechanical testing show that the coating of kaolin leads to an inc rease in impact strength of 50%.