PREPARACIÓN Y EVALUACIÓN DE COMPATIBILIZANTES PARA MEZCLAS DE POLIESTIRENO/SILICONA Y CAUCHO NATURAL/SILICONA

Abstract

Block and graft copolymers of the type polystyrene-b-poly (dimethylsiloxane)            and natural rubber-g-poly (d¡methylsiloxane), were synthesized by using a free-radical polymerization mechanism. These copolymers were characterized and evaluated as compatibilizers for non-miscible blends of polystyrene/poly (dimethyisiloxane)   and   natural rubber/poly (dimethylsiloxane) both with a mass ratio of 50/50.

The evaluation was carried out by following the mechanical behavior of the blends prepared with different percentages of compatibilizer added and comparing with the same systems without additive. The results indicated that low additions (5%-10%) of the synthesized copolymers increase tensile strength and hardness of the blends with a synergistic effect between the properties of the respective homopolymers in the blends. A good degree of morphological compatibilization was observed in thin films by optical microscopy of light transmission as a consequence of the size reduction in the dispersed microphases.