INVESTIGADORES
BARBOSA silvia Elena
artículos
Título:
Polyethylene/Polystyrene grafting reaction. Effects of Polyethylene Molecular Weight
Autor/es:
DÍAZ, MÓNICA FÁTIMA; BARBOSA, SILVIA ELENA; CAPIATI, NUMA JOSÉ
Revista:
POLYMER
Editorial:
Elsevier
Referencias:
Año: 2002 vol. 43 p. 4851 - 4858
ISSN:
0032-3861
Resumen:
Blending of different thermoplastic polymers usually results in segregated and low value materials for almost any mixing condition. Nevertheless, a synergetic combination of properties can be obtained by an adequate compatibilization via reactive blending. In this work a Friedel-Crafts alkylation reaction is used to graft polyethylene chains onto polystyrene. The relation between the initial PE molecular weight and the structure of the compatibilizer copolymer is studied by a combination of Size Exclusion Chromatography and Fourier Transform Infrared Spectroscopy. The amount of copolymer formed is estimated from the amount of polystyrene reacted. The relative lengths of the grafted polyethylene chains are assessed. It is found that lower molecular weight PE produces, upon reaction, a greater amount of short chain length grafted PE onto PS when starting with higher molecular weight PE. The results are in agreement with theories relating the component molecular weight to the reaction localization at the interface. The low cost Friedel-Crafts alkylation results in a convenient reaction for the in-situ compatibilization of PE/PS blends. It produces enough graft copolymer to compatibilize the phases without causing PS crosslinking and PE chain scission.