Effect of the molecular architecture of graft copolymers on the phase morphology and tensile properties of PS/EVA blends |
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| Authors: | Bluma G Soares Ana C F Moreira Alex S Sirqueira Ronilson V Barbosa Renata A Simão |
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| Affiliation: | 1. Instituto de Macromoléculas, Universidade Federal do Rio de Janeiro, Centro de Tecnologia, BI. J, Ilha do Fund?o, 21945‐970, Rio de Janeiro, Brazil;2. Instituto de Química, Universidade Federal do Parana, Curitiba, PR, Brazil;3. Departmento Engenharia de Materiais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil |
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| Abstract: | Graft copolymers of poly(ethylene‐co‐vinyl acetate) (EVA) grafted with polystyrene (PS) with different molecular weight and different EVA/PS ratio were prepared by coupling reaction between acyl chloride functionalized PS (PS‐COCl) and hydrolyzed EVA. PS‐COCl with controlled molecular weight was prepared by anionic polymerization of styrene, followed by end capping with phosgene. The effect of the molecular architecture of the graft copolymer on the compatibilization of PS/EVA blends was investigated. Substantial improvement in the elongation at break and ductility was observed using the graft copolymer with PS segments with molecular weight as high as 66,000 g/mol and with a PS proportion equal or higher than EVA. The effect of the compatibilization on the morphology was also investigated by scanning electron microscopy and atomic force microscopy. The blend that presented the highest value of elongation at break also displayed dispersed phase constituted by inclusions of the PS phase inside the EVA particle forming a cocontinuous structure, as observed by AFM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008 |
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| Keywords: | polystyrene EVA compatibilization molecular architecture morphology scanning electron microscopy atomic force microscopy |
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