Photodegradation of thermodegraded polypropylene/high-impact polystyrene blends: Mechanical properties
Tipo
Artigo
Data de publicação
2011
Periódico
Journal of Applied Polymer Science
Citações (Scopus)
17
Autores
Fernandes L.L.
Freitas C.A.
Demarquette N.R.
Fechine G.J.M.
Freitas C.A.
Demarquette N.R.
Fechine G.J.M.
Orientador
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ISSN da Revista
Título de Volume
Membros da banca
Programa
Resumo
The influence of the addition of high-impact polystyrene (HIPS) on polypropylene (PP) photodegradation was studied with blends obtained by extrusion with and without styrene-butadiene-styrene (SBS) copolymer (10 wt % with respect to the dispersed phase). The concentrations of HIPS ranged from 10 to 30 wt %. The blends and pure materials were exposed for periods of up to 15 weeks of UV irradiation; their mechanical properties (tensile and impact), fracture surface, and melt flow indices were monitored. After 3 weeks of UV exposure, all of the materials presented mechanical properties of the same order of magnitude. However, for times of exposure greater than 3 weeks, an increasing concentration of HIPS resulted in a better photostability of PP. These results were explained in light of morphological observations. This increase of photostability was even greater when SBS was added to the blends. It was more difficult to measure the melt flow index of the binary PP/HIPS blends than that of PP for low concentrations of HIPS; this was most likely due to energy transfer between the blend domains during photodegradation. This phenomenon was not observed for the ternary blends. © 2010 Wiley Periodicals, Inc.
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Assuntos Scopus
blends , Dispersed phase , Fracture surfaces , High-impact polystyrene , Low concentrations , Melt flow index , Morphological observations , Order of magnitude , Photo-stability , Polystyrene blends , Pure materials , Styrene butadiene styrenes , Ternary blends , UV exposure , UV irradiation