Estudo comparativo da degradação de poliestireno e de poliestireno de alto impacto por envelhecimentos natural e artificial. / Comparative study of natural and artificial weathering of polystyrene and high impact polystyrene.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

The study of weathering materials regarding to climate, stresses, time, temperature, is essential to choose the materials for a purpose. Polystyrene is a polymeric resin with much usage in the market as it is transparent and relatively cheap, but it is not indicated for outdoor purposes with much actinic radiation exposure, as it is very sensitive to weathering, tough not recommended to purposes with much exposure. The addition of rubber (styrene-butadiene copolymer) improves some of its properties, like impact resistance and ductility, but decreases other properties, like tensile strength. Regarding the weathering, although the rubber degrades very quickly, it protects the polystyrene from the ultraviolet radiation. This study aims to compare the consequences of the degradation by natural weathering and accelerated artificial weathering and try to correlate their results. Equipments for artificial weathering, tensile strength, IZOD impact, melt flow, a natural weathering station and DSC thermal analysis equipment were used. The results allowed the correlation between the natural and artificial weathering regarding the measured properties, as for the common polystyrene the artificial weathering accelerated the degradation in approximately 4 times, while for the high impact polystyrene the acceleration factor resulted in approximately 2 times.

ASSUNTO(S)

polystyrene photodegradation weathering envelhecimento fotodegradação poliestireno

ACESSO AO ARTIGO

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