Análise da influência dos óleos vegetais sobre a fotoestabilidade do polipropileno reciclado

Abstract

The application of polymeric materials in different media has been more and more frequent, presenting certain characteristics that are not presented in other types of materials. However, one of the problems is its degradation. Thus, the objective of this work was to verify the behavior of three different vegetable oils (Brazil nut oil, castor oil and grape seed oil) as possible photo-stabilizing additives for recycled polypropylene (PP rec.). The incorporation of oils into the PP rec. occurred in amounts of 0.5 phr, 1.0 phr and 1.5 phr. Sample processing took place in a twin-screw extruder. Exposure to ultraviolet (UV) was carried out for 45 days and the mechanical properties of impact resistance and tensile strength were taken as parameters for evaluation of oil performance. The experimental results indicated that Brazil nut oil and castor oil seemed crosslinked, under UV effect, and thus influence impact resistance of PP rec., although they did not respond satisfactorily to the tensile strength. In turn, grape seed oil exhibited real potential as a photostabilizer for PP rec. both in impact conditions and in tensile conditions.