Utjecaj prirodnog izlaganja vremenskim utjecajima na svojstva kompozita od drvnog brašna i recikliranog polipropilena

In this study, the effect of natural weathering on the physical and mechanical properties of wood plastic composites (WPC) made from virgin and recycled polypropylene (PP) was studied. To prepare the recycled PP, virgin PP was thermo-mechanically degraded by extrusion under controlled conditions in a single-screw extruder at a router speed of 60 rpm and temperature of 190 °C. PP (virgin and recycled), wood flour, compatibilizer, and UV absorbent were physically blended, and the samples were manufactured by a twin-screw extruder. The samples were exposed to natural weathering for 270 days. The surface characteristics of the samples were investigated before and after weathering. According to the results, the composites from recycled PP exhibited a higher weathering resistancethan those from virgin PP. The use of a UV absorber improved the flexural strength and modulus of the composites, but it could not significantly prevent the flexural properties loss and discoloration of the composites after weathering.U ovom je istraživanju proučavan utjecaj prirodnog izlaganja vremenskim utjecajima na fizička i mehanička svojstva drvno-plastičnih kompozita (WPC) izrađenih od čistoga i recikliranog polipropilena (PP). U postupku pripreme recikliranog polipropilena čisti je polipropilen termomehanički razgrađen ekstruzijom s jednim pužem u konstantnim uvjetima i pri brzini vrtnje od 60 okr./min te pri temperaturi od 190 °C. Pomiješani su čisti i reciklirani polipropilen, drvno brašno, kompatibilizator i UV apsorber, a uzorci su proizvedeni ekstruderom s dva puža. Uzorci su bili 270 dana prirodno izloženi vremenskim utjecajima. Svojstva površine uzoraka ispitana su prije i nakon izlaganja tim utjecajima. Iz rezultata je vidljivo da su kompoziti od recikliranog polipropilena pokazali veću otpornost na vremenske utjecaje nego kompoziti od čistog polipropilena. Upotreba UV apsorbera poboljšala je čvrstoću na savijanje i modul elastičnosti kompozita, ali nije značajno spriječila slabljenje svojstava savijanja i promjenu boje kompozita nakon izlaganja vremenskim utjecajima

Effect of Natural Weathering on Performance of Wood Flour-Recycled Polypropylene Composites

In this study, the effect of natural weathering on the physical and mechanical properties of wood plastic composites (WPC) made from virgin and recycled polypropylene (PP) was studied. To prepare the recycled PP, virgin PP was thermo-mechanically degraded by extrusion under controlled conditions in a single-screw extruder at a router speed of 60 rpm and temperature of 190 °C. PP (virgin and recycled), wood flour, compatibilizer, and UV absorbent were physically blended, and the samples were manufactured by a twin-screw extruder. The samples were exposed to natural weathering for 270 days. The surface characteristics of the samples were investigated before and after weathering. According to the results, the composites from recycled PP exhibited a higher weathering resistancethan those from virgin PP. The use of a UV absorber improved the flexural strength and modulus of the composites, but it could not significantly prevent the flexural properties loss and discoloration of the composites after weathering