Accelerated weathering and decay resistance of heat-treated wood reinforced polypropylene composites : Ubrzano izlaganje polipropilenskih kompozita ojačanih pregrijanim drvom vremenskim utjecajima i otpornost na propadanje / Deniz Aydemir, Mizgin Alsan, Ahmet Can, Ertugrul Altuntas, Huseyin Sivrikaya.
Sažetak

The aim of this study was to determine the accelerated weathering and decay resistance of the heattreated wood reinforced polypropylene composites (HT-WPC). Polypropylene (PP) was used as a matrix and the heat-treated wood treated at 180 °C and 220 °C as reinforcement filler. The effect of three filler type, such as 40, 60 and 100 mesh, on the outdoor performance of composites was also investigated. The composites were prepared with twin screw extruder, and the test samples were obtained with compression molding. Lightness index (L*), color changes (ΔE*) and physical changes on the surface of the composites after the accelerated weathering, and decay resistance of the composites were investigated. According to the results, the effects of heat-treated wood on color changes were found to be more than its filler size, and while the filler loadings were increased from 5 % to 20 %, it was determined to increase the color changes of the composites. In scanning electron microscopy (SEM) images, crack formation and deterioration on the surface of the composites were determined. In FTIR spectra, no difference was determined between the composites, and all peaks were similar to each one. The addition of heattreated wood improved the antifungal efficiency of the composite, and the mass losses decreased with the increasing of heat treatment temperature. As a result, adding heat-treated wood to PP was found to improve the outdoor performance of the HT-WPCs.; Cilj ovog rada bio je utvrditi otpornost na propadanje polipropilenskih kompozita ojačanih pregrijanim drvom (HT-WPC) pri ubrzanom izlaganju vremenskim utjecajima. Polipropilen (PP) upotrijebljen je kao matrica, a drvo pregrijano na 180 i 220 °C kao armaturno punilo. Ispitivan je i učinak triju vrsta punila (mreža 40, 60 i 100) na svojstva kompozita u eksterijeru. Kompoziti su pripremljeni dvostrukim vijčanim ekstruderom, a ispitni su uzorci dobiveni kompresijskim lijevanjem. Ispitivana je svjetlina (L*), promjena boje (ΔE*) i fizičke promjene na površini kompozita nakon ubrzanog izlaganja vremenskim utjecajima, kao i otpornost na propadanje kompozita. Prema dobivenim rezultatima, utvrđeno je da su učinci pregrijavanja drva na promjenu boje veći od učinka veličine punila. Nadalje, zamijećeno je povećanje promjene boje kompozita s povećanjem udjela punila od 5 na 20 %. Na snimkama dobivenim elektronskim mikroskopom (SEM) uočeno je stvaranje pukotina i propadanje površine kompozita. Međutim, na FTIR spektru nije ustanovljena razlika između kompozita i svi su vrhovi bili slični. Dodavanjem pregrijanog drva poboljšala se otpornost kompozita na gljive te se smanjio gubitak mase s povećanjem temperature pregrijavanja. Utvrđeno je da se dodavanjem pregrijanog drva u polipropilen (PP) poboljšavaju svojstva kompozita HT-WPC-a u eksterijeru.