Ferhat Özdemir

Improving dimensional stability of injection molded wood plastic composites using cold and hot water extraction methods

Dimensional stability of wood plastic composites (WPCs) made from polypropylene and pine wood flour with and without coupling agent was investigated. The pine wood flour was prepared from wood chips which had been immersed, respectively, in boiling water for 1 h, 3 h, and 5 h or in distilled water for 1 day, 3 days, and 5 days at room temperature. It was found that thickness swelling (TS) and water absorption (WA) of the WPCs made using extracted wood were lower than those of WPCs produced with unextracted wood. The TS and WA values of WPCs decreased with extraction duration both for cold and hot water extraction. The effect of hot water extraction on the TS and WA properties of the WPCs was more pronounced than cold water extraction.

Mechanical and thermal properties of Moringa oleifera cellulose-based epoxy nanocomposites

Cellulose nanowhiskers were prepared by acid hydrolysis of drumstick fruit fibers from Moringa oleifera. It was incorporated into thermosetting epoxy matrix at various weight fractions (0.06, 0.12 or 0.18 wt%) to investigate their effect on the mechanical and thermal properties of resulting epoxy resin composite. Drumstick fruit nanofibers slightly increased the thermal stability of the prepared composites. The tensile modulus (31.4%) and bending modulus (38.2%) of the epoxy composites filled with 0.18 wt% cellulose nanowhiskers significantly increased in comparison with that of the neat cured epoxy resin. However, the tensile strength (48.7%) and bending strength (41.6%) of the composites significantly decreased as the 0.18 wt% nanowhiskers were added into the epoxy matrix. The nanowhiskers (0.18 wt%) can be efficiently used in the epoxy matrix to improve considerably the tensile and bending modulus of the composites as well as a slight increase in the thermal stability.

Laminat Parkede Bazı Yanmayı Geciktirici Kimyasalların Beyaz ve Esmer Çürüklük Mantarlarına Karşı Direncinin Araştırılması

The objective of this study is to determine the effects of some fire retardants on decay resistance of the high density fiberboard (HDF) panels covered with overlay, decorative and balance papers. Borax (BX), boric acid (BA), ammonium polyphosphate (APP) and alpha-x (AX) as fire retardant (FR) chemicals were added as powder into the fibers made from 50% pine and 50% beech woods at 3%, 6% and 9% levels based on oven-dry fiber weight. HDF panels (400x400x6.5mm) were produced. After, surfaces of the panels were coated with overlay, decorative and balance papers. The panels were exposed to white (Ceriporiopsis subvermisphora) and brown (Coniophora puteana) decay fungi. The decay resistance of panels was investigated. The results showed that the addition of FR chemicals increased resistance against white and brown rot fungi of the panels. Thus, it was ascertained that concentration and type of FR chemicals are effective on decay resistance of laminate flooring.