Mürşit Tufan

Determination of biological performance, dimensional stability, mechanical and thermal properties of wood–plastic composites produced from recycled chromated copper arsenate-treated wood:

The aim of this study was to investigate the dimensional stability, mechanical and biological performance and thermal degradation of wood–plastic composites made from high-density polyethylene and recycled wood treated with chromated copper arsenate (CCA), a commonly used wood preservative chemical. Virgin pine wood samples were also prepared with and without a coupling agent and used as the control group. Samples of CCA-treated Scots pine (Pinus sylvestris L.) with varying wood content were produced by adding different ratios of the coupling agent. The recycled CCA-treated wood-filled composites exhibited better flexural and tensile strength properties and dimensional stability than the control group, whilst their impact strength was less. Biological test values showed improved durability against termites and fungus with the recycled CCA-treated wood-filled composites. In addition, the leaching of heavy metals was significantly diminished when the coupling agent was utilized at a level of 5% (w/w), thus presenting a much lower impact on the environment.

Mechanical, thermal, morphological properties and decay resistance of filled hazelnut husk polymer composites

Four different formulations of natural fiber-polymer composites were fabricated from mixtures of hazelnut (Corylus avellana) husk flour (HHF), polypropylene (PP) and high density polyethylene (HDPE). Variables examined included polymer and coupling agent types. All formulations were compression molded in a hot press for 3 minutes at 175 0C. The resulted specimens were tested for mechanical properties according to ASTM D-790 and ASTM D-638. In addition, scanning electron microscopy (SEM), thermogravimetry (TG) and Differential Scanning Calorimetry (DSC) analysis were performed to characterize rheological properties of the fabricated composite. Furthermore, decay tests were performed to determine degradation of hazelnut husk polymer matrices. Hazelnut husk polymer composites had high mechanical properties for the tested formulations. The thermal studies showed that incorporation of hazelnut husk into the polymer matrices used did not adversely affect the composite. The HDPE+50% wood + 3% MAPE (HHF2) formulation showed the highest natural durability with only 3,47% and 4,60% mass losses against Trametes versicolor and Postia plecenta, respectively, while Scots pine solid controls experienced around 32% mass loss under the same exposure condition.

Decay resistance, thermal degradation, tensile and flexural properties of sisal carbon hybrid composites

Sisal-carbon hybrid composites were produced from mixtures having different weight ratios of sisal, carbon fibers and recycled polypropylene. All formulations were tested and evaluated for tensile and flexural properties. In addition, the thermal stability of the sisal-carbon hybrid composites were examined via thermogravimetric analysis and decay tests were conducted to determine the degradation of the hybrid composites. Results showed that the biological durability and mechanical and thermal properties improved with the increasing weight ratios of carbon fiber in the hybrid composites. According to the mechanical tests, the optimum hybrid composite formulation was found to be 12% sisal fiber + 28% carbon fiber + 60% rPP.

Preparation and characterization of high-performance wood polymer nanocomposites using multi-walled carbon nanotubes:

Effect of industrial grade multi-walled carbon nanotubes on mechanical, decay, and thermal properties of wood polymer nanocomposites was investigated. To meet this objective, pine wood flour, polypropylene with and without coupling agent (maleic anhydride grafted polypropylene), and multi-walled carbon nanotube (0, 1, 3, 5 wt%) were compounded in a twin screw co-rotating extruder. The mass ratio of the wood flour to polypropylene was 50/50 (w/w) in all compounds. Test specimens were produced using injection molding machine from the pellets. The flexural and tensile properties, biological durability, and thermal analysis (thermogravimetric analysis and differential scanning calorimetry) of the nanocomposites were investigated. The flexural and tensile properties of the wood polymer nanocomposites increased with increasing content of the industrial grade multi-walled carbon nanotubes (from 1 to 5 wt%) and maleic anhydride grafted polypropylene (3 wt%). The mass loss rates of the wood polymer nanocomposites decreased with increasing amounts of the maleic anhydride grafted polypropylene and industrial grade multi-walled carbon nanotube. The differential scanning calorimetry analysis showed that the melt crystallization enthalpies of the wood polymer nanocomposites increased with increasing amount of the industrial grade multi-walled carbon nanotubes. The increase in the Tc indicated that the industrial grade multi-walled carbon nanotubes were the efficient nucleating agent for the wood polymer nanocomposites.

Insect damaged wood as a source of reinforcing filler for thermoplastic composites

In this study, wood polymer composites were manufactured using insect damaged Eastern Black Sea Fir (A. Nordmanniana) wood as filler. The effects of wood type (sound vs insect damaged) and presence of coupling agent (0% vs 3%) on the flexural, tensile, impact, thermal and morphological properties of the wood polymer composites were investigated. The mechanical property values of the wood polymer composites specimens decreased when insect damaged wood was used as filler than sound wood, except for the impact strength values. Flexural, tensile and impact strength values, insect damaged wood filled with coupling agent composites provided higher values compared to sound wood filled without coupling agent composites. However, addition of maleic anhydride-graftedpolyethylene coupling agent into polymeric matrix improved both sound and insect damaged filled composite properties. Thermogravimetric analysis analysis showed two main decomposition peaks for polymer composites. Compared to unfilled high-density polyethylene, addition of both sound and insect damaged wood reduced decomposition peak but increased the residue due to the charring of the wood. The results of differential scanning calorimeter analysis showed that addition of sound or insect damaged wood in polymer matrix increase the crystallinity compared the unfilled high-density polyethylene due to the nucleating effect of the filler. Among the composite maleic anhydride-graftedpolyethylene modified composites provided higher crystallinity than unmodified ones.

Hizmet Ömrünü Doldurmuş Emprenyeli Ağaç Malzemenin Geri Dönüşüm Yöntemleri Üzerine Genel Bir Değerlendirme

Wood presevatives such as creosote, pentaclorophenol (PCP) and chromated copper arsenate (CCA) have been widely used over the years in order to extend wood products’ service life. CCA was known as most widely used wood preservative chemical in residendial and commercial applications world wide until 2004 volanteered phase out of the chemical from residential use bye the major manufacturers. Over the years CCA treated wood acuumulated in service reaching millions of cubic meters. But there is growing concern about the environmental impacts and increasing difficulty in disposing of treated wood products in many countries. Since disposal of CCA treated wood material poses greater problems than the other treated wood products due to heavy and toxic metal componets of CCA such as chromium and arsenic Traditional disposal methods like landfillig or incineration, both have negative environmental consequences. For that reason the increasing volume of CCA-treated wood products coming out of service requires alternative disposal methods and recycling techniques never tried before. The main purpose of this study, except for traditional methods like landfilling and incineration, is to evaluate the current alternative disposal and recycling methods for CCA treated wood removed from service.