Fatih Mengeloglu

The Manufacture of Particleboards using Sunflower Stalks (helianthus annuus l.) And Poplar Wood ( populus alba L.)

In this study, three-layer particleboards are produced from a mixture of sunflower stalks (Helianthus annuus L.) and poplar wood (Populus alba L.) at certain ratios utilizing urea-formaldehyde (UF) adhesives. Panels with a density of 0.7 g/cm 3are manufactured with the ratios of 25, 50, and 75 percent particles from sunflower stalks or poplar. For comparison, panels are solely manufactured with sunflower stalks and poplar wood. All panels are tested for physical properties (thickness swelling (TS) and water absorption (WA)) and mechanical properties (internal bond (IB), modulus of elasticity (MOE), modulus of rupture (MOR), and screw holding capacity (SHC)). Results show that all the panels provide properties required by the Turkish standards for general purpose-use particleboards. Furthermore, properties of the panels have improved with the rising percentage of poplar particles in the panels. The combination of sunflower stalks and poplar particles can be used at different ratios and the resulting panels can be utilized in indoor applications for general purposes such as furniture manufacturing. This result may prove that sunflower stalks can be an alternative raw material for the manufacture of particleboards.

Tea mill waste fibers filled thermoplastic composites: the effects of plastic type and fiber loading

The objective of this study was to investigate the utilization of tea mill waste fibers (TMWF) in thermoplastic composites. For this purpose, two plastic types: polypropylene (PP) and high density polyethylene (HDPE), were used as thermoplastic material while TMWF was utilized as a lignocellulosic filler. HDPE or PP and up to 50% TMWF were compounded in the single screw extruder and extrudates were compression molded into thermoplastic composite panels. The effects of plastic type and fiber loading rate on mechanical (flexural, tensile, and impact properties), physical (water absorption and thickness swelling), thermal properties, and morphological of the produced composites were determined. Tensile modulus, flexural modulus, water absorption, and thickness swelling of the produced composites were increased with the rise of the TMWF amount in the thermoplastic matrix. On the other hand, TMWF increase in the thermoplastic matrix reduced the tensile strength, flexural strength, and impact strength of the produced composites. It should also be noted that both flexural strength and flexural modulus have satisfied the requirements of ASTM D 6662. In the case of thermal properties, addition of TMWF into the thermoplastic matrix did not change the initial degradation significantly. However, the char rate of the composites increased. It appears that tea mill waste fibers may have a potential usage as filler in the PP- and HDPE-based thermoplastic composites.

Some Properties of Composite Panels Made from Wood Flour and Recycled Polyethylene

This study investigated the effect of board type (unmodified vs. MAPE modified) on the surface quality and thickness swelling-water absorption properties of recycled high density polyethylene (HDPE) based wood plastic composites. Additionally, two commercially available coatings (cellulosic coating and polyurethane lacquer coating) were also applied to composite surfaces and their adhesion strength, abrasion and scratch resistance, and gloss values were determined. This study showed that modification of the composites with MAPE coupling agent increased the surface smoothness and reduced the water absorption and thickness swelling of the panels. Abrasion resistance of the composites was also improved through MAPE modification. Regardless of board type, higher scratch resistance and gloss values were observed for polyurethane lacquer coated samples compared to those of cellulosic varnish coated ones. Improvement of adhesion strength was also seen on SEM micrographs.

Technological properties of thermoplastic composites filled with fire retardant and tea mill waste fiber

In this study, physical, mechanical, thermal, fire and biological properties of thermoplastic composites filled with fire retardant and tea mill waste fiber were investigated. The composites produced with the extrusion method were accomplished by using tea mill waste fiber as lignocellulosic materials and high-density polyethylene and polypropylene as thermoplastic polymer. Aluminum trihydrate and zinc borate were incorporated with different contents into polymer matrix for improving fire properties of the composites, and their effects on technological properties of the composites were evaluated. Aluminum trihydrate had a positive effect on the tensile modulus of the composites whilst zinc borate had adverse effect on that of the composites. The strength properties of the composites slightly decreased with usage of fire retardant. In the light of obtained results, it was specified that use of fire retardants improved physical, biological, thermal and fire properties of tea mill waste fiber-filled thermoplastic composites.

Long-Term Leaching Effect on Decay Resistance of Wood-Plastic Composites Treated with Boron Compounds

In this study, water absorption, thickness swelling and decay resistance of thermoplastic composites treated with three types of boron compounds was investigated. Spruce wood flour was treated with boric acid (BA), borax (BX) and mixture of BA–BX, and then was reinforced at two loading rate (20 and 40 wt%) in polymer matrix. Decay test of the composites was performed using with a brown rot fungus Coniophora puteana and a white rot fungus Trametes versicolor both for leached and unleached samples. The morphologic evaluations of decayed samples were done by scanning electron microscopy. Composites containing higher wood flour loading resulted in increased water absorption, thickness swelling, weight loss and moisture content. Fungal decay susceptibility of WPCs was influenced by leaching test for 60 days. Boron compound treated composites showed higher weight loss and moisture content than controls in decay test. All tested performance parameters were considerably increased in BX containing composites.

Nanoboron nitride-filled heat-treated wood polymer nanocomposites: Comparison of different multicriteria decision-making models to predict optimum properties of the nanocomposites:

The aim of this study is to investigate the effects of nanoboron nitride on the physical, mechanical, morphological and thermal properties of heat-treated wood high-density polyethylene composites. Three different multicriteria decision-making models such as the technique for order preference by similarity to ideal solutions, multi-attribute utility theory and compromise programming were used to predict the nanocomposites having optimum properties. High-density polyethylene as a matrix, heat-treated wood (30%) as a reinforcement filler and nanoboron nitride (0.5%, 1% and 2%) for improving the thermal stability were used; the composites prepared were grounded in a single-screw extruder, and the test samples were prepared with injection molding. According to the results, both testing and multicriteria decision-making models showed that heat-treated wood polymer nanocomposites with 2% nanoboron nitride have the optimum properties. Multicriteria decision-making methods are thought to be useful tools for materials having the optimal properties. It can be said that this study will be a guide for future material selection studies.