Alperen Kaymakci

Waste chestnut shell as a source of reinforcing fillers for polypropylene composites

In this study, we evaluated dimensional stability and some mechanical properties of polypropylene composites filled with chestnut shell flour (CSF). To meet this objective, CSF was compounded with polypropylene with and without coupling agent in a twin screw corotating extruder and then were manufactured by injection molding process. The thickness swelling and water absorption of the samples increased with increasing CSF content. The flexural and tensile modulus improved with increasing CSF content, while the flexural and tensile strengths of the samples decreased. The use of maleic anhydride polypropylene had a positive effect on the dimensional stability and mechanical properties of the polypropylene composites filled with CSF. This work showed that the composites treated with maleated polypropylene could be efficiently used as decking products, due to high-dimensional stability and satisfactory mechanical properties of the composites.

Reduction of formaldehyde emission from light MDF panels by adding chestnut shell flour

Abstract Formaldehyde (FA) emission, dimensional stability, and mechanical properties of urea-formaldehyde (UF) resin-bonded light medium density fiberboards (MDFs) made of mixtures of hardwood fiber (Fagus orientalis Lipsky) and chestnut (Castanea sativa Mill.) shell flour have been evaluated. Six panel types were made of mixtures of the wood fiber and chestnut shell with ratios of 10/0, 9/1, 8/2, 7/3, 6/4, and 5/5 (by weight). FA emissions from the panels were significantly decreased with increasing content of the chestnut shell flour (CSF). However, the dimensional stability, the flexural properties, and the internal bond strength were negatively affected by increasing content of the shell flour. The FA reduction can be mainly attributed to a high amount of the phenolic extractives in the chestnut shell. Chestnut shell has a high potential as an effective FA scavenger in the manufacture of UF resin-bonded wood-based panels if optimized properly.

Surface roughness and wettability of polypropylene composites filled with fast-growing biomass: Paulownia elongata wood

This study investigated the surface roughness and wettability of polypropylene composites filled with Paulownia elongata wood flour with and without maleic anhydride-grafted polypropylene at different wood flour contents (30, 40, 50, and 60 wt%). The surface roughness values of the filled polypropylene composites decreased with increasing content of the polypropylene. The polypropylene composites without the maleic anhydride-grafted polypropylene were found to have higher surface roughness but better wettability as compared with the ones with the maleic anhydride-grafted polypropylene. The wettability of polypropylene composites increased with increasing content of the wood flour. The incorporation of the coupling agent in the polypropylene composites decreased the wettability of the specimens compared with untreated ones. The test result showed that P. elongata wood flour could be utilized in the production of the filled polypropylene composites because of their satisfying surface properties of the composites.

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.

The impact of density and mixture ratio of melamine on some properties of oriented strand board

The aim of this study is to determine the effects of density and melamine rate on thickness swelling, moisture resistance, modulus of elasticity in bending, bending strength and tensile strength of Oriented Strand Board. For this purpose, Oriented Strand Board panels were produced at three different density (550 - 570 - 590 kg.m-3 in size of 2440 x 1220 x 11 mm) and at five different mixture ratio of melamine in urea formaldehyde resin (0% - 2.5% - 5% - 15% - 20%). Urea formaldehyde and melamine urea formaldehyde included 65% solid content was used of 9.5% ratio relatively dry wood chip weight. At the process of Oriented Strand Board panels, Black pine (Pinus nigra), Scots pine (Pinus sylvestris) and Fir wood (Abies nordmanniana) chips were used at a rate of 80%, 15%, and 5%, respectively. Obtained results show that a linear correlation between the value of horizontal bending resistance, modulus of elasticity with panel density and melamine amount. It was understood that the values of longitudinal bending resistance did not show a direct increasing or decreasing in melamine amount and value of density. As it is seen that the values of longitudinal modulus of elasticity increases in proportion with the increase in the density. In perpendicular tensile strength to the surface; it is seen that values of all glue groups and density values which are intended by the standard for density values are covered. As melamine reinforcement ratio increases, average values of free formaldehyde decrease. It was determined that there was no direct correlation between the value of thickness swelling and panel density, and it had a correlation with used glue type.

PHYSICAL, MECHANICAL AND THERMAL PROPERTIES OF WOOD/ ZEOLITE/PLASTIC HYBRID COMPOSITES

Effect of zeolite content on the physical, mechanical and thermal properties of wood plastic composites was investigated in this study. To meet this objective, pine wood flour (0, 10, 20, 30, 40, 50 wt%) with compatibilizing agent, zeolite (0, 10, 20, 30, 40, 50 wt%), and polypropylene 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. Physical and mechanical, and thermal (Thermogravimetry Analysis/Differential Scanning Calorimetry) properties of the wood plastic composites were determined. The water absorption and thickness swelling properties of wood plastic composites improved with increasing zeolite content. The flexural and tensile properties of the wood plastic composites decreased with increasing zeolite content. All the wood plastic composites provided the values of flexural strength (58,4-72,9 MPa) and flexural modulus (2718-5024 MPa) that were well over the requirement by the standard specified in ASTM D 6662. The mass loss rates values of wood plastic composites increased with increasing zeolite contents. The Differential Scanning Calorimetry analysis showed that the melt crystallization enthalpies and degree of crystallization of wood plastic composites decreased with increasing zeolite content. The decrease in the Tc and Xc indicated that zeolite was the poor nucleating agent for the wood plastic composites.

Potential use of cotton dust as filler in the production of thermoplastic composites

The effect of cotton dust as filler on the mechanical and thermal properties of polypropylene composites was investigated and the results were compared with the properties of wood plastic composites. Cotton dust was obtained from the dust filtration system located in a textile manufacturing unit. Different mixtures of cotton dust (30 to 60 wt%) or wood flour (30 to 60 wt%) were compounded with polypropylene with a coupling agent (maleic anhydride grafted polypropylene 3 wt%) in a twin-screw co-rotating extruder. The test specimens were produced by injection molding machine. The tensile strength and flexural modulus of the specimens improved with the increase in the filler content. There was no significant difference in the strength and modulus values between the cotton dust and wood flour filled composites. The highest thermal stability was found to be in the composites produced with 40 wt% of cotton dust according to the results of differential scanning calorimetry analysis. Based on the findings obtained from the present study, the optimum mechanical and thermal properties for the filled polypropylene composites were found to be a 50/50/3 formulation of cotton dust, polypropylene, and maleic anhydride grafted polypropylene, respectively.

PAVLONYA KERESTELERİNİN TUTKALLI LAMİNE KESRETE ÜRETİMİNDE ORTA TABAKADA KULLANIM OLANAKLARI

Bu calismanin amaci hizli gelisen ve gorece dusuk kalitede bir oduna sahip olan pavlonya (Paulownia elongata)’nin lamine yapi kerestesi uretiminde orta tabakalarda kullanilma olanaklarinin arastirilmasidir. Boylece ekonomik degeri dusuk olan pavlonya odununun katma degeri yuksek bir urune donusturulmesi amaclanmaktadir. Bu amacla 10×110×1000 mm olculerinde lameller ve poliuretan tutkali kullanilarak ortadaki uc tabakasi pavlonya, alt ve ust yuzey tabakasi saricam olmak uzere 5 tabakadan olusan 5 adet deney ornegi uretilmistir. Karsilastirmak amaciyla tamami saricam lamellerden olusan 5 adet kontrol ornegi uretilmistir. Uretilen deney ornekleri uzerinde yogunluk, egilme direnci ve egilmede elastikiyet modulu denemeleri gerceklestirilmistir. Elde edilen sonuclar laminasyonda orta tabakada pavlonya kullanilan orneklerin yogunluk degerlerinin onemli oranda azaldigini, buna karsin egilme direnci ve egilmede elastikiyet modulu degerlerinde istatistik olarak anlamli bir kayip meydana gelmedigini gostermistir. Sonuc olarak laminasyonda dolgu malzemesi olarak orta tabakada pavlonya kullanilmasinin yapisal bakimdan avantaj saglayan hafif, buna karsin yeterli dirence sahip yapi elemanlarinin uretimine imkân saglayacagi ve ekonomik degeri dusuk pavlonya odununun ekonomik degeri yuksek bir urune donusturulebilecegi tespit edilmistir.