scholarly journals EFFECT OF THE ACIDIC TREATMENT OF DOMESTIC WOOD RESIDUE ON BIOCOMPOSITE WETTABILITY AND MOISTURE SORPTION PROPERTIES

Author(s):  
Jevgenijs Jaunslavietis ◽  
Galia Shulga ◽  
Jurijs Ozolins ◽  
Brigita Neiberte ◽  
Anrijs Verovkins ◽  
...  

The aim of the work was to evaluate the effect of the acidic treatment temperature of aspen sawdust as a filler on the moisture sorption, wetting and mechanical properties of wood-polymer composites. Aspen wood sawdust was treated with the dilute hydrochloric acid solution at 60oC and 90oC during 5 h. Both the treated particles and the filled composites were studied in terms of moisture sorption and wettability; their surface free energy was calculated using the Owens-Wendt-Rabel-Kaelble (OWRK) approach. The obtained results have shown that the acidic treatment of aspen wood sawdust at 90oC leads to an increase in its hydrophobicity that decreases the wettability and moisture sorption of the obtained composite and increases its mechanical properties.

2018 ◽  
Vol 762 ◽  
pp. 176-181
Author(s):  
Jevgenijs Jaunslavietis ◽  
Galia Shulga ◽  
Jurijs Ozolins ◽  
Brigita Neiberte ◽  
Anrijs Verovkins ◽  
...  

In this study, hydrophobic-hydrophilic characteristics, including contact angle and moisture sorption of a modified wood filler and the wood-polymer composites (WPC) containing it was investigated. The wood filler obtained from aspen sawdust was modified by mild acid hydrolysis and by ammoxidation. Contact angles of the wood particles and the WPC samples were measured with Kruss K100M using the Washburn and Wilhelmy methods, respectively. Work of adhesion was calculated using Young-Dupre equation. Surface free energy as well as its dispersive and polar parts were found using Owens-Wendt-Rabel-Kaelble approach. It was found that the hydrolysis and the ammoxidation led to decrease of the hemicelluloses content in the lignocellulosic matrix. Beside this, the ammoxidation favours the formation of amide bonds in the ammoxidised particles. These changes enhanced the contact angles, decreased the work of adhesion, and decreased surface free energy of the WPC samples filled with the modified particles in comparison with the WPC sample that contained the unmodified ones. The treatment of the wood particles decreased the wettability towards water, but increased it towards recycled polypropylene. This positively effects mechanical properties of the samples.


2019 ◽  
Vol 800 ◽  
pp. 200-204
Author(s):  
Jevgenijs Jaunslavietis ◽  
Galia Shulga ◽  
Jurijs Ozolins ◽  
Brigita Neiberte ◽  
Anrijs Verovkins ◽  
...  

As the demand for sustainable environment friendly materials increases, the biocomposites such as wood-polymer composite (WPC) have gained more attention in past years. Wood wastes and by-products like sawdust, chips, bark and wood residues as well as recycled polymers can serve as raw materials for production of WPC. However, there are still many issues obtaining WPCs, mainly a poor compatibility between a hydrophobic polymer matrix and a hydrophilic wood filler. In the present study, mechanical and mechanochemical activation of aspen wood waste were performed to increase their compatibility with recycled polypropylene matrix in the WPC, and the impact of both methods on the biocomposite properties were studied. It was found, that mechanochemical activation (MCA) of aspen wood particles leads to increased hydrophobicity of the obtained WPC compared to the WPC with mechanically activated (MA) particles. Work of adhesion with water was remarkably lower for the WPC modified by MCA which also correlates with moisture sorption results. Surface free energy of the WPC modified by MCA was lower compared to the WPC modified by MA, mostly due to decreased the polar component of surface free energy. The modulus of elasticity (MOE) were competitive for both the WPC formulations, however, MCA led to increased flexural strength of WPC compared to MA.


Holzforschung ◽  
2007 ◽  
Vol 61 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Xiaolin Cai ◽  
Bernard Riedl ◽  
S.Y. Zhang ◽  
Hui Wan

Abstract Wood polymer nanocomposites were prepared from solid aspen wood, water-soluble melamine-urea-formaldehyde (MUF) resin, and silicate nanoclays. The nanofillers were ground with a ball-mill before being mixed with the MUF resin and impregnated into the wood. The water-soluble prepolymer was mixed with the nanoclays at a mixing speed of 3050 rpm for 20 min to form impregnation solutions. Wood was impregnated with resin, which polymerized in situ under certain conditions. The physical and mechanical properties of the composite and the effect of ball-milling treatment of nanofillers on these properties were investigated. Significant improvements in physical and mechanical properties, such as density, surface hardness, and modulus of elasticity, were obtained for specimens impregnated with MUF resin and nanoclay-MUF resin mixtures. Ball-mill treatment favors dispersion of the nanofillers into the wood, but also appears to interfere with particle-resin adhesion.


2010 ◽  
Vol 70 (1) ◽  
pp. 45-52 ◽  
Author(s):  
I. Połeć ◽  
P.J. Hine ◽  
M.J. Bonner ◽  
I.M. Ward ◽  
D.C. Barton

2013 ◽  
Vol 1 (4) ◽  
pp. 334
Author(s):  
Alperen Kaymakcı

İki ya da daha fazla materyalin bir araya getirilmesi ile oluşan ve çoğu zaman kendilerini oluşturan materyallerden daha faydalı özelliklere sahip olan malzemelere kompozit malzeme denmektedir. Termoplastik esaslı polimer kompozitlerin üretiminde ise lignoselülozik materyaller ile polietilen (PE), polipropilen (PP), polivinil klorür (PVC) gibi plastikler kullanılmaktadır. Lignoselülozik materyaller ve termoplastik esaslı polimerlerin karışımıyla, plastik içerikli ürünlere benzer yöntemlerle üretilen malzemelere Ahşap-polimer kompozitleri (APK) denir. Ahşap polimer kompozit üretiminde çeşitli organik ve inorganik dolgu maddeleri kullanılmaktadır. Kalsiyum karbonat, talk, kalsiyum sülfat, alüminyum silikat ve Titanyum Dioksit gibi inorganik dolgu maddelerinin fiyatının pahalı oluşu ve makine aksamında yapmış olduğu aşınma dolayısıyla araştırmacılar ve endüstri kuruluşları alternatif dolgu materyali arayışına girmiştir. İnorganik dolgu materyaline alternatif olarak düşünülen buğday sapı, odun unu, orman endüstri atıkları ve yıllık bitkiler gibi organik dolgu maddeleri doğada bol olarak bulunmaları ve fiyatının ucuz oluşu dolayısıyla oldukça büyük avantajlar sağlamaktadır. Organik dolgu maddeleri ürünün maliyetini düşürdüğü gibi aynı zamanda ciddi performans artışları da sağlamaktadır. APK üretiminde saf (bakir) plastik kullanılabildiği gibi geri dönüşüm plastiklerde kullanılabilmektedir. Ülkemizdeki mevcut orman endüstrisinin oluşturmuş olduğu atıklar ve tarımsal atıklar ve bunun yanı sıra oluşan ciddi plastik atığı göz önüne alındığında bu tip malzemelerin APK üretiminde değerlendirilmesi potansiyeli görülmektedir. Bu nedenle ülkemizdeki tarımsal ve orman endüstrisi atıkları kullanılarak saf veya geri dönüşüm plastiklerle OPK üretiminde, üretim parametrelerinin ve üretilen malzemelerin özelliklerin belirlenmesi, bu potansiyeli ortaya çıkarmak için zaruri hale gelmiştir. Bu çalışmada atık alüminyum polietilen (Tetrapak) ve atık pirinç saplarından elde edilen unlar kullanılarak ahşap polimer kompozitler üretilmiştir. Ekstrüzyon ve enjeksiyon kalıplama işlemlerine tabi tutularak üretilen kompozitler üzerinde çekme ve eğilme direnci dayanımı testleri gerçekleştirilmiştir. Kompozit bünyesindeki pirinç sapı unu miktarındaki artışın kompozitlerin çekme ve eğilmede elastikiyet modülü değerlerini iyileştirdiği ancak kompozitlerin çekme, eğilme direnci değerlerinde genel olarak bir azalmaya sebep olduğu tespit edilmiştir. Determination of Mechanical Behaviour of Wood Polymer Composites Manufactured Using Waste Aluminium Polyethylene (Tetra Pak) and Brass Handle In this study, we evaluated some mechanical properties of aluminum polyethylene (Tetra Pak) composites reinforced with rice husk flour. To meet this objective, rice husk flour was compounded with aluminum polyethylene with coupling agent (MAPE) in a twin screw co-rotating extruder and then was manufactured by injection molding process. The modulus in the flexural and tensile improved with increasing rice husk flour content while the tensile and flexural strengths of the samples decreased. The use of maleic anhydride polyethylene had a positive effect on the mechanical properties of the aluminum polyethylene composites reinforced with rice husk flour. This work showed that the composites treated with maleated polyethylene could be efficiently used as decking products, due to satisfactory mechanical properties of the composites.


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