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The Effect of Chopped Glass and Carbon Fiber Reinforcement on Physical, Mechanical, and Fire Performance of Wood Plastic Composites

Durmaz Sefa, Aras Uğur, Avci Erkan, Mengeloğlu Fatih, Atar İlkay

Drewno : prace naukowe, doniesienia, komunikaty

2023

Vol. 66, nr 212

Art. no. 177638

Wood plastic composites are among the most popular engineering materials, used as deck materials as well as in construction. To improve the properties of wood plastic composites, they are reinforced with various materials. This study investigates the synergic effect of glass fiber and carbon fiber reinforcement on wood plastic composites regarding their physical, mechanical, and fire resistance performance. The reinforcement materials significantly limited the water absorption due to their hydrophobic nature. The reinforcement fibers acted as a barrier against water and limited the uptake although the water absorption and thickness swelling values increased with exposure time. Moreover, the high strength of the reinforcement fibers improved the modulus of elasticity up to 122% and 41% for the flexural strength. Additionally, the long glass fibers significantly contributed to improving the tensile strength, which indicates that fiber length is essential. The scanning electron microscope micrographs revealed that the carbon fibers had a rougher surface than the glass fibers, proving their higher resistance to stress. The observed gaps were also evidence of poor adhesion between the matrix and the fibers. On the other hand, the carbon fibers and long glass fibers positively affected the load transfer in the matrix. Unfortunately, the fiber reinforcement has only a slight effect on the fire resistance performance. Furthermore, the improvement in the limit oxygen index test values was limited. However, the reinforcement fibers exhibit a barrier effect, inhibiting dropping, which is crucial for structural integrity.

Durability in outdoor conditions of coating systems based on waterborne acrylic resin with commercial UV absorber and tree bark extract

Özgenç Özlem, Durmaz Sefa, Kuştaş Süleyman, Bilici Ebru

Drewno : prace naukowe, doniesienia, komunikaty

2021

vol. 64, nr 207

111--124

Environmentally friendly new wood preservative surface materials were developed to protect the wood surface against outdoor conditions. The durability performance of different types of waterborne acrylic resin with bark extract used as coatings on a wood surface exposed to outdoor conditions was investigated. Scots pine and Oriental beech surfaces were coated with three different waterborne acrylic resin coatings. Bark extracts from two different trees (fir and black pine) and a commercial UV absorber were used in the acrylic resin coating formulations. The durability of the coatings containing these bark extracts were compared with that of the coating with a commercial UV absorber. The wood samples coated with the test and control coatings were exposed to the QUV test in laboratory conditions. The surface colour and roughness changes on the wood samples coated with the test coatings and exposed to the accelerated weathering test were compared with the control samples. Microscopic images were taken, and the coating thicknesses of the control and test samples prepared before the outdoor test were determined. The results showed that the protective effect of the acrylic coating system containing fir bark extracts in QUV test conditions over 2016 h was similar to that of the coating containing commercial UV absorbers. However, while the fir bark extract’s antioxidant effect positively affected the beech wood to increase durability in outdoor conditions, it had a lower preservative effect on the pine wood.