Effect of bark flour on the mechanical properties of HDPE composites

Abstract

The objective of this study was to evaluate the replacement of wood flour by Turkish pine bark residues for production of wood plastic composites. High density polyethylene was chosen as matrix and seven different compositions were used for production of composites. In order to compare the effect of bark residues flour as a filler, bark residues-HDPE composites were produced with various wt% bark residues loading (10, 20, 30 and 40 wt%). Bark residues filled HDPE pellets were produced by using a twin-screw extruder, then 25 cm (l) x 25 cm (w) and 2 mm (t) composites were produced with compression molding technique according to ASTM D4703-10. For each composition, three composites were produced. Tensile and flexural tests were performed with a Universal Testing machine. Impact strength was measured with a Zwick HIT5.5P Impact Testing machine. Tensile and impact strength of the composites decreased with increasing bark flour loading whereas bending strength and modulus of eleasticity values were improved with addition of the bark flour. All produced bark flour filled composites showed better modulus of elasticity and bending strength properties than ASTM D6662-13 standard requirements for polyolefin-based plastic lumber. Morphological properties of bark residues-HDPE composites were characterized by scanning electron microscopy (SEM) technique.

Keywords

• Wood plastic composites, mechanical properties, high density polyethylene, Turkish pine bark

References

1. Popa VI and Breaban IG. Cellulose as a component of biodegradable composites. Cellulose Chemistry & Technology, 1995; 29(5): 575 – 587.
2. Rials TG, Wolcott MP and Nassar JM. Interfacial lignocellulosic fiber-reinforced polyurethane composites. Journal of Applied Polymer Science, 2001; 80(4): 546 – 5
3. Klyosov AA. Foreword-Overview: Wood-Plastic Composites. Wood-Plastic Composites. 1st edition, New Jersey John Wiley and Sons, 2007:1-49, ISBN 9780-470-14891-4.
4. Bledzki AK, Reihmane S and Gassan J. Thermoplastic reinforced with wood fillers: A literature review. Polymer Plastic Technology and Engineering, 1998; 37: 451 – 468.
5. Özmen N, Çetin NS, Mengeloğlu F, Birinci E and Karakuş K. Effect of acetylation on the properties of wood plastic composites. Bioresources, 2013; 8(1): 753 – 7
6. Sanadi AR, Caulfield DF and Jacobson RE. Agro-Fiber/Thermoplastic Composites. Paper and Composites from Agro-Based Resources, Boca Raton CRC Lewis Publishers, 2007: 377-402, ISBN 1-56670-235-6.
7. Chen XY, Guo QP and Mi XL. Bamboo fiber reinforced polypropylene composites: A study of the mechanical properties. Journal of Applied Polymer Science, 1998; 69: 1891 – 1897.
8. Panthapulakkal S, Zereshkian A and Sain M. Preparation and characterization of wheat straw fibers for reinforcing application in injection molded thermoplastic composites. Bioresource Technology, 2006; 97(2): 265 – 272.

9. Hargitai H, Racz I and Anandjiwala RD. Development of hemp fiber reinforced polypropylene composites. Journal of Thermoplastic Composite Materials, 2008; 21(2): 165 – 174.
10. Karakuş K, Güleç T., Kaymakcı, A., Mengeloğlu, F., 2010, The utilization of cornstalk flour as filler in the manufacture of polymer composites. 3rd National Blacksea Forestry Congress, Artvin, 2013-2019, 2010.
11. Mengeloğlu F and Karakuş K. Mehcanical properties of injection-molded foamed wheat straw filled HDPE biocomposites: The effects of filler loading and coupling agent contents. Bioresources, 2012; 7(3): 3293 – 3305.
12. Sewda K and Maiti SN. Mechanical properties of HDPE/bark flour composites Journal of Applied Polymer Science, 2007; 105: 2598 – 2604.
13. Saini G, Bhardwaj R, Choudhary V and Narula AK. Poly(vinyl chloride)-Acacia bark flour composite: Effect of particle size and filler content on mechanical, thermal, and morphological characteristics. Journal of Applied Polymer Science, 2010; 117: 1309 – 1318.
14. Kord B. Effect of bark flour content on mechanical properties of wood plastic composites. World Applied Sciences Journal, 2011; 14(3): 398 – 401.
15. Safdari V, Khodadadi H, Hosseinihashami SK and Ganjian E. The effects of poplar bark and wood content on the mechanical properties of wood-polypropylene composites. Bioresources, 2011; 6(4): 5180 – 5192. http://web.ogm.gov.tr/Resimler/sanalkutuphane/orman_atlasi.pdf http://web.ogm.gov.tr/birimler/merkez/isletmepazarlama/Dokumanlar/Asli_u runler/2012/2012%20Cins%20ve%20Nevilere%20G%C3%B6re%20%C3%9C retim.pdf
16. ASTM D4703-10, Standard practice for compression molding thermoplastic materials into test specimens, plaques, or sheets, 2010.
17. ASTM D638, Standard test methods for tensile properties of plastics, 2001.
18. ASTM D6109, Standard test methods for flexural properties of unreinforced and reinforced plastic lumber and related products, 2005.
19. ASTM D256, Standard test methods for impact resistance of plastics and electrical insulating materials, 2005.
20. ASTM D 6662, Standard specification for polyolefin-based plastic lumber decking boards, 2013.