CHEMICAL MODIFICATION OF PAULOWNIA, POPLAR, AND EUCALYPTUS WOOD BY ε-CAPROLACTONE GRAFTING INSIDE CELL WALLS TO IMPROVE WOOD PROPERTIES

Abstract

Wood is an excellent engineering material with its light weight and high mechanical properties, and has been used for furniture production from the early ages of humankind. However, its susceptibility to biodegradation due to its hygroscopic nature and chemical composition limits usage of wood as outdoor furniture. For the outdoor utilization, chemical modification methods may provide long service-life to the products. Water repellence and dimensional stability can be both improved up to 70% and 40% respectively by inserting hydrophobic molecules inside spruce wood cell walls. Paulownia, Poplar, and Eucalyptus are fast growing trees and their wood has different properties. In this study, a pretty new modification method was carried out by grafting a hydrophobic polymer poly(ε-caprolactone) (PCL) onto economically valuable Paulownia, Poplar, and Eucalyptus wood cell walls. The water absorption, dimensional stability (ASE), equilibrium moisture content (EMC), and density change of poly(ε-caprolactone) grafted wood were characterized and found that dimensional stability and water repellence has significantly better compared to references for poplar wood but not for the paulownia and eucalptus. 

Keywords

• poli(ε-caprolacton)
• wood
• chemical modification
• dimensional stability

PAVLONYA, KAVAK VE ÖKALİPTUS AHŞABININ ÖZELLİKLERİNİN İYİLEŞTİRİLMESİ İÇİN ԐKAPROLAKTON İLE KİMYASAL MODİFİKASYONU

Öz

Ahşap düşük özgül ağırlığına karşın yüksek direnç özelliklerine sahip olması nedeniyle mükemmel bir mühendislik malzemesidir ve insanlığın erken çağlarından bu yana mobilya üretiminde kullanılmaktadır. Bununla birlikte, biyolojik bozunmaya duyarlılığı, higroskopik yapısı ve kimyasal bileşiminden dolayı dış ortam mobilyalarında kullanımı kısıtlıdır. Dış mekanda kullanım için kimyasal modifikasyon metotları ürünlere uzun servis ömrü sağlayabilir. Ladin odun hücre duvarlarına hidrofobik moleküller yerleştirerek su iticiliği ve boyutsal kararlılığı sırasıyla %70 ve %40 oranında arttırılabilir. Pavlonya, Kavak ve Ökaliptus hızlı büyüyen ağaçlardır ve ahşapları farklı özelliklere sahiptir. Bu çalışmada ekonomik olarak değeri olan Pavlonya, Kavak ve Ökaliptus ahşap hücre çeperlerine hidrofobik bir polimer olan poli(ε-kaprolakton) (PCL) aşılanmasıyla çok yeni bir modifikasyon yöntemi uygulanmıştır Poli (ε-kaprolakton) aşılanmış farklı ahşap türlerinin su emme, boyutsal kararlılığı (ASE), denge rutubet miktarı (DRM) ve yoğunluk değişimi karakterize edildi. Kavak ahşabının özelliklerinin yüksek oranda iyileşmiş ancak pavlonya ve okaliptüste iyileşme görülmemiştir.

 

Anahtar Kelimeler

• poli(ε-kaprolakton)
• ahşap
• kimyasal modifikasyon
• boyutsal stabilite

References

1. [1]. Fengel D. and Wegener, G., (1984). Wood: Chemistry, Ultrastructure, Reactions, W. de Gruyter, Berlin/New York. [2]. Rowell R.M., (2005). Handbook of Wood Chemistry and Wood Composites, CRC Press, Boca Raton, Florida, USA. [3]. Hill, C.A.S., (2006). Wood Modification: Chemical, Thermal and Other Processes, John Wiley & Sons, Chichester, England; Hoboken, NJ. [4]. Gibson, L.J., (2012). The hierarchical structure and mechanics of plant materials, Journal of Royal Society Interface, 9(76), 2749-2766. [5]. Hill, C.A.S., Hale, M.D., Ormondroyd, G.A., Kwon, J.H., Forster, S.C., (2006). Decay resistance of anhydride-modified Corsican pine sapwood exposed to the brown rot fungus Coniophora puteana, Holzforschung, 60, 625–629. [6]. Furuno, T., Imamura, Y., and Kajita, H., (2004). The modification of wood by treatment with low molecular weight phenol-formaldehyde resin: a properties enhancement with neutralized phenolic-resin and resin penetration into wood cell walls, Wood Science and Technology, 37, 349-361. [7]. Donath, S., Militz, H., and Mai, C., (2004). Wood modification with alkoxysilanes, Wood Science and Technology, 38, 555-566. [8]. Rowell, R.M., (1984): Penetration and reactivity of cell wall components. Chapter 4, p. 175–210. In: Rowell, R. M., ed. Chemistry of Solid Wood. Adv. Chem. Ser. 207. American Chemical Society, Washington, DC. [9]. Nordstierna, L., Lande, S., Westin, M., Karlsson, O., Furo´, I., (2008). Towards novel wood-based materials: chemical bonds between lignin-like model molecules and poly(furfuryl alcohol) studied by NMR, Holzforschung, 62, 709–713. [10]. Cabane, E., Keplinger, T., Merk, V., Hass, P. and Burgert, I., (2014). Renewable and functional wood materials by grafting polymerization within cell walls, ChemSusChem, 7(4), 1020–1025. [11]. Ermeydan, M.A., Cabane, E., Gierlinger, N., Koetz, J. and Burgert, I., (2014). Improvement of wood material properties via in situ polymerization of styrene into tosylated cell walls, RSC Advances, 4, 12981-12988. [12]. Ermeydan, M.A., Cabane, E., Hass, P., Koetz, J., and Burgert, I. (2014). Fully biodegradable modification of wood for improvement of dimensional stability and water absorption properties by poly(ε-caprolactone) grafting into the cell walls, Green Chemistry, 16, 3313-3321. [13]. Keplinger, T., Cabane, E., Chanana, M., Hass, P., Merk, V., Gierlinger, N., Burgert, I., (2015). A versatile strategy for grafting polymers to wood cell walls, Acta Biomaterialia, 11, 256-263. [14]. Keplinger, T., Cabane, E., Berg, J.K., Segmehl, J.S., Bock, P., and Burgert, I. (2016). Smart Hierarchical Bio-Based Materials by Formation of Stimuli-Responsive Hydrogels inside the Microporous Structure of Wood, Advance Materials Interfaces, 3, 1600233. [15]. Ermeydan, M.A., Tomak E. D., (2016). The Combined Effects of Boron and Polymer Modification on Decay Resistance and Properties of Wood, 16th International Materials Symposium, Denizli, 1574-1581. [16]. Ermeydan, M.A., (2016). Chemical Modification of Spruce Wood with Combination of Mesyl Chloride and Poly(ε-caprolactone) for Improvement of Dimensional Stability and Water Absorption Properties, Kastamonu University Journal of Forestry Faculty, 16(2), 541-552. [17]. Tokiwa, Y., Calabia, B. P., Ugwu, C. U., & Aiba, S., (2009). Biodegradability of Plastics. International Journal of Molecular Sciences, 10(9), 3722–3742. [18]. Rowell, R.M., and Ellis, W.D., (1978). Determination of dimensional stability of wood using the water-soaking method. Wood and Fiber, 10(2), 104-111. [19]. Storey, R.F., and Sherman, J.W., (2002). Kinetics and mechanism of the stannous octoate-catalyzed bulk polymerization of ε-caprolactone, Macromolecules, 35, 1504-1512. [20]. Wiltshire, J.T., and Qiao, G.G., (2006). Degradable core cross-linked star polymers via ring-opening polymerization, Macromolecules, 39, 4282-4285. [21]. Labet, M., and Thielemans, W., (2009). Synthesis of polycaprolactone: a review, Chemical Society Reviews, 38, 3484-3504. [22]. Makiguchi, K., Satoh, T., and Kakuchi, T., (2011). Diphenyl Phosphate as an Efficient Cationic Organocatalyst for Controlled/Living Ring-Opening Polymerization of δ-Valerolactone and ε-Caprolactone, Macromolecules, 44, 1999-2005. [23]. Kusumi, R., Teramoto, Y., and Nishio, Y., (2011). Structural characterization of poly(ε-caprolactone)-grafted cellulose acetate and butyrate by solid-state 13C NMR, dynamic mechanical, and dielectric relaxation analyses, Polymer, 52, 5912-5921. [24]. Lönnberg, H., Zhou, Q., Brumer, H., Teeri, T.T., Malmstrom E., and Hult, A., (2006). Grafting of cellulose fibers with poly(epsilon-caprolactone) and poly(L-lactic acid) via ring-opening polymerization, Biomacromolecules, 7, 2178-2185. [25]. Labet , M., Thielemans, W., (2011). Improving the reproducibility of chemical reactions on the surface of cellulose nanocrystals: ROP of ε-caprolactone as a case study. Cellulose, 18 (3), 607-617 [26]. Carlmark, A., Larsson, E., Malmström, E., (2012), Grafting of cellulose by ring-opening polymerisation −A review, European Polymer Journal, 48 (10), 1646-1659. [27]. Morais, M. C., Pereira, H., (2012). Variation of extractives content in heartwood and sapwood of Eucalyptus globulus trees, Wood Science and Technology, 46(4), 709–719.