The effects of Spartium junceum (SJ) flour content, treatment time, and temperature on the mechanical and rheological properties of low density polyethylene/Spartium junceum flour (LDPE/SJ) composites were studied. SJ flour was treated with NaOH (5% wt) for 24, 48, and 72？h at 25°C and 40°C. FTIR results showed that there is a partial removal of lignin and hemicelluloses after treatment which improved the interfacial adhesion matrix/SJ flour. Also, the alkaline treatment improved notably the tensile strength and Young's modulus and increased slightly the elongation at break of LDPE/SJ composites compared to those with untreated flour. 1. Introduction Natural organic fibers from renewable natural resources offer the potential to act as biodegradable reinforcing materials as an alternative for the use of glass or carbon fiber and inorganic fillers [1, 2]. These fibers offer several advantages including high specific strength and modulus, low cost, low-density, renewable nature, biodegradability, absence of associated health hazards, easy fiber surface modification, and wide availability [3]. But, the main drawbacks of such composites are their water sensitivity, their relatively poor dimensional stability, the changing of fiber characteristics with origin, poor adhesion to basically all matrix polymers, and poor processability at high fiber contents. Much work has been done on virgin thermoplastic and natural fiber composites, which have successfully proven their applicability to various fields of technical applications, especially for load-bearing application. Indeed, thermoplastics, such as polyethylene (PE) [4, 5], polypropylene (PP) [6–9], polyvinyl chloride (PVC) [10], and polystyrene (PS) [11], have been compounded with natural fibers (such as wood, kenaf, flax, hemp, cotton, sisal, jute, abaca, etc.) to prepare composites. Nekkaa et al. [12] reported that the use of silane Z-6020 for SJ fibers modification improves the dynamic mechanical properties of PP/SJ fibers composites. Also, the results of water absorption showed that silane treatment reduced the water absorption capacity compared to untreated composites. The absorption of water by PP/SJ fibers composites approaches the kinetics of a Fickian diffusion case I at ambient temperature [13]. The alkaline treatment is also another method to treat vegetable fibers to increase the contact fiber matrix and thus their adhesion to each other. So, the aim of this work is to study the effects of untreated and treated Spartium junceum flour content as well as the time and the temperature of flour surface
References
[1]
Y. Lei, Q. Wu, and F. Yao et Y. Xu, “Préparation et propriétés de PEHD recyclé/Composites fibres naturelles,” Composites Part A, vol. 38, no. 7, pp. 1664–1674, 2007.
[2]
A. K. Bledzki and J. Gassan, “Composites reinforced with cellulose based fibres,” Progress in Polymer Science, vol. 24, no. 2, pp. 221–274, 1999.
[3]
A. C. Milanese, M. O. H. Cioffi, and H. J. C. Voorwald, “Mechanical behavior of natural fiber composites,” Procedia Engineering, vol. 10, pp. 2022–2027, 2011.
[4]
D. Pasquini, E. D. M. Teixeira, A. A. D. S. Curvelo, M. N. Belgacem, and A. Dufresne, “Surface esterification of cellulose fibres: processing and characterisation of low-density polyethylene/cellulose fibres composites,” Composites Science and Technology, vol. 68, no. 1, pp. 193–201, 2008.
[5]
F. G. Torres and M. L. Cubillas, “Study of the interfacial properties of natural fibre reinforced polyethylene,” Polymer Testing, vol. 24, no. 6, pp. 694–698, 2005.
[6]
M. Zampaloni, F. Pourboghrat, S. A. Yankovich et al., “Kenaf natural fiber reinforced polypropylene composites: adiscussion on manufacturing problems and solutions,” Composites Part A, vol. 38, no. 6, pp. 1569–1580, 2007.
[7]
Z. Dominkovics, L. Dányádi, and B. Pukánszky, “Surface modification of wood flour and its effect on the properties of PP/wood composites,” Composites Part A, vol. 38, no. 8, pp. 1893–1901, 2007.
[8]
M. Bengtsson, M. L. Baillif, and K. Oksman, “Extrusion and mechanical properties of highly filled cellulose fibre-polypropylene composites,” Composites Part A, vol. 38, no. 8, pp. 1922–1931, 2007.
[9]
G. Gong, B. H. Xie, M. B. Yang, W. Yang, W. Q. Zhang, and M. Zhao, “Mechanical properties and fracture behavior of injection and compression molded polypropylene/coal gangue powder composites with and without a polymeric coupling agent,” Composites Part A, vol. 38, no. 7, pp. 1683–1693, 2007.
[10]
V. O. Guffey and A. B. Sabbagh, “PVC/wood-flour composites compatibilized with chlorinated polyethylene,” Journal of Vinyl and Additive Technology, vol. 8, no. 4, pp. 259–263, 2002.
[11]
S. Mishra and J. B. Naik, “Effect of treatment of maleic anhydride on mechanical properties of natural fiber: polystyrene composites,” Polymer. Plastics Technology and Engineering, vol. 44, no. 4, pp. 663–675, 2005.
[12]
S. Nekkaa, N. Haddaoui, A. C. Grillet, and G. Merle, “Thermal, thermomechanical, and morphological properties of spartium junceum fiber reinforced polypropylene composites,” International Journal of Polymeric Materials, vol. 55, no. 11, pp. 837–853, 2006.
[13]
S. Nekkaa, M. Guessoum, and N. Haddaoui, “Water absorption behavior and impact properties of spartium junceum fiber composites,” International Journal of Polymeric Materials, vol. 58, no. 9, pp. 468–481, 2009.
[14]
K. Sirisinha and D. Meksawat, “Comparison in processability and mechanical and thermal properties of ethylene-octene copolymer crosslinked by different techniques,” Journal of Applied Polymer Science, vol. 93, no. 3, pp. 1179–1185, 2004.
[15]
A. C. H. Barreto, D. S. Rosa, P. B. A. Fechine, and S. E. Mazzetto, “Properties of sisal fibers treated by alkali solution and their application into cardanol-based biocomposites,” Composites Part A, vol. 42, no. 5, pp. 492–500, 2011.
[16]
S. K. Madhuban, S. K. Bhaduri, S. K. Banerjee, and K. P. Sao, “Acetylation of jute and infrared spectra of acetylated jute,” Indian Journal of Textile Research, vol. 10, no. 68, pp. 68–70, 1985.
[17]
F. Corrales, F. Vilaseca, M. Llop, J. Gironès, J. A. Méndez, and P. Mutjè, “Chemical modification of jute fibers for the production of green-composites,” Journal of Hazardous Materials, vol. 144, no. 3, pp. 730–735, 2007.
[18]
X. Colom, F. Carrasco, P. Pagès, and J. Canavate, “Effects of different treatments on the interface of HDPE/lignocellulosic fiber composites,” Composites Science and Technology, vol. 63, no. 2, pp. 161–169, 2003.
[19]
P. W. Balasuriya, L. Ye, and Y. W. Mai, “Mechanical properties of wood flake-polyethylene composites. Part I: Effects of processing methods and matrix melt flow behaviour,” Composites Part A, vol. 32, no. 5, pp. 619–629, 2001.
[20]
K. Oksman and C. Clemons, “Mechanical properties and morphology of impact modified polypropylene-wood flour composites,” Journal of Applied Polymer Science, vol. 67, no. 9, pp. 1503–1513, 1998.
[21]
E. T. N. Bisanda and M. P. Ansell, “The effect of silane treatment on the mechanical and physical properties of sisal-epoxy composites,” Composites Science and Technology, vol. 41, no. 2, pp. 165–178, 1991.
[22]
Y. Habibi, W. K. El-Zawawy, M. M. Ibrahim, and A. Dufresne, “Processing and characterization of reinforced polyethylene composites made with lignocellulosic fibers from Egyptian agro-industrial residues,” Composites Science and Technology, vol. 68, no. 7-8, pp. 1877–1885, 2008.
[23]
A. K. Mohanty, M. A. Khan, and G. Hinrichsen, “Surface modification of jute and its influence on performance of biodegradable jute-fabric/Biopol composites,” Composites Science and Technology, vol. 60, no. 7, pp. 1115–1124, 2000.
[24]
S. M. B. Nachtigall, G. S. Cerveira, and S. M. L. Rosa, “New polymeric-coupling agent for polypropylene/wood-flour composites,” Polymer Testing, vol. 26, no. 5, pp. 619–628, 2007.
[25]
L. Dányádi, T. Janecska, Z. Szabó, G. Nagy, J. Móczó, and B. Pukánszky, “Wood flour filled PP composites: compatibilization and adhesion,” Composites Science and Technology, vol. 67, no. 13, pp. 2838–2846, 2007.
[26]
A. Bendahou, Y. Habibi, H. Kaddami, and A. Dufresne, “Composite materials based on ligno-cellulosic fibres and thermoplastic matrices (IPP and LDPE),” Revue Roumaine de Chimie, vol. 54, no. 7, pp. 557–563, 2009.
[27]
L. Avérous, C. Fringant, and L. Moro, “Plasticized starch-cellulose interactions in polysaccharide composites,” Polymer, vol. 42, no. 15, pp. 6565–6572, 2001.
[28]
F. Le Digabel, N. Boquillon, P. Dole, B. Monties, and L. Averous, “Properties of thermoplastic composites based on wheat-straw lignocellulosic fillers,” Journal of Applied Polymer Science, vol. 93, no. 1, pp. 428–436, 2004.
[29]
P. V. Joseph, K. Joseph, S. Thomas et al., “The thermal and crystallisation studies of short sisal fibre reinforced polypropylene composites,” Composites Part A, vol. 34, no. 3, pp. 253–266, 2003.
[30]
S. Nekkaa, M. Guessoum, F. Chebira, and N. Haddaoui, “Effect of fiber content and chemical treatment on the thermal properties of spartium junceum fiber-reinforced polypropylene composites,” International Journal of Polymeric Materials, vol. 57, no. 8, pp. 771–784, 2008.
