Effect of Alkali and Silane Treatment on the Thermal Stability of Hemp Fibers as Reinforcement in Composite Structures

Abstract:

Natural fiber reinforced composites are being used as reinforcement material in composite system due to their positive environmental benefits. Added to that, natural fibers offer advantages such as low density, low cost, good toughness, high specific strength, relatively non-abrasive and wide availability. However, the low thermal stability of natural fibers is one of the major challenges to increase their use as reinforcing component. In this study, a thorough investigation has been done to compare the effect of two chemical treatment methods on the thermal stability of hemp fibers. 5wt% sodium hydroxide and 5wt% triethoxyvinylsilane was used for the treatment of hemp fibers. Fourier transform infrared spectroscopy, scanning electron microscopy and thermo gravimetric analysis were used for characterization of untreated and treated fiber. The results indicated that 24 hours alkali treatment and 3 hours silane treatment time enhanced the thermal stability of the hemp fiber. However, alkali treatment shows better improvement compared to silane treatment.

References

[1] Wambua, P., J. Ivens, and I. Verpoest, Natural fibres: can they replace glass in fibre reinforced plastics? Composites Science and Technology, 2003. 63(9): pp.1259-1264.

DOI: 10.1016/s0266-3538(03)00096-4

[2] Summerscales, J., et al., A review of bast fibres and their composites. Part 1 - Fibres as reinforcements. Composites Part A: Applied Science and Manufacturing, 2010. 41(10): pp.1329-1335.

DOI: 10.1016/j.compositesa.2010.06.001

[3] Mohanty, A.K., M. Misra, and L.T. Drzal, Surface modifications of natural fibers and performance of the resulting biocomposites: An overview. Composite Interfaces, 2001. 8(5): pp.313-343.

DOI: 10.1163/156855401753255422

[4] Seber, E.H.L.a.D. Bast fiber application for composites. Available from: http://www.fibrealternatives.com/bast.fiber.applacationforcomposite.htm.

[5] Mwaikambo, L.Y. and M.P. Ansell, The effect of chemical treatment on the properties of hemp, sisal, jute and kapok for composite reinforcement. Angewandte Makromolekulare Chemie, 1999. 272: pp.108-116.

DOI: 10.1002/(sici)1522-9505(19991201)272:1<108::aid-apmc108>3.0.co;2-9

[6] Li, X., L.G. Tabil, and S. Panigrahi, Chemical treatments of natural fiber for use in natural fiber-reinforced composites: A review. Journal of Polymers and the Environment, 2007. 15(1): pp.25-33.

DOI: 10.1007/s10924-006-0042-3

[7] Mukhopadhyay, S. and R. Fangueiro, Physical Modification of Natural Fibers and Thermoplastic Films for Composites - A Review. Journal of Thermoplastic Composite Materials, 2009. 22(2): pp.135-162.

DOI: 10.1177/0892705708091860

[8] Xie, Y.J., et al., Silane coupling agents used for natural fiber/polymer composites: A review. Composites Part a-Applied Science and Manufacturing, 2010. 41(7): pp.806-819.

DOI: 10.1016/j.compositesa.2010.03.005

[9] Mwaikambo, L.Y. and M.P. Ansell, Chemical modification of hemp, sisal, jute, and kapok fibers by alkalization. Journal of Applied Polymer Science, 2002. 84(12): pp.2222-2234.

DOI: 10.1002/app.10460

[10] Sgriccia, N., M.C. Hawley, and M. Misra, Characterization of natural fiber surfaces and natural fiber composites. Composites Part A: Applied Science and Manufacturing, 2008. 39(10): pp.1632-1637.

DOI: 10.1016/j.compositesa.2008.07.007

[11] Kim, H.S., et al., Thermogravimetric analysis of rice husk flour filled thermoplastic polymer composites. Journal of Thermal Analysis and Calorimetry, 2004. 76(2): pp.395-404.

DOI: 10.1023/b:jtan.0000028020.02657.9b