Advancements in Materials, Vol. 4, Issue 1, Jun  2020, Pages 1-15; DOI:

Effects of Coupling Agent on Flexural Properties of Coir-Plantain Hybrid Fiber Reinforced Polyester (CPFRP) Composites

, Vol. 4, Issue 1, Jun  2020, Pages 1-15.


Chukwunyelu Christian Ebele 1* , Enibe Samuel Ogbonna 2 , Nwosu Arinze Walter 1

1 National Engineering Design Development Institute, Nnewi, Nigeria

2 Mechanical Engineering Department, University of Nigeria, Nsukka, Nigeria

Received: 28 December 2019; Accepted: 3 April 2020; Published: 7 July 2020

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This paper investigates the effects of coupling agent and volume fraction on the flexural properties of coir-plantain hybrid fibers reinforced polyester resin composite materials. The retting process required to mechanically extract the coir and plantain fibers from the foliage of locally available coconut husks, plantain empty fruit bunch and plantain pseudo stem fruit was carried out. The problem of poor adhesion between fiber and matrix associated with natural-fiber reinforced composites is being worked. Hence, in this study, specific percentage (5%) of aqueous solution of sodium hydroxide and different percentages (0.1, 0.25, and 0.5 % w/v) of coupling agent were administered for surface modification of the fibers. Coir/plantain empty fruit bunch (CEFB) hybrid fibers and coir/plantain pseudo stem (CPS) hybrid fibers were separately used as reinforcement for coir/plantain hybrid fibers reinforced polyester resin composites. The level of compactibility between hybrid fiber and matrix were determined using scanning electron microscopy (SEM); hence the flexural properties of coir/plantain hybrid fibers reinforced polyester composite materials at three different control factors of the hybrid fibers were investigated. Applying Taguchi robust design technique for the greater-the-better, the highest signal-to-noise ratio (S/N ratio) for the quality characteristics being investigated was obtained employing Minitab 17. At the optimum setting of control factors, the flexural strength of CEFB hybrid fiber reinforced polyester composite is 97,16 N/mm2 while that of CPS hybrid fiber reinforced polyester composite is 71.78 N/mm2.


Flexural Property, Coupling Agent, Coir-Plantain Hybrid Fibers, Scanning Electron Microscopy, Taguchi


© 2017 by the authors. Licensee International Technology and Science Press Limited. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


[1]  Chand, N.Rohatgi, P.K. Natural Fibers and Their Composites. Periodical Experts Book Agency, New Delhi1994.

[2] FrancoP.J.H.Gonzalez A.V. A study of the mechanical properties of short natural-fiber reinforced composites. Compos. Pt. B: Eng., 200536(8), 597-608.

[3] BledzkiA.K.; SperberV.E.; FarukO. Natural and wood fiber reinforcement in polymers. Rapra Review Reports, 200213(8), Report 152.

[4] MishraS.; MohantyA.K.; DrzalL.T.; MisraM.Hinrichsen, G. A review on pineapple leaf fibers, sisal fibers and their biocomposites. Macromol Mater Eng., 2004289955-74.

[5] MaldasD.KoktaB.V. Role of coupling agents on the performance of wood polypropylene composites. Int J. Polym Mater, 199427(1-2), 77-88.

[6] John, M.Anandjiwala, R. Recent developments in chemical modification and characterization of natural fiber reinforced composites. Polymer composites, 200829, 187-207.

[7] ChukwunyeluC.E.OkonkwoU.C.OweziemU.B.Metu C. Effects of Chemical Treatment on Impact Property of Coir Fibre Reinforced Polyester (CFRP) Composites. American Journal of Engineering, Technology and Society, 20152(5), 125-130.

[8] KeenerT.J.StuartR.K.BrownT.K. Maleated coupling agents for natural fiber composites. Composites: Part A, 200435357-362.

[9] Joseph, K.Thomas, S.Pavithran, C. Effect of chemical treatment on the tensile properties of short sisal fiber-reinforced polyethylene composites. Polymer, 2003, 37, 5139-5149.

[10] Pritchard, G. Quick reference guide. Page 12 in Plastics additives: An A-Z reference. G. Pritchard, ed. Chapman and Hall, New York, NY1998.

[11] Krishnan M.Narayan R. Materials Interactions Relevant to recycling of Wood-Based Materials. Mater. Res. Soc. Symp. Proc., 1992, 266, 93.

[12] Štepek J.DaoustH. Additives for Plastics. Polymer/Properties and Applications 5. Springer-Verlag, New York. 1983; pp. 84. .

[13] Clint, J.H. Surfactants: applications in plastics. Pages 604-612 in G. Pritchard, ed. Plastics Additives: An A-Z Reference. Chapman and Hall, New York, NY. 1998.

[14] Raj, R.G.Kokta, B.V.Maldas, D.Daneault, C. Use of wood fibers in thermoplastic composites: VI. Isocyanate as a bonding agent for polyethylene-wood fiber composites. Polym. Comp., 1988, 9(6)404-411.

[15] Maldas, D.Kokta, B.V. and Daneault, C. Influence of coupling agents and treatments on the mechanical properties of cellulose fiber-polystyrene composites. J. Appl. Polym. Sci., 1989a, 37751-775.

[16] Oksman, K.Lindberg, H.Holmgren, A. The nature and location of SEBS-MA compatibilizer in polyethylene-wood flour composites. J. Appl. Polym. Sci., 1998, 69: 201-209.

[17] Oksman, K.Lindberg, H. Influence of thermoplastics elastomers on adhesion in polyethylene-wood flour composites. J. Appl. Polym. Sci., 1998, 68: 1845-1855.

[18] John, W. E. Isocyanate as wood binders: A review. J. Adhesion, 1982, 1559-67.

[19] Beshay, A.D.Kokta, B.V.Daneault, C. Use of wood fibers in thermoplastic composites II: Polyethylene. Polym. Comp., 1985, 6(4)261-271.

[20] Maldas, D.Kokta, B.V. Influence of polar monomers on the performance of wood fiber reinforced polystyrene composites. I. Evaluation of critical conditions. Int. J. Polym. Mater. 1990d, 14(3-4)165-189.

[21] Maldas, D.Kokta, B.V. Surface modification of wood fibers using maleic anhydride and isocyanate as coating components and their performance in polystyrene composites. J. Adhesion Sci. Technol., 1991a, 5(9)727-740.

[22] Maldas, D.Kokta, B.V. Influence of maleic anhydride as a coupling agent on the performance of wood fiber-polystyrene composites. Polym. Eng. Sci., 1991b, 31(18): 1351-1357.

[23] Gassan, J.Bledzki, A. K. Possibilities for improving the mechanical properties of jute/epoxy composites by alkali treatment of fibers. Composites Science and Technology, 1999, 59, 1303-1309.

[24] Joseph, K.Thomas, S.Pavithran, C. Effect of chemical treatment on the tensile properties of short sisal fiber-reinforced polyethylene composites. Polymer, 2003, 37, 5139-5149.

[25] Bledzki A. K.Mamun A.A.Lucka-GaborM.GutowskiV.S. The effects of acetylation on properties of flax fiber and its polypropylene composites. eXPRESS Polymer Letters, 2008, 2(6), 413-422.

[26] Kalia, S.Kaith, B.S.Kaur, I. Pretreatments of natural fibers and their application as reinforcing material in polymer composites—a review, Polym. Eng. Sci., 2009, 49(7), 1253-1272.

[27] Kalia, S.Kaith, B.S.Sharma, S.Bhardwaj, B. Mechanical properties of flax-g-poly (methyl acrylate) reinforced phenolic composites. Fibers and Polymers, 2008, 9(4), 416-422.

[28] JMP 6.0.3. Design of Experiments, Release 6, SAS Institute Inc., Cary, NC, USA. 2005.

[29] OkonkwoU.C.ChukwunyeluC.E.OweziemB.C.EkuaseA. Evaluation and Optimization of Tensile Strength Responses of Coir Fibers Reinforced Polyester Matrix Composites (CFRP) Using Taguchi Robust Design. Journal of Minerals and Materials Characterization and Engineering (JCMME), 2015, 3(4), 225-236.

[30] Geethamma, V.G.Kalaprasad, G.Groeninckx, G.Thomas, S. Dynamic mechanical behaviour of short coir fiber reinforced natural rubber composites. Composites: Part A, 2005, 36, 1499-1506.

[31] TamaraRadetiÉ. Fundamentals of Scanning Electron Microscopy and Energy Dispersive X-ray Analysis in SEM and TEM. NFMC Spring School on Electron Microscopy. 2011.

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