MSA  Vol.7 No.11 , November 2016
Effect of Environmental Conditions on Flexural Strength and Fracture Toughness of Particulate Filled Glass-Epoxy Hybrid Composites
Abstract: Multifunctional hybrid polymer composites were projected as novel solutions to meet the demands in various industrial applications ranging from automotive to aerospace. This investigation focuses on processing, flexural strength and fracture toughness characterization of the glass fabric reinforced epoxy (G-E) composites and graphite/fly ash cenosphere (FAC) modified interface between the epoxy matrix and glass fabric. Hand lay-up followed by compression moulding method was used to fabricate the laminates. Flexural and fracture toughness tests at room temperature, elevated temperature and cryogenic temperature were conducted to assess the flexural strength (FS) and mode-I plane-strain fracture toughness (KIC). The experimental and characterization efforts suggest that both graphite and FAC fillers improve bonding at the interface. The study showed that the graphite is more favorable for enhancing FS and KIC of G-E composites. Graphite filled G-E hybrid composites with significant FS and KIC to that of unfilled and FA filled G-E were successfully achieved by incorporating 10 wt% graphite. The incorporation of fillers resulted in improvement of FS, which increased by 43% and 37.7% for 10Gr+G-E and 10FAC+G-E hybrid composites respectively. All composites show a 26% improvement in KIC at cryogenic temperature and a decrease of 12.5% at elevated temperature. According to the SEM observations, fiber debonding from the matrix is suppressed due to the presence and uniform distribution of graphite. In addition, micro-pores, matrix shearing, active toughening mechanisms induced by graphite, such as crack deflection, layer breakage and delamination of graphite layers contributed to the enhanced KIC of hybrid G-E composites.
Cite this paper: Hulugappa, B. , Achutha, M. and Suresha, B. (2016) Effect of Environmental Conditions on Flexural Strength and Fracture Toughness of Particulate Filled Glass-Epoxy Hybrid Composites. Materials Sciences and Applications, 7, 710-729. doi: 10.4236/msa.2016.711057.

[1]   Masud, A.K., Zaman, A.K. and Abdallah, K. (2007) Effect of Environment on Fracture Toughness of Glass Fiber/Polymer Composites. Journal of Mechanical Engineering, 38, 38-44.

[2]   Lubin, G. (1992) Hand Book of Composites. Van Nostrand Reinhold, New York.

[3]   Young, R.J. and Beaumount, P.W.R. (1997) Failure of Brittle Polymers by Slow Crack Growth: Part 3 Effect of Composition upon Fracture of Silica Particle-Filled Epoxy Resin Composites. Journal of Material Science, 12, 684-692.

[4]   Moloney, A.C. and Kausch, H.H. (1983) The Fracture of Particulate-Filled Epoxide Resins: Part 1. Journal of Material Science, 18, 208-216.

[5]   Amar, G.C. (1986) Intralaminar Fracture in Graphite/Epoxy Laminates. Engineering Fracture Mechanics, 23, 719-733.

[6]   Makato, I. and Yashihiro, T. (2001) Fracture Toughness of Spherical Silica-Filled Epoxy Adhe Sives. International Journal of Adhesion and Adhesive, 21, 389-396.

[7]   Wong, K.J., Yousif, B.F. and Low, K.O. (2010) Effects of Fillers on the Fracture Behavior of Par Ticulatepolyester Composites. Journal of Strain Analysis for Engineering Design, 45, 67-78.

[8]   Srivastava, V.K., Shembekar, P.S. and Prakash, R. (1998) Fracture Behavior of Fly-Ash Filled FRP Composites. Composite Structure, 10, 271-279.

[9]   Shao, Y., Patrick, R., Frank, H. and Klaus, F. (2006) Epoxy Nano Composites—Fracture and Toughening Mechanisms. Engineering Fracture Mechanics, 73, 2375–2398.

[10]   Liu, Q. and Hughes, M. (2008) The Fracture Behaviour and Toughness of Woven Flax Fiber Reinforced Epoxy Composites. Composites Part A, 39, 1644-1652.

[11]   Leonard, W.H., Low, K.O. and Yousif, K.F. (2009).Fracture Behaviour of Glass Fber-Reinforced Polyester Composite. Journal of Material Science, 83, 223-228.

[12]   Pinho, S.T., Robinson, P. and Lannucci, L. (2006) Fracture Toughness of the Tensile and Compressive Fiber Failure Modes in Laminated Composites. Composite Science Technology, 66, 2069-2079.

[13]   Jang, J. and Yang, H. (2000) Toughness Improvement of Carbon Fiber/Polybenzoxazine Composites by Rubber Modification. Composites Science and Technology, 60, 457-463.

[14]   Mostovoy, S. and Riling, E.J. (1966) Fracture Toughness of an Epoxy System. Journal of Applied Polyme Science, 10, 1351-1371.

[15]   Rys, T.P., Chen, L. and Sanker, B.V. (2004) Mixed Mode Fracture Toughness of Laminated Sitched Composites.

[16]   Nishijima, S., Honda, Y. and Okada, Y.T. (1995) Application of the Positron Annihilation Method for Evaluation of Organic Materials for Cryogenic Use. Cryogenics, 35, 779-781.

[17]   Sung, W.K., Jang, K.M. and Yiu, W.M. (1993) Fracture Toughness and Failure Mechanisms in Silica-Filled Epoxy Resin Composites: Effects of Temperature and Loading Rate. Journal of Polymer, 34, 3446-3455.

[18]   Yang, Z. and Zhen, K. (2013) Simultaneous Enhanced Cryogenic Tensile Strength and Fracture Toughness of Epoxyresin by Carboxylic Nitrile-Butadiene Nano-Rubber. Compos: Part A, 55, 178-187.

[19]   Masaya, M., Yasuhide, S., Tomo, T. and Fumio, N. (2012) Interlaminar Fracture Characterization of Wove Glass/Epoxy Composites under Mixed Mode II/III Loading Condition Cryogenic Temperature. Engineering Fracture Mechanics, 96, 615-625.

[20]   Chang, S.B., Jin, G.K. and Dai, G.L. (2013) Performance Improvement by Glass Fiber of Adhesively Bonded Metal Joints at the Cryogenic Temperature. Composite Structure, 96, 321-331.

[21]   Soon, C.K., Tadaharu, A. and Wakako, A. (2008) Temperature Dependence of Fracture Toughness of Silica/Epoxy Composites. Composites Part B: Engineering, 39, 773-781.

[22]   Magid, B., SaeedZiaee, K.G. and Marcus, S. (2005) The Combined Effects of Load, Moisture and Temperature on the Properties of E-Glass/Epoxy Composites. Composite Structure, 71, 320-326.

[23]   Yong, R.J. and Spanoudakis, J. (1984) Crack Propagation in a Glass Particle Filled Epoxy Resin Effect of Particle Volume Fraction and Size. Journal of Material Science, 19, 473-486.

[24]   Hulugappa, B., Suresha, B. and Achutha, M.V. (2016) Effect of Fillers on Mechanical Properties and Fracture Toughness of Glass Fabric Reinforced Epoxy Composites. Journal of Minerals and Materials Characterization and Engineering, 4, 1-14.

[25]   Joao, M. (2012) Effect of Temperature on the Mechanical Properties of Polymer Mortars. Mate Rails Research, 15, 645-649.

[26]   Gong, M., Wang, X.F. and Zhao, J.H. (2007) Experimental Study on Mechanical Behaviour of Laminates at Low Temperature. Cryogenics, 47, 1-7.

[27]   Kim, M., kang, S. and Kim, C. (2004) Progressive Failure Analysis of Glass /Epoxy Composite at Low Temperature. Composite Science and Technology, 64, 2353-2362.

[28]   Moloney, A.C., Kausch, H. and Kaiser, T. (1987) Review-Parameters Determining the Strengthand Toughness of Particulate Filled Epoxy Resins. Journal of Material Science, 22, 381-393.

[29]   Nakamura, Y., Yamaguchi, Y. and Okubo, M. (1992) Effect of Particle Size on Mechanical and Impact Properties of Epoxy Resin Filled with Spherical Silica. Journal Applied polymer Science, 45, 1281-289.

[30]   Ma, J., Mo, M.S. Du, X.S. and Rosso, P., Friedrich, K. and Kuan, H.C. (2008) Effect of Inorganic Nanoparticles on Mechanical Property, Fracture Toughness and Toughening Mechanism of Two Epoxy Systems. Polymer, 49, 3510-3523.

[31]   Bhandakkar, A., Kumar, N., Prasad, R.C. and Sastry, M.L. (2014) Interlaminar Fracture Toughness of Epoxy Glass Fiber FAC Laminate Composite. Materials Sciences and Applications, 5, 231-244.

[32]   Tripathi, G. and Srivastava, D. (2008) Studies on the Physico-Mechanical and Thermal Characteris Tics of Blends of DGEBA Epoxy, 3,4 Epoxy Cyclohexylmethyl, 3’,4’-Epoxycy-lohexane Carboxyl Ate and Carboxyl Terminated Butadiene Co-Acrylonitrile (CTBN). Materials Science and Engineering: A, 496, 483-493.

[33]   Ashcroft, I.A., Hughes, D.J. and Shaw, S.J. (2001) Mode I Fracture of Epoxy Bonded Composite Joints: 1. Quasi-Static Loading. International Journal of Adhesion and Adhesives, 21, 87-99.

[34]   Kalarikkal, S.G. and Sankar, B.V. (2006) Effect of Cryogenic Temperature on the Fracture Toughness of Graphite Filled Glass Epoxy Composites. Journal Engineering Material and Technology, 128, 151-157.

[35]   Marom, G. (1989) Environmental Effects on Fracture Mechanical Properties of Polymer Composites. In: Friedrich, K., Ed., Application of Fracture Mechanics to Composite Materials, Elsevier, Amsterdam, 397-424.

[36]   Shen, C. and Springer, S.G. (1977) Environmental Effects on the Elastic Moduli of Composite Materials. Journal of Composite Materials, 11, 250-264.

[37]   Shen, C. and Springer, S.G. (1977) Effects of Moisture and Temperature on the Tensile Strength of Composite Materials. Journal of Composite Materials, 11, 2-16.

[38]   Srivastava, V.K. (1998) Moisture Effect on the Toughness, Mode-I and Mode-II of Particles Filled Quasi-Isotropic Glass-Fiber Reinforced Polyester Resin Composites. Journal of Materials Science, 33, 1129-1136.

[39]   Sukjoo, C. and Bhavani, V.S. (2007) Fracture Toughness of Transverse Crack in Graphite/ Epoxy Laminates At Cryogenic Conditions. Composites Part B: Engineering, 38, 193-200.