Study of the Effect of Hygrothermal Ageing on Glass/Epoxy Micro-Composites by FTIR-Imaging and Alternating DSC Techniques

Abstract

An effort was made to study the effect of hygrothermal ageing at varying intervals of time on the interphase of the fiber-reinforced polymer composites. Silane-coated glass fibers and epoxy as matrix were used to fabricate the micro-composite. Absorbance peaks of OH stretching bands were focused to study the curing mechanism of epoxy matrix and effect of hygrothermal exposure at the interphase of the micro-composite by Fourier transform infrared (FTIR) imaging. The differential scanning calorimeteric (DSC) was carried out to monitor the glass transition temperature of hygrothermally aged samples after each interval. The FTIR results shows existence of gradient in degree of curing from the interphase to the bulk matrix and with the increase in ageing time the water absorption increases at the interphase leading to improvement in the adhesion initially, as it is reflected in the results obtained with DSC analysis, i.e., increases in glass transition temperature with the ageing time was reported. Obtained improved results may be attributed to moisture induced additional ring opening polymerization of epoxide molecule and/or formation of strong hydrogen double bonds with the epoxy matrix by water molecule. Microstructural analysis was done for hygrothermally treated samples by scanning electron microscope (SEM).

Keywords

glass/epoxy micro-composite hygrothermal ageing FTIR imaging epoxy curing glass transition temperature.

Get full access to this article

View all access options for this article.

References

Dao, B. , Hodgkin, J. , Krstina, J. , Mardel, J. and Tian, W. (2006). Accelerated Aging Versus Realistic Aging in Aerospace Composite Materials. II. Chemistry of Thermal Aging in a Structural Composite , Journal of Applied Polymer Science, 102: 3221-3232.

Jedidi, J. , Jacquemin, F. and Vautrin, A. (2005). Design of Accelerated Hygrothermal Cycles on Polymer Matrix Composites in the Case of a Supersonic Aircraft, Journal of Composite Structures, 68: 429-437.

Taher, S.T. , Mahdi, E. , Mokhtar, A.S. , Magid, D.L. , Ahmadun, F.R. and Arora, P.R. (2006). A New Composite Energy Absorbing System for Aircraft and Helicopter, Composite Structures, 75: 14-23.

Eidelman, N. , Raghavan, D. , Forster, A.M. , Amis, E.J. and Karim, A. (2004). Combinatorial Approach to Characterizing Epoxy Curing, Macromolecular Rapid Communication , 25: 259-263.

Zheng, Q. and Morgan, R.J. (1993). Synergistic Thermal-Moisture Damage Mechanisms of Epoxies and Their Carbon Fiber Composites, Journal of Composite Materials, 27(14): 1465-1478.

Lee, S.M. (1993). Handbook of Composite Materials, VCH Publishers, New York.

Ray, B.C. (2006). Temperature Effect During Humid Ageing on Interfaces of Glass and Carbon Fibers Reinforced Epoxy Composites , Journal of Colloid and Interface Science, 298: 111-117.

Kelly, A. and Zweben, C. (2000). Comprehensive Composite Materials, Polymer Matrix Composites, Elsevier Science, Oxford , UK.

Agarwal, B.D. and Broutman, L.J. (1990). Analysis of Performance of Fiber Composites, Wiley-Interscience, Canada.

10.

Kim, J.K. and Mai, Y.W. (1998). Engineered Interphases in Fiber-Reinforced Composites, Elsevier, New York.

11.

Liang, L. , Zhang, S.Y. , Chen, Y.H. , Liu, M.J. , Ding, Y.F. , Luo, X.W. , Pu, Z. , Zhou, W.F. and Li, S. (2005). Water Transportation in Epoxy Resin, Chemical Materials, 17: 839-845.

12.

Ray, B.C. (2004). Effects of Crosshead Velocity and Sub-Zero Temperature on Mechanical Behaviour of Hygrothermally Conditioned Glass Fibre-Reinforced Epoxy Composites, Materials Science and Engineering A, 379: 39-44.

13.

Ray, B.C. (2004). Thermal Shock on Interfacial Adhesion of Thermally Conditioned Glass Fiber/Epoxy Composites, Materials Letters, 58: 2175-2177.

14.

Gautier, L. , Mortaigne, B. and Bellenger, V. (1999). Interface Damage Study of Hydrothermally Aged Glass-Fibre-Reinforced Polyester Composites, Composites Science and Technology., 59: 2329-2337.

15.

Xiao, G.Z. and Shanahan, M.E.R. (1997). Water Absorption and Desorption in an Epoxy Resin with Degradation, Journal of Polymer Science: Part B: Polymer Physics, 35: 2659-2670.

16.

Hull, D. and Clyne, T.W. (1996). An Introduction to Composite Materials, Cambridge Univ. Press, Cambridge, UK.

17.

Gonzalez-Benito, J. (2003). The Nature of Structure Gradient in Epoxy Curing at a Glass Fiber/Epoxy Matrix Interface Using FTIR Imaging, Journal of Colloid Interface Science, 267: 326-332.

18.

Olmos, D. , Lopez-Moron, R. and Gonzalez-Benito, J. (2006). The Nature of the Glass Fibre Surface and its Effect in the Water Absorption of Glass/Epoxy Composites . The use of Fluorescence to Obtain Information at the Interface, Composites Science and Technology, 66: 2758-2768.

19.

Tsenoglou, C.J. , Pavlidou, S. and Papaspyrides , C.D. (2006 ). Evaluation of Interfacial Relaxation Due to Water Absorption in Fiber-Polymer Composites, Composites Science and Technology , 66: 2855-2864.

20.

Gonzalez-Benito, J. , Olmos, D. , Sanchez , P.G. , Aznar, A.J. and Baselga, J. (2003). Kinetic Study of the Cure Process at the Silica Microfibers/Epoxy Interface Using Pyrene Fluorescence Response, Journal of Materials Processing Technology, 143: 153-157.

21.

Surendra Kumar, M. , Chawla, N. , Priyadarsini , A. , Mishra, I. and Ray , B.C. (2007). Assessment of Microstructural Integrity of Glass/Epoxy Composites at Liquid Nitrogen Temperature, Journal of Reinforced Plastics and Composites, 26: 1083-1089.

22.

Magid, B.A. , Ziaee, S. , Gass , K. and Schneider, M. (2005). The Combined Effects of Load, Moisture and Temperature on the Properties of E-Glass/Epoxy Composites , Composite Structures, 71: 320-326.

23.

Jang, B.Z. (1994). Advanced Polymer Composites: Principles and Applications , ASM International, Materials Park, OH.

24.

Wu, P. and Siesler, H.W. (2003). Water Diffusion Into Epoxy Resin: A 2D Correlation ATR-FTIR Investigation, Chemical Physics Letters, 374: 74-78.

25.

Mohan, J. (2000). Organic Spectroscopy, Narosa Publication House, New Delhi, India.

26.

Noobut, W. and Koenig, J.L. (1999). Interfacial Behavior of Epoxy/E-Glass Fiber Composites Under Wet-Dry Cycles by Fourier Transform Infrared Microspectroscopy, Polymer Composites, 20: 38-47.

27.

Clegg, D.W. and Collyer, A.A. (1993). Polymeric Materials, The Institute of Materials, London.

28.

Lin, Y.C. and Chen, X. (2005). Moisture Sorption-Desorption-Resorption Characteristics and its Effect on the Mechanical Behavior of the Epoxy System , Polymer, 46(25): 11994-12003.

29.

Popineau, S. , Mouro, C.R. , Gaillet, C.S. and Shanahand , M.E.R. (2005). Free/Bound Water Absorption in an Epoxy Adhesive, Polymer , 46: 10733-10740.