*Corresponding author: adrian.circiumaru@ugal.ro WATER ABSORBTION BEHAVIOUR OF NANO-FERRITES MODIFIED EPOXY RESINS Cristian MUNTENIȚĂ 1, Claudia UNGUREANU 1,, Vasile BRIA 1,, Marius BODOR 1,2, Iulia GRAUR 1,2, Adrian CÎRCIUMARU 1,2 *Corresponding author: adrian.circiumaru@ugal.ro ¹Research and Development Center for Thermoset Composites, “Dunărea de Jos” University of Galati, Romania ²Diagnose and Measurement Group, 41st Rosiori Str., Galați 800044, Romania INTRODUCTION The special properties of nano-sized ferrites had generated an increasing interest regarding the modification they can induce when they are dispersed into polymers. Other studies had shown that if the size of ferrites is at micro level they tend to aggregate inside the pre-polymer mixture. In the case of nano-sized ferrites the aggregation is avoided due to the balance between dimensions and pre-polymer viscosity. The formed materials are designed for use in energy applications, therefore they have to show valuable properties regarding repeated modifications at environmental parameters that is why part of general study of nano-sized ferrites modified epoxy resins has to include materials behavior in environmental-like conditions and, in this regard, the water absorption is essential. MATERIALS AND METHODES Three epoxy systems were chosen mostly because of their different bisphenol A content namely Epiphen RE4020-DE 4020 (Bostik), Epoxy Resin C (R&G Gmbh Waldenbuch), and Epoxy Resin HT-2 (R&G Gmbh Waldenbuch). Ferrites used in this study are commercially available ferrite: Strontium ferrite (SrFe12O19) and barium ferrite (BaFe12O19). A mixture of strontium ferrite and barium ferrite was used for all matrix systems forming. The water absorption of nano-ferrites modified epoxy resins was determined. RESULTS Fig. 3 Fig. 1 Water absorbtion Fig. 2 Surface absorbtion Fig. 3 Specific absorbtion CONCLUSIONS After the second cycle, the nano-ferrites modified epoxy resins have attained saturation (phenomenon that prevents the water absorption on the surface of the material). No changes of the absorption of the nano-ferrites modified epoxy resins are observed compared to the epoxy resin absorption. The presence of the nano-sized strontium ferrite and barium ferrite modified epoxy resins dispersed into polymers has not influenced the effect of water absorption on the sample surface. REFERENCES [1] Kinloch, A. J., Little, M. S. G., Watts, J. F., The Role of the Interphase in the Environmental Failure of Adhesive Joints‖, Acta mater. 48, pp. 4543-4553, 2000. [2] Xiao, G. Z. Shanahan, M. E. R., Water Absorption and Desorption in an Epoxy Resin with Degradation‖, Journal of Polymer Science: Part B: Polymer Physics, Vol. 35, pp 2659–2670, 1997. [3] Kinloch, A. J., Ed. Durability of structural adhesives‖ Applied Science Publishers: England, 1983. [4] Giacomelli, P. M., Picken, S. J., Wubbenhorst, M. de Vos, G., Van,T ., Dielectric water sorption analysis, Journal Rev. Science Instrum., Volume 77, ISBN 115107-1-115107-6, 2006. [5] Kim, Y. S., Dong, L., Hickner, M. A., Glass, T. E., Webb, V., McGrath, J. E., Macromolecules, Volume 36, p. 6281-6285, 2003. Acknowledgments The authors would like to acknowledgmrnts the financial contribution of the Project 12 P01 024 21 (C11)/31. 08. 2012 (code SMIS 50414) The work of Cristian MUNTENIȚĂ was supported by the Project no. POSDRU/159/1.5/132397, 2007 – 2013.