Issue 37

P. Velev et alii, Frattura ed Integrità Strutturale, 37 (2016) 272-279; DOI: 10.3221/IGF-ESIS.37.36 272 Focused on Fracture Mechanics in Central and East Europe Novel magnetic composites based on water soluble unsaturated polyester resin and iron oxide nanoparticles Petar Velev, Rayna Bryaskova University of Chemical Technology and Metallurgy, Bulgaria, A BSTRACT . Magnetic nanocomposites on the basis of water soluble unsaturated polyester resin filled with different amount of iron oxide nanoparticles have been successfully prepared. The mechanical properties of thus prepared composites as tensile, impact and flexural strength were determined. The specific volume and surface resistance of the magnetic nanocomposites were also determined. K EYWORDS . Magnetic Nanoparticles; Unsaturated Polyester Resin; Copolymerization; Mechanical Properties; Surface Resistance. I NTRODUCTION ecently, great scientific and technological interest has been paid to the magnetic nanoparticles because of their unique properties and various applications [1-6]. They can be synthesized using different methods such as microemulsion [7], sol-gel synthesis [8], sonochemical reactions [9], hydrolysis [10] and thermolysis [11]. These methods are used for preparation of particles with homogeneous composition. The synthesis of magnetic nanoparticles is a complex process because of their colloidal nature. The first challenge consists in the determination of the experimental conditions leading to formation of uniform magnetic nanoparticles with appropriate size [12]. The second critical point is the choice of reproductive process, which can be industrialized without any additional purification procedures such as ultracentrufugation [13] or magnetic filtration [14-16]. The most used methods for the synthesis of magnetic nanoparticles is precipitation of iron salts. The production of magnetic nanoparticles in aqueous solutions is very perspective, environmental friendly process and possesses numerous advantages. It is well known that unsaturated polyester resins are a solution of unsaturated oligomers in monomer (usually styrene) which are able to copolymerize. This combination possesses a good complex of properties as relatively low viscosity, and easy and complete copolymerization after addition of initiator which makes them very suitable for different processing methods. It is established that the resin easily forms emulsion with water after alkalifying of the medium with ammonia in the range from 1.8% to 5.2% under simple stirring. The obtained emulsion is stable enough with the time in order to undergo various technological processes. It is known the preparation of suspension copolymerization of unsaturated resins with styrene and acrylonytrile using a redox system consisting of metylketohydroperoxide and cobalt naphtenate [17]. The aim of this investigation is the preparation of magnetic nanocomposites on the basis of water soluble unsaturated polyester resin and aqueous solution of magnetic nanoparticles without using of any surfactant. There are not data in the literature concerning the preparation of such water soluble unsaturated polyester resins filled with magnetic nanoparticles. The mechanical properties of the prepared magnetic nanocomposites will be investigated as well. R