Issue 37

P. Velev et alii, Frattura ed Integrità Strutturale, 37 (2016) 272-279; DOI: 10.3221/IGF-ESIS.37.36 278 0 5 10 15 20 25 30 35 40 0 0.1 0.3 0.5 Magnetic nanoparticles, % Degree of swelling,% 2 h 4 h 24 h Figure 8: Changes of degree of swelling (weight) in dependence on the amount of magnetic nanoparticles. The degree of weight swelling is increased with increasing the amount of magnetic nanoparticles in the magnetic composites. This increasing of the degree of swelling proves the presence of pores in the samples. 0 5 10 15 20 25 30 35 40 0 0.1 0.3 0.5 Magnetic nanoparticles , % Degree of swelling, % 2 h 4 h 24 h Figure 9: Changes of degree of swelling (volume) in dependence on the amount of magnetic nanoparticles. As seen from the figure, degree of volume swelling decreases irregularly with the introduction of magnetic nanoparticles. The degree of swelling is higher at the samples without magnetic nanoparticles. The weight of the samples containing higher amount of magnetic nanoparticles increases and the volume of the samples decreases when staying in a solvent (acetone) for 24h. It can be concluded that the higher amount of the magnetic nanoparticles in the composites does not disturb the crosslinking process of the resin but the prepared magnetic composites posses higher amount of open and closed pores in which enters higher amount of solution. Therefore, the density of the polymer composites decreased with increasing the amount of the magnetic nanoparticles (Tab. 3).