Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6586257 | Chemical Engineering Journal | 2015 | 10 Pages |
Abstract
Using magnetite nanoparticles (50-100Â nm) containing methacrylic groups (MNPs-MA or shortly, M) as inorganic phase into a mixture of photopolymerizable monomers with and without acid moieties in structure, a series of hybrid nanocomposites were prepared and characterized by FTIR, TEM, SEM-EDX analysis, and magnetization studies. For this purpose, two diacrylates based on castor oil triglyceride functionalized with carboxyl (CO-DAC) or phosphate (CO-DAP) groups were synthesized and incorporated in formulations besides urethane dimethacrylate (DMUO-1) and triethylene glycol dimethacrylate. Kinetic data obtained for photopolymerization in the presence of Irgacure 819, revealed that the maximum polymerization rate (RPmax) and the conversion degree (DC) are dependent on the monomer structure and the formulation composition. For instance, the inclusion of 0.1Â wt.% M had as result a slight decrease of RPmax from 0.088Â sâ1 (F1/30Â wt.% CO-DAP) to 0.075Â sâ1 (F1-0.1Â M), the highest value being found in the non-acid F3 formulation (0.1155Â sâ1). When the amount of nanoparticles increased to 1.0Â wt.%, the RPmax, DC, gel content and mechanical characteristics of the hybrid films were influenced in a different manner. TEM and SEM-EDX analysis confirm a good dispersion of nanoparticles in the organic matrix containing CO-DAC or CO-DAP monomer units, compared to the effect of crowded structure observed in the composite with no acid groups. Specifically, the magnetic hysteresis (Ms) loops indicated a ferromagnetic behavior for these composites, for which the saturation magnetization amplified with increasing amount of nanoparticles in the sample (from 37.85Â emu/g for F1-0.1Â M to 45.31Â emu/g for F1-1.0Â M).
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Engineering (General)
Authors
Violeta Melinte, Tinca Buruiana, Andreea Chibac, Nicoleta Lupu, Marian Grigoras, Emil C. Buruiana,