چكيده به لاتين
In this thesis, the copolymer of butyl acrylate, methyl methacrylate and hydroxyethyl methacrylate was produced in a closed chamber by emulsion polymerization method. Also, the effect of the monomer type and proportion of that was discussed and investigated as an effective factor in the properties of the final copolymer, so that in the first step, In order to synthesize of acrylate copolymer, hydroxyethyl methacrylate monomer, respectively in the amount of 0.0, 0.2, 0.4, 0.6 and 1 by weight, were added. Then, in the second step, silica nanoparticles were modified with the silane agent methacryloxypropyltrimethoxysilane (in order to create an effective bonds between silica nanoparticles and acrylate polymer and modify the silica surface), in amounts of 0.5, 1, 2, and 3% by weight, Also, to improve the structure and abrasion properties, they were added to the polymer structure to produce a polymer nanocomposite with acceptable properties. After the synthesis of acrylate copolymers and then the preparation of modified co-polyacrylate/silica nanocomposites, the mechanical and chemical properties of the final products were determined by tests of tensile strength, adhesion, wedge tension, infrared-Fourier spectrometry, The gel content and calorimetric test were investigated. The results of FTIR and ATR spectroscopic tests confirmed that silica nanoparticles were successfully coated by the silane agent, the surface was modified and silane groups were placed on the surface of the nanoparticles. Also, the results obtained from the differential scanning calorimeter test showed that the addition of hydroxyethyl methacrylate monomer and nano silica increases the glass transition temperature of copolymer samples. Also, the glass transition temperature of the sample containing 3% nanosilica increased by 22 degrees compared to the sample without it (containing 0.5 grams of hydroxyethyl methacrylate. The results of the wedge adhesion and tensile test showed that in the amount of 0.5 grams of hydroxyethyl methacrylate, the amount of adhesion strength and crack length increased by 28% and decreased by 50%, respectively, compared to the sample without hydroxyethyl methacrylate. The results of the wedge tensile test confirmed the results of the adhesion test well, and the nanocomposite samples containing 0.5% and 1% of nanoparticles showed the best adhesion properties compared to the rest of the samples. The results obtained from the tensile test also showed that, in general, samples containing 0.5% and 1% of nanoparticles have better and higher tensile properties.
