Nanocomposites and nanomaterials

Features of the formation of polymer-mineral composites on the polystyrene and disperse oxides Fe2O3, Cr2O3, V2O5 basis
Dutka V.S., Kovalskyi Ya.P., Oshchapovska N.V.
Ivan Franko National University of Lviv, 6, Kyryla & Mefodia str.
79005, Lviv, Ukraine,
E-mail: vdutka@ukr.net

Polymer-mineral composites (PMCs), which are form during the polymerization of vinyl monomers in the presence of disperse oxides have unique properties. The disperse oxide in the polymer matrix performs many functions. The filler may be a polymer pigment or stabilizer. Due to the developed surface of the disperse oxide and the selective adsorption of the initiator and the monomer, a significant change in the conditions of PMC formation can be expected in comparison with the homogeneous systems.
In this paper, the features of styrene polymerization were study in the presence of dispersed oxides Fe2O3, Cr2O3, V2O5, and as initiators used benzoyl peroxide (PB), oligomeric peroxide of sebacic acid (OPS), diperoxides and hydroperoxides. Adsorption of peroxides on the surface of the oxides studied is well describe by the known Langmuir equation. The basic parameters of the adsorption process are find. The reaction of the thermal decomposition of the peroxide compounds are studied. In particular, the thermal decomposition of PB occurs in the solution and on the surface of the disperse oxide. The mechanism of destruction of PB on the surface has an oxidation-reducing nature. The activation total energy of thermal decomposition of peroxide process is find. The activation energy of PB decomposition on the surface is much smaller than the corresponding value in a styrene solution.
Disperse oxides influence on the rate of polystyrene formation. Formation of a polymer takes place in a solution and on a surface of a dispersed mineral. Depending on the nature of the oxide, the rate of polymerization may increase or decrease. Disperse oxides are involved in the process of initiating polymerization and breakage of growing polymer chains. The influence of the studied oxides surface on the polymerization process can be trace to 10% conversion of the monomer. In the further, the surface of the dispersed mineral is block by macromolecules of polystyrene and is exclude from the polymerization process. The degree of grafting of polystyrene macromolecules to the surface of disperse oxides is found. The molecular masses of polystyrene, which are form in systems containing dispersed oxides Fe2O3, Cr2O3, V2O5, are find.