STUDY OF DILUTED SOLUTIONS OF PORPHYRIN-CONTAINING POLYMERIC SYSTEMS BASED ON POLY-4-VINYLPYRIDINE

Abstract

The dynamic light scattering method was used to determine the diffusion coefficients and hydrodynamic radius of particles in diluted dimethylformamide solutions of poly-4-vinylpyridine, polystyrene, styrene and 4-vinylpyridine copolymers with different comonomer compositions and poly-4-vinylpyridine modified by zinc meso-tetraphenilporphrine. The temperature range was from 20 °C to 25 °C. The copolymers were obtained in different conditions - by thermal and microwave heating. In order to determine the optimal conditions for the behavior of macromolecular reactions involving these polymers, diluted solutions of all samples were studied by the viscometric method. For these systems, a solvent of appropriate quality was selected, the structure of the solution was studied, the interaction of the solvent with the polymer was evaluated, the parameters of the macromolecular ravel were calculated: characteristic viscosities, Huggin’s constants, root-mean-square distances between the ends of the chains and the specific indicator of the system taking into account the molecular weight of the polymers was presented. It is shown, that the values of characteristic viscosity fall with increasing temperature, the Huggin’s constant, on the contrary increases. These data indicate that the "quality" of the solvent for the systems under study is deteriorating, that is, the tangle of macromolecules in dimethylformamide shrinks with increasing temperature. This behavior is typical for systems with a lower critical temperature of dissolution. The introduction of the porphyrin fragment into the polymer macromolecule loosens the macromolecular coil, but does not change the behavior of the system in the solution as a whole. The results obtained by the quasi-elastic light scattering method are consistent with the data obtained by the viscometric method. The surface morphology and elemental composition of poly-4-vinylpyridine and coordination-related porphyrin polymers on its basis were studied by scanning electron microscopy.