Abstract

The study of the rheological properties of polymers, and also the establishment of quantitative dependencies, along with the problem of the relationship of molecular characteristics with the synthesis conditions, is an important scientific and practical task. The solution of this problem gives to predict the behavior of polymers, to develop and find the optimal modes and parameters of obtaining materials with predetermined properties. For a research of chemical interaction between macromolecules in solutions, the dilute solutions rheology of copolymers of glycidylmethacrylate and methylphaeophorbide “a” in dimethylformamide was studied. The study of dilute solutions of the corresponding copolymers was carried out by viscometric method in the temperature range of 20-35 ºC. Copolymers of glycidylmethacrylate and methylphaeophorbide “a” of different composition were obtained by radical copolymerization in solution. The synthesized copolymers are characterized by molecular-weight characteristics determined by gel-permeation chromatography. It is established that the solutions of the copolymers correspond to the systems with the lower critical temperature of dissolution. The belonging of the studied solutions to the systems with the lower critical dissolution temperature is confirmed by the dependence of the Huggins constant on the temperature. From the obtained results it follows that the ball of the macromolecule shrinks with increasing temperature. The influence of solution temperature, molecular weight and composition of copolymers on their interaction with the solvent, expressed quantitatively through the parameters of the characteristic viscosity, the Huggins constant, the mean-square distance between the ends of macromolecular chains, is shown. The mean-square distance between the ends of the chains of polymer in the solution was estimated by the equation of Flory-Fox. It is shown that for the studied copolymers the specific index decreases with increasing temperature. It was determined that the introduction of the porphyrin fragment into the structure of the polymer macromolecule retains the character of the interaction of the macromolecular tangle with the solvent.

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