Study of the reaction of radical copolymerization of unsaturated polyesters with acrylic acid
Keywords:unsaturated polyesters, radical copolymerization, kinetics, sealants, glue
Copolymers of polyethylene(propylene-)glycolfumarate with acrylic acid were obtained for the first time by a radical copolymerization reaction in a dioxane solution at various molar ratios of the initial polymer-monomer mixture in the presence of a radical-forming initiator, benzoyl peroxide, at a temperature of 333 K.
The composition of the copolymers was identified by HPLC spectroscopy by analyzing the mother liquors, the structure was confirmed by IR spectroscopy. It has been established that for any composition of the initial polymer-monomer mixture, the composition of the copolymer is enriched with acrylic acid units. The copolymerization kinetics was studied by the dilatometric method. It has been established that with an increase in the content of acrylic acid in the initial polymer-monomer mixture, the reaction rate increases significantly.
The degree of swelling of the copolymers was determined gravimetrically. It has been established that an increase in the content of unsaturated polyester in the initial polymer-monomer mixture leads to a decrease in the ability of the copolymer to absorb moisture, which makes it possible to assume their use as bases in the production of sealing and adhesive materials. On the contrary, the degree of unsaturation of copolymers, determined by the bromide-bromate method, is directly dependent on the content of unsaturated polyester in the composition of the initial polymer-monomer mixture.
Radical copolymerization constants calculated by the integral Mayo-Lewis method showed a higher activity of acrylic acid in comparison with unsaturated polyesters.