13C nuclear magnetic resonance, paramagnetic resonance, and ultraviolet spectroscopy and high-resolution gel permeation chromatography were used to investigate the process of periodate oxidation of carboxymethyl cellulose and the structure and molecular weight characteristics of its oxidised forms produced under different conditions. It was shown that, in solution and in the solid state, aldehyde groups in the oxidised units exist in the form of cyclic hemiacetals. An examination was made of the existence of all the main cyclic intramolecular hemiacetal structures, and the most probable were proposed. The influence of the degree of periodate oxidation on the molecular weight characteristics and hydrolytic stability of dialdehyde carboxymethyl cellulose was studied.

AbstractOxalyl chloride is shown to be the best chlorinating agent for the synthesis of title compound (II) which is used for the preparation of esters (VII) and (IX).

A proof of concept study has been conducted for the design of a porous biodegradable material containing nanocapsules and two actives with independent release-bimodal drug-eluting implants. Completely safe synthetic material free from risk of prion and virus contamination was tested in vivo, and a method for controlling the rate of biodegradation of poly-2-cyanoacrylic polymer was developed. Novel perfluorinated 2-cyanoacrylic esters have been applied for the chemical modification of polyethyl-2-cyanoacrlylate copolymers. Internal imide-cycle formation has been used to retard the rate of enzymatic hydrolysis of the 2-cyanoacrylic copolymer main chain.

Reaction of 2-cyanoacrylic acid with oxalyl chloride gives quantitatively 2-cyanoacryloyl chloride capable of esterifying thiols and fluorinated alcohols.

Thermomechanical studies of thermosetting copolymers of acrylonitrile with methacrylic acid and acrylamide with acrylic acid that form similar polyacrylimide foam plastics during curing have been performed. The dependence of the glass-transition temperatures of the copolymers on the degrees of intramolecular imidization has been calculated and confirmed experimentally. Procedures to control the curing rate have been proposed. The influence of plasticizing additives on the glass-transition temperatures, imidization, and foaming of foam-forming compositions has been studied. Plasticized powdered foam-forming compositions with delayed imidization have been developed, and temperature conditions for their processing have been determined.

The effect of the backbone-chain structure of acrylonitrile and methacrylic acid copolymers of various compositions on the maximum degree of intramolecular imidization has been studied. An estimating method for calculating this value on the basis of 13 C NMR spectroscopy data on the sequences of comonomers units in the initial copolymers is proposed. Poly-2-cyanoacrylic acid, in which the carboxylic acid and nitrile groups are located at the same carbon atom, has been used as a reference “ideally regular” polymer. The actual maximum degree of the intramolecular imidization of copolymers after thermolysis was ascertained by means of IR Fourier spectroscopy with the use of Lorentz approximations for deconvolution of absorption peaks in the spectra.

The kinetics of homogeneous hydrolysis of polyacrylonitrile in an aqueous solution of sodium carbonate and the chemical structure of the resulting copolymer are studied by FTIR spectroscopy, 13C NMR analysis, and titration methods. It is found that hydrolysis in the presence of sodium carbonate does not include the stage of amidine formation and does not result in the complete exhaustion of nitrile groups in a polymer. The designed partial-hydrolysis method permits the use of polyacrylonitrile for the synthesis of the copolymer with a predominant unit alternation; this copolymer is identical in terms of chemical structure to the Rohacell copolymer obtained through block copolymerization of acrylonitrile and methacrylic acid.