Determination of the azetide groups relative content in the composition of amphoteric polymer resins

Abstract

The work is devoted to the determination of the relative content of azetidine groups included in amphoteric polymer resins. The use of such resins for gluing cardboard from wastepaper ensures its strength in both dry and wet conditions. However, when choosing a resin from a fairly wide range of these reagents on the market, the content of azetidine groups is not included in the list of main characteristics. In this research work, the methods of 1H and 13C NMR spectroscopy were used which allowed carrying out the qualitative and quantitative analysis of the azetidine groups in polyamidamine-epichlorohydrin resins according to their structural and functional characteristics. In order to obtain quantitative information about individual groups of studied polyamidamine-epichlorohydrin resins a new technique was proposed for calculating the relative content of azetidine groups in resins with respect to the theoretically possible content. The essence of the technique was that the 13C NMR spectra of the investigated amphoteric polymer resins were divided into integration intervals corresponding to the nuclei of carbon atoms in the same type of structural fragments of polyamidamine-epichlorohydrin resin molecules. To determine the relative content of azetidine groups, the corresponding values of spectroscopic parameters of carbon atoms (integral line intensities and their ratio) of carboxyl and carbonyl groups, as well as carbon atoms of azetidine groups, were used. In this work, the effect of the researched resins on the main quality indicators of laboratory paper samples of different composition was studied. The research results proved the dependence of paper parameters on the relative content of azetidine groups in the resin.