<p>In this work, by potentiometric titration the dissociation of the grafted chains of polyacrylic acid in copolymer composition have been investigated. An increase in the content of units of AA in the copolymer leads to a decrease in the values of dissociation constants, that is, the acidic properties are weaken. It was shown that with the extension of the grafted copolymer chains in MC-g-PAA, as well as the enhance the interaction between the basic and graft chains of the copolymer intra- and intermolecular complexes are formed by hydrogen bonding system. Also, by viscometry the effect of the temperature and pH on the rheological properties as well as phase transitions in aqueous solutions of graft copolymers based on polyacrylic acid and methyl cellulose (MC-g-PAA) have been investigated. It was demonstrated that the content of the grafted polyacrylic acid affects to the physicochemical characteristics of the grafted copolymer. Grafting of AA onto a polysaccharide chain allows to create pH-dependent system, resulting in an increase in the solution viscosity of the copolymer with increasing pH.</p>

Current paper presents the results of chemical study of the non-polar fraction obtained from the substance isolated from the roots of Limonium gmelinii (Willd.). Limonium gmelinii is a perennial wildgrowing plant with a flowering period in June-September. It is found in all regions of Kazakhstan, western and eastern Siberia, European part of Russia, Central Asia, Southeastern Europe, Western China and Mongolia. Roots of Limonium gmelinii are introduced into the medicine and State Pharmacopoeia of the Republic of Kazakhstan. In this work, we obtained a substance using ultrasound to intensify the extraction process, which is effective, both from the economic and ecological side. Limonium gmelinii plants were harvested in Almaty region in 2018. Extracts were obtained by solvent extraction of a dry substance isolated from the roots of the studied plants with hexane, and studied by chromatography -mass spectrometry on a gas chromatograph with a mass-selective detector. In non-polar extract obtained from such substance, 27 individual compounds were identified, most of them are represented by higher fat-soluble hydrocarbons that are a part of natural waxes and resins; particularly high content of tetradecane, pentadecane, hexadecane, genicosane, octadecane, eicosane and their isomers was noted. In addition, the presence of a quinoline derivative in the form of 1,2-dihydro-2,2,4-trimethyl-quinoline was observed. For comparison, non-polar extract directly from the roots of Limonium gmelinii comprised 15 compounds belonging to the classes of hydrocarbons and esters of higher carboxylic acids. Dominating are hexadecanoic acid, ethyl ester, ethyl oleate, linoleic acid ethyl ester. In addition, a number of hydrocarbons, such as heptadecane, octadecane and tetradecane, and a quinoline derivative of 1,2-dihydro-2,2,4-trimethyl quinolone as well as phenol 2,4-bis (1,1-dimethylethyl) have been identified.