STUDY OF BIODEGRADABLE FILMS BASED ON CELLULOSE ETHERS WITH BACTERICIDAL PROPERTIES

Abstract

The article shows research on the development of the latest biodegradable films with bactericidal properties based on hydroxypropylmethylcellulose modified with brown coal humic acids. Hybrid biodegradable films with bactericidal properties were obtained by pouring solutions of hydroxypropylmethylcellulose with a concentration of 2 wt.%, to which different amounts of humic acid were added. When obtaining biodegradable films with bactericidal properties, hydroxypropylmethylcellulose of the Walocel™ brand manufactured by Dow Corning (USA) was used. As hybrid modifiers, humic acids were used, obtained by extraction of brown coal with an alkaline solution of sodium pyrophosphate, followed by extraction with a 1% sodium hydroxide solution and precipitation with mineral acid. Determination of water absorption of samples of biodegradable films in cold water was carried out according to ISO 62:2008, tensile strength properties of biodegradable films were determined according to ISO 527-2:2021, to measure the gas permeability of biodegradable films, the differential pressure method and a vacuum tester VAC-V1 were used. The effect of the hybrid modification of hydroxypropylmethylcellulose with lignite humic acids in terms of the studied performance characteristics increased in the direction of lignite humic acid types No. 3> No. 2> No. 1. It has been shown that hybrid modification by the mechanism of matrix synthesis of biodegradable films with bactericidal properties based on hydroxypropylmethylcellulose with brown coal humic acids makes it possible to reduce their water absorption, increase the basic strength characteristics and impart antibacterial properties to them, which is confirmed by the data on the time of mold appearance. Optimum in terms of strength and performance characteristics are biodegradable films with bactericidal properties at a content of 10% wt. humic acids No. 3. In general, it has been established that hybrid modification with humic acids according to the mechanism of matrix synthesis of biodegradable films based on hydroxypropylmethylcellulose makes it possible to obtain durable water-soluble films with antibacterial properties for use as packaging for dry food products (bread, cereals, nuts, etc.) with an extended shelf life. storage.