Carboxylation of Cellulose-Containing Raw Materials and Its Use in the Composition of Limited Swelling Rubbers

The purpose of the study is to develop a method for intensifying the process of obtaining a partially carboxylated product based on powdered cellulose from flax straw and to study its effect on the complex of physicomechanical and sorption properties of limited swelling rubbers based on NBR rubber. The paper considers the production of a partially carboxylated product based on powdered cellulose from flax straw. Carboxylated cellulose is used as a heavy metal sorbent, in the oil industry to control the properties of drilling fluids in well drilling, and as a swelling rubber filler for limited swelling rubbers. To intensify the carboxylation process, microwave radiation (MWR) of various powers was used. The carboxylation process was carried out in two stages. At the first stage, cellulose-containing raw materials from flax straw were treated with potassium hydroxide. Next, the calculated amount of monochloroacetic acid was added to the reaction mass. Products with the content of carboxyl groups from 23 to 42 meq have been obtained. It was found that the introduction of carboxylated powdered cellulose from flax straw, as well as powdered cellulose, into the rubber composition makes it possible to maintain the conditional tensile strength of rubbers at the level of the sample without a swelling filler, while the introduction of an industrial product of carboxylated cellulose Na-CMC leads to a significant decrease in the strength of rubber.