Water absorption and swelling of Betula pendula ROTH wood modified with oligomers from by-products of polybutadiene production

Abstract

Currently, natural wood and products based on it are in high demand. The technology of impregnation of low-value wood species on the example of B. pendula ROTH with an oligomeric material obtained from rubber production waste has been studied. Oligomers with a styrene content of 10 and 90% were obtained. In the first case, the low molecular weight copolymer had a molecular weight of 1100-1300, and in the second - 1700-2000. Impregnation of B. pendula ROTH wood was carried out in a solution of the obtained oligomer in toluene. In order to speed up the drying process of the protective coating and increase its strength, NF-1 siccative was introduced into the impregnation composition in an amount of 4-5%. The impregnation was carried out at temperatures of 60 and 120 ˚C, followed by heat treatment at temperatures of 100 and 160 ˚C. In the work, using the theory of experimental planning, a regression model was created that made it possible to describe the effects of a number of technological indicators on increasing the water and moisture resistance of modified wood. Verification of the coefficients of the models for significance was carried out using the Student's criterion. The obtained regression models make it possible to predict the characteristics of water resistance of birch wood modified due to its impregnation with a low-molecular copolymer containing styrene at specified values of technological parameters - the styrene content in the impregnating composition, the values of the impregnation temperature and heat treatment. It is shown that in order to increase the efficiency of the impregnation and heat treatment process, it is necessary to adhere to the minimum values of the considered temperature intervals, and the styrene content in the applied oligomeric product should be ~ 90% by weight. Modifying treatment of wood with an oligomer from by-products of polybutadiene production makes it possible to improve its water resistance. The use of the proposed impregnating compounds contributes to the disposal of waste and by-products of polybutadiene production.