Establishment of the regularities of the polymer cover influence on the wood bio destruction

Abstract

The process of wood biological destruction is analyzed. It was found that the neglect of environmentally friendly means of bioprotection, leads to the destruction of wooden structures under the action of microorganisms. It is established that the study of wood protection conditions leads to the creation of new types of protective materials that reduce water absorption, as well as reduce the amount of substances that are the environment for the development of wood-destroying fungi. In this regard, a computational and experimental method for determining the proportion of destroyed material under the action of microorganisms using an antiseptic has been developed. The analysis of the results shows that the maximum weight loss in the case of biodegradation of untreated wood samples ranged from 7,6 to 16 %, and the weight loss of thermally modified wood samples did not exceed 3 %, antiseptic-hydrophobicizer – was less than 2 %. It was found that the protection when treated with thermally modified wood with oil-wax and azure exceeds (compared to untreated) more than 4 times in terms of biodegradation, and treatment with antiseptic-water repellent for untreated oil-wax and azure – more than 8 times. It should be noted that the presence of oil-wax and azure leads to blockage of the wood surface from the penetration of moisture or microorganisms. Therefore, the intensity of wood-destroying fungus development on the surface of various samples are differed. Obviously, such a mechanism of the protective coating influence is the factor regulating the process, which preserves the integrity of the object. On the experimental data basis and by modeling the equations, the microorganisms population dynamics in the volume of material and the function of increasing the number of dead organisms are derived. Thus, a polymer shell was created on the surface of the sample, which significantly reduced the penetration of microorganisms into the wood, and the weight loss of wood during biodegradation did not exceed 2,5 %. Additional application of protective substances on the surface increases the protection level of untreated pine wood by 72 %, thermomodified at 190 °C – 25 %, at 220 °C – by 37 %. Similar results for hornbeam wood – 60; 37 and 28 %, for oak – 50; 37 and 37 % respectively.