CHANGE OF THE MECHANICAL PROPERTIES OF MODIFIED POLYETHYLENE FILM MATERIALS AT LOW TEMPERATURES AND THERMOCYCLING

Abstract

Abstract. Wide practical use of various types of polyethylene films in production processes is due to the fact that they are the most common protective, insulating and packaging material. The article analyzes the effect of low temperatures and cyclic temperature tests on the physical and mechanical properties of modified polyethylene film materials, which is of significant scientific interest. The aim of the article was to study the influence of low temperatures and thermocycling on the mechanical characteristics of modified polyethylene thin film materials. The peculiarities of the course of the process of changing the mechanical characteristics of polymeric materials during different periods of exposure to low temperatures are considered. It was determined that the modification of the polymer thin films material in order to provide anti-corrosion properties with a small quantity of additives in the absence of low temperatures does not lead to the change in the values of the initial characteristics of the samples. The changing of the mechanical characteristics of polymer materials during different periods of low temperatures are considered. Analysis of the influence of time periods of exposure to low temperatures on modified polyethylene film materials on changes in mechanical characteristics made it possible to determine the order of operation of the obtained materials. It was shown that lowering the temperature in the case of the study of plasticized samples led to a decrease in the tensile strength at break σpp, and thermal cycling allowed normalizing the mechanical characteristics, which approached the initial values. It was determined that the relative elongation at break is at the level of the initial values. The introduction of any components - inhibitors, plasticizers, technological additives - into the composition of the matrix polyethylene material leads to changes, the magnitude of which depends on the type and amount of the modifier, which can subsequently lead to changes in the product’s lifetime. The obtained research results generalize the influence of low temperatures on the mechanical characteristics of modified polymer materials. Further research should be directed to an in-depth study of the mechanism of changes in mechanical characteristics in the case of the complex action of various factors on modified polymer films and the speed of these processes.