Investigation of properties in nanomodified polyethylene-based wood-polymer composites

Abstract

ABSTRACT: Introduction. Polyethylene is by far the most widely used polymer in the production of wood-polymer composites both in Russia and in other countries. Nevertheless, these composites have a number of disadvantages: low adhesion between polymer matrix and wood filler, which reduces the strength characteristics of the products, high elasticity, and low weather resistance. In industry, such issues are often solved by using complex additives in the form of granules including binding agents, lubricants, and various thermo- and UV-stabilizers. Methods and materials. New experimental data on technological and operational characteristics of wood-polymer composites (WPC) based on low-pressure polyethylene modified with complex processing additive have been obtained. In addition to stabilizers and lubricants, multi-wall carbon nanotubes (MWCNT) were introduced in WPC to facilitate the extrusion process, their content was 30% of the total composition. WPC-based products are mainly intended for outdoor performance under mechanical load, which places special demands on them in terms of strength, weathering and water resistance. Results. An increase in the mechanical characteristics was found for WPC after the introduction of the complex additive: at a concentration of 2.6 phr, the tensile strength increased by 35%, and at 53.3 phr, the flexural strength became higher by 12%. The introduction of the additive led to a decrease in the abrasion and water absorption of the modified sample compared to that of the initial material. Regardless of the additive content, all the samples were uniformly colored, which indicated a uniform distribution of the modifier over the volume of the WPC melt during processing in the extruder. Conclusion. The introduction of a complex processing stabilizing additive into the composition of a wood-polymer composite based on polyethylene was carried out. The results of the research showed that the additive in a wide range of concentrations contributes to the improvement of the technological and operational properties of the resulting composites

Keywords

• wood-polymer composite
• polyethylene
• carbon nanotubes
• stabilizer
• extrusion
• microscopy