OBTAINING BIODEGRADABLE COMPOSITE MATERIALS BASED ON POLYOLEFINS AND HUSK OF SUNFLOWER SEEDS

Abstract

The paper presents the results of a comparative study of physical and mechanical, rheological, and biodegradable characteristics of a mixture containing low- and high-pressure polyethylene (HDPE 273-83 and HDPE 15303-003, respectively) in a 1:1 ratio filled with finely ground (less than 200 microns) sunflower husk (5-30% by weight). The mixture also contained 10% compatibilizer (functionalized by the method of alkaline alcoholysis of sevilen (SEVA 12206-007) and 1% of technological additive (polyethylene glycol (PEG-115 (4000). It has been established that as the content of the plant filler increases (up to 25%), the elastic modulus and tensile strength has not practically changed. The relative elongation of the composite under tension exceeds 100% (with a sunflower husk content up to 15% by weight). The complex viscosity and shear modulus of the considered melts with different filler contents are almost at the same level. The introduction of sunflower husk (up to 30%) and compatibilizer (10%) helps to reduce the viscosity and elasticity of the melts, which is evidence of a significant improvement in the processability of the compositions compared to HDPE 273-83. For a comparative assessment of composites biodegradability, moisture absorption, chemical oxygen consumption, and composites mass loss in laboratory soil during exposure for 12 months were being studied. It is shown that with increasing filler content, the ability of composites to biodegradation increases. In addition, it was found that the indicator of chemical oxygen consumption per unit surface area of the sample is a more productive and reproducible estimate in comparison with traditional methods for assessing the degradability of composite materials.