Physical-Mechanical Properties of Dynamically Vulcanized Elastoplastics Based on High Density Polyethylene and Nitrile Butadiene Rubber

The paper presents the results of a study of the effect of nitrile butadiene elastomer content on the main physical-mechanical properties of high density polyethylene based compositions. Properties such as tensile yield strength, ultimate tensile stress, elongation at break, flexural strength, thermal stability, and melt flow rate were investigated. To improve the compatibility of the mixed components, a compatibilizer was used, which is a graft copolymer of high-density polyethylene with methacrylic acid. The amount of compatibilizer in the mixture was 3.0 wt%. The concentration of the elastomer in the composition varied from 10 to 50 wt%. Elastomers containing 18, 26, and 40 wt% acrylic acid nitrile (SKN-18, SKN-26, and SKN-40) were used as nitrile butadiene elastomers. It was found that the transition from plastic strain to highly elastic for the high density polyethylene-based composite with SKN-18 starts at 30 wt% content of the elastomeric component. For compositions of high density polyethylene with SKN-26 and SKN-40, this transition occurs at 40 wt% content of the elastomeric component. The influence of the concentration of dicumyl peroxide on the regularities of changes in the properties of these compounds was also studied. It was found that the optimal concentration of the peroxide initiator is 0.5 wt%. The results of the study of electron microscopic analysis and thermomechanical characteristics of mechanical mixtures and dynamically vulcanized elastoplastics were presented, which allow obtaining additional information about the structural features and deformation characteristics of cross-linked polymeric materials.