The study of the gossypol resin impact on adhesive properties of the intermediate layer of the pipeline three-layer rust protection coating

Abstract The extrusion technique was used to obtain new compositions of the intermediate layer of the pipeline three-layer rust protection coating. Besides conventional low-density polyethylene and ethylene-vinyl acetate, the composition of the layer included various ratios of exfoliated vermiculite as mineral filler and gossypol resin. The optimal ratios of layer components were determined from the perspective of improvement of adhesion, impact strength, rest resistance, and exfoliation. The developed compositions fully meet the requirements of current technical standards in this field. Their high technical characteristics are related to the synergistic effect between the gossypol resin and the exfoliated vermiculite. Gossypol resin stabilizes polyethylene and improves the mechanical characteristics of the composition and the mineral filler. Exfoliated vermiculite enhances the interaction of the polymer matrix with the steel. As compared with the similar compositions, the content of the expensive component – ethylene-vinyl acetate – is reduced from 62–90 wt% to 7–9%.The new composition effectively protects pipelines that operate under high humidity. The developed composition uses cheap local raw materials (including waste, which has a negative impact on the environment) and improves the mechanical properties, rust resistance, and adhesion properties of the obtained coating.