Іnfluence of finishing on the material performances

Abstract

The complex of polyacrylic and polyurethane films physical and mechanical properties and the operational properties of leather decorated with them has been studied. The polyacrylate and polyurethane protective coatings formation is performed on the grain face of the semi-finished leather. 
 150–200 µm thick films are formed from the polymer solutions and aqueous dispersions. Acrylic films are obtained from a dispersion of methylbutylacrylate and a dispersion modified by acrylic lcarboxyethanolamine of kerosene-gas-oil fraction natural naphthenic acids. Polyurethane films are formed by the method of condensation structure formation in the presence of water vapor based on 4,4’-diphenylmethanediisocyanate, polyethylene glycol and polyester. Polyacrylurethane films are obtained from an aqueous dispersion of polyurethane and acrylate Lepton SPC.
 The coating is applied to the semi-finished leather by watering and spraying the polymer composition. The complex of physical-mechanical and sorption-diffusion properties of polymer films has been studied. It was found that the films obtained from the polyacrylurethane composition outperform polyurethane and polyacrylic by 1.9 and 6.7 times, respectively. Modification of the polyurethane composition with a polyacrylic polymer makes it possible to obtain films with higher sorption-diffusion properties.
 Polyurethane coated leather is superior to polyacrylic in the complex of physical and mechanical parameters, in particular in terms of adhesive strength in 3.4-4.4 times, and polyacrylurethane coated leather - in 5 times. Such leather has the highest sorbino-diffusion capacity, which is 1.4 times higher in vapor permeability compared to skins with polyacrylic coating. The acrylurethane polymer-based composition is promising formation of eco-coatings based on them in the technology of manufacturing leather materials. The studied polymeric film formers can be used for the formation of various kind protective coatings on a wide range of semi-finished leather products.