Formation of hydrophobic properties of natural leathers

Abstract

Study of the physicochemical properties of different topographic sections of hydropho­bized leather obtained from the semi-finished product of chrome tanning of horse raw materials. Determination of the dependence of the chemical composition, the amount of water soaking of the leather hydrophobized with the alkene­maleic composition obtained from different topographic sections of the raw materials on the deformation rate. Establishment of the complex of sorption-diffusion and physicomechanical properties of the hydrophobized leather of different topographic sections during watering-drying. The study is based on the hypothesis that the alkenemaleic composition of horse raw materials will allow using the leather for the manufacture of a wide range of footwear products that will withstand extreme conditions. To study the properties of the leather from horse raw materials, samples of the semi-finished product of chrome tanning obtained from the topographic sections of the croup and back with a thickness of 2.4 mm, and the neck - 1.8 mm were used. Hydrophobization of the skin was carried out with an alkenemaleic composition with a consumption of the semi-finished product mass, wt. %: alkenemaleic polymer (AMP). Control samples were treated only with AMP. It was shown that the content of bound fatty substances in the hydrophobized skin was 2.3–2.9 times higher than in the control samples. At the same time, skin samples obtained from the neck area are characterized by a higher porosity by 9.8% compared to the rump area. The dependence of the strength of the hydrophobized skin on the topographic area was established, which increases from the neck area to the rump area by 43.0% with increasing elongation. The physical and mechanical indicators of the skin change in a similar way during its spherical deformation. Cyclic watering-drying indicates the restoration of the physical and mechanical indicators of the hydrophobized skin. The dependences of the physicochemical parameters of hydrophobized leather on the thickness and topographic area and deformation conditions during its watering-drying have been established. The absolute values and dependences of the parameters of hydrophobized leather on the test conditions give reason to consider its use possible for the manufacture of waterproof footwear that will be operated in extreme conditions, which confirms the hypothesis of the study.