PHYSICAL AND CHEMICAL PROPERTIES OF MODIFIED BITUMEN PRIMERS FOR ANTI-CORROSION PROTECTION OF AGRICULTURAL MACHINERY AND EQUIPMENT

Compositions based on bitumen primers can be used for anti-corrosion protection of agricultural machinery and equipment. Their physicochemical properties were studied. It has been shown that the thickness of coatings, which is responsible for the effectiveness of barrier protection, increases as expected with an increase in the number of applied coating layers, and decreases even with a slight increase in temperature and with an increase in the amount of solvent in the case of coating by dipping. Increasing the amount of solvent added to the bitumen primer from 40 wt. % up to 67 wt. % leads to a reduction in coating thickness by 55 times. Brush application produces thinner finishes than dip application. Moisture absorption for modified BP with 67 wt. % solvent is 1-2 orders of magnitude higher than that of BP with 40 wt. % white spirit, therefore, a decrease in protective effectiveness can be expected for these materials. According to experimental studies, the contact angles for the original BP exceed 900C, which indicates the presence of hydrophobic properties. The type and concentration of additives affect the contact angles. Introduction 5 wt. % of modifying additives, paraffin P2 and Emulgin, reduces the contact angle of BP, the addition of KO-SZhK, on the contrary, increases it, improving hydrophobic properties. BP with 40 wt. % white spirit, including those with additives, shows good adhesion to carbon steel 0.8 kp. At 67 wt. % solvent in the presence of drying oil and unrefined sunflower oil additives, adhesion worsens. Viscosity-temperature dependences in semi-logarithmic coordinates for modified BP are close to linear in the temperature range 20 -60 0C with a high approximation reliability index R2 = 0.9543 - 0.9833. Based on the physicochemical properties, high anti-corrosion properties can be assumed.