The oxidation of sealing liquids has been examined in order to select the best temperatures and times for dissolving macromolecular polyisobutylene P-200 in I-20A industrial oil. Conclusions are drawn on the desirability of maintaining a temperature in the reactor in the range 110-120°C for 5-6 h in the dissolution of the polyisobutylene. Temperatures above 120C, even acting briefly, lead to extensive decomposition of the macromolecular polyisobutylene.Sealing liquids AG-4 and AG-4I (TU 26-02-592-83) are intended for protecting deaerated water and hydrophilic liquids from evaporation and saturation with gases, and also for protecting equipment from corrosion.

high-molecular-weight polyisobutylenes and antioxidants by regenerating them with selective solvents and subsequent use of the regenerated oil in production of lubricants was investigated.AG-4, AG-4I (TU 26-02-592-83) and AG-5I (0258-014-00151911 -97) protective fluids [1-3] are viscous mobile solutions of high-molecular-weight polyisobutylenes (PIB) in mineral oil stabilized with antioxidant additives. They are used in energetic to prevent evaporation of water from hot-water-supply storage tanks with volumes of 100 to 20,000 m 3 and for protecting the internal metal surface of tank equipment from corrosion. According to RD 153-34.1-40.504-00, after four years of use, these fluids should be replaced if the basic quality indexes differ from the acceptable values [4].The problem of utilizing used protective fluids has not yet been completely solved. In most cases, companies are preserving their own territory, paying for disposal of hazard class 3 wastes. VNIIneftemash Co., together with NPTsEO Co., proposed a method for utilizing AG-4I and AG-5I protective fluids by burning them together with atmospheric resid and boiler fuel in GP-1 and 7D-1 burners (TU 3689-014-27554844 -01). The fuel and protective fluid is mixed in the ratio of 5:1, and the protective fluid content has no effect on the heat-engineering characteristics of the heating plant. No release of soot occurs during combustion. However, this method is difficult to implement in plants using gas fuel alone.We investigated the possibility of regenerating used fluids with selective solvents to obtain I-20A industrial oil that satisfies the requirements of the GOST for subsequent use in production of lubricants. Protective fluids, as solutions of high-molecular-weight substances, have thermodynamic stability.Perturbation of the stability of these solutions is accompanied by conversion of the polymers from totally dissolved to insolubility or organic dissolution. In the last case, the polymer solution separates into two phases. Separation could be due to the composition of the solution changing on addition of the fluid in which the polymer does not dissolve. After addition of the insoluble fluid up to a certain limit, the stability of the solution changes sharply and the polymer separates [5]. We investigated AG-4I (TU 26-02-592 -83) protective fluid with a 3.7 wt. % of high-molecular-weight P-200 PIB content. Selective solvents -methyl ethyl ketone (MEK) and toluene -were used to separate the PIB from the used protective fluid.The effect of the following factors on separation of PIB from the protective fluid was investigated: the nature of the solvent, ratio of solvent to feedstock, method of dissolution, and filtration temperature. The efficacy of the process was evaluated with the filtration rate, yield of oil, and PIB content in the oil obtained.