The paper presents the results of anticorrosion gravimetric studies of the quaternary nitrogen-containing derivatives of 2-allyl-4-isodecylphenol, namely, the quaternary ammonium salts 2-allyl-4-isodecyl-6-diethylaminomethylphenol (I) and 2-allyl-4-isodecyl-6-piperidinomethylphenol (II) on steel St.3 plates in a system consisting of a 3

The inhibitor and bactericidal properties of a series of allyl-substituted 1,3-benzoxazines and their water-soluble derivatives in hydrogen sulfide saturated water–salt–hydrocarbon systems were studied. The inhibitor properties of the compounds with respect to St.3 steel (St3Gsp, GOST (State Standard) 380-2005) strongly depend on the number of methylene groups in the substituents bonded to the nitrogen atom in the 1,3-oxazine ring. The bactericidal activity toward the growth of sulfate-reducing bacteria (SRB) also strongly depends on the structure of the compounds. With an increase in the number of methylene groups in the molecule, the protective properties of the compounds increase, whereas the bactericidal properties decrease. Compounds with an aromatic substituent at the nitrogen atom of the 1,3-oxazine ring exhibit higher inhibiting (maximal degree of protection ~97%) and bactericidal (maximal degree of SRB growth suppression ~100%) power.

The results of gravimetric and potentiostatic studies of pyridinium salts, derived from alkenylphenols, as inhibitors of hydrogen sulfide corrosion of steel St 3 in aqueous saline and hydrocarbon systems and testing the salts for bactericidal activity against sulfate-reducing bacteria (SRB) are reported. It has been found that the test compounds with a concentration of 50–150 mg/L slow down the cathodic and anodic reactions and significantly increase the polarization resistance ( R p ) of St 3. The best protective properties have been shown by 1-(2-propenylphenoxytetramethylene)- N -pyridinium bromide (III) and 1-(2-allylphenoxytetramethylene)- N -pyridinium bromide (VI): the corrosion protection by III and VI is respectively 87 and 83% at a concentration of 50 mg/L or 96 and 93% at a concentration of 150 mg/L. The pyridinium salts synthesized in this study also exhibit bactericidal activity in a concentration of 50–200 mg/L. High bactericidal properties have been found for 1-(2-propenylphenoxytetramethylene)- N -pyridinium bromide. The SRB growth inhibition at its concentration of 50 or 75 mg/L is 75 or 100%, respectively.

Pyridinium salts have been synthesized by reacting 2-allyl- and 4-propenylphenoxy(C2–C4)bromoalkanes with pyridine and further examined as inhibitors of hydrogen sulfide corrosion of St3 steel in water-salt systems containing H2S. The dependence of the protective properties of the test compounds on their structure has been revealed. It has been found that N-(2-propenylphenoxytetamethylene)pyridinium bromide exhibits the best inhibitory properties (degree of corrosion protection at a concentration of 100 mg L−1 is 96.0%).

A number of aminomethylated derivatives of 2-propenyl-, 4-isopropenylphenols have been synthesized and their antimicrobial properties have been studied in M-12 engine oil and TS-1 jet fuel (at concentrations of 1–2% and 0.3–0.5%, respectively). They have been found to possess bactericidal and fungicidal properties and significantly improve the antimicrobial properties of both of the materials (as compared to the well-known antimicrobial additive, 8-hydroxyquinoline). The presence of an alkenyl substituent along with an aminomethyl group in the structure of the substances in question has been demonstrated to enhance the antimicrobial properties. The formation of an intermolecular and intramolecular hydrogen bond in the initial and synthesized phenolic compounds has been studied.

A series of aminomethylated allylphenol derivatives was studied as antimicrobial additives for the jet fuel TS-1. It was found that these compounds at concentrations of 0.25 and 0.5% suppress the growth of microorganisms and do not rank below the well-known antibacterial additive 8-hydroxyquinoline in performance; moreover, 2-allyl-6-(dimethylamino)methylphenol,2-allyl-6-(diethylamino)methylphenol, and 2-allyl-6-piperidinomethylphenol are superior to this additive and, as such, can be recommended as effective antimicrobial additives for the TS-1 fuel. The formation of intermolecular and intramolecular hydrogen bonds in the reactants and the synthesized products was also studied.

A series of nitrogen-containing compounds was synthesized by Mannich condensation of allylsubstituted derivatives of phenol and o -and p -cresols with formaldehyde and secondary amines. These compounds were studied as antimicrobial additives to motor oil (at a content of 1–2 wt %).