New Nitrogen-containing Conjugated Heterocyclic Lubricant Extreme Pressure And Antiwear Agent Design, Synthesis And Testing

With the development of modern industry and the strengthening of environmental awareness, traditional extreme pressure anti-wear agents such as zinc dialkyl dithiophosphate (ZDDP) made of sulfur, phosphorus and other elements have exposed a growing number of shortcomings. Automotive catalyst poisoning by phosphorus, sulfur pollution of the environment and other issues are imminent. Researchers begin to appeal to low (no) S, low (no) P, low (no) ash extreme pressure anti-wear agents which environment allowed. In order to agree with the needs of the times, we seek to synthesize the new type of extreme pressure anti-wear agents.Based on the concept of anion radical proposed by Kajdas and applied to friction, we extend it to the structure of nitrogen-containing conjugated heterocyclic compounds, in which the lone pair electrons of nitrogen atom react with the positively charged substance. In the friction process, it can complex with the empty d orbital of metal atom, combined with aromatic compact structure, a stable surface film with good strength can be formed, which protects metal surfaces from damage. According to this theoretical basis, we designed and synthesized three types of extreme pressure anti-wear agents for lubricant, that is, nitrogen-containing conjugated triazine type, phthalocyanine type, and benzotriazole type, totally six compounds.Four compounds of nitrogen-containing conjugated triazine type were synthesized when four equivalent value dodecylamine took place the second and third substitution with the intermediates obtained from reactions between p-phenylenediamine, benzidine,4,4'-diaminodiphenyl methane,4,4'-diaminodiphenyl ether and two equivalent value cyanuric chloride; For the phthalocyanine type, we started with the melting method mentioned in literature to synthesize 2,9,16,23-tetra-nitro zinc phthalocyanine, then reduced it to 2,9,16,23-tetra-amino zinc phthalocyanine with sodium sulfide nonahydrate, which finally took place substitution reaction with 1-bromooctane, synthesizing 2,9,16,23-tetra-simamino zinc phthalocyanine; The benzotriazole type were synthesized when two equivalent value dodecylamine took place the second and third substitution with the intermediates obtained from reactions between homemade benzotriazole (or 1-aminobenzotriazole) and cyanuric chloride, and the synthetic route with 1-aminobenzotriazole needs to be explored. The six synthetic compounds were verified to be correct through structural confirmation by IR,1H NMR, MALDI-TOP-MS.In addition, representatives of each class of compounds were chosed for performance evaluation, according to SH/T0202 "Determination of extreme pressure properties of lubricating grease (four-ball machine method)". The results show that all the three compounds can improve the extreme pressure or anti-wear properties of the lubricants slightly, but still far away from the desired effect. We analyze the reasons and proposed some methods for improvement. The 2,9,16,23-tetra-simamino zinc phthalocyanine is regarded as the best of three types after evaluation, just a little improvement should be done according to the literature:remove the metal complex zinc atoms, effectively match the nitrogen atom with the metal surface, and build strength chemical film to prevent wear on metal surfaces. This method is still in the exploratory stage.