Abstract: In order to reduce the environmental pollution caused by oil, new biodegradable lubricating oil additives 1,4-bis (dithiocarbamoyl-n-hexylamine) piperazine (NP) and 1,4-bis (dithiocarbamate) piperazine (DP) were synthesized with piperazine (PP) as a precursor, dichloromethane as solvent, triethylamine as acid binding agent, n-hexylamine, dodecylamine and chloroacetyl chloride as raw materials. The structures and thermal stability of products were characterized by FT-IR, 1HNMR and TG techniques. Using rapeseed oil as lubricating base oil, the anti-wear performance and biodegradabilities, BDI index of additives were tested. The results showed that the thermal decomposition temperature is 305℃, and the solubility in rapeseed oil is better(up to 2.58%). The anti-wear performance of DP is better than NP, while the anti-friction performance of NP is better than DP. Both NP and DP have excellent biodegradability (BDI> 80%).

Key words: piperazine derivative, lubricating additive, acid binding agent, biodegradability