Organobismuth——The synthesis of bismuth naphthenate can be accomplished by a metathesis synthesis method using water as the solvent. and direct synthesis in non-aqueous solvents.
1. Metathesis synthesis method
In metathesis synthesis, first react naphthenic acid and sodium hydroxide solution to form sodium naphthenate aqueous solution, and then react with bismuth nitrate solution to generate bismuth naphthenate. The reaction formula is as follows:
RCOOH+NaOH RCOONa+H2O
RCOONa+Bi(NO3)3 (RCOO) 3Bi+NaNO3
2. Direct synthesis method of non-aqueous solvents
The direct synthesis method of organic bismuth-bismuth naphthenate is to combine naphthenic acid raw materials under 160~200! temperature conditions and the action of a catalyst. It reacts directly with bismuth oxide to produce the products bismuth naphthenate and water. The reaction formula is as follows:
In the two synthesis methods, the metathesis reaction using water as the solvent, due to the reactants The solubility of bismuth salt water is not good. Even under the action of the heterogeneous catalyst quaternary ammonium salt, the reaction speed is still slow and it is difficult to complete the reaction. Adding alcohols to the reaction increases the reaction speed slightly. In the direct reaction of non-aqueous solvents, the reactants can be better dispersed in the solution system, and the reaction can proceed faster under the action of appropriate temperature and catalyst. At the same time, the product has good oil solubility and stability. The formation of bismuth naphthenate was confirmed by EDTA metal ion complex measurement and infrared spectrum analysis.
With the development of modern science and technology and oil application technology, the performance requirements of oil products are getting higher and higher. , Modern lubricating oil products, in addition to excellent extreme pressure anti-wear performance, anti-oxidation and stability performance, also require good environmental adaptability and green environmental protection performance.
Organobismuth is a non-toxic heavy metal and has good extreme pressure resistance when combined with sulfide Anti-wear properties. Therefore, organobismuth compounds such as bismuth dialkyldithiocarbamate are used in high-load lubricants due to their excellent extreme pressure and anti-wear properties. It has been widely used and has good application prospects.
