木素多功能水处理剂的功能化设计及机理研究

Industrial lignin comes from pulping industry as a by-product, which is very.abundant and rather cheap. Up to now, the application of lignin is greatly limited mainly.because of its inferior performance. Circulating cooling water system can reduce much process.water and release water resource crisis. But it needs a large quantity of water treatment reagents..The main corrosion and scale inhibitors used now are phosphorated organic compounds, which.consume a large quantity of petroleum resource. And its discharge has broken the ecological.balance of water. In order to operate durable development strategy and keep ecological balance,.it is significant to search a realizable way for developing a green corrosion and scale inhibitor.from lignosulfonates..In this project, the corrosion and scale performances of sodium lignosulfonate in circulating.cooling water was studied systematically at first. Then the reason of the inferior performance of.sodium lignosulfonate was discussed based on its surface physico-chemical properties and.molecular structure. The green corrosion and scale inhibitor GCL2 was further prepared by.oxidation, grafting copolymerization and chelation. Finally, the corrosion and scale performance.of GCL2 and its action mechanism were studied..It was found that the static scale inhibition ratio of sodium lignosulfonate is less than 5%. The.corrosion inhibition ratio is 48.1%. The sodium lignosulfonate with low molecular weight.which has more hydroxyl groups and sulfonic groups, less methoxyl groups, has better.corrosion and scale inhibition performances. Sodium lignosulfonate was studied by infrared.spectrum, gel permeation chromatography and surface physico-chemical properties.determinations. It was found that there are fewer groups which have strong chelation to calcium.ion and fewer groups which have strong adsorption on the surface of metal in sodium.lignosulfonate molecule. The large molecular size and its three-dimensional network structure.make the repulsion potential energy of adsorption much high. All these lead to the inferior.corrosion and scale inhibition performances..The effects of reaction factors of oxidation, grafting copolymerization and chelation on the.corrosion and scale inhibition performance of modified product were studied. The process.parameters of the synthesis reaction were optimized by orthogonal experiment. And a good.corrosion and scale inhibitor GCL2 was prepared. After purification and analysis by IR it is.found that carboxyl group has been grafted into sodium lignosulfonate. The content of carboxyl.国家自然科学基金资助项目结题报告.5.group in GCL2 is 0.0067mol/g, while there is no carboxyl group in sodium lignosulfonate. The.number-average molecular weight decreases from 7467 to 3951. The dispersion degree.decreases from 1.329 to 1.183..The static scale inhibition ratio of GCL2 reaches 45.2%. The corrosion inhibition ratio.reaches 98.6% in the rotary test pieces experiment. It was found from electrochemical.measurements that GCL2 can decrease the self-corrosion current and increase the polarization.resistance of carbon steel greatly. It shows that GCL2 has good corrosion inhibition.performance. The influences of different pre-filming and running conditions on the corrosion.inhibition performance were studied. The corrosion mechanism of GCL2 was studied by.electrochemical measurement. These proved that GCL2 can be adsorbed and form dense and.stable film on the surface of metal. It was found that GCL2 has good anti-pitting corrosion.performance by SEM and cyclic voltammetry curve determination. The scale inhibition.mechanism of GCL2 includes chelation, disperse and lattice deformation..Key words: lignosulfonate; circulating cooling water; corrosion and scale inhibition;

通过研究木素磺酸盐的主要功能基团种类、含量、分子量大小及分子构型对络合、吸附、分散等表面性能的影响，进一步研究缓蚀、阻垢的关系，探索多功能水自理剂协同增效作用机制，提出木素多功能水处理剂的功能化设计改性原则；拓宽了水处理剂的原料来源，为其提供理论基础和制备思路。开拓了以生物质资源为原料制备水处理剂的绿色化学工艺。