Preparation And Evaluation Of Efficient And Biodegradable Scale Ans Corrosion Inhibitor

The shortage of water resources and intensifying of water pollution compel people to save water and protect the environment. The consumption of cooling water account for a large proportion in the production of modern industry. Treating the cooling water to prolong its usage is necessary to save water. Some water treatment agents possessing efficient scale or corrosion inhibition performance are applied in the cooling water treatment industry. However, a series of environmental problems such as eutrophication, gene mutation of the aquatic organism and so on are brought about because most of the water treatment agents are phosphorous and toxic. On account of this, water treatment regents is limited to use in many countries. In this context, the development of industrial cooling water treatment industry is hoped to be "green and efficient". Polyaspartic acid (PASP) become a research hotspot because of its excellent scale inhibition efficiency for CaCO3 and Ca3(PO4)2. In this article, polyaspartic acid was modified to improve its improve its integrative performances. Details are as follows:1. Polysuccinimide (PSI) was synthesized by means of the thermal polycondensation reaction of maleic anhydride and ammonia. PASP was obtained after PSI was hydrolyzed under alkaline conditions. PASP/tyramine, PASP/adenine and PASP/3,5-diamino-benzoic acid grafted polymer were synthesized respectively. Their structures were characterized by FTIR.2. Their scale inhibition performances against CaCO3, CaSO4 and Ca3(PO4)2 and corrosion inhibition property were investigated by static scale method respectively. Results showed the introduction of adenine and 3,5-diamino-benzoic acid could increase the scale inhibition property of PASP for CaSO4 and Ca3(PO4)2 greatly. In addition, the introduction of 3,5-diamino-benzoic acid could improve the scale inhibition property of PASP for CaCO3.3. The corrosion inhibition performances of the three modifiers of PASP were researched by weight loss method. Results showed the corrosion inhibition property were developed obviously after the tyramine and adenine were introduced in to PASP. The corrosion inhibition performance of PASP/adenine was investigated by electrochemical method. The results of the electrochemical study revealsed PASP/adenine was a mixing type inhibitor. The results of AC impedance indicated that PASP/adenine could absord on the steel surface and prevent the steel contacting with the etching solution.4. The biodegradation abilities of PASP, PASP/tyramine, PASP/adenine and PASP/3,5-diamino-benzoic acid were researched by aerobic biodegradation. All of them were biodegradable. Its order of their degradability was as flows:PASP/3,5-diamino-benzoic, PASP/adenine, PASP, PASP/tyramine. And their degradation rate in 28 d were 81%,71%,65%,56% respectively.