The Study Of The Synthesis And Application Of A New Scale Inhibitor And Anticorossion-DAATMP

In this paper, A new phosphonate corrosion and scale inhibitor 2,5-diaminoadipic acid—N, N, N',N'-tetramethylidene-phosphonic acid (DAATMP)was designed and synthesized according to optimized molecule structure theory. It had common feature and molecule structure of Phosphonate and Phosphonopoly carboxylic acid corrosion and scale inhibitors. Furthermore, it decreased amino acid structure. So its biodegradability was improved. It can replace existing phosphonate corrosion and scale inhibitors. It can solve high Phosphonate content and hard biodegradability in using Phosphonate and Phosphonopoly carboxylic acid corrosion and scale inhibitors. So it is accorded with the requirements of environmental protection. It can be extensively applied in circulating cooling water and chemical cleaning drug.2,5-diaminoadipic acid - N,N,N,N-tetramethylidene-phosphonic acid is synthesized through three reactive steps by using adipic acid, bromine and phosphite as raw material in acidic condition. The product (DAATMP) was purified by multi-times recrystallization, multi-times dehydrated, dried in vacuum. The character DAATMP was characterized by IR, MS ,NMR spectra and element analysis .The antiscaling property of synthetic product was studied by using method of bubble, the effect of scale inhibitor concentration , [Ca²⁺], pH, as well as reaction time on DAATMP performance were discussed. The results showed: in the condition of [Ca²⁺] 240mg/L,scaling reaction time 6h and pH 7.0, increased DAATMP concentration can add scale inhibiting performance; In the water condition of DAATMP scale inhibiting performance, alkalescence is better than acidity. According to the experiment ,the optimal scale inhibiting performance condition is that [Ca²⁺] 120 mg/L, pH 8.5 ,temperature 60℃,DAATMP 5mg/L,and the optimal scale inhibition ratio can be up to 89.05%.A rotary hanged weight losing method was used to measure the anticorrosion properties of the synthetic products in different dosages. The result indicate , in the stimulant water quality (CaC1.2H₂O 735mg/L, MgSO₄.7H₂O 493mg/L, NaCl 658mg/L, NaHCO₃ 168 mg/L), anticorrosion reaction time 72 h , 60mg/L of DAATMP shows well effect of anticorrosion rate for A₃ carbon steel and anticorrosion rate reach 72.28%;If it is used inpretreatment film, 10 mg/L of DAATMP is enough to reach a well effect and anticorossion ratio be up to 90%. Furthermore, Zn²⁺ greatly enhanced the anticorossion effect of DAATMP. When it is used in pretreatment film, 5-10 mg/L of DAATMP show that anticorossion ratio be up to 90%.