Synthesis And Properties Of Polymer Silicon Scale Inhibitor

In industrial circulating water treatment systems such as oil fields,steam boilers,paper making and reverse osmosis membranes,raw water and circulating water will contain a certain amount of silica and its compounds,which are easily deposited in the form of silicon scale,which affects the safety of the system,run.The addition of a scale inhibitor to a circulating water system is a commonly used method for inhibiting the deposition of silicon scale.In this paper,by analyzing the scale formation of scale and scale inhibition mechanism of scale inhibitor,the molecular scale design of polymer scale inhibitor was carried out,and a zwitterionic polymer scale inhibitor was synthesized.Firstly,a trishydroxyethylallyl quaternary ammonium salt cation(THAAC)monomer was synthesized and the synthesis conditions were optimized.The results showed that water was used as the solvent,the reaction temperature was 40 ?,n(triethanolamine):n(chloropropene)When the reaction time is 2 h,the yield of THAAC cation in the product can reach 79.8%.Then,three kinds of monomers were selected from THAAC quaternary ammonium salt cation,AMPS,AM,AA,MAH and MA for copolymerization reaction,and the effects of different functional groups on scale inhibition were investigated.The experimental results show that the amphoteric polymer scale inhibitor A-A/TAC obtained by polymerization of THAAC quaternary ammonium salt cation,AM and AMPS has better scale inhibition effect.The optimum polymerization conditions of AA/TAC were studied and optimized by single factor experiment and orthogonal experiment respectively.The optimal synthesis conditions were as follows:monomer ratio n(THAAC):n(acrylamide):n(AMPS)was 1:2:1,the polymerization temperature is 60 ?,the reaction time is 4 h,the initiator mass fraction is 4.5%,and the A-A/TAC scale inhibitor mass fraction is about 40%of the total mass,the scale inhibition effect is optimal,and the silicic acid is retarded.The scale inhibition rate of salt scale can reach 76%,and the scale inhibition rate of resistant silica scale can reach 68%.Structure and performance characterization of A-A/TAC polymer:A-A/TAC polymer scale inhibitor showed good hydrolysis and thermal stability,solid content was 54.98%,density was 1.186 g/cm3,and viscosity-average molecular weight was 3100.SEM scanning images of polymer scale inhibitor A-A/TAC and non-polymer scale inhibitor showed that A-A/TAC polymer scale inhibitor could effectively inhibit scale deposition.In A-A/TAC scale inhibitor concentration of 120 mg/L,system pH range between 6 to 9,and the system temperature of 30 ?,dosing time within 48 h,A-A/TAC polymer scale inhibitors resistance silicate scale inhibition rate can reach 77%,the resistance colloidal silicon scale scale inhibition rate can reach 65%,the scale inhibition performance is stable,can be applied to the industrial production field.Four scale inhibitors commonly used at home and abroad,PESA,HEDP,ATMP,PASP and A-A/TAC,were selected for the compound experiment.A-A/TAC had good scale inhibition performance against colloidal scale and calcium silicate scale,and the scale inhibition rate of calcium silicate scale after the mixture with PESA or HEDP was about 76.6%,with satisfactory effect.The scale inhibition rate of colloidal scale was 58%,with poor effect.