【作者】 林晓霖；

【导师】 袁斌；

【作者基本信息】 广东工业大学 ， 环境科学， 2008， 硕士

【摘要】 根据分子构效理论,设计并合成了一种新型有机膦羧酸水质稳定剂—2,6-二膦酸基庚二酸（DPPA）。该水稳剂分子中只含有膦酸基和羧基,含磷量只有20.4%,含磷量比目前常用的二乙烯三胺五甲叉膦酸（DETPMP）的含磷量22.83%低,可见新型水稳剂更加符合环保要求;新型水稳剂含有的膦酸基个数比2-膦酸基丁烷-1,2,4-三羧酸（PBTCA）分子多一个,可以预期其缓蚀阻垢效果不比PBTCA差;新型水稳剂含氧量（52.64%）与PBTCA含氧量（53.31%）几乎相当,而比DETPMP含氧量（44.26%）高出8%,这意味着新型水稳剂更易于生物降解。研究以庚二酸、液溴、亚硫酰氯为主要原料,经酰卤化、溴化、酯化三步（一锅法）合成出2,6-二溴代庚二酸二乙酯,然后在碱性条件下,与亚磷酸二乙酯反应,再水解后得到产品。通过产物的磷元素分析和红外光谱,确定了产物的结构式。采用鼓泡法测定了合成药剂的阻垢率,采用正交试验方法探讨了该药剂的浓度、溶液pH值、钙离子浓度、反应时间等对阻垢性能的影响。试验结果表明:在钙硬为240 mg/L、pH为6.5、水温60℃、加药量40 mg/L、阻垢时间6 h的实验条件下,合成产物对CaCO₃的阻垢率达到97.3%;各类因素对阻垢率的影响次序为:pH＞温度＞药剂量＞硬度。与常用阻垢剂DETPMP和PBTCA的阻垢对比试验结果表明:在低硬度条件下,DPPA阻垢效果比PBTCA、DETPMP好。但是在高硬度水样中,不如DPPA和DETPMP的阻垢效果好。采用旋转挂片失重法分别考察了合成产品在单独使用、预膜处理和锌盐复配的情况下的缓蚀性能。结果表明:合成产物在pH为7、药剂用量为20 mg/L的条件下,单独使用时A3钢片的缓蚀率为72.28%;用浓度为120 mg/L产物预膜处理后,在10 mg/L运行浓度条件下,A₃钢片的缓蚀率90%以上;与4mg/L Zn²⁺复配时有良好的协同效应,只需加入10 mg/L DPPA的药剂量,缓蚀率可达到92.92%。在药剂对碳钢缓蚀效果的最佳条件下:铜片用120 mg/L DPPA加6 mg/L的Zn²⁺预膜24 h,然后在10 mg/L的DPPA和2 mg/L的Zn²⁺条件下运行6小时,其缓蚀效果可达94.06%。研究结果表明,合成产品具有良好的阻垢缓蚀性能,可应用于工业循环冷却水处理系统中。更多还原

【Abstract】 In this paper,a new phosphonate corrosion and scale inhibitor-2, 6-diphosphonoheptane-1,7-dicarboxylic acid（DPPA）was designed and synthesized according to optimized molecule structure theory.It has the common feature and molecule structure of phosphonate and phosphonopoly carboxylic acid corrosion and scale inhibitors.Furthermore,it containes phosphate content and Carboxyl structure. Its phosphor content is 20.4%.It’s lower than DETPMP whose phosphor content is 22.83%.So its biodegradability is improved.It can replace lower oxygen content of DETPMP（44.26%）and PBTCA（53.31%）which with one less phosphate.So it is accorded with the requirements of environmental protection and avoided the nitrogen cycling.It can be extensively applied in circulating cooling water.One-Pot Synthesis of 2,6-dibromo diethyl pimelate was synthesized through three reactive steps by using heptanedioic acid,bromine and phosporus trichloride as raw material.In alkaline condition,combined with Diethyl phosphite,then was purified by multi-times recrystallization,multi-times dehydrated,dried in vacuum. The character of DPPA was characterized by phosphor content test and IR spectra.The antiscaling property of synthetic product was studied by using method of bubble,the effect of scale inhibitor concentration;Ca²⁺concentration,pH,as well as reaction time on scale inhibiting performance were discussed.The results showed: increased DPPA concentration,pH and decreased Ca²⁺concentration,action time can add scale inhibiting performance.The results showed that DPPA is fit for conditions as follows:middle rigidity（calcium concentration 240 mg/L）,pH value 6.5,water temperature 60℃.The synthetic product has 97.3%favorable scale inhibiting properties for CaCO₃.Under low hardness,DPPA is better than PBTCA and DETPMP.A rotary hanged weight losing method was used to measure the anticorrosion properties of the synthetic products in different dosages.The result indicates:Under pH 7,20 mg/L of DPPA shows well effect of 72.28%anticorrosion rate for A₃ carbon steel.If 120 mg/L of DPPA is used in pretreatment film,10 mg/L of DPPA is enough to reach the same effect.Furthermore,between 4 mg/L to 10 mg/L of Zn²⁺greatly enhance the anticorrosion effect of DPPA.When it is used in pretreatment film,10 mg/L of DPPA shows up to 90%anticorrosion rate.If 120 mg/L of DPPA and 6 mg/L of Zn²⁺are used in pretreatment film for 24h,10 mg/L of DPPA and 2 mg/L of Zn²⁺are enough to reach the same effect in 48h（94.06%）.Furthermore,between 4 mg/L to 10 mg/L of Zn²⁺greatly enhance the anticorrosion effect of DPPA.When it is used in pretreatment film,10 mg/L of DPPA shows up to 92.92%anticorrosion rate.The studied results show:the synthetic products have excellent anticorrosion and antiscaling properties,so the product can be used in industrial cooling water treatment system.更多还原