【作者】 孙绪兵；

【导师】 梁兵；

【作者基本信息】 四川大学 ， 材料学， 2007， 硕士

【摘要】 本文选用聚乙二醇单甲醚丙烯酸酯(MPEGAA)及丙烯酸(AA)为共聚单体，采用水溶液共聚的方法制备出了具有长侧链醚基的共聚物阻垢分散剂P(AA／MPEGAA)。研究了单体配比、引发剂用量、链转移剂用量、反应温度及反应时间对共聚物阻垢性能的影响；考察了共聚物浓度、钙离子浓度、pH值、阻垢温度、阻垢时间以及不同侧链聚合度对碳酸钙垢、磷酸钙垢及硫酸钙垢的作用；考察了共聚物溶液分散氧化铁、缓蚀碳钢、影响体系浊度的能力；比较了常用阻垢剂聚丙烯酸(PAA)、聚丙烯酸／2-丙烯酰胺-2-甲基丙磺酸P(AA／AMPS)与聚醚型阻垢分散剂的阻垢性能；并采用红外光谱、热重、扫描电镜、X衍射等对共聚物的结构、耐热性能，以及钙垢的形貌和晶型等进行了表征。研究结果表明，聚合反应条件对共聚物阻垢剂P(AA／MPEGAA)阻垢性能的影响主要是通过调节聚合物分子量的大小来实现，而且对阻碳酸钙垢率影响较大，对阻磷酸钙垢率影响较小；所合成的共聚物具有优异的阻磷酸钙垢、硫酸钙垢和较好的阻碳酸钙垢的性能；聚合物的阻垢性能随着钙离子浓度的增加、阻垢温度的升高、pH值的增大及阻垢时间的延长而存在着程度不同的下降趋势，但仍能适用于较高浓缩倍数的循环水体系。通过对PAA、P(AA／AMPS)和不同侧链聚合度的P(AA／MPEGAA)阻垢率的比较，表明羧基是影响碳酸钙成垢的主要因素，而分散作用机理则是阻磷酸钙垢和阻硫酸钙垢的主要机理。醚基的存在赋予阻垢分散剂在具有阻垢分散作用的同时具有絮凝功能，能够将溶液中的钙垢等微小颗粒聚集在一起，形成尺寸较大易于机械分离的聚集体，从而降低体系的浊度。扫描电镜照片进一步证实，阻垢剂的加入改变了碳酸钙的结晶方式，使垢样的形貌发生了改变。添加PAA后尽管表面不再平整但仍能观察到比较规整的四面体晶体结构；而添加P(AA／MPEGMA)后晶体形状被彻底破坏，垢样成为疏松、多孔、絮状的无定形聚集体。X衍射谱图也表明，添加P(AA／MPEGMA)后垢样中方解石含量减少甚多，垢样变得疏松。更多还原

【Abstract】 The water-soluble copolymer P（AA/MPEGAA） of acrylic acid （AA） andmethoxy polyethylene glycol acrylate （MPEGAA） containing aether groups in theside chains were synthesized by radical aqueous solution copolymerization. Theeffects of the reaction conditions such as ratio of monomer, dosage of initiator,dosage of chain transfer agent, reaction temperature and reaction time on theanti-scaling performance of the copolymer were studied. The effects of thecopolymer concentration, calcium concentration, pH value, inhibiting temperatureand inhibiting time on the anti-scaling rate of calcium carbonate, calcium phosphateand calcium sulphate were investigated. The performances of copolymer ofdispersing ferric oxide, anti-corrosing and influencing the turbidity were studied too.The copolymer structure and heat resistance were respectively characterized by IRSpectrum and Tg. The crystal morphology of CaCO₃ phase was characterized bySEM and XRD.The results show that the influence of reaction conditions on the performanceof the copolymer mainly depends on the molecular weigh of the copolymer whichhas more effect on inhibiting calcium carbonate than inhibiting calcium phosphate.The copolymer has excellent performances of inhibiting calcium phosphate, calciumsulphate and very good performance of inhibiting calcium carbonate. Theanti-scaling performances of copolymer become bad a little with the calciumconcentration increasing or inhibiting temperature rising or the pH value increasingor inhibiting time prolonging, but the copolymer can be still used in cooling watersystem of much high cycle of concentration. The carboxyl group is the primary factor of inhibiting calcium carbonate scale,while mechanism of inhibiting calcium phosphate and calcium sulfate is dispersionby contrasting the inhibiting performance of PAA, P（AA/AMPS） withP（AA/MPEGAA）. The copolymer can reduce the turbidity of the cycle system bycongregating the small particles such as calcium scales which form biggish congeriesand are easily mechanically separated because aether groups endow the copolymerwith inhibiting, dispersing and flocculating fuctions.SEM micrographs further approve that the copolymer changes the crystalmorphology of calcium carbonate. The morphology of calcium carbonate scale withthe presence of the PAA is not in order any more, but can be still observed the shapeof cubic structure. The crystal morphology of calcium carbonate scale with addingP（AA/MPEGAA） is completely destroyed, and XRD spectrums show the quantity ofcalcite reduces, so the scales become loose, spongy, floccular and amorphous.更多还原