端羧基超支化聚酯阻垢剂的制备及性能研究

Preparation and properties of carboxyl-terminated hyperbranched polyester scale inhibitor

以季戊四醇(PE)与2,2-二羟甲基丙酸(DMPA)为原料,采用“一步法”合成二代超支化聚酯(HBPE-OH),通过马来酸酐(MAH)对HBPE-OH进行改性、羧酸化,生成超支化聚酯(HBPE-COONa)。使用红外光谱和核磁共振对超支化聚酯进行结构表征,用静态阻垢法测定阻垢率,探究合成和改性过程中时间、温度、催化剂用量对阻垢率的影响。结果表明,阻垢剂合成最佳温度为145℃,合成时间6 h,催化剂用量为0.5%(质量分数);改性最佳温度105℃,改性时间3 h,催化剂用量0.1 mL。冷却循环水中含有超支化阻垢剂6 mg/L时,对硫酸钙的阻垢率可达97.1%,优于聚环氧琥珀酸钠和聚丙烯酸钠等市售阻垢剂。

Using pentaerythritol(PE)and 2,2-dimethylolpropionic acid(DMPA)as raw materials,the second-generation hyperbranched polyester(HBPE-OH)is synthesized by the“one-step method”,and the second-generation hyperbranched polyester(HBPE-OH)is synthesized through maleic anhydride(MAH).Generation of hyperbranched polyester(HBPE-OH)is modified and carboxylated to produce hyperbranched polyester(HBPE-COONa).The structure of hyperbranched polyester was characterized by infrared spectroscopy and nuclear magnetic resonance,and the scale inhibition rate was measured by static scale inhibition method,the influence of time,temperature and catalyst dosage on the scale inhibition rate in the synthesis and modification process.The results show that the optimal temperature for the synthesis of scale inhibitor is 145℃,the synthesis time is 6 h,the amount of catalyst is 0.5%(mass fraction);the optimal temperature for modification is 105℃,the modification time is 3 h,and the amount of catalyst is 0.1 mL.When the cooling circulating water contains 6 mg/L of hyperbranched scale inhibitor,the scale inhibition rate of calcium sulfate can reach 97.1%,which is better than commercial scale inhibitors such as sodium polyepoxysuccinate and sodium polyacrylate.