无皂乳液聚合制备PMA-MMA乳液及其净水性能

Preparation of PMA-MMA Emulsion by Soap-Free Emulsion Polymerization and Evaluation of Water-Purification Performance

刘宗昭郭海军李 娟

LIU Zong-Zhao GUO Hai-Jun LI Juan

以甲基丙烯酸（MA）和甲基丙烯酸甲酯(MMA)为单体、过硫酸铵为引发剂，通过无皂乳液聚合制备高MA、MMA质量比的PMA-MMA乳液。考察了不同反应条件对聚合结果的影响，得到制备PMA-MMA乳液的最佳合成条件为：反应温度70℃、MA与MMA质量比6:1，总单体质量分数13%，引发剂与总单体质量比2‰，在MA和引发剂反应25 min后加入MMA继续反应5 h。所得白色乳液产品的黏度为280 mPa·s，转化率99.1%，凝胶率0.5%，常温放置1个月不分层。处理南海东部某油田含油污水的结果表明，在加药量为15 mg/L时，PMA-MMA乳液除油率为95%，优于在用国外药剂（92%）。现场试验加药量为10 mg/L，可将外排污水含油量从原来的15 mg/L降至8 mg/L。

PMA-MMA emulsion with high mass ratio of methacrylic acid (MA) and methyl methacrylate (MMA) was prepared using MA and MMA as monomers and ammonium persulfate as initiator by soap-free emulsion polymerization. The effect of different reaction conditions on polymerization was studied. The optimum reaction condition of PMA-MMA emulsion was obtained as follows: 70℃ reaction temperature, 6:1 mass ratio of MA and MMA, 13% total monomer mass fraction, 2‰ mass ratio of initiator and total monomer, 25 min?reaction time of MA and initiator and then MMA adding, 5 h continuous reaction time. The viscosity of the obtained white emulsion was 280 mPa·s, the conversion rate was 99.1% and gel rate was 0.5%, without separation after storage for one month at normal temperature. PMA-MMA emulsion was used to treat the oilfield oily wastewater in the east of South China Sea, the results showed that the oil removal efficiency could reach 95% when emulsion dosage was 15 mg/L, which was superior to that of on-site foreign reagent (92%). The oil content of discharged production waste water decreased from15 mg/L to 8 mg/L when the emulsion dosage on site was 10 mg/L.