长链疏水改性苯丙共聚物乳液的合成及固沙性能

以苯乙烯(St)和甲基丙烯酸甲酯(MMA)为硬单体，丙烯酸丁酯(BA)、丙烯酸(AA)和丙烯酸羟乙酯(HEA)为软单体，丙烯酸十八酯(SA)为功能单体，过硫酸钾(KPS)为引发剂，聚氧乙烯辛基苯酚醚-10(OP-10)和十二烷基硫酸钠(SDS)为复合乳化剂，采用种子乳液聚合，制备了长链疏水改性苯丙共聚物乳液，采用氢核磁共振(1H NMR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、热重分析(TGA)等对共聚物进行表征并研究其固沙性能. 结果表明:当乳化剂SDS与OP-10的质量比为1 ∶ 1，亲油亲水平衡值(HLB)为27.50时，乳液最稳定，平均粒径为1.423 μm，乳液分散指数(TSI)为0.413. 丙烯酸十八酯质量分数为3%(占单体总质量的比例)时，聚合物热分解温度约为340 ℃，胶膜硬度达到3 H，吸水率降低至3.25%，水接触角提高至78.6°. 改性苯丙共聚物乳液作为固沙剂使用，当固沙剂固含量(质量分数)为15%、添加量为5 g/cm3时，沙柱的无侧限抗压强度为118.32 kPa、内聚强度为16.53 kPa、内摩擦角为8.68°，沙盘的相对冲刷保留率为98.2%，相对风蚀保留率为100%.

The Synthesis and Sand Solidification Properties of Long Chain Hydrophobic Modified Styrene-acrylic Copolymer Emulsion

A long chain hydrophobic modified styrene-acrylic copolymer emulsion was prepared with seed emulsion polymerization using styrene(St) and methyl methacrylate(MMA) as hard monomer, butyl acrylate(BA), acrylic acid(AA) and hydroxyethyl acrylate(HEA) as soft monomer, stearyl acrylate(SA) as functional monomer, potassium persulfate(KPS) as initiator, polyoxyethylene octyl phenol ether-10(OP-10) and sodium dodecyl sulfate (SDS) as compound emulsifier. the copolymer was characterized with 1HNMR, SEM, TEM, TGA, etc. And its sand-fixation performance was studied. The results showed that when the mass ratio of emusifiers of SDS to OP-10 was 1 ∶ 1 and the hydrophilic lipophilic balance(HLB) was 27.50, the emulsion was the most stable with an average particle size of 1.423 μm and a TSI of 0.413. When the amount of stearyl acrylate(SA) was 3%(the total mass of monomer), the thermal decomposition temperature of polymer was about 340 ℃, the hardness of film reached to 3 H, the water absorption rate decreased to 3.25% and the water contact angle increased to 78.6°. The modified styrene-acrylic copolymer emulsion could be used as a sand solidification agent with a solid content of 15% and a dosage of 5 g/cm3, the unconfined compressive strength of the sand column was 118.32 kPa, the shear strength was 16.53 kPa, the internal friction angle was 8.68°, the relative resistance to erosion rate of the sand table was 98.2%, and the relative resistance to wind erosion rate was 100%.