干水法制备核壳聚合物微球及其性能评价

Preparation and properties of core-shell polymer microspheres prepared by dry water method

以丙烯酰胺、2-丙烯酰胺基-2-甲基丙磺酸为单体,N,N’-亚甲基双丙烯酰胺为交联剂,过硫酸铵和亚硫酸氢钠为引发剂,水为溶剂,疏水Si O_(2)为壳层原料,采用干水法制备干水微反应器,将其干燥后即得核壳聚合物微球(PMS@SiO_(2))。考察了SiO_(2)疏水性、疏水Si O_(2)与水相质量比、搅拌速度和搅拌时间对形成稳定干水微反应器的影响,通过正交实验对PMS@SiO_(2)的制备条件进行了优化。采用FTIR、TGA、激光粒度仪、SEM和TEM对样品进行了表征,评价了PMS@SiO_(2)吸水膨胀性能和调驱性能。结果表明,PMS@SiO_(2)的最佳制备条件为m(SiO_(2)-R812S)∶m(水相)=1∶10,搅拌速度12000 r/min,搅拌时间120 s,交联剂用量0.10%(以单体总质量为基准,下同),引发剂用量0.15%,反应温度50℃,反应时间4 h。与常规聚合物微球PMS相比,PMS@SiO_(2)在90℃环境中水化20 d,膨胀倍数约为5.0,具有缓膨特性;PMS@SiO_(2)的封堵率达90.39%,残余阻力系数为10.409,采收率增幅可达34.02%。

Core-shell polymer microspheres(PMS@SiO_(2))were obtained after drying of the dry water microreactor,which was prepared by dry water method with acrylamide,2-acrylylamine-2-methylpropanesulfonic acid as monomers,N,N’-methylene bisacrylamide as crosslinking agent,ammonium persulfate and sodium bisulfite as initiator,water as solvent and hydrophobic SiO_(2)as shell raw material.The effects of SiO_(2)hydrophobicity,mass ratio of hydrophobic SiO_(2)and water phase,stirring speed and stirring time on dry water microreactor were investigated,and the polymerization conditions of PMS@SiO_(2)were optimized by orthogonal experiment.The PMS@SiO_(2)samples obtained were characterized by FTIR,TGA,laser particle size analyzer,SEM and TEM,followed by evaluation on their water absorption expansion properties and profile control and displacement performance.The results showed that the optimum preparation conditions of PMS@SiO_(2)were as follows:m(SiO_(2)-R812S)∶m(water phase)=1∶10,stirring speed of 12000 r/min,stirring time of 120 s,crosslinking agent dosage of 0.10%(based on the total mass of monomers,the same below),initiators dosage of 0.15%,reaction temperature of 50℃and reaction time of 4 h.In comparison to conventional polymer microspheres PMS,the PMS@SiO_(2),when hydrated at 90℃for 20 d,exhibited an expansion ratio of ~5.0 showing characteristics of slower expansion.Meanwhile,PMS@SiO_(2)displayed a plugging ratio of 90.39%,residual resistance coefficient of 10.409,and the recovery rate increased by 34.02%.