摘要
本文以丙烯酰胺(AM)单体水溶液为分散相,Span80/Tween80为乳化剂,白油为分散介质,配制了稳定的丙烯酰胺微乳液。依据HLB值和最大增溶水相量原则,配制了油相质量分数为45.0%、Span80/Tween80(质量比3∶1)复合乳化剂质量分数为19.5%、水相质量分数为35.5%的W/O微乳液(以体系总质量计),40℃下利用反相微乳液聚合法反应2h,制备了纳米交联聚丙烯酰胺微球。结合转化率的计算,探讨了聚合反应温度、反应时间、引发剂用量及交联剂用量等合成条件对交联PAM微球转化率的影响,确定了具有较高转化率的交联PAM微球的优化合成条件:交联剂(N,N-亚甲基双丙烯酰胺)MBA用量为0.10%、引发剂(APS/SHS)用量为0.50%(以单体质量计)。采用扫描电子显微镜(SEM)和偏光显微镜对PAM微球的形貌进行了表征。SEM和偏光显微镜结果显示,微球具有较规则的球型,粒径分布较为均一,约为50~100 nm。对微球的应用性能进行了评价,结果显示,PAM微球具有较高的固形物含量以及较大的吸水膨胀倍率。填砂管封堵实验表明,聚合物微球对提高采收率具有较为明显的作用。
A stable acrylamide microemulsion was prepared using acrylamide(AM) monomer aqueous solution as the dispersed phase,Span80/Tween80 as the emulsifier and white oil as the dispersion medium.According to the principle of HLB value and maximum compatibilized water phasor,W/O micro with oil phase fraction 45.0%,Span80/Tween80(mass ratio 3:1) composite emulsifier mass fraction 19.5% and water phase mass fraction 35.5% were prepared.The emulsion(based on the total mass of the system) was prepared by reverse phase microemulsion polymerization at 40 ℃ for 2 h to prepare nano-crosslinked polyacrylamide microspheres.Combined with the calculation of conversion rate,the effects of polymerization temperature,reaction time,amount of initiator and amount of cross-linking agent on the conversion of cross-linked PAM microspheres were investigated.The cross-linked PAM microspheres with higher conversion rate were determined.The optimized synthesis conditions were as followed:crosslinking agent(N,N-methylenebisacrylamide) MBA dosage 0.10%,and initiator(APS/SHS) dosage 0.50%(by mass of monomer).The morphology of PAM microspheres was characterized by scanning electron microscopy(SEM) and polarized light microscopy.The results of SEM and polarized light microscopy showed that the microspheres had a relatively regular spherical shape with a uniform particle size distribution of about 50~100 nm.The application properties of the microspheres were also evaluated.The results showed that the PAM microspheres had a high solid content and a large water absorption expansion ratio.The plugging experiment of the sand filling tube showed that the polymer microspheres had a significant effect on the enhanced oil recovery work.
引文
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