不稳定交联凝胶类堵剂的探索研究

不稳定交联（稳定交联剂和不稳定交联剂复合使用）技术是近年来出现的一种新型交联技术，逐步在预交联颗粒、聚合物微球等凝胶类堵水剂中应用。利用稳定交联剂MBA和不稳定交联剂PS-11合成一种高交联度的吸水树脂，考察不稳定交联剂对凝胶吸水性能、耐盐性能及弹性强度的影响，并结合扫描电镜观察凝胶内部骨架结构。研究表明：高温环境中（90 ℃）不稳定交联剂PS-11分解较快，但分解不完全，高质量分数的不稳定交联剂有一定缓膨效果；PS-11分解有助于提高凝胶的耐盐性能，矿化度20×10⁴ mg/L条件下，凝胶吸水倍率达21 g/g，同时弹性强度也显著增加；电镜扫描结果证实PS-11发生分解，凝胶内部结构变得混乱。据此提出不稳定交联凝胶类堵剂未来可能的发展方向。

Labile cross-linked technology (stable and unstable cross-linking agent used in combination) is a new type of cross-linked technology emerging in recent years and have being gradually applied in pre-crosslinked particles, polymer microspheres such as gel plugging agent. In this paper, we developed a new water absorbent resin with high cross-linking degree using both stable(MBA) and labile(PS-11) cross-links, the impact of labile cross-linkers to water absorption, salt resistance properties and elastic strength of gels was tested. We also observed the internal frame structure of the gel by Scanning Electron Microscope(SEM). The results show that labile cross-links (PS-11) decompose rapidly, but not completely in the high temperature of 90 ℃. High concentration of labile cross-links can play effect of retarding swelling; the decomposition of PS-11 can also attribute to improve expansion ratio in the brine, the volume expansion rate reaches to 21 g/g at 0.2 million mg/L salt solution and significantly increases the elastic strength at the same time. SEM results confirm PS-11 have decomposed, making the gel structure chaotic. Based on this, the possible directions for future development are pointed out.