不稳定交联剂在微球合成中的应用及性能影响

Application of Labile Crosslinking Agent in the Synthesis of Microspheres and Property Impacts

摘要:

通过Ⅰ型稳定交联剂（MBA）与Ⅱ型不稳定交联剂（PEGDA）复合使用，采用反相乳液聚合法制备一种不稳定交联微球。通过本体聚合法考察PEGDA的分解温度为60-65℃，并结合激光粒度仪研究Ⅱ型交联剂对微球粒径、膨胀性能的影响，SEM观察微球水化前后的形态。研究发现，适量的Ⅱ型交联剂与MBA复合使用能够减小微球的初始粒径；微球水化前后形态近似球形，初始粒径约为3μm，膨胀后颗粒间发生团聚作用；不稳定交联微球尺寸分布较宽，在常温下几乎不膨胀，60℃后Ⅱ型交联剂失效，微球膨胀速率加快，膨胀倍率优于单一交联微球，19.5×104mg/L矿化度地层水中，微球18h内中值粒径（D0.5）从13.94μm增加到70.71μm。

Abstract:

A polymer microsphere was prepared using stable crosslinker typeⅠ(MBA) and typeⅡ(PEGDA) labile crosslinker composite，typeⅡcross-linking agent has a decomposition temperature of 60-65℃ tested by bulk polymerization and the microspheres were prepared by inverse emulsion polymerization. The impacts of type Ⅱcrosslinkers to microsphere size and expansion properties were investigated using particle size analyzer，We also observed microspheres morphology before and after hydration combined with Scanning Electron microscope (SEM) . The results showed that the right amount of typeⅡcrosslinkers and MBA can reduce the primary particle diameter; microspheres were approximately spherical shape before and after hydration and the primary particle size was about 3μm，reunite effect was observed between particles after expansion；Unstable cross-linked microspheres had wide size distribution and swelled hardly at room temperature and the failure of type Ⅱ crosslinker resulted microspheres swelled faster after 60℃，Microspheres median diameter (D0.5) ranged from 13.94μm to 70.71μm at 19.5×104mg/L salt solution within 18h.