含磷络合剂提高HPAM冻胶热稳定性机理

Study on Mechanism of Phosphorus-containing Complexing Agents Improving Thermal Stability of HPAM Hydrogel

研究了含磷络合剂(POP)对聚丙烯酰胺(HPAM)冻胶热稳定性的影响,考察了POP对HPAM黏度、重均分子量和第二维里系数的影响,通过红外光谱技术和核磁共振氢谱技术分析了POP与HPAM的反应机理和POP抑制冻胶失水机理。结果表明,POP能有效抑制冻胶失水,当POP质量分数为0.03%时,聚丙烯酰胺冻胶失水率最低。POP和HPAM发生交联反应生成C—O—P化学键,使得HPAM聚合物分子的重均分子量、第二维里系数和流体力学半径增加,HPAM冻胶的稳定性得到改善,失水率降低。

The effect of phosphorus-containing complexing agents(POP)on the thermal stability of hydrolyzed polyacryamide(HPAM)hydrogel was studied.The effects of POP on the viscosity,weight average molecular weight and second virial coefficient of HPAM were investigated.The reaction mechanism of POP and HPAM and the mechanism of POP inhibiting the syneresis of hydrogel were analyzed by infrared spectroscopy and NMR.It is found that the syneresis of the hydrogel can be effectively suppressed by adding POP.When the mass fraction of POP is 0.03%,the water loss rate of HPAM hydrogel is suppressed most obviously.The C-O-P chemical bond generated through the cross-linking reaction of POP and HPAM at high temperatureleads to the increase of the weight average molecular weight of HPAM polymer molecules,the second virial coefficient,and the hydrodynamic radius.Therefore,the stability of POP/HPAM hydrogel is improved,and the water loss rate of hydrogel is reduced.