溶解氧及除氧剂对聚合物溶液黏度和长期热稳定性的影响

Experimental Study on the Effect of Dissolved Oxygen and Deoxidants on the Viscosity and Long-term Stability of Polymer Solution

在聚合物溶液配制过程中,溶解氧是导致聚合物溶液化学降解、溶液黏度和长期热稳定性下降最重要的因素之一。以具有抽真空、充氮气功能的手套箱作为实验主体,搭建了一种新的溶解氧浓度控制实验装置,利用该装置研究了溶解氧及除氧剂对聚合物溶液熟化阶段的黏度和长期热稳定性的影响。实验结果表明:无还原性物质存在(即Fe^(2+)质量浓度为0)的条件下,溶解氧浓度对聚合物溶液的溶胀-溶解过程无明显影响,溶液黏度无明显下降趋势;还原性物质存在(即Fe^(2+)质量浓度为2.5 mg/L)的条件下,当溶解氧浓度极低(即0.05～0.1 mg/L)时,溶液黏度短时间内没有明显下降趋势;随着溶解氧浓度逐渐升高,溶解氧对聚合物溶液黏度的影响变得更为复杂。在还原性物质存在的条件下,喹啉化合物类除氧剂MO-1和胺类除氧剂MO-2的浓度为150 mg/L、温度为60℃时,聚合物溶液长期热稳定性得到有效提高,溶液黏度保留率可超过100%。

In the process of polymer solution preparation,dissolved oxygen is one of the most important factors that lead to the chemical degradation of polymer solution and the decrease of viscosity and long-term heat stability of the solution.A new experimental device for controlling the concentration of dissolved oxygen is set up by using the glove box with the function of vacuuming and nitrogen filling as an experimental subject.Based on the device,the effect of dissolved oxygen and deoxidants on the viscosity and long-term heat stability at the ripening stage of polymer solution is studied.The experimental results show that without reducing substances(i.e.,the mass concentration of Fe^2+is 0 mg/L),the concentration of dissolved oxygen has no significant impact on the swelling-dissolution process of polymer solution,and the viscosity has no significant downward trend.In the presence of reducing substances(i.e.,the mass concentration of Fe^2+is 2.5 mg/L),when the dissolved oxygen concentration is extremely low(0.05-0.1 mg/L),the viscosity of the solution in a short time is not significantly decreased.With the increase of dissolved oxygen concentration,the effect of dissolved oxygen on the viscosity of polymer solution becomes more complex.In the presence of reducing substances,when the quinoline compound deoxidant MO-1 and the amine deoxidant MO-2 at the concentration of 150 mg/L and the temperature of 60℃,the long-term thermal stability of polymer solution can be effectively improved,and the viscosity retention rate of solution is over 100%.