高黏度聚醚多元醇水分测定方法的改进研究

Improvement of Moisture Determination Method for High Viscosity Polyether Polyols

目前聚氨酯行业常用的水分检测方法是卡尔-费休法,在测定常规黏度的聚醚多元醇时,测量结果比较准确。但在测量高黏度的聚醚多元醇时,黏度对测定结果影响较大,特别是低温测定时,由于溶解时间的加长,聚醚多元醇黏度随温度下降而近一步增大,从而导致测定结果出现较大误差。但将高黏度聚醚多元醇样品温度加热到80℃,粘度降至3000 mPa·s以内时,水分的测定结果相对比较准确,并且粘度降至3000 mPa·s时,黏度对水分的测定结果基本无影响。

Karl Fischer moisture meter is a common method for measuring moisture in polyurethane industry at present.When measuring polyether polyols with conventional viscosity,the measuring results are quite accurate.But when measuring the high viscosity polyether polyols,the measurement results will be biased due to the increase of the solution time,especially in the case of low temperature in winter,the viscosity of the sample will increase with the decrease of the temperature Thus,the result of the determination has a large error.However.However,when the temperature of high viscosity polyether polyols is heated to 80℃,or the viscosity is reduced to 3000 mPa·s,the measurement results are relatively accurate,and when the viscosity is reduced to 3000 mPa·s,the viscosity has little effect on the measuring results.