用卡尔费休库仑法测定橡胶中的水分含量

Determination of water content in rubber by coulometric Karl Fischer method

采用卡尔费休库仑滴定法测定了橡胶中的水分含量,研究了环境水分、漂移值、加热温度、载气流量、试样量等因素对测定结果的影响,确定了方法的重复性和再现性。结果表明,选择干燥氮气作为载气、载气流量为50~70 mL/min、漂移值为20μg/min和试样量为0.5~1.0 g时,该测定方法的重复性较好。当水分质量分数小于0.5%时,实验室内的重复性小于0.019%,实验室间再现性小于0.053%。

The water content in rubber was determined by coulometric Karl Fischer titration method.The effects of environmental moisture,drift value,heating temperature,carrier gas flow and sample mass on test results were studied,the repeatability and reproducibility of the determination method were established.The results showed that repeatability of this determination method was better when dry nitrogen gas was selected as carrier gas,carrier gas flow rate was between 50 mL/min and 70 mL/min,drift value was 20μg/min and sample mass was between 0.5 g and 1.0 g.When the water mass fraction was less than 0.5%,the repeatability within laboratory was less than 0.019%and the reproducibility between laboratories was less than 0.053%.