热熔型氟树脂涂料中PVDF树脂含量测定及其不确定度评估

采用溶剂萃取-碱熔融-离子色谱法对热熔型氟树脂涂料树脂组分中的聚偏二氟乙烯(PVDF)成分进行测定,测定方法具有环保、快速、准确度高等优点。离子色谱法测定溶液中F-含量过程中,当校准曲线浓度范围较大时,弱电解质的非完全电离会导致曲线弯曲。通过数学代换将二次曲线乘幂线性化,结合样品溶解过程中的样品称量、定容体积、标准溶液配制、仪器测量重复性等影响测量不确定度的主要分量,对新方法的测量不确定度进行了系统分析,结果显示该方法的扩展不确定度为±0.96%。

Determination of PVDF content in fluorine paintings and its uncertainty evaluation

The poly (vinylidene fluoride) (PVDF) content in resin component of hot-melt fluorocarbon resin coatings is determined by means of solvent extraction-alkali fusion-ion chromatography technology, which shows advantages of environmental friendliness, quickness and accuracy. Incomplete ionization of weak electrolyte fluoride will lead to the non-linear fitting results, while F- content is determined by ion chromatography. In this paper, the non-linear curve is transformed into linear curve by power algorithm, and then the uncertainty of the novel determination method is evaluated combined with other main factors, such as sample weighing, constant volume, standard solution preparation and instrument measurement repeatability. The results show that the expanded uncertainty of this method is ±0.96%.