离子型聚丙烯酰胺离子度的测定

Measurement of ionic degree for ion polyacrylamide

用胶体滴定法测试聚丙烯酰胺的阳离子度，用胶体反滴定法和溴代十六烷基吡啶滴定法测试聚丙烯酰胺的阴离子度，用傅里叶红外光谱对自制的聚丙烯酰胺进行官能团分析，并对常温条件下，pH值、指示剂用量、滴定速度以及聚合物残留乳化剂对离子度测定的影响进行研究。研究结果表明：对阳离子聚丙烯酰胺，当采用胶体滴定法测试阳离子度，pH=2-3，滴定速度约为25μL／s时，测试结果准确；而对阴离子聚丙烯酰胺，当采用反滴定法测定阴离子度时，在pH=9～10，滴定速度约为25μL／s时，测试结果准确；当采用溴代十六烷基吡啶滴定法时，只有在阴离子度大于30％时才可以准确测出样品的阴离子度。

The colloidal titration, the anticolloidal titration and the titration of cetyl pyridine bromide were used to measure the cationic degree and anion degree of polyacrylamide, respectively. The structures of polymers were characterized by Fourier transform infrared ray. At room temperature, the influences of pH value, dosage of indicator, speed of titration and residuum of emulsion on the measurement of ionic degree were investigated. The results show that the measurements are exact under the following conditions： for cationic degree, pH=2-3 and the rate of titration is 25μL/s; for anion degree, pH=9-10 and the rate of titration is 25μL/s. The exact results are obtained when the anion degree of polyacrylamide is bigger than 30% by the titration of cetyl pyridine bromide.