水溶性高分子链中磺酸盐基团含量的电导滴定测定法

研究了N ,N ,N 三甲基十六烷基溴化铵 (CTAB)与丙烯酰胺 (AM) 2 丙烯酰胺基 2 甲基丙磺酸钠盐(NaAMPS)二元共聚物P(AM co NaAMPS)的复合作用 .在复合作用过程中 ,由于不断释放出高导电性的无机盐小离子 ,故随着表面活性剂的加入 ,聚电解质水溶液的电导率不断增大 .当采用较低浓度 (0 0 0 1mol·L- 1 )且使二者的离子等摩尔量发生复合作用时 ,体系的电导率会发生明显的转折 .利用电导率的这一转折性变化 ,建立起了复合作用电导滴定法测定共聚物P(AM co NaAMPS)分子链中磺酸盐单体NaAMPS含量的新方法 .与元素分析进行比较的结果表明 ,上述复合作用电导滴定法可作为测定水溶性大分子链中磺酸盐单体含量的方便而又准确的方法 ,而且预计还可用作为测定水溶性大分子链中其它离子性基团含量的简捷方法

DETERMINATION OF THE CONTENT OF SULFONATE MONOMER IN WATER-SOLUBLE COPOLYMER BY COMPLEX REACTION CONDUCTOMETRIC TITRATION

In aqueous solutions,orderly polyelectrolyte-surfactant complex precipitates can been formed through electrostatic interaction.During complexing process,the conductivity of polyelectrolyte aqueous solution increases with adding of surfactant because of release of small inorganic electrolyte ions which have high conductivity.When polyelectrolyte and surfactant react according to equivalence and their concentrations are lower,the conductivity is distinctly turned.So the conductometric titration method can be used for measuring the composition of water-soluble copolymer containing ion monomer through complex reaction between polyelectrolyte and surfactant.In this investigation,the composition of copolymer P(AM-co-NaAMPS) of acrylamide (AM) and 2-acrylamido-2-methyl-propanesulfonate sodium (NaAMPS) has been determined with the aqueous solution of cetyl trimethyl ammonium bromide (CTAB) as titrant at a concentration of 0.001 mol·L -1 by conductometric titration method.The results obtained were compared with the results of element analysis,and were very satisfactory.It can be expected that the contents of ionic groups in water-soluble macromolecules can all be measured by using above complex reaction conductometric titration method.