摘要
利用聚丙烯酸(PAA)和聚丙烯酸钠(NaPAA)的水溶液作为溶剂,测定了不同浓度的十六烷基三甲基溴化铵(CTAB)在高分子溶剂中的相对粘度rη,结果表明:对PAA溶液来说,随着CTAB浓度的增加,其rη经历了迅速下降、保持恒定和迅速上升直到溶液中出现沉淀的过程;对NaPAA溶液来说,随着CTAB浓度的增加,其rη虽然同样经历了迅速下降、保持恒定和迅速上升的过程,但是NaPAA溶液rη上升幅度显著减小.当NaPAA中和度达到0.042时,NaPAA溶液rη上升的幅度完全可以忽略,溶液也不出现沉淀.溶液中高分子链电荷密度的不同是导致PAA和NaPAA与CTAB在溶液中聚集行为不同的根本原因,具体表现为PAA溶液和NaPAA溶液rη对CTAB浓度依赖性出现显著差异.
The relative viscosity of cetytrimethylammonium bromide （CTAB） in solutions containing a certain concentration of poly（acrylic acid） （PAA） neutralized partly with NaOH was measured. It is shown that the relative viscosity of CTAB in PAA solution, ηr, exhibits initial rapid decrease and the subsequent little change and final significant increase with increasing surfactant concentration of CTAB. A similar relationship between ηr and the concentration of CTAB was obtained for CTAB in partly neutralized PAA solutions. However, the increase of ηr for CTAB in partly neutralized PAA solutions diminishes significantly for CTAB in PAA solution. When the degree of neutralization is 0.042, the increase of ηr at high concentration of CTAB is negligible. On such an occasion, no precipitate was observed even at high concentration of CTAB. The experimental results indicate that the aggregation of CTAB with oppositelycharged chains in solution is greatly affected by the charge density of polymer chains in solution.
基金
国家科技攻关项目(2003BA613A-06)
安徽省自然科学基金(00046310)资助
关键词
相对粘度
聚丙烯酸
表面活性剂
聚集行为
relative viscosity
poly（acrylic acid）
surfactant
aggregation
