物理化学学报 >> 1986, Vol. 2 >> Issue (04): 356 -362 .doi: 10.3866/PKU.WHXB19860415

研究论文 上一篇    下一篇

粘度法研究外加盐对离子聚合物在水中形态的影响

李卓美; 钟垣真   

  1. 中山大学高分子研究所
  • 收稿日期:1985-10-21 修回日期:1986-04-04 发布日期:1986-08-15

INFLUENCE OF ADDED SALTS ON THE CONFORMATION OF 6, 10Br IONENE POLYMER IN AQUEOUS SOLUTION

Li Zhuomei; Zhong Yuanzhen   

  1. Institute of Polymer Science, Zhongshan University
  • Received:1985-10-21 Revised:1986-04-04 Published:1986-08-15

摘要: 本文考察外加盐浓度、反离字半径和价数对6, 10Br大分子形态的影响。计算表征分子尺寸的各种参数。表明6, 10Br分子形态的转变是主链上正氮离子的静电斥力和—CH_3之间亲合力协同作用的结果。对大分子卷曲的影响是: I~->Br~->Cl~-。在KI溶液中, 6, 10Br转变为6, 10I而导致沉淀, 估计与I~-的极化率大易变形有关, 也与6, 10Br主链的结构特点有关。多价反离子(SO~(2-)_4, PO~(3-)_4)对大分子形态的影响与Cl~-和Br~-没有明显不同。

Abstract: Influence of added salts on the conformation of 6,10 Br ionene polymer has been examined by viscometry. Molecular dimensions of 6,10 Br in aqueous KBr solutions for the range between 0 to 0.4 mol L~(-1) were calculated. Results showed that corresponding changes had taken placed in four parameters which indicated the long-range interactions: the Huggins constant K' increased the Mark-Houwink exponent a decreased until approximated to 0.5, the solvent-polymer interaction parameter B reduced nearly to zero, and the expansion factor a decreased until approximated to unity when the concentration of KBr increased. These results showed that the 0.4 mol L~(-1) KBr aqueous solution was close to θ-condition. However, the parameters which related to the short-range effects (K_0 and the steric factor σ) did not appear to be affected by the concentration of added salt.
A conformational change was observed for 6,10Br from a swollen random coil in medium of low ionic strength to a compact random coil in medium of high ionic strength. The transition was interpreted in terms of simultaneous decrease in electrostatic repulsion and an increase in hydrophobic attraction among the methyl groups. Since the former interaction was more sensitive to salts than the latter did, a break appeared in the curve of log [η] plotted against the salt concentration C_s....