Abstract

A series of water-soluble comb-like copolymers of N-methyl-N-vinylacetamide and N-methyl-N-vinylamine (MVAA‒со‒MVA) bearing hydrophobic dodecyl side groups С₁₂Н₂₅ has been investigated by means of molecular hydrodynamics (viscometry, translational diffusion, and analytical ultracentrifugation) in dilute solutions in 0.1 M NaCl, under conditions of suppression of the polyelectrolyte effects. The issues of homology of these amphiphilic copolymers have been considered. The viscometry data plotted as lnη_r as function of c[η] have allowed to distinguish between macromolecules of the copolymers according to their hydrophobicity. Positive values of the second derivative B₂ determined from the initial parts of these curves have served as a measure of hydrophobicity of the amphiphilic copolymers. The noticeable differences in the B₂ values for different copolymers have shown that they do not form true homologous series. For the quasi-homologous series of the MVAA–со–MVAC₁₂H₂₅·HI copolymers with close values of B₂, the Kuhn–Mark–Houwink–Sakurada relationships have been obtained and the equilibrium rigidity of the chains has been assessed using the modified Gray–Bloomfield–Hearst equation.

中文翻译：

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中等十二烷基侧接枝密度的 N-甲基-N-乙烯基乙酰胺和 N-甲基-N-乙烯基胺系列两亲性梳状统计共聚物中的同源破坏

摘要

通过分子流体力学研究了一系列带有疏水性十二烷基侧基 С ₁₂ Н _25的N -甲基- N -乙烯基乙酰胺和N -甲基- N -乙烯基胺 (MVAA- со -MVA) 的水溶性梳状共聚物（粘度测定、平移扩散和分析超速离心）在 0.1 M 氯化钠稀溶液中，在抑制聚电解质效应的条件下。已经考虑了这些两亲共聚物的同源性问题。将粘度测定数据绘制为 lnη _r作为c [η] 的函数，可以根据共聚物的疏水性区分它们的大分子。由这些曲线的初始部分确定的二阶导数B ₂的正值已用作两亲共聚物疏水性的量度。不同共聚物的B ₂值的显着差异表明它们不形成真正的同系物。对于B ₂值接近的MVAA– со –MVAC ₁₂ H ₂₅ ·HI 共聚物的准同系系列，获得了 Kuhn–Mark–Houwink–Sakurada 关系，并使用以下公式评估了链的平衡刚性修正的格雷-布卢姆菲尔德-赫斯特方程。