Solution Properties of Intramolecularly Crosslinked Polyelectrolyte.

本文从链内交联、交联和反离子间相互作用的角度阐明了聚合物溶液中的相互作用。（乙烯醇）（PVA）/硼砂（Na_2B_4O_7）体系，揭示了下列实验事实：1、PVA与硼酸根离子B（OH）_4^-的络合作用（单二醇和双二醇）只发生在分子内，不改变PVA的分子量。结果表明，两种复合物的形成常数随PVA浓度C_B的增大而急剧减小，并在较高的C_B下趋于稳定，第二维里系数也是如此，这些结果可以很好地解释PVA/Borax复合体系中电荷膨胀和链内交联收缩之间的平衡。此外，络合硼酸根离子与PVA链上的电荷之间的相互排斥作用强烈地抑制了PVA链上的进一步络合作用.与上述溶液行为相关，我们还发现，相对较小的疏水性离子（乙基苯磺酸根阴离子）本身没有自缔合能力，但可以通过其疏水相互作用在聚离子（聚烯丙基铵阳离子）周围相互缔合.

The present study was carried out to clarify the mutual interaction in the polymer solution from view point of the intrachain crosslinks, polyelectrolyte, and interaction among counterions.About an interesting polyelectrolyte solution behabior observed in aqueous poly(vinyl alcohol)(PVA)/Borax(Na_2B_4O_7) systems, the following experimental facts were revealed : 1, complexations(mono-diol and di-diol) of PVA with borate ion, B(OH)_4^-, which introduce simultaneously the charges and crosslinks to the PVA chain, occur only intramolecularly, being unchanged the molecular weight of PVA. 2, the formation constants of both complexes decrease sharply with borax concentration C_b and this decrease levels off at higher C_b, as well as the second virial coefficient does.These results can well interpret the polyelectrolyte behaviorof PVA/Borax systems in terms of a favorable balance between expansion due to charges and contraction due to intrachain crosslinks in the complexed PVA. Also, the mutual charge repulsion between the complexing borate ion and the charges on the complexed PVA chain depresses strongly a further complexation onto the PVA chain.In relation to the above-polyelectrolyte solution behavior, we found also that a relatively small hydrophobic ion(ethylbenzensulfonate anion), which has not self-association ability itself, can associate each other around a polyion(poly(allylammonium)cation)through its hydrophobic interaction.