聚乙烯醇在强碱性水溶液中与Fe(Ⅲ)离子间的配位-交联反应

THE COORDINATION CROSS-LINKAGE REACTION BETWEEN PVA IN STRONG BASIC AQUEOUS SOLUTION WITH Fe(III) ION

在不断搅拌1×10^(-4)m^3 pH>13的5％ PVA碱性水溶液中,缓慢地添加1×10^(-4)kgFeCl_36H_2O,溶液中即析出红棕色树胶状物.以XPS、ESR和IR等研究该析出物的组分及其形成过程.推定PVA部分羟基在上述条件下发生脱质子反应而提供L^-配位体,Fe(Ⅲ)盐水解生成初生Fe(OH)_3的Fe^(3+),它既有空轨道,又有较强的正电场,故能吸引PVA高分子配位体L^-上的氧而形成O→Fe配位键,从而发生L^-与Fe^(3+)离子间的交联反应,生成多核Fe(Ⅲ)-PVA配位聚合物而析出红棕色树胶状物。

The reddish brown resinoid substance was separated out, when 1×10-4kg of FeCl36H2O was added slowly to 1×10-4m3 of 5% PVA basic (pH>13) aqueous solution with stirring. Its composition and forming process was studied by XPS, IR and ESR, etc. It follows that the de-protonic reaction of hydroxide group for PVA had taken place in above solution, and the coordination group for deprotonic oxygen of PVA had produced more. These ligands interact with some Fe3+ of ferric hydroxide while the ferric hydroxide in new emergence is forming, causing the formation of Fe (III)-PVA coordination polymer-the composition of the reddish brown resinoid substance.