木质素磺酸-栲胶接枝共聚物在Fe^(2+)存在下的螯合收缩效应

THE CHELATION SHRINKAGE EFFECT OF GRAFT-COPOLYERS OF LIGNOSULFONIC ACID/TANNIN IN THE PRESENCE OF FERROUS ION

本文以 Fe^(2+)-木质素磺酸-栲胶合成体系为研究对象,通过粘度测定、电镜观察和吸附试验,研完了这种有机降粘剂在高价金属离子存在下的螯合收缩效应。在 Fe^(2+)存在下,木质素-栲胶接枝共聚物(LGV)分子会发生螯合收缩,此效应在一定条件下会影响 LGV 分子在粘土上的吸附性能。

In developing lignosulfonic acid/tannin graft-copolymers in the presence of ferrous ion as Cr-free thinner for drilling fluids a specific phenomenon of molecular shrinkage of these copolymers caused by their chelation with Fe^(++) is observed and studied.With increasing Fe^(++) amount introduced,the characteristic viscosity [η] of the Fe^(++)-chelated copolymer decreases,its adsorption on clay increases at the first stage and then decreases.The scanning electron micrographs clearly manifest that the morphology of precipitated from dilute solution Fe^(++)-chelated copolymers changes from a loose,more extended coil ensemble to a tightly coiled,sphere-like one with increasing Fe^(++) amount introduced in their synthesis.