Acrylamide polymerization photoinitiated by HCrO₄⁻

Abstract

The photoredox process occurring between HCrO, and acrylamide (AAm) leads to the formation of chromium(I11) and polyacrylamide. The influence of pH, monomer concenlration, absorbed light intensity I , and chromium(V1) concentration on the polymerization rate R , are reported. Two different domains are detected as a function of chromium(V1) concentration: At low concentration, where R , increases with chromium concentration, a process of termination by mutual annihilation of the macroradicals accounts for the experimental dependence R , a [AAmI3l2 .Id'*. At higher concentration, R , decreases when the chromium concentration increases; a process of oxidative termination of the radicals by chromium(V1) is involved corresponding to a dependence R , a [AAm]' . I , . The evolution of the polymer molecular weight as a function of the different parameters controlling the polymerization is described.

Photopolymerization: A Review

“…Fageol and Bolte [38] studied acrylamide (AA) polymerization photoinitiated by hydrogen chromate ion. The photoredox process occurring between HCrO À 4 and AA leads to the formation of Cr(III) and poly AA.…”