The polymerization of acrylamide in aqueous solution. Part 3.—The hydrogen peroxide photosensitized reaction at 25° C

Abstract

The hydrogen peroxide photosensitized polymerization of acrylamide in aqueous solution at 25°C using 3130A light proceeds at a rate proportional to the square root of the absorbed light intensity and the first power of the monomer concentration. The primary quantum yield for chain initiation is 0-87 & 0.05 and the values at 25" C of the rate constants determined by the rotating sector method are :The values of the viscosity of aqueous solutions of the polymer indicate that slight monomer transfer (rate constant kf,, ml) and slight initiator transfer (rate constant ktr, i) take place, approximate values of the constants being ktr, *, = 2.2 x 10-1 1. mole-1 sec-1 and ktr, = 9 1. mole-1 sec-1.Immediately following light extinction the rate of polymerization falls, rapidly at first, then more slowly, finally reaching a value which decays extremely slowly. The properties of this after-effect are described and explained in terms of the hypothesis that a polymer radical which is initially reactive goes through several cycles of activity and inactivity which are probably caused by tautomeric changes before it is destroyed by mutual termination. The kinetic consequences of this hypothesis are explored and shown to be in accord with the experimental findings.

Aqueous electropolymerization of polyacrylamide onto AS‐4 graphite fibers

“…f, is independent of Cd Using eqs. (26) or (27) for transfer or primary radical termination, Rp~yCd'.~, which is close to the 0.54 actually observed, leads to the deduction that termination by transfer or by primary radicals is more probable. Similar experiments using poly ( N,N' dimethylacrylamide ) give an experimental exponent for Cd of 0.4.…”

Preparation of poly( N ‐isopropylmethacrylamide) latexes kinetic studies and characterization

“…In all cases, whatever the initiator concentration, monomer conversion, as determined by 1 H-NMR analysis, is almost completed (90 to 95%) after 150 min, a time much longer than for NIPAM polymerization (around 20 min) under identical experimental conditions as reported by Wu et al 26 and Meunier et al 22 Such a difference can be explained by the higher propagation rate constant (k p ) for NIPAM than for NIPMAM, and more generally for alkylacrylamides compared to alkylmethacrylamides (for instance, at 25°C, k p is order of 18000 l ⅐ mol Ϫ1 ⅐ s Ϫ1 for acrylamide 38,39 and only 800 for methacrylamide 40 ). Figure 1 shows NIPMAM monomer conversion vs. reaction time for three initiator concentrations (one with two different crosslinker concentrations).…”

Photografting of methacrylic acid on polyethylene film: Effect of mixed solvents consisting of water and organic solvent

“…AQ 29,30 is known as a water-soluble photoinitiator for the photopolymerization of vinyl monomers. H 2 O 2 is known to be decomposed by ultraviolet light, [31][32][33] and the resulting hydroxyl radicals initiate the polymerization of vinyl monomers.…”