Acrylamide was polymerized in aqueous solution with chlorate‐sulfite initiator under the following conditions: temperature, 15–75°C.; pH, 1.5–3.9; monomer concentration, 0.3–1.1 mole/liter; NaClO3 concentration, 0.26–2.1 × 10−4 mole/liter; and Na2‐SO3 concentration, 0.79–6.3 × 10−4 mole/liter. The weight‐average molecular weight of the polymers formed under these conditions is in the range of 1–3 × 106. It was found that up to 40–50% conversion, the following rate equation holds: where Rp is the overall rate of polymerization, [M] the instantaneous monomer concentration at time t, and [M]0 the initial monomer concentration. At 50°C., K = 6.9 ± 0.9 l. mole−1 sec.−1 Activation energy within the temperature range studied was found to be 7.3 kcal./mole. The value of k 2italicp/kt at 50°C. was estimated to be about 30 l. mole−1 sec.−1 The rate dependence on [M]5/2[M]−3/20 is explained by assuming that the polymer formed binds part of the remaining monomer. The presence of ferrous ions in the polymerization system increases the rate but decreases the molecular weight of the polymer formed. Up to 3.6 × 10−3 mole/l. of [Fe++], the rate is affected in such a manner that Chromic ions tend to retard and nickel ions tend to accelerate the rate of polymerization. It was found that HSO3− is an effective chain transfer agent. Its chain transfer constant was estimated to be about 0.17.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.