Is there intramolecular catalysis of polyacrylamide and acrylamide-acrylic acid copolymers?

CONCLUSIONS We have carried out some experimental investigations of hydrolysis of polyacrylamide and acrylamide-acrylic acid copolymers over a range of pH where the mechanism has not already been elucidated. Our results confirm the existence of intramolecular catalysis by undissociated neighbouring carboxylate groups at low pH.

What is the acceleration effect of polyacrylamide hydrolysis?

(ii) Constant pH. In Figure 14 some predictions of hydrolysis kinetics of polyacrylamide are given for different constant pH and three values of Z. These simulations correspond to a polymer concentration of 8 x 10-4gcm-3 and T= 80. The acceleration effect is significant for pH up to 7 and becomes negligible for higher pH.

What are the hydrolysis kinetics of polyacrylamide?

The present paper deals with the hydrolysis kinetics in the range of neutral pH for which few reliable data are available. It is well known that base hydrolysis of polyacrylamide obeys autoretarded kinetics due to the electrostatic repulsion between the anionic reagent and the polymeric substrate3-5.

What is the difference between alkaline hydrolysis and polyacrylamide hydrolysis?

The polymers hydrolysed at low pH are expected to be less stable than those prepared by alkaline hydrolysis. Copolymers. The program described for polyacrylamide can be used but a preliminary step must be developed in order to take into account the initial monomer distribution.

What is the hydrolysis of acrylamide-acrylic acid copolymers?

Compagnie Franise des Pdtroles, Centre de Recherche de Beauplan, Route de Versailles, 78470 St-Remy les Cheweuse, France (Received 26 June 1987; accepted 5 November 1987) The hydrolysis of acrylamide-acrylic acid copolymers has been studied as a function of pH and of the initial composition of the samples.

How do cations affect the hydrolysis of Pam/HPAM polymers?

These cations not only can form complexes (gels or precipitates) with the carboxylic groups with HAPM to alter their rheological and phase properties, they can also catalyze the amide hydrolysis reaction to increase the degree of hydrolysis of PAM/HPAM polymers.