Synthesis of High Molecular Weight Partially Hydrolyzed Polyacrylamide and Investigation on its Properties

Acontinuous process for the polymerization of acrylamide and hydrolysis of functional groups in alkaline condition has been carried out. It was found that acrylamide may be polymerized and hydrolyzed in a single consequential step, whereby, both degrees of polymerization and hydrolysis can be carefully controlled. The hydrolysis of polyacrylamide up to 10 and 60% degrees was facilitated in suitable amount of different alkalines. The degree of hydrolysis of samples was determined by a back titration method. We have found that sodium carbonate as an hydrolyzing agent, also acts as a retarder and its addition to polymerization solution reduces the rate of polymerization reaction. The measured molecular weight of samples shows that we have reached a high molecular weight (about 12 million) and excellent water solubility. Another interesting result obtained is that the copolymer solutions showed a non-newtonian shear thinning behaviour. On the other hand, the associative behaviour is observed between the samples.