Conformational Energy and Configurational Statistics of Polyacrylamide

One sort of very important polyelectrolytes, polyacrylamide (PAA) and its copolymers with acrylic acid, on the one hand, have been widely applied as commercial products as flocculants and mobility control fluids in enhanced oil recovery. On the other hand, these polymers relate to the fundamental point of polymer physics, a configuration of very long chain molecules containing many hydrogen-bonding groups.

One sort of very important polyelectrolytes, polyacrylamide (PAA) and its copolymers with acrylic acid, on the one hand, have been widely applied as commercial products as flocculants and mobility control fluids in enhanced oil recovery. On the other hand, these polymers relate to the fundamental point of polymer physics, a configuration of very long chain molecules containing many hydrogen-bonding groups. The statistical behaviour of the whole chain dimension depends on the property of local conformations statically and dynamically. At the first approximation, Flory's generator matrix method[1] can be adopted to treat these polymers. However, determination of the conformational states of backbone of these polymers is still a thorny subject. This is because (i) the strong secondary interactions may cause either intrachain or interchain association; (ii) a suitable molecular model is positively needed to carry out the conformational energy calculation. In the present note, we have developed a method to build up a reasonable molecular model and to obtain a more reliable contour map. The conformational energies and the unperturbed characteristic ratios of PAA chains with different stereo-regularities are explored here. The extensively theoretical and computational approaches of the configurations in aqueous solutions will be the subject of latter papers.