Adsorbed metal ions as stabilizers for the thermal degradation of polyacrylamide

Determination of charge density of anionic polyacrylamide flocculants by NMR and DSC

“…The reaction seems to occur exclusively between the acrylamide monomers since poly(sodium acrylate) is stable at that temperature range. The reactions probably involve the formation of imide and aitrile in the adjacent amide groups with the evolution of NH3 and H20 res p ectivel y [ 12,13 ]. Thus, T g's Which.…”

Template polymerization synthesis of hydrogel and silica composite for sorption of some rare earth elements

“…Fig. 10a, indicating the presence of four peaks relating to three thermal decomposition steps of the macromolecules fragments [17]. The degradation of P(VP-AMPS) hydrogel proceeds in three stages.…”

“…The second stage from 184 to 527°C which can be attributed to desulphonation of sulphonic acid with the weight loss of 64.9%. The third stage from 527 to 1000°C may be due to chain scission, removal of volatile hydrocarbons, complete degradation to the oxides and the possibility of metal carbide formation [17].…”

Separation of copper ions from iron ions using PVA-g-(acrylic acid/N-vinyl imidazole) membranes prepared by radiation-induced grafting

“…On the other hand Fe ions did not penetrate to the receiver compartment at these pH values. This result can be attributed to the fact that trivalent Fe ion form a more stable and stronger complexes with functional groups compared with divalent Cu ion because Fe has a d 5 electronic configurations; metals with d 5 and d 10 electronic configurations have a high complexation constants [19].…”