Novel biodegradable flocculating agents prepared by grafting polyacrylamide to Konjac

Abstract

Grafting copolymers of polyacrylamide (PAM) with Konjac gum (KGM) have been synthesized using ceric-ion-induced initiation technique. The copolymers were characterized using several instrumental techniques, including infrared (IR) spectroscopy, elementary analysis, scanning electron microscopy (SEM), size exclusion chromatography (SEC) analysis, and intrinsic viscosity to confirm the success of grafting. The flocculation performance of graft copolymers was characterized by two methods. One was to study the relationship between the flocculants doses in kaolin suspension and the supernatant transmittance, and the other is to examine the time dependence of sediment height of kaolin suspensions. It was found that the graft copolymer is better than KGM and pure PAM. Biodegradation behavior was testified by monitoring the decay of relative viscosities, and approved by KGM ether bonds breaking in IR spectra and the molecule weight reduction in SEC analysis. The results indicate that the grafted KGM copolymers have improved both, flocculation performance and better biodegradable properties than the unmodified parent KGM and pure PAM.

Synthesis and Characterization of Poly(Acrylamide-Co-Acrylic Acid) Flocculant Obtained by Electron Beam Irradiation

“…For two polymers with approximately similar molecular weight, the branched polymer has lower hydrodynamic volume compared to its linear counterpart and thus has lower intrinsic viscosity value. Furthermore, the longer the branching the higher is the intrinsic viscosity and vice versa 31 . The intrinsec viscosity of a polymer is dependent on its molecular weight and chain dimension 32,33 .…”

“…Radius of gyrations is a parameter which characterizes the size of a particle of any shape. The higher the radius of gyration larger will be the polymer dimensions, affecting the flocculation characteristics synergistically 31 . The molecular weight and radius of gyrations are represented in Figures 7 and 8.…”

“…The mechanism is favored when the polymers has a long chain. In order to create effective bridges, there must be sufficient polymeric chains, which are able to extend far enough to facilitate the attachment of other particles 31 . From the experiments is observed the effectiveness of polymers as the bridging flocculants depends greatly on their properties: molecular weight and thus the intrinsic viscosity.…”

Synthesis and characterization nanocomposite of polyacrylamide-rGO-Ag-PEDOT/PSS hydrogels by photo polymerization method

“…The absorption peak at around 1350 cm À1 was assigned to the C-N stretching vibration. [34,35] FTIR spectrum of PAAm-rGO-Ag-PEDOT/PSS (Fig. 1c) hydrogel, the peak of -N-H stretching of the amide unit, -COOH (carboxyl), -C-O-C-(epoxy), and -C-OH (hydroxyl) could be found but the peak at around 3500 cm À1 of graphene oxide disappeared compared to the hydroxyl group of the graphene oxide (Fig.…”

Heavy Metals Removal from Contaminated Water Using Poly(Acrylamide-co-Acrylic Acid)-Sodium Alginate Flocculant Obtained by Electron Beam Irradiation

“…For two polymers with approximately similar molecular weights, the branched polymer has lower hydrodynamic volume compared to its linear counterpart and thus has lower intrinsic viscosity value. Furthermore, long branches determine higher intrinsic viscosity and vice versa (Xie et al, 2009).…”