Studies on poly(acrylic acid)/attapulgite superabsorbent composite. I. Synthesis and characterization

Abstract

A novel poly(acrylic acid)/attapulgite superabsorbent composite was synthesized by graft copolymerization reaction of acrylic acid (AA) on attapulgite micropowder using N,NЈ-methylenebisacrylamide (MBA) as a crosslinker and ammonium persulfate (APS) as an initiator in aqueous solution. The effects on water absorbency of such factors as reaction temperature, initial monomer concentration, degree of neutralization of AA, amount of crosslinker, initiator, and attapulgite were investigated. These crosslinked superabsorbent composites were characterized by thermogravimetetric analysis and scanning electron microscopy. The graft copolymerization reaction of AA on attapulgite micropowder was characterized by FTIR. The water absorbencies for these superabsorbent composites in water and saline solutions were investigated and water-retention tests were carried out. Results obtained from this study show that the water absorbency of the superabsorbent composite synthesized under optimal synthesis conditions with an attapulgite content of 10% exhibited an absorption of 1017 g H 2 O/g sample and 77 g H 2 O/g sample in distilled water and in 0.9 wt % NaCl solution, respectively.

Effect of Surface Modification of Palygorskite on the Properties of Polypropylene/Polypropylene-g-Maleic Anhydride/Palygorskite Nanocomposites

“…Pal mineral (100 g), as received, was dispersed mechanically with 3 L of distilled water for 1 h. Subsequently, the slurry was filtered through a 70 mesh sieve (0.224 m, standard ASTM E 11-70) and 100 mL of hydrochloric acid solution (1 N) was added to the Pal slurry and stirred mechanically for 1 h. Several cycles of washing/centrifuge were carried out until a pH ∼7 was achieved [39]. Finally, the purified Pal (Pal-1) was dried in a convection oven at 100 ∘ C for 24 h. A cation exchange capacity of 26.2 meq/100 g was determined for Pal, following the procedure reported in the literature [40].…”

A pH-, salt- and solvent-responsive carboxymethylcellulose-g-poly(sodium acrylate)/medical stone superabsorbent composite with enhanced swelling and responsive properties

“…The Si-O bending vibration at 468 cm -1 can be observed in the spectrum of CMC-g-PNaA/MS with weakened intensity. This information gives direct evidence that MS participated in the graft copolymerization reaction through its active silanol groups [33][34][35]. Moreover, a schematic structure illustration of the CMC-g-PNaA/ MS superabsorbent composite is presented in Figure 2, the MS existed in the polymer matrix can be classified as two kinds: chemically bonding and physically filling [35].…”

Synthesis, characterization and swelling properties of guar gum-g-poly(sodium acrylate-co-styrene)/muscovite superabsorbent composites

“…The (Si)O-H stretching vibration of MVT at 3623 cm -1 disappeared after the reaction, and the Si-O absorption bands of MVT at 1028 cm -1 emerged in the spectrum of the composite with a weakened intensity (figures 1(a), (d) and (e)). This indicates that MVT also takes part in the polymerization reaction via its active silanol groups [25,26]. However, the characteristic absorption of St cannot be observed owing to the low concentration of St and the overlap of absorption bands.…”