Synthesis and properties of poly(sodium acrylate‐co‐2‐acryloylamino‐2‐methyl‐1‐propanesulfonic acid)/attapulgite as a salt‐resistant superabsorbent composite

Abstract

A novel salt‐resistant superabsorbent composite was prepared by copolymerization of partially neutralized acrylic acid, 2‐acryloylamino‐2‐methyl‐1‐propanesulfonic acid (AMPS) and attapulgite (APT). To enhance the swelling rate (SR) of the copolymer, sodium bicarbonate was used as a foaming agent in the course of copolymerization. Furthermore, for improving the properties of swollen hydrogel, such as strength, resilience and dispersion, the copolymer was surface‐crosslinked with glycerine and sodium silicate, and then the surface‐crosslinked copolymer was blended with aluminum sulfate and sodium carbonate in post treatment process. The influences of some reaction conditions, such as amount of AMPS, APT, and initiator, and neutralization degree of acrylic acid on water absorbency in 0.9 wt% NaCl aqueous solution both under atmospheric pressure (WA) and load (WAP, P ≈ 2 × 103 Pa) were investigated. In addition, the effect of them on SR was also studied. The WA and WAP of the superabsorbent composite prepared under optimal conditions in 0.9 wt% NaCl aqueous solution were 52 g·g−1 and 8 g·g−1, respectively. Besides, the SR was fast, and it could reach 0.393 mL·(g·s)−1. Moreover, the swollen hydrogel possessed excellent salt resistance, hydrogel resilience and dispersion. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers

Preparation and properties of an organic–inorganic composite superabsorbent based on attapulgite

“…The introduction of rigid APT particles into polymeric network can relieve the entanglement of graft polymeric chains and weaken the hydrogen-bonding interaction among -COOH groups, and then decreased the physical crosslinking degree and improved polymeric network structure. 23 However, the further increase of APT content in composite superabsorbent from 12 to 14 wt% resulted in a remarkably decrease of water absorbency. This result may be attributed to the fact that the excess ultrafine APT powder can act as an additional crosslinking point in the polymeric network, increasing the amount of APT powder will induce a larger crosslink density and the space network for water molecules to penetrate becomes smaller, the water absorbency decreases gradually.…”

Structurally Enhanced Hydrogel Nanocomposites with Improved Swelling and Mechanical Properties

“…Furthermore, 2-acrylamide-2-methyl-propane Downloaded by [McMaster University] at 00: 19 27 December 2014 sulfonic acid has a sulfonic acid group which can dissociate extensively in a wide range of pH values (21). Its copolymers with various comonomers and also nanocomposites synthesized with the addition of clay substances were also received attention in various applications (18,(21)(22)(23)(24)(25)(26)(27). In our previous work, we synthesized acrylamide/2-acrylamide-2-methyl-propane sulfonic acid hydrogel nanocomposites by using natural MMT with high clay ratios (17).…”

“…The synthesis of nanocomposite hydrogels by the incorporation of clay-like fillers into the polymer structure has been widely studied in recent years (15)(16)(17)(18)(19). Clays have sandwich types of structures with one octahedral Al sheet and two tetrahedral Si sheets, the so-called phyllosilicate (20).…”

Fast‐swelling oxidized starch phosphate–poly(acrylate/acrylamide/2‐acryloylamino‐2‐methyl‐1‐propanesulfonic acid) superabsorbent composite

“…Therefore, based on our previous studies [25][26][27], a superabsorbent composite with an improved swelling rate was synthesized using partially neutralized AA, AM, AMPS and oxidized starch phosphate. Sodium bicarbonate, ethanol, propyl alcohol, and butyl alcohol were employed to enhance the swelling rate, and hydrogen peroxide and Lascorbic acid were used as a redox initial system.…”