Formulation design, optimization, characterization and swelling behaviour of a cationic superabsorbent based on a copolymer of [3‐(methacryloylamino)propyl]trimethylammonium chloride and acrylamide

Abstract

A series of crosslinked copolymers with cationic nature have been prepared based on acrylamide (AAm) and [3-(methacryloylamino)propyl]trimethyl ammonium chloride (MAPTAC) using N,N methylene-bis-acrylamide (MBA) as crosslinking agent. Taguchi's method has been employed for the purpose of formulation design and optimization as well as investigating the effects of various compositional parameters, such as total monomer concentration, cationic monomer and crosslinking agent concentration. The swelling behaviour of the synthesized gels in electrolyte solutions composed of ions with different valency has been studied and compared with an anionic-based superabsorbent. The swelling capacity and absorbency were found to be enhanced with increase of the MAPTAC moieties of the copolymer chains, and therefore increase of their cationic character. All the cationic hydrogels prepared had greater swelling capacity, with less change in their swelling behaviour, when immersed into aqueous solutions containing multivalent cations. The anionic-based hydrogels collapsed in similar ionic solutions with moderate-to-high ionic strength and did not show any tendency to re-swell. The complex modulus (G * ) of the crosslinked copolymers in the equilibrium swollen state was measured by rheomechanical spectroscopy and was correlated with the chemical composition of the network. Thermogravimetric analysis of the dry cationic superabsorbent showed more bound water but similar thermal behaviour to crosslinked polyacrylamide 

A Novel N‐Succinylchitosan‐graft‐Polyacrylamide/Attapulgite Composite Hydrogel Prepared through Inverse Suspension Polymerization

“…Following the second stage, there are two evident weight losses in the 273.2–410.9 °C (38.29% for NSC‐ g ‐PAM and 34.14% for NSC‐ g ‐PAM/APT) and 410.9–541.7 °C (39.17% for NSC‐ g ‐PAM and 38.05% for NSC‐g‐PAM/APT) regions. The third stage (273.2–410.9 °C) is attributed to the decomposition of amide side‐groups of AM and MBA in the network and similar thermal decomposition behavior has been reported by Mathakia et al and Saeidi et al for polyacrylamide, respectively 31, 32. Thermal decomposition of COCH 2 CH 2 COOH group of NSC may also contribute to the weight loss in this stage.…”

Multiphysics modeling of responsive characteristics of ionic-strength-sensitive hydrogel

“…In MECis model, however, the strength of the hydrogel reflects the structure of the hydrogel. Experiments show that, the total monomer concentration and the ratio of crosslinking agent influence the strength of hydrogel to a large extent (Baker et al 1994;Saeidi et al 2004). The strength of hydrogel is considered in MECis model based on a mechanical theory, Young's modulus of the hydrogel increases with the increase of the total monomer concentration and amount of crosslinking agent.…”

Synthesis and characterization of functionalized acrylic‐acrylamide‐based superabsorbent gels

“…To further improve the salt‐resistance of the superabsorbent gels, there are several articles have been reported to introduce functional monomer to the AA‐based composites. Such as, adding anionic monomer 2‐acrylamido‐2‐methyl propanesulfonic acid, zwitterionic monomer 3‐methacrylamido propyl trimethylammonium, 2‐acryamido‐2‐methylpropane sulfonate, and cationic monomer [(3‐acryloylamino) propyl] trimethylammonium chloride, etc 19–23. However, there are quite few studies focusing on introducing different charged functional monomer to the AA–AM‐based matrix by solution free radical polymerization.…”