Swelling Modelling and Kinetics Investigation of Polymer Hydrogel Composed of Chitosan-g-(AA-AM)

Abstract

Swelling is one of the distinct properties and a significant parameter in the characterization of the crosslinked hydrogels. Swelling investigation at different temperatures was conducted for the produced hydrogel of chitosan grafted acrylamide/acrylic acid. Peleg's model is a two parameters model, which can be used to describe the absorption of water or swelling. The data show that the swelling degree increases with temperature until it reaches 60°C, after which it decreases as the temperature rises higher. At RT, 30, 40, 60, and 80 °C, the swelling degree values of 1.4, 1.5,1.4, 2.3 and 0.7 g water/g dry hydrogel were observed after 8 hours. The applied models provided a good agreement with the experimental data with high values of the coefficient of determination ( 2 ). The observed F values and the standard error indicate the validity of the proposed model to describe the swelling of hydrogel at different temperatures. The swelling rate and swelling degree can be expressed using a 4 th degree polynomial. It was concluded that the exponential association equation model represents swelling characteristics better than the others.

Production of Polymer Hydrogel Composites and Their Applications

“…In another study, a novel composite hydrogel adsorbent has been developed. The composite hydrogel is composed of zeolite and crosslinked chitosan and has been applied to remove acid red 88 dye from an aqueous solution [69].…”

Incorporation of organic acids in the crosslinking of polyvinyl alcohol hydrogels

“…This behaviour is because the longer the thermal reaction takes, the greater the percentage of cross-linking in the samples, promoting lower swellings but longer stability in liquids, respectively, but the crosslinking kinetics with citric acid does not favour chemical stability which is evidenced by the total hydrolysis of the hydrogel, which will be confirmed in the following topic of swelling kinetics. This behaviour has been studied and reported by several researchers [2,[22][23][24][25][26][27] .…”

Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions

“…There were no distinct steps in the values of swelling. This pattern of temperature-dependence is characteristic of simple hydrophilic materials [ 39 ]. It can also be noted that for all the samples, the swelling approximately doubled between 35 and 75 °C, so that their volume expansion or shrinkage in response to a larger temperature stimulus was approximately the same.…”