Superabsorbent Poly(isoprenecarboxylate) Hydrogels from Glucose

Abstract

Isoprenecarboxylic acid (ICA-H), available from glucose via one of its major metabolites mevalonate, has been converted to cross-linked networks by radical polymerization. Monomer feeds comprising various ratios of ICA-H and its sodium salt (ICA-Na) were used to give hydrogels that show attractive performance in comparison with (nonbioderived) poly­(acrylate) hydrogels. In particular, these new materials show increasing levels of water uptake (i.e., swelling ratio) across the entire range of ionization (10–90 %Na). This behavior is attributed to the larger distance between carboxylate moieties in the hydrogels, a feature that reduces the average amount of charge repulsion between proximal sodium carboxylate ion pairs (counterion condensation).

Synthesis of a Cellulose-Co-AMPS Hydrogel for Personal Hygiene Applications Using Cellulose Extracted from Corncobs

“…Hydrogels are macromolecular gels that are superabsorbent, gained by the chemical stabilization of hydrophilic polymers that can absorb and hold water more than 100 times the mass of dried polymer networks [ 1 , 2 , 3 ]. Depending on the number of polymer types which hydrogels are composed of, they can be homo-polymeric or co-polymeric [ 4 , 5 ].…”

High-Toughness and Biodegradable Superabsorbent Hydrogels Based on Dual Functional Crosslinkers

“…Superabsorbent hydrogels (SAHs), represented by crosslinked sodium polyacrylate, often exhibit an impressive water absorption capacity equivalent to thousands of times their dry weight. , They are used in numerous fields, including agriculture, − biomedical research, , and hygiene products. − However, SAHs are considered significant environmental pollutants owing to their non-sustainable and non-renewable properties that may be attributed to the carbon main crosslinking networks, − which affect their absorption performance. In addition, SAHs are ranked among the most dangerous and toxic pollutants in U.S. landfills and limited burying in the ground because of their prolonged decomposition process of nearly 500 years. ,, …”

“…Even if the water absorption capacity is negatively correlated to the crosslinking density of the network, reducing the crosslinking density is rarely favorable for the production of ideal semisynthetic SAHs. 1,30,36 swollen conditions, a sparse gel network may not be strong enough to transfer loads since the uncontrolled distribution of crosslinking points and resultant gel strength decreases significantly, which is unacceptable for applications such as disposable diapers and feminine napkins. 16,30,37 Although there are existing solutions for multiple network structures 38−40 or dynamic interactions, 12,41−43 the complicated processes and corresponding high cost reduce the competitiveness of degradable SAHs as a commercial product.…”

CO2-Responsive Superabsorbent Hydrogels Capable of >90% Dewatering When Immersed in Water

“…1−3 The defining quality of SAP hydrogels lies in their ability to absorb a mass of water at least 100 times greater than the mass of the dry hydrogel without dissolving in the surrounding solution. 2,4 The ability to swell by absorbing and retaining water is due to hydrophilic functional groups in the polymer, which attract water molecules while exerting electrostatic repulsion between similarly charged groups, and the elasticity of the polymer chains, enabling the gel network to expand to accommodate water molecules ("free volume" theory). 5 Apart from the traditional applications SAP hydrogels fulfill (e.g., disposable diapers and incontinence products), 6 they are increasingly being considered for use in a wide range of nonsanitary applications such as CO 2 capture, 7,8 slow nutrient release (to reduce fertilizer loss and usage), 9 self-healing of cracks in concrete, 10 removal of body fluids during surgery, 11 and water purification.…”

“…Superabsorbent polymer (SAP) hydrogels are lightly cross-linked, insoluble polymeric materials capable of absorbing and retaining large amounts of water. − The defining quality of SAP hydrogels lies in their ability to absorb a mass of water at least 100 times greater than the mass of the dry hydrogel without dissolving in the surrounding solution. , The ability to swell by absorbing and retaining water is due to hydrophilic functional groups in the polymer, which attract water molecules while exerting electrostatic repulsion between similarly charged groups, and the elasticity of the polymer chains, enabling the gel network to expand to accommodate water molecules (“free volume” theory) . Apart from the traditional applications SAP hydrogels fulfill (e.g., disposable diapers and incontinence products), they are increasingly being considered for use in a wide range of nonsanitary applications such as CO 2 capture, , slow nutrient release (to reduce fertilizer loss and usage), self-healing of cracks in concrete, removal of body fluids during surgery, and water purification. − Approaches to recycling used SAP hydrogels are gaining attraction as a research focus to address current environmental concerns over single-use superabsorbent (plastic) materials. , A major factor impeding the release of fluids from swollen SAP gels (and therefore recycling of the gels) is the strong hydration force between the water molecules and the ionic functional groups within the swollen hydrogels .…”