Micelle Crosslinked Polyacrylic Acid Hydrogels with Resilience and Self‐Recovery Properties

Abstract

Micelle crosslinking method is one of the several techniques to fabricate hydrogels with good mechanical performance. Micelle crosslinked hydrogels reported so far are fabricated using a multistep preparation process due to the functionalization of block copolymers or surfactants with acrylate, aldehyde, azo, or reversible addition‐fragmentation chain transfer groups to create a polymer network. Herein, a simple one‐step approach is introduced to produce resilient hydrogels prepared by bulk polymerization of acrylic acid and esterification with Triton X‐100 (TX‐100) in the presence of catalyst sulfuric acid (H2SO4). The advantage of this study is that TX‐100 surfactants self‐assembling into micelles are directly bonded onto polymer chains through an ester bond without any further modification. The obtained hydrogels exhibit tensile strengths up to 135 ± 8 kPa and compressive strengths up to 16 ± 1 MPa over 94% strains as well as complete self‐recovery and high resilience abilities (≈86% at strains up to 400%) originating from hydrophobic associations in the core of micelles acting as dynamic cross‐linkers along with hydrogen bonds and entanglements between polymer chains acting as additional crosslink points. The overall results show that the hydrogels can be good candidate as elastic materials in many fields.

Mechanochromic Self-Healing Materials with Good Stretchability, Shape Memory Behavior, Cyclability, and Reversibility Based on Multiple Hydrogen Bonds

“…Second, the hydrophobic aggregation of the PPO chain improved the toughness. Third, the crystallization of the PEO chain in the surface of PE-PU polymers contributed to the increase of mechanical strength. − In other words, by adding the appropriate amount of poloxamer, the PE-PU3 sample with high tensile strength, robust toughness, good Young’s modulus, and excellent stretchability was achieved.…”

Dual Cross‐Linked Polymethacrylic Acid Hydrogels with Tunable Mechanical Properties and Shape Memory Behavior

“…[46][47][48] The proven successful incorporation of TX-100 into polymer network was consistent with the results of a previous study on the grafting of TX-100 to PAAc. [45] After 24h reaction time, the obtained bulk polymer samples were allowed to swell in a large amount of distilled water for at least a few weeks until reaching equilibrium. During swelling, the water was refreshed daily to extract released and unreacted MAAc, TX-100, and catalyst H 2 SO 4 reactants.…”

“…The ratio of H 2 SO 4 , (the molar ratio relative to TX‐100) was kept constant at 0.5, which was the optimum value according to previous work. [ 45 ] H 2 SO 4 acts as both a catalyst and dehydrating agent, so that it increased the rate of esterification reaction and shifted the equilibrium towards products. In preliminary experiments at various synthesis temperatures, uniform and intact polymer network could not be obtained at lower synthesis temperatures than 80 °C due to inadequate cross‐linking and polymerization of MAAc.…”

“…[ 46–48 ] The proven successful incorporation of TX‐100 into polymer network was consistent with the results of a previous study on the grafting of TX‐100 to PAAc. [ 45 ]…”

Preparation and characterization of tough and highly resilient nanocomposite hydrogels reinforced by surface‐grafted cellulose nanocrystals

“…13 On the other hand, numerous synthetic hydrogels with high resilience have been fabricated. Among them, a widely used strategy is designing special multifunctional crosslinkers, including macromolecular crosslinkers, [14][15][16] micellar crosslinkers, [17][18] inorganic nanoparticle crosslinkers, [19][20][21] and organic nanoparticle crosslinkers. [22][23] The designed multifunctional crosslinkers were used either individually 16,[17][18][19][20]22 or with low-molecular-weight crosslinkers [14][15]21,23 to form unique crosslinking network.…”