Anisotropic Nanocomposite Hydrogels with High Mechanical Strength Using Hydrophilic Reactive Microgels and Self-Assemble

Abstract:

Anisotropic hydrogels based on acrylamide were prepared by frontal photopolymerization. First hydrophilic microgels (HM) were spreparaed by inverse emulsion photopolymerization, and secondly hydrophilic reactive microgels (HRM) with C=C double bonds were synthesis by chemical modification of the HM used N-methylolacrylamide, Last, HRM hydrogels were synthesis by frontal photopolymerization using HRM as crosslinkers. Only one direction of the HRM hydrogels show excellent fracture strength and tensile elongation but the other two directions show little fracture strength and tensile elongation. The reason of the high mechanical performance in the given direction is that the hydrogels are crosslinked by HRM as a new crosslinking agent instead of the conventional crosslinking agents and these nanoparticles can self-assemble into anisotropic structures and the structure can be stabilized by free radical polymerization. The anisotropic hydrogels could use potential materials such as artificial muscles tissue.

• Periodical: Applied Mechanics and Materials (Volumes 110-116)
• Pages: 1923-1927
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.110-116.1923
• Online since: October 2011
• Authors: Xu Ping Qin, Fang Zhao, Sheng Yu Feng
• Keywords: Anisotropic, Hydrogel, Mechanical Strength, Microgel, Photopolymerization

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DOI: 10.1021/ma048569y

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[9] K. Haraguchi, H. Li, Macromolecules 2006, 39, 1898. Figure 1. A, Photographs of anisotropic hydrogels, B-D, Photographs of easy tearing character of two sections that is easy to tear, E-H, The knotting and elongation character of one direction has high high mechanical strength, I, Almost immediately returned to its original shape when it is allowed to recover after elongation. Table 1. Swelling character and mechanical properties of only one direction of the anisotropic hydrogels. Hydrogel HRM content (wt. %) Equilibrium in distilled water (Ws/Wd) Fracture tensile strength (kPa) Elongation at break (%) HRM-1 1 18. 23 47. 86 872 HRM-2 2 16. 26 57. 69 749 HRM-3 3 13. 23 74. 45 611 A B Figure 2. A, Stress–strain curves of the anisotropic hydrogels with different HRM content (lift). B, Differential scanning calorimetry (DSC) curves for HRM-2 and for HM2. 4-2. 5.

[5] (right).