A Robust, Tough and Multifunctional Polyurethane/Tannic Acid Hydrogel Fabricated by Physical-Chemical Dual Crosslinking

• Published in: Polymers Vol. 12; no. 1; p. 239
• Main Authors: Wen, Jie, Zhang, Xiaopeng, Pan, Mingwang, Yuan, Jinfeng, Jia, Zhanyu, Zhu, Lei
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.01.2020; MDPI
• Subjects: Biomedical materials; Catechol; Crosslinking; double crosslinking; Equilibrium; Fourier transforms; Hydrogels; Hydrogen bonds; Hydroxyl groups; Laboratories; Mechanical properties; multifunction; Polyethylene glycol; polyurethane hydrogel; Polyurethane resins; Spectrum analysis; Substrates; Tannic acid; Tensile strength; Tissue engineering; Urethane groups; Beijing China; China; Germany; tannic acid; polyurethane hydrogel; mechanical properties; double crosslinking; multifunction
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/POLYM12010239

Commonly synthetic polyethylene glycol polyurethane (PEG-PU) hydrogels possess poor mechanical properties, such as robustness and toughness, which limits their load-bearing application. Hence, it remains a challenge to prepare PEG-PU hydrogels with excellent mechanical properties. Herein, a novel double-crosslinked (DC) PEG-PU hydrogel was fabricated by combining chemical with physical crosslinking, where trimethylolpropane (TMP) was used as the first chemical crosslinker and polyphenol compound tannic acid (TA) was introduced into the single crosslinked PU network by simple immersion process. The second physical crosslinking was formed by numerous hydrogen bonds between urethane groups of PU and phenol hydroxyl groups in TA, which can endow PEG-PU hydrogel with good mechanical properties, self-recovery and a self-healing capability. The research results indicated that as little as a 30 mg·mL TA solution enhanced the tensile strength and fracture energy of PEG-PU hydrogel from 0.27 to 2.2 MPa, 2.0 to 9.6 KJ·m , respectively. Moreover, the DC PEG-PU hydrogel possessed good adhesiveness to diverse substrates because of TA abundant catechol groups. This work shows a simple and versatile method to prepare a multifunctional DC single network PEG-PU hydrogel with excellent mechanical properties, and is expected to facilitate developments in the biomedical field.