Mechanical properties of an interpenetrating network poly(vinyl alcohol)/alginate hydrogel with hierarchical fibrous structures

An Yumin; Dong Liguo; Yang Yi; Jia Yongna

doi:10.1039/d1ra07368k

Mechanical properties of an interpenetrating network poly(vinyl alcohol)/alginate hydrogel with hierarchical fibrous structures

RSC Adv. 2022 Apr 14;12(19):11632-11639. doi: 10.1039/d1ra07368k. eCollection 2022 Apr 13.

Authors

An Yumin^{1

2}, Dong Liguo^{1

2}, Yang Yi^{1

2}, Jia Yongna³

Affiliations

¹ State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology Tianjin PR China.
² School of Mechanical Engineering, Hebei University of Technology Tianjin 300401 PR China.
³ School of Artificial Intelligence, Hebei University of Technology Tianjin 300401.

Abstract

Bioinspired hierarchical fibrous structures were constructed in an interpenetrating poly(vinyl alcohol, PVA)/alginate hydrogel network to improve its mechanical properties. The interpenetrating hydrogel network with hierarchical fibrous structures was prepared by combining the confined drying method and freeze-thaw method. First, Ca²⁺ cross-linked alginate formed a nano-micro hierarchical fibrous structure via the confined drying method. Then, PVA that was uniformly distributed among the Ca²⁺-alginate chains was cross-linked by hydrogen bonding via the freeze-thaw method, further dividing the hierarchical fibers into finer fibers. The results of a tensile test demonstrated that both the tensile stress and fracture energy improved by more than double after the introduction of 2 wt% PVA, achieving a combination of high strength (∼12.9 MPa), high toughness (∼13.2 MJ m^-3) and large strain (∼161.4%). Cyclic tensile tests showed that a hysteresis loop existed on the loading-unloading curves of the hydrogel along the fibrous directions, and a good self-recovery property emerged after resting for a period of time. The hydrogel with hierarchical fibrous structures constructed by alginate and PVA can be employed in biomedical applications in the future.