Facile preparation of transparent poly (γ‐glutamic acid) modified poly (vinyl alcohol) hydrogels with high tensile strength and toughness
Hailin Wu, Jing Chen, Jiyoung Kim, Peizhi Zhu, Jiadeng Zhu, Qiang Gao, Chunxia Gao
Abstract
Abstract In the present work, a transparent poly (γ‐glutamic acid) modified polyvinyl alcohol (γ‐PGA/PVA) hydrogel with excellent tensile strength and toughness was prepared by a simple and effective immersion method. Results revealed that γ‐PGA concentration and immersion time have great influence on the mechanical properties of prepared γ‐PGA/PVA hydrogels. The mechanical tensile strength of γ‐PGA/PVA hydrogel reached to 16.68 ± 0.43 MPa with the strain of 511.64% ± 23.38% when prepared PVA hydrogel was immersed in 20% γ‐PGA solution for 24 h (denoted as 20% γ‐PGA/PVA). Meanwhile, 20% γ‐PGA/PVA hydrogel exhibited excellent mechanical properties, such as high‐level torsion, knotting and puncture resistant, and can lift a 5 kg weight without obvious rupture. The morphology, structure, compositions and mechanism of enhanced mechanical properties were investigated. Besides the excellent mechanical properties, 20% γ‐PGA/PVA hydrogel possessed good conductivity as well as high sensitivity to external strain. Furthermore, in vitro good cytocompatibility of 20% γ‐PGA/PVA hydrogels was demonstrated by using MC3T3‐E1 cells. Therefore, the prepared 20% γ‐PGA/PVA hydrogel may provide the possibility for the applications in the field of cartilage repair/regeneration, artificial skin and human motion sensor.