Preparation of hydrogel with self-healing properties based on poly(vinyl alcohol)/corn starch/zeolite/cellulose nanocrystals for wound dressing applications

Abstract

The purposes of this research are divided into three parts. Firstly, to prepare hydrogel of poly(vinyl alcohol) (PVA) and corn starch in different weight ratios between PVA and corn starch at 1:1, 2:1, 3:1, 4:1, and 5:1 by adding boric acid as crosslink agent. It revealed the ratio of PVA and corn starch at 3:1 had appropriate value for mechanical properties. Secondly, the influence of boric acid as crosslink agent and glycerol as plasticizer are investigated on properties of hydrogel. The addition of boric acid would increase the tensile strength at yield (TS), young’s modulus (YM), and water vapor transmission rate (WVTR) of PVA/corn starch films. However, by doing so would decrease elongation at break (EB) and swelling degree of hydrogel. Meanwhile, adding of glycerol lead to decrement of TS and YM but increasing EB, swelling degree, and WVTR of PVA/corn starch films. Lastly, the influence of zeolite and cellulose nanocrystals content (0.1, 0.3, and 0.5%wt) on properties of PVA/corn starch composite films are also studied. The addition of either zeolite or cellulose nanocrystals would decrease TS, YM and WVTR but increase swelling degree. Furthermore, the PVA/corn starch films incorporated with cellulose nanocrystals possesses relatively higher TS and YM than the ones with zeolite. For self-healing tests, all samples could be self-healed in wet condition.