The preparation and properties of starch based shape memory hydrogel

Abstract

In this work, the –catechol and –thiol modified starch was prepared by the esterification and amino condensation reaction, then a fully starch based hydrogel was prepared via the thiol-catechol Michael addition reaction. The starch hydrogel gained shape memory behaviors by coordinate with Fe3+ ions at alkaline condition.1H-NMR had been used to character the structure of the starch derivatives and its character peaks. The hydrogel’s modulus had also been measured before and after coordinating with Fe3+ ions in linear area and the result showed that both the hydrogel’s storage modulus and loss modulus kept constant in linear area from 0.1 rad/s to 100 rad/s, which demonstrated a good network was formed inside the hydrogel. Furthermore, the shape memory behaviors had been tested by changing the pH value in solution. The result showed that the hydrogel can keep its temporary shape in high pH condition and recover to its original state after the shaped hydrogel immersed into acidic solution. This hydrogel might have great application prospects in the field of biomedical and engineering.