The Fabrication And Characterization Of Tough Hydrogel And UV-controlled Shape Memory Hydrogel

Due to their excellent mechanical properties and potential application in tissue engineering, tough hydrogels have attracted extensive research interest.Meanwhile, shape memory polymers also exhibit broad application prospect, for example, artificial robots. In this article, we have employed novel methods to prepare tough polypseudorotaxane hydrogel and rarely reported light-controlled shape memory hydrogel. The main contents of this thesis are as follows.(1) In order to prepare compressible tough polypseudorotaxane hydrogel, this thesis combine high temperature and hydrogen bonding weakening agent (acrylamide) to screen hydrogen bonding between a-CDs. With the proceeding of polymerization, acrylamide monomers are immobilized onto polymer chain and cannnot effectively screen the hydrogen bonding. Thus the α-CD/PEG can form polypseudorotaxane and physical cross-linking, contributing to the formation of physical hydrogel. Meanwhile, the high temperature (60℃)helps to integrate more a-CD into hydrogel, providing more polypseudorotaxane as joints for energy dissipation and enhancing the mechanical property of hydrogel. The hydrogel can also endowed with dual stimuli-responsive (redox and thermal) shape memory performance.(2) This thesis combines the photolysis reaction of Photoacid Generator (PAG) and pH-sensitive imidazole-Zn2+ coordination interaction to prepare UV-controlled shape memory hydrogel. In the same time, we demonstrate the feasibility of applying this PAG strategy to other pH-sensitive hydrogels, for example, poly(vinyl alcohol) hydrogel.