Preparation And Research Of Polyethylene Glycol(PEG)/ Polyvinyl Alcohol(PVA) Hydrogels And Nanocomposite

Polyethylene glycol (PEG) hydrogel is a good biocompatible material without toxicity and immunogenicity, doing well in water absorbing and water keeping, thus it has extensive application in production and daily life. Generally, hydrogel performs badly in mechanical properties. In order to solve this shortcoming and improve the comprehensive performance of PEG hydrogel, this article grafts PEG onto polyvinyl alcohol (PVA) to prepare copolymer hydrogel with good mechanical properties. Then the comprehensive performance of copolymer hydrogel is studied by using some relevant tests as well as to explore the effect of molecular weight and content of PEG. On this basis, different nanocomposite hydrogels are synthesized. The function of different nano-particles and the effect of its content is sdudied.With hydroxyl groups, isocyanate group tends to have chemical reaction. Using this feature, PEG with isocyanate groups as an end group is prepared. Then, this article synthesizes PEG-IPDI-PVA hydrogels. Test study indicates that copolymer has high grafting efficiency. Larger percent grafting is observed with increase of molecular weight of PEG and its content. Hydrogels have the good swelling properties. The higher the molecular weight of PEG, the faster it absorbs water. Swelling ratio becomes larger with the increase of molecular weight of PEG, and it shows a trend of decrease after increase in the first place along with the increasing content of PEG Obvious negative temperature responsiveness is observed. Mechanical strength and toughness are affected by molecular weight and content of PEG.On this basis, this article synthesizes Laponite nanocomposite hydrogel、TiO2 nanocomposite hydrogel and LDH nanocomposite hydrogel. Till now, in-depth study specific to Laponite/PEG-PVA hydrogel is relatively rare. Test study indicates that compared with pure composite hydrogels ,three nanocomposite hydrogels has faster water absorption speed and better swelling property. Swelling ratio of Laponite nanocomposite hydrogel is up to 4 times of that of composite hydrogel and it possesses positive temperature responsiveness. TiO2 and LDH play the reinforcing function,improving the tensile strength of hydrogel, while elongation at break decreased, Laponite plays dual function of reinforcing and toughening, nanocomposite hydrogel has good mechanical properties. The viscoelastic property of copolymer hydrogel is better than that of composite hydrogel.