Preparation And Research Of Polyethylene Glycol(PEG)Hydrogels And Composite Gel

Polyethylene glycol(PEG)with hydrophilic chain segments can improve the water absorption properties.PEG-based hydrogel has good water absorption,water retention and biocompatibility,which could be applied in vivo on the human body without causing inflammation,and could be quickly discharged from body without toxic effects.Polyvinyl alcohol(PVA)have many excellent properties,such as good film forming properties,wear resistance,impact resistance,tensile strength,good insulation,strong adhesion and good smoothness.poly-N-isopropylacrylamide(PNIPAm)hydrogels could exhibit sensitive volume phase transition in response to external stimuli such as temperature(at the lower critical solution temperature "LCST"of 32 °C),belonging to a typical heat shrinkable hydrogel.If the structure of hydrogels were tuned by the different amount of hydrophilic components to hydrophobic components in the polymer backbone,the LCST can also be changed up and down.This study consists of two parts.Firstly,a series of PEG-IPDI-PVA graft copolymer were prepared by isocyanating with PEG,PVA and IPDI.Laponite and montmorillonite(MMT)were also added into the above mentioned hydrogels to explore the effect of nanofillers on the performance.The results showed that the swelling ratio of the materials was significantly increased.The internal structure,physical and chemical properties of the hydrogel were also improved.The temperature sensitivity of the material was detected from 35 ℃ to 40 ℃ by the swelling ratio rapidly increasing.The addition of MMT can effectively strengthen the mechanical properties of the polymerIn the second part,the P(NIPAm-PEGMA)hydrogel were prepared by free radical copolymerization with N-isopropylacrylamide(NIPAm)and polyethylene glycol methacrylate(PEGMA),methylene bisacrylamide(BIS)as crosslinker,potassium persulfate(KPS)and N,N,N’,N’-tetramethylethylenediamine(TEMED)as initiator.A new series of nano-hybrid gels were prepared by adding Laponite as the reinforcing agent.The results indicate that the addition of PEGMA and Laponite could change the internal structure and properties of the gel,improve the mechanical properties and the temperature sensitivity of the hydrogel.