Synthesis And Characterization Of Functional Polymethacrylic/Laponite Nanocomposite Hydrogels

In this thesis, functional Polymethacrylic (PMAA)/Laponite nanocomposite (NC) hydrogels were synthesized and characterized. They are ideal candidates for tissue adhesives, wound dressing and controlled drug delivery.Their synthesis was performed by free radical polymerization and copolymerization of acrylic acid, methacrylic acid and acrylamide in the aqueous of Laponite solution. Then the properties of these hydrogels were investigated further by rheological method, swelling studies,180°peel strength tests and so on. The main content of this thesis includes:(1)PMAA nanocomposite (NC) hydrogels and PMAA ordinary (OR) gels were synthesized by free radical polymerization of methacrylic acid by using Laponite and BIS as crosslinkers. The PMAA NC gels showed good adhesion while PMAA OR gels showed both pH- and temperature-sensitive. And it was found that the storage modulus (G') and loss modulus (G") of PMAA NC gels increased significantly upon increasing the content of Laponite and decreasing the pH value, while the storage modulus and loss modulus of PMAA OR gels increased upon increasing the amount of BIS by rheological method.(2)Intelligent P(AAm-co-MAA)/Laponite NC gels were synthesized by free radical copolymerization of acrylamide and methacrylic acid by using Laponite as crosslinkers. These hydrogels were both pH- and temperature-sensitive, their swelling degree of the gels increased upon increasing the pH value and temperature of the solution. The storage modulus and loss modulus increased significantly upon increasing the content of Laponite and AAm, which effecting the crosslinking density of gels.(3)P(AA-co-MAA)/Laponite NC gels were synthesized by free radical copolymerization of acrylic acid and methacrylic acid by using Laponite as crosslinkers. The effect of AA content, Laponite content, the total monomer content and pH value on the adhesion and rheological method and 180°peel measurement. P(AAm-co-AA)/Laponite NC gels consisting of AAm, AA and Laponite were synthesized and their properties were characterized by Rheology.The innovation of this paper includes using MAA as monomers to synthesis functional nanocomposite hydrogels for the first time and using other monomers to copolymerize with MAA aiming at improving the original system's temperature-sensitivity and adhesion.