The Preparation Of Environmental Responsive Polymer And The Study Of Its Performance

Because of its rapid response to specific external stimuli,environmental responsive polymer materials have been widely used in various fields such as drug controlled release,biological tissue sensors and so on.As a drug carrier,the responsive polymer micelles not only can improve the absorption efficiency of poorly soluble drugs,but also can realize the controlled release of hydrophobic drugs.Therefore,compared with the traditional methods of oral administration and injection,polymeric micelles have a good application prospects in the field of biomedicine.Among all types of environmental stimuli,light,temperature and pH is widely studied,since light stimulation can be precisely controlled to achieve the drug "timing,fixed point,fixed speed" release,pH and temperature stimulation can according to the environment that organism itself provided to achieve controlled release.On the basis of a large number of literature review,this paper using reversible addition fragmentation chain transfer radical polymerization(RAFT)and ring opening reaction methods to synthesize two kinds responsive polymers,and the responsive performances of these polymers were studied.(1)Design and synthesize light?pH and temperature responsive amphiphilic polymers.First synthesized spiropyran monomers,then using RAFT polymerization polyethylene glycol methyl ether methacrylate,glycidyl methacrylate,spirobenzo-pyran acrylate monomers to prepared the light and temperature responsive block and random copolymers,last 2-aminoethyldiisopropylamine were introduced to the GMA brushes by ring-opening the epoxy groups,making the polymer with pH responsiveness.The final amphiphilic polymers could form polymeric micelles in water.And used the nuclear magnetic resonance hydrogen spectroscopy(1HNMR)and gel permeation chromatography(GPC)to characterize the molecular structures of the polymers,the light response properties and temperature response properties were characterized by the ultraviolet visible light spectrum,the pH response properties were studied by the pH titrationthe,the critical micelle concentration(CMC)was tested by fluorescence probe method,dynamic laser light scattering(DLS)and transmission electron microscopy(TEM)and fluorescence spectra were used to study the self-assembly and responsive controlled release behaviors of the amphiphilic polymeric micelles.(2)Design and synthesize temperature and pH responsive polymers.Using RAFT polymerization glycidyl methacrylate,N-isopropyl acrylamide monomers to prepared the temperature responsive block copolymers PGMA-b-NIPAAm,then 2-aminoethyldiisopropyl-amine were introduced to the GMA brushes by ring-opening the epoxy groups,making the polymer with pH responsiveness.Used the 1HNMR and GPC to characterize the molecular structures of the polymers,ultraviolet visible light spectrum and pH titrationthe were used to study the pH response properties,ultraviolet visible light spectrum was used to study the temperature response properties.