Study On Design, Synthesis And Properties Of Functional Polymer With Novel Morphology

The studies on design, synthesis of functional polymer with novel morphology (hollow core/pore shell structure, cross-linked micelles as photo-responsive and microcrystalline gels) and their applications in environment, medicine and other fields are the main aims of this disfucation.With the constant development of functional polymer on biocompatibility and environmental friendliness, more and more functional polymer with novel morphology come into people’s field of vision. The research progress of design, synthesis and applications of them are reviewed in this paper; Polysulfone (PSF) microspheres with hollow core/pore shell structure are developed and applied in oil-water sparation; Two kinds of cross-linking micelles (dextran-hemin, polyvinyl alcohol-hemin) as photo-responsive release drugs carriers, combining chemotherapy and photodynamic therapy for multimodal cancer therapy, are designed and synthesized; The microcrystalline polyacrylic acid gels are synthesized by emulsion polymerization. The modern instrument technology is used for characterizing the synthesis and varies of structure of polymers in the emulsion system.The main contents and results of the work are as follows:1. The porous polysulfone (PSF) microspheres are prepared by using emulsion solvent evaporation technique. The morphology can be controlled by varying the type of surfactant, the preparation temperature and the emulsion type from W/O to either O/W or multiple W/O/W. The results demonstrate that the type of surfactant is the important point in to the morphology. The PSF microspheres with hollow core/pore shell structure can be obtained using oleic acid as surfactant. Contact angles test show that there is no obvious difference among all kinds of microspheres, but a considerable gap in the oil-water separation. The PSF microspheres with hollow core/pore shell structure have higher absorption capacity, causing by floatation performance and high porosity and appropriate void size of sorbent provided large amounts of storage volume for oil, acting as an oil reservoir, which was the key for the high adsorption capacity. The separation efficiency of the porous PSF microspheres is33.6g/g, which is44.8times higher than that of the pristine PSF powder. The PSF microspheres possess simple and excellent pore structure, which is expected to be widely used in oil-water separation.2. Double bond in hemin-crosslinked dextran (polyvinyl alcohol) micelles were designed for photo-triggered release of5-fluorouracil (5FU), an antitumor drug. The crosslinked micelles were stable even high dilution, In vitro release studies showed light-responsive release of5FU. For the cross-linking micelles of dextran-hemin, only15%5FU was released from dextran-hemin, after383min in10mM PB.92%5FU was released in383min in laser irradiation under the same conditions. However, for the cross-linking micelles of polyvinyl alcohol-hemin, the stability become higher,36%5FU was released in360min in laser irradiation. Using1,3-Diphenylisobenzofuran (DPBF) as a chemical trapping agent, the as-prepared crosslinked micelles can generate singlet oxygen effectively through ultravioler spectroscopy detecting device, this is due to photosensitive of heme. The photo-responsive5-FU loaded cross-linked micelles combining chemotherapy and photodynamic therapy observed by MTT and fluorescence microscopy. These novel nano-vehicles have the advantages of convenient preparation, favorable biocompatibility, degradability, and effective antitumor activity with promising applications.3. Surfactant has dual roles of polymer crystallization nucleating agent and emulsifiers in the polymerization process. Experiment design will be in the process of emulsion polymerization. In this system, emulsion (sodium dodecyl sulfate) acts as a nucleating agent. Experimental results show that microcrystalline polyacrylic acid gels can be obtained through a simple emulsion polymerization method. In the process of polymerization, proper emulsifier holds the adjacent molecules together, making PAA microgels growth along crystallographically possible reactive directions. The experimental conditions influence the crystallinity and morphology of PAA microgels. It should be noted that the Young’s modulus of microcrystalline polyacrylic acid gels is7.8times of amorphous gel. This indicates that the synthesis of microcrystalline PAA gles is conducive to improve mechanical properties.