Synthesis Of Styrene Derivatives And Their Applications In The Preparation Of Functional Polymer Microspheres

Recently, functional polymeric microspheres have aroused significant interest due to their wide application in building materials, catalyst scaffold and biological medicine. Generally, there are two methods for the preparation of functional polymeric microspheres. One is the functionalization of preformed microspheres with functional groups. The other involves the direct copolymerization of a main monomer with a functional monomer. The former needs at least two reaction steps including the first preparation of polymer microspheres by emulsion or dispersion polymerization and followed the incorporation of functional groups. The latter is indeed a simple and direct technique to fabricate functional polymeric microspheres.Therefore, the design of new functional monomers and their application in preparation of functional polymeric microspheres are recently hot topics. The purposes of this dissertation are synthesis of functional monomers of styrene derivatives and their application in preparation of functional polymeric microspheres.Generally speaking, the content of this dissertation involves two aspects:(1) Fabrication of superhydrophobic surface with controlled wetting property by hierarchical particlesHierarchical particles were prepared by synthetically joining appropriately functionalized polystyrene spheres of poly[styrene-co-(3-(4-vinyl phenyl)pentane-2,4-dione)](PS-co-PVPD) nano-particles and poly(styrene-cochloromethylstyrene)(PS-co-PCMS) microparticles. The coupling reaction of nucleophilic substitution of pendent β-diketone groups with benzyl chloride was used to form the hierarchical particles. Since the polymeric nanoparticles and microparticles were synthesized by dispersion polymerization and emulsion polymerization, respectively, both the core microparticles and the surface nanoparticles can be different size and chemical composition. By means of changing the size of the PS-co-PVPD surface nanoparticles, a series of hierarchical particles with different scale ratio of the micro/nano surface structure were successfully prepared. These as-prepared hierarchical particles were subsequently assembled on glass substrates to form particulate films. Contact angle measurement shows thatsuperhydrophobic surfaces can be obtained and the contact angle of water on the hierarchically structured surface can be adjusted by the scale ratio of the micro/nano surface structure of hierarchical particles.(2) Preparation of core-shell microspheres with surface antibacterial property employing N-(4-vinylbenzyl)-N,N-diethylamine hydrochloride as surfmer.Synthesis of core-shell microspheres by exploringly introducing a quaternary ammonium cationic surfmer of N-(4-vinylbenzyl)-N,N-diethylamine hydrochloride(VEAH) to emulsion polymerization of styrene(St) and their antibacterial property are discussed.Due to the surface activity and moderate reactivity and hydrophilicity of the surfmer,VEAH acts not only as the copolymerization monomer but also an efficient surfactant. This leads to the copolymerization of VEAH with St at interfacial layer and its coagglutination of(co-)oligomers onto core surface and therefore formation of core-shell structures. It is found that the diameter, core radii and shell thickness of resultant core-shell microspheres could be simply controlled by the weight ratio of VEAH and St monomer. Moreover, antibacterial activity of resulted microspheres against Gram-positive bacteria, S. aureus and Gram-nagative bacteria, E. coli were assayed. The result demonstrated that the antimicrobial activity of the core-shell microspheres showed size dependence and core-shell microspheres with smaller particle size displayed higher antimicrobial activity.As a whole, in this dissertation two kinds of new styrene derivatives functional monomers of N-(4-vinylbenzyl)-N,N-diethylamine hydrochloride summer and3-(4-vinylphenyl)-pentane-2,4-dione) are synthesized and their application in preparation of functional polymeric microspheres are discussed. A new method for the preparation of hierarchical particles by synthetically joining appropriately functionalized polystyrene spheres of poly[styrene-co-(3-(4-vinylphenyl)pentane-2,4-dione)](PS-co-PVPD) nanoparticles and poly(styrene-cochloromethylstyrene)(PS-co-PCMS) microparticles and strategies for one-stage synthesis of core-shell polymeric microspheres with surface antibacterial property have been proposed.