Preparation Of "Living" Polymer By RAFT Controlled Polymerization Method And Its Basic Application

Due to the strict law of low detection limit of harmful substances and the complexity of the target compounds’ matrices issued by the national regulatory authority,which aimed to provide better protection for consumers,higher requirements for the sample preparation materials has been proposed in the actual detection process.Therefore,the development of a kind of pretreatment materials with high sensitivity,large sample load,and small amounts of chemical reagents has become the focus of our research area,which puts forward higher requirements for the study of sample preparation materials.This project proposes a simple and effective method which combines reversible addition-fragmentation chain transfer with a variety of free radical polymerization methods for the preparation of controllable living materials.Furthermore,a successful preparation of the poly 4-vinylpyridine balls and uniform and monodisperse polystyrene living microspheres which can be used for functionalization can be done by this method.In addition,this project tries to coat them with functionalized shells and apply them to the adsorption of hippuric acid.This paper mainly includes the following contents:(1)Using reversible addition-fragmentation chain transfer precipitation polymerization to prepare poly 4-vinylpyridine microspheres with chain transfer groups on the surface.Furthermore,changing the polymerization reaction conditions(the ratio of initiator to chain transfer agent,reaction time,reaction temperature)to optimize the preparation conditions.The results showed that poly4-vinylpyridine microspheres with suitable particle size can be successfully prepared,and it was found that when they are applied to the adsorption of hippuric acid,the load on hippuric acid was large.(2)Using reversible addition-fragmentation chain transfer soap-free emulsion polymerization to prepare polystyrene microspheres with chain transfer groups on the surface.Furthermore,changing the polymerization conditions(the ratio of initiator to chain transfer agent,reaction temperature,reaction time)to optimize the preparation conditions.The results showed that polystyrene microspheres with uniform,monodisperse and controllable particle size can be successfully prepared.(3)Using polystyrene microspheres with chain transfer groups,which as the core carrier,and functional polymer shells which synthesize outside through the surface-initiated RAFT polymerization reaction to prepare core-shell polymer microspheres.Furthermore,changing the polymerization method to optimize the preparation conditions.The results showed that through a series of characterization and adsorption tests on hippuric acid,the polystyrene microspheres obtained in this paper can be applied to the coating of a variety of functional shells,which provides a broad prospect for its future application in sample preparation materials.