The Preparation And Study Of Polyamide Microcapsules

In recent years,polymer microcapsule which has many advantages in the size,structure and surface physical and chemical properties,etc.can be used in many fields such as chemical,biological technology and material science,as a limiting reactor,the drug delivery system and nuclear material protection.Polyamide microcapsules are widely used with the advantages of good mechanical strength,thin capsule wall,and small pore and so on.It is the polymer microcapsule which is often prepared.Interfacial polymerization is a traditional preparation method of the polyamide microcapsules.In the process,the disperse phase is needed to be dispersed in the continuous phase to form a stable emulsion.In this paper,the traditional mechanical agitation and the emerging technology of microfluids are used to attain stable emulsion.Terephthaloyl chloride,1,6-hexamethylenediamine and dithylenetriamine are chosen as the reactive monomer that synthesis microcapsules wall.In this paper the synthetic mechanism of microcapsules membrane and how to select raw materials are introduced.In accordance with this we choose the appropriate raw materials.And then the influence of monomer concentration,the quantity of emulsifier and protective agent composition of oil phase,molar ration of amine and the stirring speed,reaction time in mechanical stirring and two-phase flow in microfluidics are discussed.The particle size and distribution of polyamide microcapsules are also analyzed.In the technology of microfluidics,the flow pattern of liquid-liquid flow in microchannel and relationship between droplet size and flow ration are investigated.The traditional mechanical agitation method has certain damages to the capsules,and reduces the yield.Moreover,the capsules prepared through this method have big size and wide distribution.Those limit the application of microcapsules.Preparation of microcapsules by a microchip is a new technology with the advantages of low energy consumption,high utilization rate of raw materials,uniform particle size and so on.