Preparation of Polystyrene Polyoxyethylene Amphiphilic Magnetic Polymer Microspheres by Dispersion Polymerization

Preparation of Polystyrene, Ethylene Oxide Amphiphilic Magnetic Polymer Microspheres by Dispersion Polymerization Liu Xueyong Bubin Zheng Zhaohui Zhang Wenchuan Peng Yuxing Chen Xinzi Li Wei21 Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 61004i 2 Applied Biotechnology and Biotechnology, Hong Kong Polytechnic University The Department of Chiral Technology Open Laboratory, Hong Kong prepared amphiphilic magnetic polymer microspheres to study the effect of polymerization conditions on the size of microspheres. By changing the polymerization conditions, an average particle size of 3 can be obtained!

2 Synthesis of Polyoxyethylene Macromer MPEO 5 Poly-e.g. 1500 Dissolved in 4, anhydrous, added. In 4, the reaction was stirred and then 31 pairs of chloromethylstyrene were added. The reaction 16 was continued and the reaction product was poured into ether and filtered to obtain a crude product. The crude product was dissolved in methyl chloride and filtered to remove insolubles. The polyethyl alcohol macromer was precipitated with diethyl ether. The crude product was obtained by suction filtration. The crude product was solved in ethanol in water and the insoluble matter was removed by filtration. The product is re-precipitated with ether and the product is isolated by suction filtration. The product is separated and iteratively carried out. The product is then dried in a milk-drying oven to obtain the desired poly(ethylene macromonomer) with a yield of 8 orphans 3 amphiphilic. Synthesis of polymeric microspheres Amphiphilic magnetic separations, microspheres using Acetonitrile as a medium, potassium persulphate cesium 3 as initiator, watts, 400 as a dispersant, in the presence of 63,4 magnetic fluid, through styrene The specific operation obtained by copolymerization with the polyoxyethylene macromonomer is as follows: the required amount of ai; JIglJ 4200, iron is divided, repeated dialysis with heavy distilled water, and after magnetic separation, it is soaked in 1% and medium; 481; Unenveloped, 5, 4 Finally, the microspheres were prayed to the Zhongluo, and the Polygyiyi was sent to the structure of the Zijin body with 41 such as gt; The structure of the microspheres is based on infrared spectroscopy still 0 on 2 coffee 1. Tablet compression, microspheres average particle size surface morphology Scanning Electron Microscopy 1 Stiffness, Stochasticity 00 Progression Symptoms Results and Discussion 2 The molecular composition of the amphiphilic magnetic polymeric microspheres is spherical, with an average particle size of about 16, and the particle size distribution of the microspheres is polydisperse. Near normal distribution, the effect of particle size 3 reaction conditions of magnetic microspheres over 93 on the synthesis of microspheres was affected by the mean particle size of the spheres. From the same five-port 1 to, as f 伲, 臧 concentration, and increase, the average particle size of the microspheres decreases because f acts as a co-stable f agent in the copolymerization process. Because the polyoxyethylene segment has water-reducing properties, the polyoxyethylene vinyl segment forms a layer of water in the blood of the microspheres. The stability of the microspheres in the water layer is very helpful. It reduces the microspheres. The mutual condensation between the microspheres makes the particle size of the microspheres increase with the concentration of I degree, and the decrease of the concentration of styrene in the microspheres of the microspheres can be seen as 6 with the increase of the styrene concentration. The average particle size increases the increase in styrene concentration, so that the relative concentration of dispersant decreases. The protection of the microspheres by the dispersant is reduced by the monthly factory; the same as the concentration of styrene increases. The solution of the reaction medium increases the polymer cracking degree and increases the particle size of the microspheres. As can be seen from FIG. 7 , the average particle size of the microspheres decreases significantly as the dispersant concentration increases. In the dispersion polymerization process, with the concentration of dispersant added, the stability of the dispersant on the system is enhanced, which helps to improve the stability of the microspheres and reduce the mutual aggregation between the microspheres; at the same time, the dispersant concentration Increasing the viscosity of the continuous phase, which also contributes to the stability of the reaction system, results in a decrease in the diameter of the system.