Synthesis And Property Of P (St/AA) Magnetic Polymer Microspheres

Magnetic polymer microspheres(MPM)are a kind of microspheres with special structure and magnetism,which is composed of organic polymer and inorganic magnetic particles.Because of its can be separated quickly and easily from mixtures by exterior magnetic field,also has the characteristics of polymer particles,so they have been widespread concern.MPM in the cell separation,the immobilized enzyme, immunoassays,targeting drugs,chemical separation and analysis,organic and biochemical synthesis,environmental / food microbiology testing,and other areas have broad application prospects.In this paper,we improved experimental methods on the basis of Chinese and foreign research results.Prepared poly(styrene -Acrylic acid) magnetic polymer microspheres with monodispersity,narrow particle size distribution, and higher surface carboxyl functional group content and strong magnetic response.The mainly properties of magnetic polymer microspheres is magnetic responsiveness and reactivity of surface function based,therefore,the selection of appropriate magnetic material,polymerization system and polymerization method for preparation of a good magnetic polymer microspheres very important.According to this situation our paper taking preparation of magnetic fluid and polymer microspheres for basis,system study on carboxyl surface of the magnetic polymer microspheres's Preparation,Characterization and Properties.The Properties of inorganic magnetic particles is mainly factors influence the nature of magnetic polymer microspheres magnetic responsiveness.In this paper selection nanoparticles of Fe₃O₄ for magnetism sources.The nanoparticles of Fe₃O₄ were prepared by a chemical precipitation method.The nanoparticles of Fe₃O₄ size is about 11.7 nm.Nanoparticles was obtained by PEG;distilled water as a carrier liquid, prepared the water-based magnetic fluid,Then study on PEG concentration influence of modification effect.Before prepared magnetic polymer microspheres,we first use dispersion polymerization prepared polystyrene polymer microspheres.Research on the initiator amount,temperature,dispersion stability amount,monomer dosage and the dispersion medium polarity effect to its size and size distribution.The results show that when prepared polystyrene polymer microspheres the best dosage of initiator and dispersion stability was 4%and 10%of monomer quality,reaction temperature is 70℃and the ethanol content was 85%of dispersion medium.Reference the conclusions of prepared polystyrene polymer microspheres,the magnetic poly(styrene-acrylic acid)microspheres were prepared by dispersion polymerization,using water-based magnetic fluid as magnetic material.Analysis of test results showed that the magnetic polymer microspheres,as well spherical,better monodisperse,nano-particles dispersed in magnetic microspheres and showed a trade surplus paramagnetic virtually no hysteresis.The magnetic composite polymer microsphere with 0.5320 mmol/g carboxyl functional groups and the magnetic content was15.2%(mass).In this paper the cross-linking monomer N,N'-methylene-bis-acrylamide was first use to dispersion polymerization system prepared magnetic polymer microspheres.The influence of N,N'-methylene-bis-acrylamide on magnetic polymer microspheres were researched.The results showed that with the increase of cross-linking agent, microspheres particle size become small,particle size distribution broadens,surface carboxyl content increases,acid and alkaline resistance enhancements.The magnetic polymer microsphere prepared by This paper,have high surface carboxyl content,good magnetic response,strong acid and alkaline resistance.