Synthesis Of Tens Of Micrometers Sized Chloromethylated Polystyrene Spheres And Immobilization Of L-leucine

With the more profound awareness of chiral drug and rising demand for itevery year, chiral drug separation has become a hot assue. HPLC chiral stationaryphase method has widely application in the field of chiral drugs because of its highefficiency, high sensitivity and reproducibility. chiral stationary phases are the mainpart of the chromatographic column. A variety of chiral stationary phases have beensynthesized by domestic and foreign, but they are far from the requirements ofchromatographic separation due to diversity of the chiral drugs and other factors. Sothe synthesis of high chemical stability, high efficiency chiral stationary phases ishotspot in the research area. The analysis shows that the suitable size ofmicrospheres for chiral stationary phases is range from10μm to100μm, it is littleresearch in the present study. In this paper, several parts were mainly done in orderto get the size of chiral microspheres.(1) The10μm to100μm sized chloromethylated crosslinked polystyrenemicrospheres were synthesized by a new method which is between dispersionpolymerization and and suspension polymerization in ethanol/H2O rection mediumwith chloromethylated styrene （CMS） and styrene as compound monomer,divinylbenzene （DVB） as a crosslinker poly(N-vinyl pyrrolidone)(PVP) andhydroxypropylmethyl cellulose (HPMC) as compound dispersant,azo-bis-isobutyronitrile (AIBN) as initiator. The effects of different ethanol/H2Omedium ratio on chloromethylated crosslinked PS microspheres size and sizedistribution were studied extensively. The results show that when the concentrationof HPMC and PVP is3wt%, volume ratio of ethanol/H2O ratio is20/30, the CMS/Stratio is3/7, the mass percentage of microspheres ranged from30μm to50μmreached to64.8%。(2) On the basis of the first step, with volume ratio of ethanol/H2O is10/40as standard formulation, replace part of ethanol with n-hexanol as theco-dispersant for the polymerization of microspheres. The effects of differentamount of n-hexanol on chloromethylated crosslinked PS microspheres size distribution were studied extensively. The results show that when concentration ofn-hexanol is1%, the size distribution of microspheres is relatively narrow, the masspercentage of microspheres ranged from50μm to100μm reached to58%.(3) On the basis of the first step, with volume ratio of ethanol/H2O n-hexanolis19.5/30/0.5as the standard formulation, changed the CMS/St ratio for thepolymerization of microspheres, The effects of different ratio of CMS/St onchloromethylated crosslinked PS microspheres size and size distribution and thechlorine content were studied extensively. The results show that when the CMS/Stratio was3/7、5/5、7/3, the chlorine content was5.82%、10.52%、18.64%, when theCMS/St ratio is7/3, the mass percentage of microspheres ranged from30μm to50μm reduced to23.7%.(4) Polystyrene supported chiral compounds were prepared from chloro-methylated crosslinked polystyrene Homemade as the substrate with L-leucine aschiral molecules. Infrared spectroscopy indicated that, L-leucine were successfulsupported on chloromethylated crosslinked polystyrene. Elemental analysis showedthat the degree of reactions was63.4%according to the content of N.