A polymer microsphere

[0024] Example one:

[0025] This embodiment provides a method for preparing polymer microspheres, which includes the following steps:

[0026] 1. Surface bond and initiator molecule of microsphere

[0027] Combine monodisperse polystyrene-divinyl phenyl spheres with a crosslinking degree of 80% and a particle size of 10 microns with a-halogenated acid halide, catalyst (the molar ratio of catalyst to α-halogenated acid halide is 1:1) Mix with an appropriate amount of solvent and stir for 24 hours at a temperature of 40°C to obtain microspheres with surface bonds and initiator molecules.

[0028] In this embodiment, the α-halo acid halide can be α-bromobutyryl bromide, α-bromoisobutyryl bromide, α-bromopropionyl bromide, α-chlorobutyryl bromide, and α-chloride. One of isobutyryl bromide or α-chloropropionyl bromide. Catalyst can choose FeCl 3 , SnCl 4 , BF 3 , ZnCl 2 Or one of AlCl. The solvent can be selected from dichloromethane, 1,2-dichloroethane, carbon disulfide or nitrobenzene.

[0029] 2. The surface of the microspheres is grafted with polyglycidyl methacrylate

[0030] Add the first set of catalysts, the second set of catalysts, ligands and GMA to the reactor at a molar ratio of 1:0.2:2:100, and then add the bonded initiator obtained after step 1 treatment Of polystyrene-divinylbenzene (DMF) microspheres and water, by volume ratio, DMF:H 2 O=1:1, prepared as a mixed solvent, and reacted for 24 hours under vacuum and room temperature conditions to obtain microspheres whose surface grafts are polyglycidyl methacrylate.

[0031] In this embodiment, the first group of catalysts is selected from cuprous chloride or cuprous bromide; the second group is selected from copper chloride or copper bromide; the ligand is selected from 2-bipyridine, tetramethylethylenediamine (TMEDA), N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA) and 1,1,4,7,10,10'-hexamethyltriethylenetetramine One of the amines (HMETE-TA).

[0032] 3. The ring-opening reaction on the surface of the microspheres

[0033] The microspheres prepared in step 2 are added to the nucleophile and solvent, and the epoxy groups in the polyglycidyl methacrylate grafted on the surface of the microspheres are subjected to a ring-opening reaction to obtain a surface grafted product of polymethylmethacrylate. Microspheres based on glycidyl acrylate derivatives. Different nucleophiles are used to obtain different derivatives through ring opening.

[0034] In this embodiment, the nucleophiles used are as follows:

[0035] a. Use the polymethyl methacrylate glycidyl ester modified microspheres obtained in step 2 with one of ammonia, diethylamine, 3,3-diaminopropylimine or 1,6-diaminohexane Kinds of ring-opening reaction to obtain microspheres with polyamino groups on the surface;

[0036] b. The polymethyl methacrylate glycidyl ester modified microspheres obtained in step 2 are ring-opened with hydrazine to obtain microspheres containing polyhydrazine groups on the surface;

[0037] c. Disperse the polymethyl methacrylate glycidyl ester-modified microspheres obtained in step 2 in a 0.3mol/L sulfuric acid solution to obtain microspheres with polyhydroxyl groups on the surface;

[0038] d. Combine the polymethyl methacrylate glycidyl ester modified microspheres obtained in step 2 with excess HN(CH 2 COOC 2 H 5 ) 2 Mixing reaction to obtain microspheres with polyamino and carboxyl groups on the surface;

[0039] e. The polymethyl methacrylate glycidyl ester modified microspheres obtained in step 2 are ring-opened with ethylene dithiol to obtain microspheres containing polysulfhydryl groups on the surface.

[0040] The surface grafts prepared according to the technical scheme of this embodiment are microspheres of polyglycidyl methacrylate or derivatives, which can be used as chromatographic column packing with different exchange functional groups according to the different grafts.

[0041] Embodiment two:

[0042] This embodiment provides a method for preparing polymer microspheres, which includes the following steps:

[0043] 1. Using Friedel-Crafts acylation reaction to prepare microspheres with surface bonds and initiator molecules

[0044] Add 8g of raw material microspheres into a dry 250ml two-necked flask. The microspheres are monodisperse polystyrene-divinylbenzene microspheres with a crosslinking degree of 60% and a particle size of 20 microns, and then add solvents 1, 2 -46ml of dichloroethane, slowly add 21.76g of anhydrous aluminum trichloride under magnetic stirring, and then add 7.2ml of acylation reagent chloropropionyl chloride dropwise, and then react for 24 hours at a temperature of 30°C. 4ml of concentrated hydrochloric acid and 144g of crushed ice were added to the reacted system, stirred for 20 minutes, filtered with suction, and washed with water, ethanol, and acetone several times, respectively. Perform surface element analysis on the obtained microspheres, see attached figure 1 , It is the surface elemental analysis (EDX) map of polymer microspheres with initiator molecules on the surface prepared according to the technical scheme of this embodiment. figure 1 The curve can clearly see the presence of chlorine on the surface of the polymer microspheres, which shows that the initiator molecules have been successfully introduced on the surface of the microspheres.

[0045] 2. Use atom transfer radical polymerization (ATRP) to initiate monomer glycidyl methacrylate (GMA) polymer on the surface of the microspheres obtained in step 1

[0046] In a 250ml two-necked flask, add 3g, 2, 2 、 -Pyridine 0.3420g, copper chloride 0.0300g and cuprous chloride 0.1080g, repeatedly pumped and filled with argon three times, then sealed with a rubber stopper, and injected N,N-dimethylformamide: water (V:V) =1:1 mixed solution 50ml, react for 24 hours under argon protection, magnetic stirring, and room temperature. The product after the reaction was washed several times with a large amount of acetone to obtain microspheres grafted with polyglycidyl methacrylate on the surface. Refer to Figure 3, which is a scanning electron microscope (SEM) image of polymer microspheres. Figure a is a microsphere with initiator molecules (obtained in step 1) on the surface; Figure b is a surface grafted polymethacrylic acid. Microspheres of glycidyl esters (obtained in step 2). by figure 2 Comparing the middle figure a and figure b, it can be seen that the surface of the microspheres shown in figure a is relatively smooth, while the surface of the microspheres shown in figure b is relatively rough. This phenomenon preliminarily proves that after the treatment of step 2, polyglycidyl methacrylate The ester has been grafted to the surface of the microspheres.

[0047] 3. The ring-opening reaction on the surface of the microspheres

[0048] In a dry 250ml two-necked flask, add 2g of polyglycidyl methacrylate grafted microspheres prepared in step 2, 18.4200g of anhydrous calcium chloride, 75ml of anhydrous acetonitrile, and 9.6ml of ethylenediamine, under magnetic stirring React at room temperature for 18 hours. Add anhydrous ether to the reaction system to dilute, and then add saturated saline, the water layer is suction filtered, the filter cake was washed with water, ethanol, and acetone several times to obtain microspheres with high-density amine groups on the surface, after analysis and testing , See Table 1 for the composition and content of some elements in the microspheres.

[0049] Table I

[0050] Microsphere mass (mg) Element content (%) 2.7400 N: 4.932; C: 60.43; H: 8.947

[0051] It can be seen from Table 1 that the presence of nitrogen in the microspheres once again proves that polyglycidyl methacrylate has been grafted to the surface of the microspheres, and the epoxy groups in polyglycidyl methacrylate have been ammoniated. 化.