Method for synthesizing monodisperse polymer microspheres in a pure water medium

Abstract

The invention belongs to the technical field of polymer microsphere preparation, and specifically relates to a method for synthesizing monodisperse polymer microspheres in a pure water medium. A reversible chain transfer agent and a photoinitiator enable the present invention to prepare polymer microspheres with uniform particle size distribution in pure water and low temperature conditions. On the one hand, it can avoid the problem of inability to form microspheres because the solubility characteristics of the monomer and the resulting polymer in water will be affected by temperature factors, and on the other hand, it also solves the problem that it is difficult to form monodisperse microspheres due to nucleation and growth too fast. question. at the same time. Since the present invention uses water instead of organic solvents as the dispersion medium, the influence of organic solvents on biological drugs can be avoided, and there is no pollution to the environment. In addition, since the present invention does not require heating, it is also beneficial to the synthesis of microspheres with biomedical loads.

Description

technical field [0001] The invention belongs to the technical field of polymer microsphere preparation, and in particular relates to a method for synthesizing monodisperse polymer microspheres in a pure water medium. Background technique [0002] Biological and medical technologies often require the use of polymer microspheres as carriers, such as biomolecular recognition, targeted drug delivery, drug sustained release, etc. In these application fields, the preparation process of microspheres often needs to be carried out in a non-organic solvent medium, and the synthesis process also needs to avoid excessively high temperatures, so as not to cause denaturation of biomedical components under the influence of organic solvents. Existing polymer microsphere synthesis systems mainly include emulsion polymerization, suspension polymerization and dispersion polymerization. Among them, emulsion polymerization can use pure water as the medium, but emulsion polymerization requires th...

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Problems solved by technology

Existing polymer microsphere synthesis systems mainly include emulsion polymerization, suspension polymerization and dispersion polymerization. Among them, emulsion polymerization can use pure water as the medium, but emulsion polymerization requires the use of emulsifiers, and the particle size control of microspheres is inflexible; suspension polymerization Pure water can also be used as the medium, but the particle size uniformity of the obtained microspheres is poor

Dispersion polymerization, as a mature polymer microsphere synthesis system, can synthesize monodisperse microspheres with a particle size of 0.1-15 mm. It has also been reported to prepare microspheres by dispersion polymerization in aqueous medium, but because the polymerization reaction requires heating conditions The reaction time is up to 24 hours, these conditions are limited in some biological applications

Moreover, since dispersion polymerization has special requirements on the solubility of monomers and polymers (monomers need to be dissolved in the dispersion medium, and polymers must be precipitated when they reach a certain chain length), when using aqueous media, the temperature has a great impact on the monomers. And the solubility of the polymer is particularly obvious, often resulting in uneven microspheres, or even no microspheres

The photoinitiation system can make the dispersion polymerization proceed rapidly at room temperature, but because the reaction speed is too fast, the nucleation is easily disturbed, and the growing microspheres cannot be stabilized in time, so it is difficult to obtain monodisperse microspheres

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