阅读说明：本技术 一种一步合成聚吡唑囊泡的方法 (Method for synthesizing polypyrazole vesicles in one step ) 是由 肖龙强 郭博庚 赵玉来 侯琳熙 潘瑶琪 张永乐 于 2020-07-30 设计创作，主要内容包括：本发明涉及一种一步合成聚吡唑囊泡的方法。本发明反应单体为一种同时含有重氮基团和炔烃为端基的化合物,将该单体置于聚合管中,搅拌并加热,加热下经过1,3-环加成反应后得到产物,将产物用重沉淀,离心后真空干燥得到产物。本发明制备的聚合物结构中,在主链上引入吡唑来增加聚合物刚性,提高其稳定性。本发明制备方法无需引发剂、催化剂和溶剂,制备过程简单快速,后处理简便。(The invention relates to a method for synthesizing a polypyrazole vesicle in one step. The reaction monomer is a compound simultaneously containing diazo groups and alkyne as end groups, the monomer is placed in a polymerization tube, stirred and heated, and is subjected to 1, 3-cycloaddition reaction under heating to obtain a product, and the product is subjected to heavy precipitation, centrifugation and vacuum drying to obtain the product. In the polymer structure prepared by the invention, pyrazole is introduced to the main chain to increase the rigidity of the polymer and improve the stability of the polymer. The preparation method of the invention does not need initiator, catalyst and solvent, and has simple and rapid preparation process and simple and convenient post-treatment.)

1. A method for synthesizing a polypyrazole vesicle in one step is characterized in that a reaction monomer is a compound containing a diazo group and alkyne as end groups, the monomer is placed in a polymerization tube, stirring and heating are carried out, a product is obtained after 1, 3-cycloaddition reaction is carried out under heating, and the product is obtained by re-precipitation, centrifugation and vacuum drying.

2. The method for synthesizing the polypyrazole vesicle according to claim 1, wherein the polypyrazole vesicle has a specific general formula as follows:

wherein n is any integer greater than zero; r is one of straight-chain alkane or aromatic hydrocarbon.

3. The method for synthesizing the polypyrazole vesicle according to claim 1, wherein the structural formula of the reaction monomer is as follows:

4. The method for synthesizing the polypyrazole vesicle in one step according to claim 1, wherein the specific process comprises the following steps: heating the reaction monomer to 80-150 deg.C^oAnd C, stopping the reaction when the reaction is changed from a liquid state to a solid state, cooling to room temperature after the reaction is finished, and carrying out reprecipitation and vacuum drying to obtain the polypyrazole.

5. The method for synthesizing the polypyrazole vesicle according to claim 1, wherein the solvents used for re-precipitation are dimethyl sulfoxide and methanol.

Technical Field

The invention relates to a method for synthesizing a polypyrazole vesicle in one step.

Background

In nature, the phenomenon of self-assembly of small molecules is ubiquitous, and the small molecules possess a hydrophilic segment and a hydrophobic segment, and form various morphologies such as spheres, columnar sheets and vesicles when assembled in bulk and aqueous solutions, as well as self-assembly of polymers. Compared with small molecule self-assembly, the polymer assembly has better stability and durability, thereby having great application value in the fields of biological medicine, photoelectric materials, catalysts and the like.

The polymersome is a spherical nanoparticle with a hollow structure, and is a double-layer membrane structure formed by assembling amphiphilic polymers. Due to the higher molecular weight of the block polymer, the polymersome has more excellent stability and higher strength than the small molecule vesicles. In recent years, polymersomes have often been used as drug carriers in drug delivery systems.

Polymersomes are generally prepared by self-assembly of block polymers, and are classified into co-solvent methods and direct dissolution methods. The co-solvent method is to prepare aggregates using different ratios of organic solvent and selective solvent (e.g., water) and then dialyze against water to remove the co-solvent. The direct dissolution method is to directly add the polymer into a selective solvent and prepare the aggregate by using methods such as mechanical stirring, ultrasound and the like. Self-assembly is affected by many factors, such as polymer composition, concentration, solvent ratio and physical process strength, to give different aggregate morphologies. The traditional self-assembly of polymers is to synthesize two or more block polymers with hydrophilic and hydrophobic properties, and the regular morphology is formed by utilizing the hydrophilic and hydrophobic properties of the block polymers, so that not only are a plurality of synthesis steps required, but also a plurality of influence factors are required.

Therefore, it is necessary to invent a homopolymer that can stably form vesicles in a common solvent without using a specific ratio of a cosolvent and without using physical methods such as mechanical and ultrasonic methods.

Disclosure of Invention

The invention aims to provide a method for synthesizing a polypyrazole vesicle in one step. The preparation method is simple and the synthesis efficiency is high.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for synthesizing a polypyrazole vesicle in one step, wherein the polypyrazole vesicle is specifically a cyclic polypyrazole and has the following specific general formula:

；

wherein n is any integer greater than zero; r is one of straight-chain alkane or aromatic hydrocarbon.

The preparation method comprises the following steps: heating a diazo salt and an alkyne compound respectively serving as end groups to 80-150 DEG C^oAnd C, stopping the reaction when the reaction is changed from liquid state to solid state, cooling to room temperature after the reaction is finished, and carrying out reprecipitation and vacuum drying to obtain the cyclic polypyrazole.

The specific synthetic route is as follows:

。

the reaction monomer is a compound containing diazo group and alkyne as end groups, the monomer is placed in a polymerization tube, stirred and heated, and subjected to 1, 3-cycloaddition reaction under heating to obtain a product, the product is subjected to heavy precipitation by dimethyl sulfoxide/methanol, and the product is obtained by vacuum drying after centrifugation.

Wherein the structure of the reaction monomer is as follows:(ii) a R is one of straight-chain alkane or aromatic hydrocarbon.

Methods for the synthesis of reactive monomers are referenced chem. commun., 2018,54, 3516-.

The main chain of the polymer obtained by the synthesis method provided by the invention consists of pyrazole and ester, and no chain end group exists. Diazo in the reaction monomer is a compound which is unstable at high temperature and needs to be freshly prepared and used.

The invention has the outstanding characteristics that:

1. the polymer prepared by the invention can obtain vesicles after being subjected to a purification step without additional steps.

2. The polymer obtained by the invention is a brand-new material, has a novel structure and is widely applied.

3. The preparation method of the invention does not need initiator, catalyst and solvent, and has simple and rapid preparation process and simple and convenient post-treatment.

Drawings

FIG. 1 shows the nuclear magnetic spectrum of the monomer prepared in example 1.

FIG. 2 is a nuclear magnetic spectrum of the monomer prepared in example 2.

FIG. 3 is a nuclear magnetic spectrum of a monomer prepared in example 3.

FIG. 4 shows the NMR spectra of the polymer prepared in example 1.

FIG. 5 is an IR spectrum of the polymer prepared in example 1.

FIG. 6 is a differential scanning calorimetry thermogram, T, of the polymer prepared in example 1_gIs the glass transition temperature of the polymer.

FIG. 7 is a thermogravimetric analysis spectrum of the polymer prepared in example 1, in which T is_LRefers to the temperature at which the polymer loses 5% by weight.

FIG. 8 is a scanning electron micrograph of the polymer prepared in example 1.

FIG. 9 is a transmission electron micrograph of the polymer prepared in example 1.

FIG. 10 is a transmission electron micrograph of the polymer prepared in example 1.

Detailed Description

The salient features and the considerable advances of the invention are further clarified below by the examples, which are intended to be illustrative only and not limiting.