Dopamine cross-linked polyphosphazene microspheres with difunctional groups as well as preparation and application of dopamine cross-linked polyphosphazene microspheres

Abstract

The invention relates to the technical field of high polymer materials, in particular to dopamine cross-linked polyphosphazene microspheres with double functional groups and preparation and application thereof. The specific structure is as follows. The preparation method comprises the following steps: respectively adding phosphonitrilic chloride trimer and dopamine hydrochloride into a solvent to obtain a solution a and a solution b; slowly dropwise adding the solution b into the solution a while stirring for continuous reaction; after the reaction is finished, centrifuging, washing and drying to obtain the dopamine cross-linked polyphosphazene microspheres with the difunctional groups. A cross-linked structure is formed through stepwise polymerization of dopamine and phosphonitrilic chloride trimer, oxidative polymerization of a single dopamine structure is avoided, the stability of active groups is improved, phenolic hydroxyl groups and amino groups are introduced into cyclic cross-linked polyphosphazene at the same time, and the application of the cyclic cross-linked polyphosphazene adsorbent in the aspect of complex printing and dyeing wastewater treatment is improved; the method is suitable for complex wastewater environments.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer materials, and more particularly to dopamine cross-linked polyphosphazene microspheres with bifunctional groups and preparation and application thereof. BACKGROUND

[0002] In recent years, with the continuous acceleration of industrialization, the wide application of organic dyes in the textile, printing and dyeing, papermaking, leather and other industries leads to a large amount of dye wastewater discharge, causing serious pollution to the water environment. The organic dyes in such wastewater usually have the characteristics of stable chemical structure and difficult biodegradation, can long-term remain in natural water bodies, not only cause color pollution, reduce water transparency, affect the photosynthesis and ecological balance of aquatic ecosystems, but also some dyes have biological toxicity such as carcinogenicity, teratogenicity and mutagenicity, which pose potential threats to human health and environmental safety. In the existing wastewater treatment technology, adsorption method is widely valued due to its simple operation, high treatment efficiency and wide applicability; this technology mainly relies on the porous structure and surface active functional groups of the adsorbent to realize physical or chemical adsorption of dye molecules, thereby achieving efficient removal.

[0003] Polyphosphazene is a kind of inorganic-organic hybrid high polymer material composed of phosphorus-nitrogen main chain (–P=N–), which can be functionally modified by nucleophilic substitution reaction of P-Cl bond with organic compounds containing hydroxyl, amino and other functional groups. Among them, the ring cross-linked polyphosphazene shows good application potential in the field of adsorption and separation due to its excellent chemical stability and thermal stability endowed by the cross-linked network structure. At present, a variety of single functional group modified ring cross-linked polyphosphazene adsorbents have been successfully developed, such as the polyphosphazene materials containing only amino or only hydroxyl prepared by the reaction of hexachlorocyclotriphosphazene with 3,5-diamino-1,2,4-triazole, 4,4'-dihydroxydiphenyl sulfone, benzidine and other bifunctional compounds. However, the single type of surface functional groups of such materials limits their adsorption performance and application range in complex dye wastewater systems, so it is urgent to develop new polyphosphazene adsorbents with multiple active groups and better adsorption performance. SUMMARY

[0004] The present application aims to at least solve one of the technical problems existing in the prior art, and for this purpose, one aspect of the present application aims to provide dopamine cross-linked polyphosphazene microspheres with bifunctional groups, which contain a ring cross-linked polyphosphazene structure with hydroxyl and amino groups, and the specific structure is as follows: .

[0005] Another aspect of the present application aims to provide a preparation method of dopamine cross-linked polyphosphazene microspheres with bifunctional groups, and the specific steps of the preparation method are as follows: S1. Six chlorocyclotriphosphazene and dopamine hydrochloride are added into solvent respectively to obtain solution a and solution b; S2. Solution b is transferred to a constant pressure funnel, and solution a is added dropwise under stirring to continue the reaction; S3. After the reaction is completed, centrifugation, washing and drying are performed to obtain dopamine cross-linked polyphosphazene microspheres with bifunctional groups.

[0006] Preferably, the solvent in S1 is one or more of acetone, tetrahydrofuran, pyridine, acetonitrile, ethanol, methanol, benzene, toluene, n-hexane and / or N,N-dimethylformamide.

[0007] Preferably, the mass ratio of six chlorocyclotriphosphazene to solvent in S1 is 1:150-1:800.

[0008] Preferably, the mass ratio of dopamine hydrochloride to solvent in S1 is 1:100-1:600.

[0009] Preferably, in S2, the dropwise addition is performed at 60°C under nitrogen protection.

[0010] Preferably, in S2, the volume ratio of solution a to solution b is 100:1.

[0011] Preferably, in S2, the dropwise addition speed of solution b is 0.5-20mL / min, and the reaction time is 60-600 minutes.

[0012] Preferably, in S3, the centrifugation speed is 6000rpm, the washing frequency is 3 times, the washing agent is deionized water, anhydrous ethanol or a mixture thereof, the drying time is 24 hours, and the drying temperature is 40°C.

[0013] Still another aspect of the present application aims to provide an application of dopamine cross-linked polyphosphazene microspheres with bifunctional groups, which are used as organic dye adsorbents in complex dye wastewater environment.

[0014] The present application has the following beneficial effects: The active groups are rich and the adsorption performance is excellent: the microspheres contain phenolic hydroxyl and amino bifunctional active groups, can efficiently adsorb various organic dyes in complex wastewater, have strong adaptability and remarkable removal effect.

[0015] The structure is stable and the physicochemical performance is outstanding: the cross-linked structure is formed by the step-by-step polymerization of dopamine and six chlorocyclotriphosphazene, which avoids the oxidative polymerization of dopamine alone, improves the stability of active groups, introduces phenolic hydroxyl and amino groups into cyclodextrin cross-linked polyphosphazene, improves the application of cyclodextrin cross-linked polyphosphazene adsorbents in complex printing and dyeing wastewater treatment, and is suitable for complex wastewater environment.

[0016] Uniform morphology and good dispersibility: the obtained microspheres are uniform in size, good in monodispersity, and the particle size is mainly distributed in 0.4-0.55 mu m, which is beneficial to form a stable dispersion system, improve the adsorption efficiency and operation convenience.

[0017] Simple preparation process, easy to popularize: the method has raw materials, simple synthesis steps, good producibility and potential for large-scale application, and is beneficial to popularization and use in actual wastewater treatment.

[0018] Great environmental application potential: can be used as a high-efficiency adsorbent for purifying complex dye wastewater, and provides a new way for solving the problems of single function, poor stability and uneven size of adsorbents in the prior art.

[0019] Additional aspects and advantages of the present application will become apparent in the description that follows, or will be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the description that follows, combined with the accompanying drawings, wherein: Figure 1 is a scanning electron microscope photo of dopamine cross-linked polyphosphazene microspheres with bifunctional groups prepared in Example One of the present application; Figure 2 is a transmission electron microscope photo of dopamine cross-linked polyphosphazene microspheres with bifunctional groups prepared in Example One of the present application; Figure 3 is an infrared spectrum of dopamine cross-linked polyphosphazene microspheres with bifunctional groups prepared in Example One of the present application; Figure 4 is a dye adsorption kinetics curve of dopamine cross-linked polyphosphazene microspheres with bifunctional groups prepared in Example One of the present application. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be further described in detail below in combination with the drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0022] In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from the description, therefore, the protection scope of the present application is not limited by the specific embodiments disclosed below.

[0023] Example One S1. In a reaction device equipped with magnetic stirring, thermometer, spherical condenser and constant pressure funnel, 0.3 g of hexachlorocyclotriphosphazene and 100 mL of acetonitrile solvent were added into a 250 mL three-necked round bottom flask to disperse solution a; 0.5 g of dopamine hydrochloride was added into 50 mL of acetonitrile solution to disperse solution b.

[0024] S2. Solution b was transferred to the constant pressure funnel, and solution a was slowly added at a speed of 5 mL / min under the conditions of 60°C and nitrogen protection with stirring, and the reaction was continued for 360 min.

[0025] S3. After the reaction was completed, centrifugation (6000 rpm), deionized water washing 3 times, and drying at 40°C for 24 hours were adopted to obtain polyphosphazene microspheres with dopamine structure embedded, and the results showed that the average particle size of the prepared polyphosphazene microspheres was 0.5 um, mainly distributed in the range of 0.4-0.55 um.

[0026] As shown in the scanning electron microscope photos of Figure 1 , the results showed that the prepared polyphosphazene microspheres were uniform in size, good in monodispersity, and smooth in surface; as shown in the transmission electron microscope photos of Figure 2 , the results showed that the prepared polyphosphazene microspheres were solid microspheres; as shown in the infrared spectrum of Figure 3 , and the dye adsorption kinetics curve of Figure 4 .

[0027] Example Two S1. In a reaction device equipped with magnetic stirring, thermometer, spherical condenser and constant pressure funnel, 0.3 g of hexachlorocyclotriphosphazene and 100 mL of acetonitrile solvent were added into a 250 mL three-necked round bottom flask to disperse solution a; 0.5 g of dopamine hydrochloride was added into 50 mL of acetonitrile solution to disperse solution b.

[0028] S2. Solution b was transferred to the constant pressure funnel, and solution a was slowly added at a speed of 5 mL / min under the conditions of 60°C and nitrogen protection with stirring, and the reaction was continued for 360 min.

[0029] S3. After the reaction was completed, centrifugation (6000 rpm), deionized water washing 3 times, and drying at 40°C for 24 hours were adopted to obtain polyphosphazene microspheres with dopamine structure embedded, and the results showed that the average particle size of the prepared polyphosphazene microspheres was 0.5 um, mainly distributed in the range of 0.4-0.55 um.

[0030] Example Three S1. In a reaction device configured with magnetic stirring, thermometer, spherical condenser and constant pressure funnel, 0.3g hexachlorocyclotriphosphazene and 100mL acetonitrile solvent were added into a 250mL three-necked round bottom flask to disperse solution a; 0.5g dopamine hydrochloride was added into 20mL acetonitrile solution to disperse solution b.

[0031] S2. Solution b was transferred to the constant pressure funnel, and solution a was slowly added at a speed of 5mL / min under the conditions of 60℃ and nitrogen protection with stirring, and the reaction was continued for 360min.

[0032] S3. After the reaction was completed, centrifugation (6000rpm), deionized water washing 3 times, and drying at 40℃ for 24 hours were adopted to obtain polyphosphazene microspheres with dopamine structure embedded therein. The results show that the average particle size of the prepared polyphosphazene microspheres is 0.5um, and is mainly distributed in the range of 0.4-0.55um.

[0033] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can also have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. Dopamine cross-linked polyphosphazene microspheres having bifunctional groups, characterized in that: The dopamine cross-linked polyphosphazene microspheres contain a hydroxyl and amino ring cross-linked polyphosphazene structure, and the specific structure is as follows: 。 2. The process for the preparation of dopamine cross-linked polyphosphazene microspheres with bifunctional groups as claimed in claim 1, wherein: The preparation method has the following specific steps: S1. Six chloro-cyclotriphosphazene and dopamine hydrochloride are respectively added to a solvent to obtain solution a and solution b; S2. Solution b is transferred to a constant pressure funnel, and solution a is slowly added dropwise under stirring to continue the reaction; S3. After the reaction is completed, centrifugation, washing and drying are performed to obtain dopamine cross-linked polyphosphazene microspheres with bifunctional groups.

3. The process for the preparation of dopamine cross-linked polyphosphazene microspheres with bifunctional groups as claimed in claim 2, wherein the process comprises the steps of: The solvent in S1 is one or more of acetone, tetrahydrofuran, pyridine, acetonitrile, ethanol, methanol, benzene, toluene, n-hexane and / or N,N-dimethylformamide.

4. The process for the preparation of dopamine cross-linked polyphosphazene microspheres with bifunctional groups as claimed in claim 2, wherein the process comprises the steps of: The mass ratio of six chloro-cyclotriphosphazene to the solvent in S1 is 1:150-1:

800.

5. The method for preparing dopamine cross-linked polyphosphazene microspheres with bifunctional groups according to claim 2, characterized in that: The mass ratio of dopamine hydrochloride to the solvent in S1 is 1:100-1:

600.

6. The method for preparing dopamine cross-linked polyphosphazene microspheres with bifunctional groups according to claim 2, characterized in that: In S2, the solution is added dropwise under the condition of 60°C and nitrogen protection.

7. The method for preparing dopamine crosslinked polyphosphazene microspheres with bifunctional groups according to claim 2, characterized in that: The volume ratio of solution a to solution b in S2 is 100:

1.

8. The method for preparing dopamine cross-linked polyphosphazene microspheres with bifunctional groups according to claim 2, characterized in that: The dropwise speed of solution b in S2 is 0.5-20 mL / min, and the reaction time is 60-600 minutes.

9. The method for preparing dopamine crosslinked polyphosphazene microspheres with bifunctional groups according to claim 2, characterized in that: The centrifugal speed in S3 is 6000 rpm, the washing frequency is 3 times, the washing agent is deionized water, anhydrous ethanol or a mixture thereof, the drying time is 24 hours, and the drying temperature is 40°C.

10. Use of dopamine cross-linked polyphosphazene microspheres having bifunctional groups according to claim 1, characterized in that: The application of dopamine cross-linked polyphosphazene microspheres with bifunctional groups as an organic dye adsorbent in a complex dye wastewater environment.

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