Method for synthesizing six-long-chain alkyl polyoxyethylene ether cyclotriphosphazene without solvent

Abstract

The invention belongs to the field of fine chemicals, and particularly relates to a solvent-free method for synthesizing six-long-chain alkyl polyoxyethylene ether cyclotriphosphazene. In a reaction container, alkyl (phenol) polyoxyethylene ether and phosphonitrilic chloride trimer are used as raw materials, and under the solvent-free condition, the six-long-chain alkyl polyoxyethylene ether cyclotriphosphazene is obtained through reaction. The synthesis method is simple and convenient, does not need to use an organic solvent and an acid-binding agent, and does not need processes of filtration, distillation and the like; and moreover, the raw material conversion rate is high, and a high-quality hydrochloric acid byproduct can be obtained. The prepared six-long-chain alkyl polyoxyethylene ether cyclotriphosphazene has higher surface activity and lower critical micelle concentration, is rich in phosphorus and nitrogen elements, has a better flame-retardant effect, and can be used as an additive of fine chemicals such as an emulsifier, a dispersant, a fire extinguishing agent, a flame retardant and the like.

Description

Technical Field

[0001] The invention belongs to the field of fine chemicals, and in particular relates to a method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene. Background Art

[0002] Polyphosphazene is a general term for a large class of polymers whose main chains are composed of alternating phosphorus and nitrogen atoms and whose side chains are combined with other functional groups. According to the molecular structure, it can be divided into linear polyphosphazene and ring-crosslinked polyphosphazene. Hexahalocyclotriphosphazene is a typical ring-crosslinked polyphosphazene. Its structure is a six-membered ring conjugated structure formed by alternating three nitrogen atoms and three phosphorus atoms, and each phosphorus atom is connected to two halogen elements. Since the halogen element connected to phosphorus has high activity, it is very easy to be replaced by other groups, thereby preparing various cyclophosphazene derivatives. Because its derivatives also have phosphorus-nitrogen six-membered ring conjugated bonds, phosphazene derivatives also have flame retardant properties.

[0003] The preparation route of cyclophosphazene derivatives is mainly to remove the hydrogen halide from hexahalocyclotriphosphazene and a compound containing active hydrogen. CN112457347A discloses a preparation method of phosphazene derivatives. Aminophenol, phenol and alkali metal hydroxide (acid binding agent) are placed in a dispersant and stirred to obtain a phenolate solution. HCCP is added to the phenolate solution, and after the reaction is completed, hexaaminophenoxycyclotriphosphazene is obtained by distillation and washing. Finally, hexaaminophenoxycyclotriphosphazene and dialkylphosphinic acid are placed in a protective agent for reaction, and a crude product is obtained by filtration. The crude product is then washed with water and dried to obtain a phosphazene derivative.

[0004] CN116640168A discloses a method for preparing a cyclotriphosphazene-based silicon-containing flame retardant. Using dioxane as a solvent, HCCP and an allyl-containing phenolic compound are subjected to a nucleophilic substitution reaction in the presence of an acid-binding agent and a catalyst, and then the intermediate HEP is obtained by filtering and removing salt, rotary evaporation to remove the solvent, and washing with ethanol. Under the conditions of N2 protection and the presence of a catalyst, HEP and a silane compound are reacted and placed in a vacuum drying oven overnight, and finally a cyclotriphosphazene-based silicon-containing flame retardant is obtained.

[0005] CN117736243A discloses a method for preparing ethoxy (pentafluoro) cyclotriphosphazene. HCCP and lithium ethoxide ethanol solution are reacted in an organic solvent, and then solid-liquid separation is performed, and the filtrate is collected and desolventized to obtain the intermediate ethoxy (pentachloro) cyclotriphosphazene. Subsequently, the ethoxy (pentachloro) cyclotriphosphazene is subjected to a first heat treatment, and then a fluorinating agent is added to perform a second heat treatment, and finally the reaction solution is subjected to solid-liquid separation, and the filtrate is purified to obtain the ethoxy (pentafluoro) cyclotriphosphazene.

[0006] CN114394997A discloses a method for preparing pentafluorophenoxy cyclotriphosphazene. In the presence of a catalyst, a fluoride salt and HCCP are reacted in an organic solvent, and the reaction solution is filtered and distilled under reduced pressure to obtain hexafluorocyclotriphosphazene. Subsequently, hexafluorocyclotriphosphazene and a phenoxy salt are reacted in an organic solvent, and after the reaction is completed, the final product pentafluorophenoxy cyclotriphosphazene is obtained by distillation.

[0007] CN113004332A and CN112175010A both disclose a method for synthesizing hexafluorocyclotriphosphazene. In the former, HCCP is dissolved in a non-polar solvent, a fluorinating agent and a catalyst are added, and a fluorination reaction is carried out and then distillation is performed to obtain the target product hexafluorocyclotriphosphazene. The difference between the latter and the former is that the solvent used is changed to an organic solvent, and the type of catalyst used is also different.

[0008] In summary, the prior art discloses a variety of synthetic process routes for phosphazene derivatives, but these routes all need to be carried out in specific solvents, and an acidifying agent needs to be added to increase the conversion rate of the product, which makes it necessary to add separation and purification processes such as distillation, filtration, recrystallization, etc. to the entire process to obtain a pure product, thereby increasing the complexity of the process, and there are many by-products, which is not environmentally friendly. Summary of the invention

[0009] In order to overcome the current situation that the synthesis and purification process of phosphazene derivatives are relatively complicated, the present invention provides a method for solvent-free synthesis of six long-chain alkyl polyoxyethylene ether cyclotriphosphazenes. It is firstly found that hexachlorocyclotriphosphazene (HCCP) has very good solubility in alkyl (phenol) polyoxyethylene ether, therefore, HCCP is directly dissolved in alkyl (phenol) polyoxyethylene ether for reaction. This method does not require solvent addition, does not require the use of an acid coating agent, can directly react to obtain a product, does not require separation and purification, and can also obtain high-quality hydrochloric acid byproducts, thus having the characteristics of simple process and green environmental protection. The obtained product six long-chain alkyl polyoxyethylene ether cyclotriphosphazenes has the characteristics of high surface activity and flame retardancy, and can be used as an additive for fine chemicals such as flame retardants, dispersants and emulsifiers.

[0010] The method for synthesizing six long-chain alkyl polyoxyethylene ether cyclotriphosphazenes of the present invention refers to directly reacting alkyl (phenol) polyoxyethylene ether with hexachlorocyclotriphosphazene (HCCP) in the absence of solvent and acidifying agent to obtain six long-chain alkyl polyoxyethylene ether cyclotriphosphazenes, and the reaction equation is as follows:

[0011]

[0012] R=C m H 2m+1 - or C m H 2m+1 (C6H4)-, m≥8, n≥3.

[0013] The specific synthesis method is: under the condition of continuous nitrogen introduction, alkyl (phenol) polyoxyethylene ether and hexachlorocyclotriphosphazene (HCCP) are mixed, first pre-reacted at low temperature for a period of time, then the temperature is increased to continue the reaction for a period of time, and the hydrogen chloride gas generated during the reaction is collected. After the reaction, hexachlorocyclotriphosphazene is obtained.

[0014] Among them, the reaction raw material alkyl (phenol) polyoxyethylene ether includes but is not limited to octylphenol polyoxyethylene ether (OPEO), nonylphenol polyoxyethylene ether (NPEO) or fatty alcohol polyoxyethylene ether (AEO7, AEO9), and the molar ratio of alkyl (phenol) polyoxyethylene ether and HCCP is 6:1.

[0015] The pre-reaction temperature is 30-60°C, and the pre-reaction time is 12-24h.

[0016] The temperature of the high temperature reaction is 80-140°C, and the high temperature reaction time is 24-48h.

[0017] There are two ways of high temperature reaction: one is direct one-step heating method, and the other is staged heating method. Direct heating is simple and convenient, but it is easy to cause side reactions; staged heating has fewer side reactions, but the reaction time is longer.

[0018] The staged heating is two or more stages of heating.

[0019] Beneficial effects of the present invention:

[0020] The invention uses a one-pot method to prepare hexachloro-long-chain alkylphenol polyoxyethylene ether cyclotriphosphazene from alkyl (phenol) polyoxyethylene ether and hexachloro-cyclotriphosphazene in the absence of solvent and without adding an acid-binding agent. After the reaction is completed, a high-purity phosphazene derivative with surface activity can be directly obtained without complicated and tedious purification treatment.

[0021] The present invention discovers for the first time that hexachlorocyclotriphosphazene has very good solubility in liquid alkyl (phenol) polyoxyethylene ether, while the by-product HCl generated by the reaction is insoluble in the raw material alkyl (phenol) polyoxyethylene ether. Therefore, the by-product HCl gas can be continuously removed to make the reaction proceed to the right, thereby having a very high conversion rate, and further realizing a solvent-free and acid-free reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 . Gel permeation chromatogram of hexa(octylphenol polyoxyethylene ether) cyclotriphosphazene; DETAILED DESCRIPTION

[0023] The present invention is exemplarily described below in conjunction with specific embodiments, but the embodiments are given only as examples and are not considered to be the entire technical solution of the present invention, nor are they intended to limit the overall technical solution of the present invention. Anything with the same or similar technical features, simple changes or substitutions, falls within the scope of protection of the present invention.

[0024] Example 1

[0025] In an environment where nitrogen is continuously introduced, 11.679 g of OPEO and 1.043 g of HCCP are added to a reaction vessel, and pre-reacted at 30° C. for 24 h under uniform stirring conditions, then the temperature is raised to 120° C. for reaction for 24 h. After the reaction, hexa(octylphenol polyoxyethylene ether) cyclotriphosphazene is obtained.

[0026] The hydroxyl values ​​of OPEO and the product were determined according to GB / T 12008.3-2009. The conversion rate of OPEO was calculated to be 92.29% based on the hydroxyl values ​​of the two.

[0027] The product was analyzed by hydrogen spectrum using 400M nuclear magnetic resonance equipment, and the analysis results are as follows: 1 H NMR (400MHz, CDCl3) δ7.24(d,J=8.8Hz,2H),6.81(d,J=8.7Hz,2H),4.10(t,J=4.9Hz,2 H),3.83(t,J=4.9Hz,2H),3.76-3.57(m,37H),1.68(s,2H),1.32(s,6H),0.69(s,10H).

[0028] The molecular weight of the product was determined by gel chromatography with tetrahydrofuran as the mobile phase. Figure 1 As shown, the average molecular weight was measured to be 4390 g / mol.

[0029] Example 2

[0030] In an environment where nitrogen is continuously introduced, 11.679 g of OPEO and 1.043 g of HCCP are put into a reaction container, and pre-reacted at 60° C. for 24 h under uniform stirring conditions. The temperature is then raised to 80° C. for 12 h, 100° C. for 12 h, and 120° C. for 12 h. After the reaction, hexa(octylphenol polyoxyethylene ether) cyclotriphosphazene is obtained.

[0031] The hydroxyl values ​​of OPEO and the product were determined according to GB / T 12008.3-2009. The conversion rate of OPEO was calculated to be 93.61% based on the hydroxyl values ​​of the two.

[0032] Example 3

[0033] In an environment where nitrogen is continuously introduced, 11.556 g of NPEO and 1.043 g of HCCP are put into a reaction container, pre-reacted at 60° C. for 12 h under uniform stirring conditions, and then the temperature is successively raised to 80° C. for 12 h, 100° C. for 12 h, 120° C. for 12 h, and 140° C. for 12 h. After the reaction, hexa(nonylphenol polyoxyethylene ether) cyclotriphosphazene is obtained.

[0034] The hydroxyl values ​​of NPEO and the product were determined according to GB / T 12008.3-2009. The conversion rate of NPEO was calculated to be 94.15% based on the hydroxyl values ​​of the two.

[0035] The molecular weight of the product was determined by gel chromatography with tetrahydrofuran as the mobile phase, and the average molecular weight was determined to be 4534 g / mol.

[0036] Example 4

[0037] In an environment where nitrogen is continuously introduced, 8.905 g of lauryl alcohol polyoxyethylene ether-7 (AEO-7) and 1.043 g of HCCP are put into a reaction container. After pre-reacting at 40° C. for 24 hours under uniform stirring conditions, the temperature is raised to 100° C. and reacted for 24 hours. After the reaction, hexa-(lauryl alcohol polyoxyethylene ether-7) cyclotriphosphazene is obtained.

[0038] The hydroxyl values ​​of AEO-7 and the product were determined according to GB / T 12008.3-2009. The conversion rate of AEO-7 was calculated to be 92.46% based on the hydroxyl values ​​of the two. The molecular weight of the product was determined by gel chromatography with tetrahydrofuran as the mobile phase, and the average molecular weight was 4234 g / mol.

[0039] Example 5

[0040] In an environment where nitrogen is continuously passed through, 10.491 g of lauryl alcohol polyoxyethylene ether-9 (AEO-9) and 1.043 g of HCCP are put into a reaction container. After pre-reacting at 40°C for 12 hours under uniform stirring conditions, the temperature is raised to 80°C for reaction for 24 hours, and finally the temperature is raised to 140°C for reaction for 24 hours. After the reaction, hexa-(lauryl alcohol polyoxyethylene ether-9) cyclotriphosphazene is obtained.

[0041] The hydroxyl values ​​of AEO-9 and the product were determined according to GB / T 12008.3-2009. The conversion rate of AEO-9 was calculated to be 96.24% based on the hydroxyl values ​​of the two.

[0042] The molecular weight of the product was measured by gel chromatography with tetrahydrofuran as the mobile phase, and the average molecular weight was 4542 g / mol.

[0043] Comparative Example 1

[0044] 11.679g OPEO, 1.043g HCCP, 5mL triethylamine and 40mL benzene solution were mixed and added to a three-necked flask, and placed in an oil bath at 65°C for 6h. After the reaction was completed, the salt was removed by filtration, and the filtrate was finally subjected to reduced pressure distillation to remove the benzene solvent to obtain hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene.

[0045] The hydroxyl values ​​of OPEO and the product were determined according to GB / T 12008.3-2009. The conversion rate of OPEO was calculated to be 44.31% based on the hydroxyl values ​​of the two.

[0046] Application Example 1

[0047] The hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene prepared in Example 1 was dissolved in an ethanol reagent to prepare solutions with mass concentrations of 1%, 5%, 10%, 15%, and 20%. Five pieces of cotton cloth with an area of ​​30cm*8.9cm were respectively soaked in the above five solutions of different concentrations for a period of time and then dried, and the mass of the cotton cloth after drying was recorded. The cotton cloth was hung vertically and ignited with an alcohol lamp. After the flame was extinguished, the mass of the cotton cloth after ignition was recorded. The residual carbon rate was calculated based on the mass change before and after combustion, and the results are shown in Table 1. The residue of pure cloth after burning in air was only 0.38%, while the residual carbon rate of the cloth with 20% hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene reached 15.77%, proving that it has good flame retardancy.

[0048] Table 1. Carbon Residue Rate of Hexa(Octylphenol Polyoxyethylene Ether) Cyclotriphosphazene

[0049]

[0050] Application Example 2

[0051] Table 2. CMC values ​​of OPEO and hexa(octylphenol polyoxyethylene ether) cyclotriphosphazene (25°C)

[0052]

[0053] OPEO and the hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene prepared in Example 1 were each prepared into an aqueous solution with a mass concentration of 0.2%, and the surface tension and critical micelle concentration (CMC) of the sample aqueous solution were measured using a K100 KRUSS automatic surface tension meter by the surface tension method. The results are shown in Table 2. As can be seen from the table, hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene has a lower CMC value and its surface activity is significantly improved.

Claims

1. A method for solvent-free synthesis of six long-chain alkyl polyoxyethylene ether cyclotriphosphazene, characterized in that: The method comprises: dissolving hexachlorocyclotriphosphazene in alkyl (phenol) polyoxyethylene ether under the condition of continuous nitrogen flow, and then pre-reacting at low temperature, and then reacting at high temperature to obtain hexachlorocyclotriphosphazene, wherein the reaction equation is as follows: R=C m H 2m+1 - or C m H 2m+1 (C6H4)-, m≥8, n≥3.

2. The method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene according to claim 1, characterized in that: The alkyl (phenol) polyoxyethylene ether is selected from octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether or fatty alcohol polyoxyethylene ether.

3. The method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene according to claim 1, characterized in that: The molar ratio of the alkyl (phenol) polyoxyethylene ether to the hexachlorocyclotriphosphazene is 6:

1.

4. The method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene according to claim 1, characterized in that: The pre-reaction temperature is 30-60° C., and the pre-reaction time is 12-24 hours.

5. The method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene according to claim 1, characterized in that: The temperature of the high temperature reaction is 80-140° C., and the high temperature reaction time is 24-48 hours.

6. The method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene according to claim 5, characterized in that: The high temperature reaction is a one-step temperature increase or a staged temperature increase.

7. The method for solvent-free synthesis of hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene according to claim 6, characterized in that: The staged heating includes heating in two stages or more.

8. The hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene synthesized according to the method of claim 1 is used as an additive for emulsifiers, dispersants, fire extinguishers or flame retardants.

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