Process for the solvent-free synthesis of hexa-long-chain-alkyl polyoxyethylene ether cyclotriphosphazene

Abstract

The application belongs to the field of fine chemicals, and particularly relates to a method for synthesizing hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene without solvent. In a reaction container, alkyl (phenol) polyoxyethylene ether and hexachlorocyclotriphosphazene are used as raw materials to obtain hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene under the condition of no solvent. The synthesis method is simple and convenient, and does not need to use organic solvent and acid binding agent, and does not need processes such as filtering and distilling. Moreover, the raw material conversion rate is high, and high-quality by-product hydrochloride can be obtained. The prepared hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene has higher surface activity, lower critical micelle concentration, rich phosphorus and nitrogen elements, and better flame retardant effect, and can be used as an additive of fine chemicals such as emulsifier, dispersant, extinguishing agent and flame retardant.

Description

Technical Field

[0001] This invention belongs to the field of fine chemicals, specifically relating to a solvent-free method for synthesizing hexa-long-chain alkyl polyoxyethylene ether cyclotriphosphazene. Background Technology

[0002] Polyphosphazenes are a broad class of polymers whose main chain consists of alternating phosphorus and nitrogen atoms, with side chains bonded to other functional groups. Based on molecular structure, they can be divided into linear polyphosphazenes and cyclic crosslinked polyphosphazenes. Hexahalocyclic triphosphazenes are a typical example of cyclic crosslinked polyphosphazenes. Their structure is a six-membered ring conjugated structure formed by alternating links of three nitrogen atoms and three phosphorus atoms, with two halogen elements bonded to each phosphorus atom. Because the halogen elements bonded to phosphorus are highly reactive, they are easily replaced by other groups, thus producing various cyclic phosphazene derivatives. Furthermore, because their derivatives also possess phosphorus-nitrogen six-membered ring conjugated bonds, phosphazene derivatives also exhibit flame-retardant properties.

[0003] The preparation route of cyclophosphonitrile derivatives mainly involves the dehydrohalogenation of hexahalocyclic triphosphonitriles with compounds containing active hydrogen. CN112457347A discloses a method for preparing phosphonitrile derivatives. Aminophenol, phenol, and an 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 complete, the solution is distilled and washed with water to obtain hexaaminophenoxycyclotriphosphonitriles. Finally, hexaaminophenoxycyclotriphosphonitriles are reacted with dialkylphosphonic acid in a protective agent, filtered to obtain a crude product, and then washed with water and dried to obtain the phosphonitrile 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 undergo a nucleophilic substitution reaction in the presence of an acid-binding agent and a catalyst. The resulting product is then purified by filtration to remove salt, rotary evaporation to remove solvent, and washing with ethanol to obtain the intermediate HEP. Under N2 protection and in the presence of a catalyst, HEP is reacted with a silane compound and dried overnight in a vacuum drying oven to finally obtain a cyclotriphosphazene-based silicon-containing flame retardant.

[0005] CN117736243A discloses a method for preparing ethoxy(pentafluoro)cyclotriphosphazene. The method involves reacting HCCP and lithium ethanol solution in an organic solvent, followed by solid-liquid separation. The filtrate is collected and solvent-removed to obtain the intermediate ethoxy(pentachloro)cyclotriphosphazene. Subsequently, the ethoxy(pentachloro)cyclotriphosphazene undergoes a first heat treatment, followed by a second heat treatment with the addition of a fluorinating agent. Finally, the reaction solution is subjected to solid-liquid separation, and the filtrate is purified to obtain ethoxy(pentafluoro)cyclotriphosphazene.

[0006] CN114394997A discloses a method for preparing pentafluorophenoxycyclotriphosphazene. In the presence of a catalyst, a fluoride salt and HCCP are reacted in an organic solvent. 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. After the reaction is complete, the final product, pentafluorophenoxycyclotriphosphazene, is obtained by distillation.

[0007] CN113004332A and CN112175010A both disclose a method for synthesizing hexafluorocyclic triphosphazene. The former involves dissolving HCCP in a nonpolar solvent, adding a fluorinating agent and a catalyst, and then distilling the mixture after a fluorination reaction to obtain the target product, hexafluorocyclic triphosphazene. The latter differs from the former in that it uses an organic solvent and a different type of catalyst.

[0008] In summary, existing technologies disclose various synthetic routes for phosphazene derivatives, but these routes all require specific solvents and the addition of acidifying agents to improve product conversion rates. This necessitates the addition of separation and purification processes such as distillation, filtration, and recrystallization to obtain pure products, thus increasing process complexity, generating numerous byproducts, and being environmentally unfriendly. Summary of the Invention

[0009] To overcome the cumbersome synthesis and purification processes of phosphazene derivatives, this invention provides a solvent-free method for synthesizing hexachlorocyclotriphosphazene (HCCP) alkyl(phenol) polyoxyethylene ethers. For the first time, it was discovered that hexachlorocyclotriphosphazene (HCCP) has excellent solubility in alkyl(phenol) polyoxyethylene ethers; therefore, HCCP is directly dissolved in the alkyl(phenol) polyoxyethylene ether for the reaction. This method requires no solvent addition, no acid-coating agent, and the product can be directly obtained without separation and purification. High-quality hydrochloric acid byproducts are also obtained, making the process simple and environmentally friendly. The resulting hexachlorocyclotriphosphazene alkyl(phenol) polyoxyethylene ether exhibits high surface activity and flame retardant properties, making it suitable as an additive in fine chemicals such as flame retardants, dispersants, and emulsifiers.

[0010] The method for synthesizing hexachlorocyclotriphosphazene (HCCP) of the present invention refers to the direct reaction of alkyl (phenol) polyoxyethylene ether with hexachlorocyclotriphosphazene (HCCP) under solvent-free and acid-free conditions to obtain hexachlorocyclotriphosphazene (HCCP). 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 as follows: Under the condition of continuous nitrogen gas introduction, alkyl (phenol) polyoxyethylene ether is mixed with hexachlorocyclotriphosphazene (HCCP), pre-reacted at low temperature for a period of time, and then the temperature is increased to continue the reaction for a period of time. The hydrogen chloride gas generated during the reaction is collected. After the reaction is completed, hexachlorocyclotriphosphazene is obtained.

[0014] The reaction raw materials, alkyl (phenol) polyoxyethylene ethers, include but are 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 ethers to HCCP is 6:1.

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

[0016] The high-temperature reaction temperature is 80–140℃, and the high-temperature reaction time is 24–48 hours.

[0017] There are two methods for high-temperature reactions: direct one-step heating and staged heating. Direct heating is simple and convenient, but it is prone to side reactions; staged heating has fewer side reactions, but the reaction time is longer.

[0018] Segmented heating refers to heating in two or more stages.

[0019] The beneficial effects of this invention are:

[0020] This invention prepares hexachlorocyclotriphosphazene from alkyl (phenol) polyoxyethylene ether and hexachlorocyclotriphosphazene in a one-pot process without solvent or acid-binding agent. After the reaction, a high-purity phosphazene derivative with surface activity can be obtained directly without complicated and tedious purification treatment.

[0021] This invention is the first to discover that hexachlorocyclotriphosphazene has excellent solubility in liquid alkyl (phenol) polyoxyethylene ether, while the byproduct HCl generated in the reaction is insoluble in the raw material alkyl (phenol) polyoxyethylene ether. Therefore, the byproduct HCl gas can be continuously removed, allowing the reaction to proceed to the right, resulting in a very high conversion rate. This enables the reaction to be carried out without solvents or acid-coating agents. Attached image description:

[0022] Figure 1 .6-(octylphenol polyoxyethylene ether)cyclotriphosphazene gel permeation chromatogram; Detailed Implementation

[0023] The present invention will be illustrated below with reference to specific embodiments. However, these embodiments are given as examples only and are not considered as all the technical solutions of the present invention, nor are they a limitation on the overall technical solution of the present invention. Any modifications or substitutions with the same or similar technical features are within the protection scope of the present invention.

[0024] Example 1

[0025] In an environment with continuous nitrogen purging, 11.679 g of OPEO and 1.043 g of HCCP were added to a reaction vessel and pre-reacted at 30 °C for 24 h under uniform stirring. Then, the temperature was raised to 120 °C and reacted for another 24 h. After the reaction was completed, hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene was obtained.

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

[0027] The product was analyzed by hydrogen spectroscopy using a 400M nuclear magnetic resonance spectrometer, and the 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 permeation chromatography, with tetrahydrofuran as the mobile phase. Figure 1 As shown, its average molecular weight was measured to be 4390 g / mol.

[0029] Example 2

[0030] In an environment with continuous nitrogen purging, 11.679 g of OPEO and 1.043 g of HCCP were added to a reaction vessel. After a pre-reaction at 60 °C for 24 h under uniform stirring, the temperature was successively increased to 80 °C for 12 h, 100 °C for 12 h, and 120 °C for 12 h. After the reaction was completed, hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene was obtained.

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

[0032] Example 3

[0033] In an environment with continuous nitrogen purging, 11.556 g of NPEO and 1.043 g of HCCP were added to a reaction vessel and pre-reacted at 60 °C for 12 h under uniform stirring. Then, the temperature was successively increased 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 was completed, hexa-(nonylphenol polyoxyethylene ether) cyclotriphosphazene was obtained.

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

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

[0036] Example 4

[0037] In a nitrogen-filled environment, 8.905 g of lauryl alcohol polyoxyethylene ether-7 (AEO-7) and 1.043 g of HCCP were added to a reaction vessel. After a 24-hour pre-reaction at 40 °C under uniform stirring, the temperature was raised to 100 °C and reacted for another 24 hours. After the reaction was completed, hexa-(lauryl alcohol polyoxyethylene ether-7)cyclotriphosphazene was obtained.

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

[0039] Example 5

[0040] In a nitrogen-filled environment, 10.491 g of lauryl alcohol polyoxyethylene ether-9 (AEO-9) and 1.043 g of HCCP were added to a reaction vessel. After a 12-hour pre-reaction at 40 °C under uniform stirring, the temperature was raised to 80 °C for 24 hours, and finally raised to 140 °C for 24 hours. After the reaction was completed, hexa-(lauryl alcohol polyoxyethylene ether-9)cyclotriphosphazene was obtained.

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

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

[0043] Comparative Example 1

[0044] 11.679 g OPEO, 1.043 g HCCP, 5 mL triethylamine, and 40 mL benzene solution were mixed and added to a three-necked flask. The flask was then placed in an oil bath and reacted at 65 °C for 6 h. After the reaction was complete, the mixture was filtered to remove salts. Finally, the filtrate was subjected to vacuum distillation to remove the benzene solvent, yielding hexa-(octylphenol polyoxyethylene ether)cyclotriphosphazene.

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

[0046] Application Example 1

[0047] The hexa-(octylphenol polyoxyethylene ether) cyclotriphosphazene prepared in Example 1 was dissolved in ethanol 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 soaked in the above five solutions of different concentrations for a period of time and then dried. The mass of the dried cotton cloth was recorded. The cotton cloth was hung vertically and ignited with an alcohol lamp. After the flame went out, the mass of the cotton cloth after ignition was recorded. The char residue was calculated based on the mass change before and after combustion, and the results are shown in Table 1. The residue of the pure cloth after burning in air was only 0.38%, while the char residue 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 of hexa-(octylphenol polyoxyethylene ether)cyclotriphosphazene

[0049]

[0050] Application Example 2

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

[0052]

[0053] Aqueous solutions of OPEO and hexa-(octylphenol polyoxyethylene ether)cyclotriphosphazene prepared in Example 1 were prepared at a mass concentration of 0.2%. The surface tension and critical micelle concentration (CMC) of the sample aqueous solutions were measured using a K100 KRUSS fully automated surface tension meter via the surface tension method. The results are shown in Table 2. As can be seen from the table, hexa-(octylphenol polyoxyethylene ether)cyclotriphosphazene exhibits a lower CMC value, indicating a significantly improved surface activity.

Claims

1. A solvent-free method for synthesizing hexa-chain alkyl polyoxyethylene ether cyclotriphosphazene, characterized in that, The method is as follows: under continuous nitrogen purging, hexachlorocyclotriphosphazene is dissolved in alkyl (phenol) polyoxyethylene ether, pre-reacted at low temperature, and then reacted at high temperature to obtain hexachlorocyclotriphosphazene with long-chain alkyl polyoxyethylene ether. The reaction equation is as follows: ， The alkyl (phenol) polyoxyethylene ether is selected from octylphenol polyoxyethylene ether, nonylphenol polyoxyethylene ether, lauryl alcohol polyoxyethylene ether-7 or lauryl alcohol polyoxyethylene ether-9. The pre-reaction temperature is 30~60 ℃, and the pre-reaction time is 12~24 h; The high-temperature reaction is carried out by one-step heating or segmented heating; the temperature of the high-temperature reaction is 80~140 ℃, and the reaction time is 24~48 h.

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

1.

3. The method for solvent-free synthesis of hexa-chain alkyl polyoxyethylene ether cyclotriphosphazenes according to claim 1, characterized in that, The segmented heating refers to heating in two or more stages.

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