Multifunctional macromolecular flame retardant and preparation method thereof

Abstract

The invention relates to the technical field of flame retardant synthesis, and discloses a multifunctional polymer flame retardant and a preparation method thereof. The structure of the multifunctional high-molecular flame retardant is shown in the specification, the high-molecular flame retardant can be directly used as a flame-retardant high-molecular coating of a cotton fabric, the flame retardance of the cotton fabric can be well improved, and the multifunctional high-molecular flame retardant is widely applied to the fields of clothing, home furnishing, medical treatment and the like; and the flame retardant can be directly used as a flame retardant polymer additive of plastics such as PBAT, PLA, PP and EP, can well improve the flame retardant property of the plastics such as PBAT, PLA, PP and EP, and is widely applied to the fields of buildings, electronics, automobiles, home furnishing, packaging, aerospace and the like.

Description

Technical Field

[0001] The invention relates to the technical field of flame retardant synthesis, and more specifically to a multifunctional polymer flame retardant and a preparation method thereof. Background Art

[0002] With the development of modern industry, the demand for efficient, environmentally friendly and safe flame retardant materials is becoming more and more urgent. Flame retardant materials are widely used in the fields of construction, electronics, aerospace, etc., and higher requirements are placed on their performance. Traditional flame retardants often have problems such as high toxicity, poor processing performance, and environmental pollution. Therefore, finding new efficient and environmentally friendly flame retardants has become an issue of increasing concern to people today.

[0003] Although polymer flame retardants have received extensive attention due to their advantages such as good formability and thermal stability, they still have the problem of single function. Chinese patent CN112126125A discloses a method for preparing a composite plastic flame retardant, using bis(bistrimethylsilyl)amine zinc as a modifier, using a physical modification method to physically modify inorganic flame retardant magnesium hydroxide to obtain bis(bistrimethylsilyl)amine zinc modified magnesium hydroxide, and adding a solid organic phosphorus flame retardant to obtain a composite flame retardant. Although the composite flame retardant can give PVC materials excellent flame retardant properties, it has a single function and only improves its flame retardant properties, and sacrifices the mechanical properties of PVC products.

[0004] Therefore, how to provide a multifunctional polymer flame retardant and a preparation method thereof is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] In view of this, the present invention provides a multifunctional polymer flame retardant and a preparation method thereof, so as to solve the problems existing in existing organic or inorganic flame retardants such as single function.

[0006] The first technical purpose of the present invention is to provide a multifunctional polymer flame retardant, the structural formula of the polymer flame retardant is as follows:

[0007] a.

[0008] b.

[0009] c.

[0010] d.

[0012] e. .

[0013] It should be noted that the present invention achieves controllable adjustment of structural properties by changing the copolymer units of the polymer flame retardant; for example, the introduction of phosphorus element can not only capture free radicals in the gas phase, but also promote carbonization in the condensed phase; the introduction of benzene ring structure can not only enhance the thermal stability of the material, but also improve the mechanical properties of the material.

[0014] The second technical purpose of the present invention is to provide a method for preparing the multifunctional polymer flame retardant as described above, comprising the following steps:

[0015] Step S1, in a nitrogen atmosphere, subjecting the reaction raw materials including hydroxyethyl methacrylate and diphenylphosphinyl chloride to a substitution reaction to obtain 2-diphenylphosphinoyloxyethyl 2-methylprop-2-enoate, wherein the structural formula of 2-diphenylphosphinoyloxyethyl 2-methylprop-2-enoate is as follows:

[0016]

[0017] Step S2, in a nitrogen atmosphere, subjecting the reaction materials including hydroxyethyl methacrylate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a substitution reaction to obtain 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate, wherein the structural formula of 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate is as follows:

[0018]

[0019] Step S3, in a nitrogen gas atmosphere, copolymerizing the reaction raw materials including hydroxyethyl methacrylate and sodium vinyl sulfonate to obtain a product system a of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and sodium vinyl sulfonate to obtain a product system b of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and hydroxyethyl methacrylate to obtain a product system c of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate to obtain a product system d of a novel polymer flame retardant; wherein the structural formulas of the product systems a, b, c and d of the polymer flame retardant are as follows:

[0020] a.

[0021] b.

[0022] c.

[0023] d.

[0024] The reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate are copolymerized to obtain a product system e of a novel polymer flame retardant; wherein the structural formula of the obtained product system e of the novel polymer flame retardant is as follows:

[0025] e.

[0026] Furthermore, the molar ratio of the hydroxyethyl methacrylate to the diphenylphosphinyl chloride is 1.01-1.03:1; the molar ratio of the hydroxyethyl methacrylate to the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1.01-1.03:1.

[0027] Furthermore, the substitution reaction of the hydroxyethyl methacrylate and the diphenylphosphinyl chloride is firstly carried out at a temperature of 5°C to -5°C and then at room temperature. Preferably, the total time of the substitution reaction is 10 to 14 hours.

[0028] Furthermore, the substitution reaction of the hydroxyethyl methacrylate and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is first carried out at a temperature of 5°C to -5°C and then at room temperature. Preferably, the total time of the substitution reaction is 20 to 26 hours.

[0029] Furthermore, the above-mentioned substitution reaction raw materials also include a catalyst, and the substitution reaction catalyst is 4-dimethylaminopyridine; preferably, the molar ratio of the hydroxyethyl methacrylate, the diphenylphosphinyl chloride and the catalyst is 1.01-1.03:1-0.01-0.05.

[0030] Furthermore, the copolymerization reaction is first carried out at a temperature of 40°C to 45°C, and then at a temperature of 60°C to 65°C. Preferably, the total time of the copolymerization reaction is 14 to 18 hours.

[0031] Furthermore, the copolymerization reaction raw material also includes a catalyst, and the copolymerization reaction catalyst is azobisisobutyronitrile; preferably, the molar ratio of the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the hydroxyethyl methacrylate, the sodium vinyl sulfonate and the catalyst is 1:1:1:0.04 to 0.06.

[0032] Furthermore, the above-mentioned reaction raw materials and the substitution reaction raw materials also independently include a solvent, preferably the hydroxyethyl methacrylate and the diphenylphosphinyl chloride and a solvent; the volume ratio of hydroxyethyl methacrylate and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the solvent is 1:2-3, and preferably the solvent is dichloromethane.

[0033] Furthermore, the above-mentioned reaction raw materials and the copolymerization reaction raw materials also independently include a solvent, preferably the hydroxyethyl methacrylate and the sodium vinyl sulfonate and a solvent; sodium vinyl sulfonate and the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and a solvent; hydroxyethyl methacrylate and the 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate and a solvent; hydroxyethyl methacrylate and the sodium vinyl sulfonate and the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and a solvent; the volume ratio of the 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate and the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate to the solvent is 1:2-3, and the solvent is preferably any one or more of dichloromethane, methanol, and ethanol.

[0034] Furthermore, the system of the above-mentioned substitution reaction product 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is subjected to one washing and two washings, and the washing liquid used in the first washing is preferably a polar solution, and the polar solution is preferably distilled water; the washing liquid used in the second washing is preferably a polar solution, and the polar solution is preferably a saturated sodium chloride solution.

[0035] Furthermore, the system of the substitution reaction product 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate is washed once, twice and three times, and the washing liquid used in the first washing is preferably a non-polar solution, and the non-polar solution is preferably a 3% NaOH solution; the washing liquid used in the second washing is preferably a polar solution, and the polar solution is preferably distilled water; the washing liquid used in the third washing is preferably a polar solution, and the polar solution is preferably a saturated sodium chloride solution.

[0036] Furthermore, the product system is subjected to liquid separation and drying to remove water, and preferably the solution left after the liquid separation is the lower layer solution; preferably, the solvent used for the drying to remove water is any one or more combinations of anhydrous sodium sulfate and anhydrous magnesium sulfate.

[0037] Furthermore, the product system is subjected to reduced pressure distillation at 25°C to 40°C to obtain a distilled product.

[0038] The present invention also provides an application of the multifunctional polymer flame retardant as described above in flame retardant polymers, wherein the novel polymer flame retardant is loaded on a substrate such as cotton fabric or plastic.

[0039] It can be seen from the above technical solution that, compared with the prior art, the beneficial effects of the present invention are:

[0040] (1) The novel polymer flame retardant polymer copolymerized with hydroxyethyl methacrylate and sodium vinyl sulfonate of the present invention; the novel polymer flame retardant polymer copolymerized with 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and sodium vinyl sulfonate; the novel polymer flame retardant polymer copolymerized with 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and hydroxyethyl methacrylate; the novel polymer flame retardant polymer copolymerized with 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate; the novel polymer flame retardant polymer copolymerized with 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate has a simple reaction path, good product quality and high yield, low impurity content, simple and easy product post-processing method, significantly improved product performance, easy storage, convenient product use, and is suitable for industrial production.

[0041] (2) In the preparation method of the novel polymer flame retardant of the present invention, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is prepared by using hydroxyethyl methacrylate and diphenylphosphinyl chloride as main raw materials in a nitrogen gas atmosphere, using 4-dimethylaminopyridine catalyst catalytic synthesis and purification technology, and vacuum distillation technology. The product yield can reach 97.83%, and the product purity can reach 97.4%, meeting the market demand of the industry for the product. The preparation method is simple and easy, and a high-purity product is obtained, which greatly saves production costs and achieves high-quality production of the target product.

[0042] (3) In the preparation method of the novel polymer flame retardant of the present invention, 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate is prepared by using hydroxyethyl methacrylate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide as main raw materials in a nitrogen atmosphere, using 4-dimethylaminopyridine catalyst catalytic synthesis and purification technology, and vacuum distillation technology. The product purity can reach 90.08%, meeting the market demand of the industry for the product. The preparation method is simple and easy, and a high-purity product is obtained, which greatly saves production costs and achieves high-quality production of the target product.

[0043] (4) In the preparation method of the novel polymer flame retardant of the present invention, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate, 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate and sodium vinyl sulfonate are used as main raw materials in a nitrogen gas atmosphere, two or three of them are copolymerized, and azobisisobutyronitrile catalyst is used for catalytic synthesis and purification technology and vacuum distillation technology to obtain a novel polymer flame retardant product system. The product of the present invention has excellent thermal stability, high relative molecular weight, low amount of flame retardant added, good compatibility with various substrates such as cotton fabrics and plastics, significantly improved flame retardant performance, environmental protection and energy saving, and easy large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0045] Figure 1 The present invention provides a novel polymer flame retardant, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, with a nuclear magnetic hydrogen spectrum (a) and a nuclear magnetic phosphorus spectrum (b).

[0046] Figure 2 The present invention provides a novel polymer flame retardant, 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate, with a nuclear magnetic resonance hydrogen spectrum (a) and a nuclear magnetic resonance phosphorus spectrum (b).

[0047] Figure 3 The nuclear magnetic hydrogen spectrum (a) and nuclear magnetic phosphorus spectrum (b) of the new polymer flame retardant e provided by the present invention. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The word "embodiment" used here as an "exemplary" does not necessarily mean that any embodiment described is superior to or better than other embodiments. Unless otherwise specified, the performance index tests in the embodiments of this application are performed using conventional test methods in the art. It should be understood that the terms described in this application are only used to describe specific implementation methods and are not used to limit the content disclosed in this application.

[0050] Unless otherwise specified, the technical and scientific terms used in this document have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs; other experimental methods and technical means not specifically specified in this application refer to experimental methods and technical means commonly used by ordinary technicians in this field.

[0051] In order to better illustrate the content of the present application, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present application can also be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0052] Under the premise of no conflict, the technical features disclosed in the embodiments of the present application can be combined arbitrarily, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present application.

[0053] The invention discloses a multifunctional polymer flame retardant and a preparation method thereof.

[0054] As analyzed in the background technology of this application, existing polymer flame retardants still have some challenges, such as unstable flame retardant effect, insufficient heat resistance, poor processing performance and other problems, which limit their promotion and application scope in practical applications. In order to solve this problem, this application provides a new polymer flame retardant and its preparation method and application.

[0055] In a typical embodiment of the present application, a novel polymer flame retardant is provided, and the structural formula of the novel polymer flame retardant is:

[0056] a. b.

[0057] c.

[0058] d. e.

[0059] In a typical embodiment of the present application, a method for preparing the aforementioned novel polymer flame retardant is provided, the preparation method comprising:

[0060] Step S1, in a nitrogen atmosphere, subjecting the reaction raw materials including hydroxyethyl methacrylate and diphenylphosphinyl chloride to a substitution reaction to obtain 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, wherein the structural formula of the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is as follows:

[0061]

[0062] Step S2, in a nitrogen atmosphere, subjecting the reaction raw materials including hydroxyethyl methacrylate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a substitution reaction to obtain 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate, wherein the structural formula of the 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate is as follows:

[0063]

[0064] Step S3, in a nitrogen atmosphere, copolymerizing the reaction raw materials including hydroxyethyl methacrylate and sodium vinyl sulfonate to obtain a product system a of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and sodium vinyl sulfonate to obtain a product system b of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and hydroxyethyl methacrylate to obtain a novel polymer flame retardant. Flame retardant product system c; copolymerization of reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate to obtain a novel polymer flame retardant product system d; copolymerization of reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate to obtain a novel polymer flame retardant product system e. The structural formulas of the novel polymer flame retardant product systems a, b, c, d and e are as follows:

[0065] a. b.

[0066] c.

[0067] d. e.

[0068] The novel polymer flame retardant obtained above is a novel, high-performance, efficient, halogen-free and environmentally friendly flame retardant, which has comprehensive properties such as strong flame retardant effect, high temperature resistance, hydrophobicity and antifouling. In addition, the above preparation method is simple, and has the advantages of easy availability of raw materials, mild reaction conditions, simple process, rapid and easy, low cost, and easy large-scale production.

[0069] Preferably, the molar ratio of the hydroxyethyl methacrylate to the diphenylphosphinyl chloride is 1.01-1.03:1, so that the yield of the product 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is the highest.

[0070] Preferably, the molar ratio of the hydroxyethyl methacrylate to the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1.01-1.03:1, so that the yield of the product 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate is the highest.

[0071] In order to improve the efficiency of the substitution reaction and the copolymerization reaction, it is preferred that the substitution reaction is first carried out at a temperature of 5°C to -5°C and then at room temperature. Preferably, the total time of the substitution reaction is 10 to 14 hours.

[0072] In one embodiment of the present application, the above-mentioned substitution reaction raw materials also include a catalyst, and preferably the molar ratio of hydroxyethyl methacrylate, diphenylphosphinyl chloride and the catalyst is 1.01-1.03:1:0.01-0.05.

[0073] Preferably, the molar ratio of hydroxyethyl methacrylate, diphenylphosphinyl chloride and catalyst is more conducive to controlling the progress and efficiency of the substitution reaction.

[0074] In order to further enhance the synergistic effect of the catalyst with hydroxyethyl methacrylate and diphenylphosphinyl chloride, thereby enhancing the effect of the catalyst, the preferred catalyst is 4-dimethylaminopyridine.

[0075] Preferably, the copolymerization reaction is first carried out at a temperature of 40°C to 45°C, and then at a temperature of 60°C to 65°C. Preferably, the total time of the copolymerization reaction is 14 to 18 hours, which is beneficial to control the efficiency of the copolymerization reaction.

[0076] The above-mentioned copolymerization reaction raw materials also include a catalyst, preferably hydroxyethyl methacrylate and sodium vinyl sulfonate and a catalyst; sodium vinyl sulfonate and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and a catalyst; hydroxyethyl methacrylate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and a catalyst; the molar ratio of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and a catalyst is 1:1:0.04-0.06.

[0077] The copolymerization raw materials also include a catalyst, and preferably the molar ratio of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate to the catalyst is 1:1:1:0.04-0.06.

[0078] Preferably, the molar ratio of the above-mentioned hydroxyethyl methacrylate and sodium vinyl sulfonate and catalyst; sodium vinyl sulfonate and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and catalyst; hydroxyethyl methacrylate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and catalyst; 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and catalyst; hydroxyethyl methacrylate and sodium vinyl sulfonate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and catalyst is more conducive to controlling the progress and efficiency of the copolymerization reaction.

[0079] In order to further improve the synergistic effect of hydroxyethyl methacrylate, sodium vinyl sulfonate and a catalyst; sodium vinyl sulfonate and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and a catalyst; hydroxyethyl methacrylate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and a catalyst; 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and a catalyst; hydroxyethyl methacrylate and sodium vinyl sulfonate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate and a catalyst, thereby improving the effect of the catalyst, the catalyst is preferably azobisisobutyronitrile.

[0080] The above-mentioned reaction raw materials and the substitution reaction raw materials also independently include a solvent, preferably the hydroxyethyl methacrylate and a solvent; the diphenylphosphinyl chloride and a solvent; the volume ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to the solvent is 1:2-3, and the solvent is preferably dichloromethane.

[0081] The above-mentioned solvent is preferably conducive to the dissolution of the reaction raw materials and the substitution reaction raw materials therein, and the above-mentioned solvent is inert to the raw materials, thereby helping to reduce the probability of side reactions.

[0082] The above-mentioned reaction raw materials and the copolymerization reaction raw materials also independently include a solvent, preferably the mixed solution of hydroxyethyl methacrylate and sodium vinyl sulfonate and the solvent; the mixed solution of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and sodium vinyl sulfonate and the solvent; the mixed solution of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and hydroxyethyl methacrylate and the solvent; the mixed solution of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate and the solvent; the volume ratio of the mixed solution of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate to the solvent is 1:2-3, and the solvent is preferably any one or more of dichloromethane, methanol and ethanol.

[0083] The above-mentioned solvent is preferably conducive to the dissolution of the reaction raw materials and copolymerization reaction raw materials therein, and the above-mentioned solvent is inert to each raw material, thereby helping to reduce the probability of occurrence of side reactions.

[0084] The system of the above-mentioned substitution reaction product 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is washed once and twice, and the washing liquid used in the first washing is preferably a polar solution, and the polar solution is preferably distilled water; the washing liquid used in the second washing is preferably a polar solution, and the polar solution is preferably a saturated sodium chloride solution.

[0085] The system of the substitution reaction product 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate is washed once, twice and three times, preferably the washing liquid used in the first washing is a non-polar solution, preferably the non-polar solution is a 3% NaOH solution; preferably the washing liquid used in the second washing is a polar solution, preferably the polar solution is distilled water; preferably the washing liquid used in the third washing is a polar solution, preferably the polar solution is a saturated sodium chloride solution.

[0086] The above reduced pressure distillation is beneficial to remove most of the solvents in the product system, and the sequential washing treatment of the polar solvent is beneficial to further remove the unreacted raw materials and by-products therein, thereby obtaining high-purity 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and high-purity 2-((6-oxidized dibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate.

[0087] The above product system is separated and dried to remove water, and the solution left by the separation is preferably the lower layer solution; the solvent used for the drying and removing water is preferably any one or more of anhydrous sodium sulfate and anhydrous magnesium sulfate.

[0088] The above liquid separation operation is conducive to removing most of the unreacted raw materials and by-products in the product system, and the drying operation is conducive to water absorption, thereby obtaining a high-purity new polymer flame retardant system.

[0089] The above product system is subjected to reduced pressure distillation at 25°C to 40°C to obtain a distilled product.

[0090] The above reduced pressure distillation is beneficial to remove most of the solvents in the product system to obtain a high-purity new polymer flame retardant.

[0091] In another typical embodiment of the present application, several novel polymer flame retardants are provided for use in flame retardant polymers. The novel polymer flame retardants are loaded on a substrate such as cotton fabric or plastic.

[0092] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0093] Embodiment 1;

[0094] In a nitrogen atmosphere, 70 ml of dichloromethane, 13.01 g of hydroxyethyl methacrylate, 10.12 g of triethylamine and 0.362 g of 4-dimethylaminopyridine were added to a three-necked flask, and 22.10 g of diphenylphosphinyl chloride was added dropwise to the flask in 50 ml of dichloromethane. The reaction was stirred at 0 ° C for 1 hour, and then reacted at room temperature and nitrogen for 16 hours. After that, water and saturated salt water were added three times and separated. After the lower clear liquid was obtained, vacuum filtration was performed to obtain a crude product, and the crude product was distilled under reduced pressure to obtain 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate. In a nitrogen atmosphere, 2.5 g of hydroxyethyl methacrylate, 2.5 g of sodium vinyl sulfonate, 20 g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 60 ml of dichloromethane were added to the flask and stirred. After the temperature rises to 40°C, 0.812 g of azobisisobutyronitrile is added, and the mixture is heated to 65°C in a water bath and reacted for 12 hours. After that, the mixture is distilled under reduced pressure, and ultrapure water and n-hexane are added successively to precipitate the polymer product. The crude product is vacuum filtered and dried in a vacuum drying oven at 60°C to obtain a new polymer flame retardant, which is then applied to cotton fabric at room temperature.

[0095] Embodiment 2:

[0096] The difference from Example 1 is that the solvent in the copolymerization reaction of hydroxyethyl methacrylate, sodium vinyl sulfonate and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is methanol, and a new polymer flame retardant product is finally obtained.

[0097] Embodiment 3:

[0098] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and the amount of azobisisobutyronitrile are 2.5g of hydroxyethyl methacrylate, 11.25g of sodium vinyl sulfonate, 11.25g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, and 1.15g of azobisisobutyronitrile are added to finally obtain a new polymer flame retardant product.

[0099] Embodiment 4:

[0100] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the choice of solvent and the amount of azobisisobutyronitrile, 2.5g of hydroxyethyl methacrylate, 11.25g of sodium vinyl sulfonate, 11.25g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate were added, the solvent was methanol, and the amount of azobisisobutyronitrile was 1.15g, and finally a new polymer flame retardant product was obtained.

[0101] Embodiment 5:

[0102] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the choice of solvent and the amount of azobisisobutyronitrile, 2.5g of hydroxyethyl methacrylate, 11.25g of sodium vinyl sulfonate, 11.25g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate were added, the solvent was ethanol, and the amount of azobisisobutyronitrile was 1.15g, and finally a new polymer flame retardant product was obtained.

[0103] Embodiment 6:

[0104] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the selection and amount of the solvent and the amount of azobisisobutyronitrile are added. 2.36ml of hydroxyethyl methacrylate, 1.47ml of sodium vinyl sulfonate, 11g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate are added, the solvent is 30ml of methanol, and the azobisisobutyronitrile is 0.55ml, and finally a new polymer flame retardant product is obtained.

[0105] Embodiment 7:

[0106] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the selection and amount of solvent and the amount of azobisisobutyronitrile are added. 1.58ml of hydroxyethyl methacrylate, 2.20ml of sodium vinyl sulfonate, 11g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, 30ml of methanol as solvent, and 0.55ml of azobisisobutyronitrile are finally obtained to obtain a new polymer flame retardant product.

[0107] Embodiment 8:

[0108] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the selection and amount of the solvent and the amount of azobisisobutyronitrile are added. 1.58ml of hydroxyethyl methacrylate, 1.47ml of sodium vinyl sulfonate, 13.2g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate are added, the solvent is 30ml of methanol, and the azobisisobutyronitrile is 0.55ml, and finally a new polymer flame retardant product is obtained.

[0109] Embodiment 9:

[0110] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the selection and amount of solvent and the amount of azobisisobutyronitrile are added. 0.79 ml of hydroxyethyl methacrylate, 2.94 ml of sodium vinyl sulfonate, 11 g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate are added, the solvent is 30 ml of methanol, and the azobisisobutyronitrile is 0.55 ml, and finally a new polymer flame retardant product is obtained.

[0111] Embodiment 10:

[0112] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the selection and amount of the solvent and the amount of azobisisobutyronitrile are added. 1.58 ml of hydroxyethyl methacrylate, 4.40 ml of sodium vinyl sulfonate, 4.4 g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate are added, the solvent is 30 ml of methanol, and the azobisisobutyronitrile is 0.55 ml, and finally a new polymer flame retardant product is obtained.

[0113] Embodiment 11:

[0114] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the choice of solvent, the amount of azobisisobutyronitrile and the substrate used, 11.25g of hydroxyethyl methacrylate, 2.5g of sodium vinyl sulfonate, 11.25g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the solvent is methanol, and the amount of azobisisobutyronitrile is 1.15g, and finally a new polymer flame retardant product is obtained, 1.8g of the new polymer flame retardant is taken, and it is blended with 4.8g of PBAT for extrusion and injection molding.

[0115] Embodiment 12:

[0116] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the choice of solvent and the amount of azobisisobutyronitrile, 11.25g of hydroxyethyl methacrylate, 2.5g of sodium vinyl sulfonate, 11.25g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate were added, the solvent was methanol, and the amount of azobisisobutyronitrile was 1.15g, and finally a new polymer flame retardant product was obtained. 1.8g of the new polymer flame retardant was taken and blended with 4.8g of PLA for extrusion and injection molding.

[0117] Embodiment 13:

[0118] The difference from Example 1 is that the amount of hydroxyethyl methacrylate, sodium vinyl sulfonate, and 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the choice of solvent and the amount of azobisisobutyronitrile are added. 8.325g of hydroxyethyl methacrylate, 8.325g of sodium vinyl sulfonate, and 8.325g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate are added, the solvent is methanol, and the amount of azobisisobutyronitrile is 1.26g. Finally, a new polymer flame retardant product is obtained. 1.8g of the new polymer flame retardant is taken and it is blended with 4.8gPP for extrusion and injection molding.

[0119] Embodiment 14:

[0120] In a nitrogen atmosphere, 70 ml of dichloromethane, 13.01 g of hydroxyethyl methacrylate, 10.12 g of triethylamine and 0.362 g of 4-dimethylaminopyridine were added to a three-necked flask, and 22.10 g of diphenylphosphinyl chloride in 50 ml of dichloromethane was dripped into the flask. The mixture was stirred at 0°C for 1 hour, and then reacted at room temperature under nitrogen for 16 hours. Water and saturated brine were then added three times and separated. After the lower clear liquid was obtained, vacuum filtration was performed to obtain a crude product, and the crude product was distilled under reduced pressure to obtain 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate. Under nitrogen atmosphere, 43.2g 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was dissolved in 500mL dichloromethane, poured into a 1000mL three-necked bottle, placed in a 0℃ ice-water bath, added with 40mL carbon tetrachloride and stirred for 20min, then slowly added with 40mL triethylamine and stirred for 1min, and then added dropwise with 48.5mL hydroxyethyl methacrylate and stirred for 20min. Finally, it was transferred to an oil bath, heated to room temperature, and stirred for 24 hours. The crude product was filtered, washed, separated, and rotary evaporated to obtain ethyl 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)methacrylate. In a nitrogen atmosphere, add 74.32g of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 25.83g of 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate and 240ml of dichloromethane to the flask and stir. After the temperature rises to 40°C, add 2.49g of azobisisobutyronitrile, heat in a water bath at 65°C, and react for 12 hours. Then, distill under reduced pressure, add ultrapure water and n-hexane successively to precipitate the polymer product, vacuum filter the crude product and dry it in a vacuum drying oven at 60 degrees Celsius to obtain a new polymer flame retardant, take 6.6g of the flame retardant, mix it evenly with 100g of epoxy resin and 25g of 4,4-diaminodiphenylmethane under the action of a mechanical stirrer, and high-temperature curing and demolding.

[0121] Embodiment 15:

[0122] The difference from Example 14 is the amount of flame retardant used: 10.1 g of flame retardant was added.

[0123] Embodiment 16:

[0124] The difference from Example 14 is the amount of flame retardant used: 13.8 g of flame retardant was added.

[0125] The content of the present invention is not limited to the content of the above embodiments. The combination of one or more embodiments can also achieve the purpose of the present invention.

[0126] In order to further demonstrate the beneficial effects of the present invention and to better understand the present invention, the following comparative examples are used to further illustrate the technical features disclosed in the present invention, but they should not be construed as limiting the present invention. Other improvements made by those skilled in the art based on the above invention content without inventive work are also considered to fall within the scope of protection of the present invention.

[0127] Comparative Example 1:

[0128] Apply 60 ml of ethanol on the cotton fabric at room temperature.

[0129] Comparative Example 2:

[0130] 6 g PBAT was extruded and injection molded.

[0131] Comparative Example 3:

[0132] 6 g PLA was extruded and injection molded.

[0133] Comparative Example 4:

[0134] 6 g PP was extruded and injection molded.

[0135] Comparative Example 5:

[0136] 100g of epoxy resin was cured and demoulded.

[0137] The novel polymer flame retardants obtained in the above Examples 1 to 10 and the novel polymer flame retardant obtained in Comparative Example 1 were coated on cotton fabric at room temperature. The size of the cotton fabric was 8.9 cm×30 cm. The cotton fabric was tested for vertical combustion flame retardancy. The fire source was removed after ignition for 12 seconds. The self-extinguishing time of the flame, the smoldering time and whether the cotton was ignited were recorded. The results are shown in Table 1.

[0138] Table 1

[0139] Implementation / Comparative Example Self-extinguishing time Smoldering time Whether to ignite Example 1 5s 0s no Example 2 2s 0s no Example 3 1s 5s no Example 4 0s 10s no Example 5 0s 10s no Example 6 1s 0s no Example 7 1s 0s no Example 8 0s 0s no Example 9 1s 6s no Example 10 5s 0s no Comparative Example 1 8s 14s no

[0140] The novel polymer flame retardants obtained in the above Examples 11 to 13 and the novel polymer flame retardants obtained in Comparative Examples 2 to 4 were respectively subjected to plastic vertical combustion flame retardancy tests in plastic systems, and were respectively subjected to blending extrusion and injection molding to prepare 1 cm×9.5 cm specimens. The addition amount of the flame retardant was 20wt% of the plastic. In the vertical combustion flame retardancy test, the fire source was evacuated after ignition for 12 seconds, and the self-extinguishing time of the flame, whether it dripped and whether it ignited the cotton were recorded. The results are shown in Table 2.

[0141] Table 2

[0142] Implementation / Comparative Example Self-extinguishing time Is it dripping? Whether to ignite Embodiment 11 1s no no Example 12 1s yes no Embodiment 13 0s no no Comparative Example 2 8s yes yes Comparative Example 3 15s yes yes Comparative Example 4 17s yes yes

[0143] The novel polymer flame retardants obtained in the above Examples 14 to 16 and the novel polymer flame retardant obtained in Comparative Example 5 were respectively subjected to plastic vertical combustion flame retardancy tests in plastic systems, and were respectively subjected to curing and demolding to prepare 12.7 cm×1.27 cm specimens for vertical combustion flame retardancy tests. The fire source was evacuated 10 seconds after the first ignition, and the flame self-extinguishing time, whether it dripped, and whether it ignited cotton were recorded; the fire source was evacuated 10 seconds after the second ignition, and the flame self-extinguishing time, whether it dripped, and whether it ignited cotton were recorded. The results are shown in Table 2.

[0144] Table 3

[0145]

[0146]

[0147] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0148] The above-mentioned new polymer flame retardant of the present application can be directly used as a flame retardant polymer coating for cotton fabrics after copolymerization of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate, and can well improve the flame retardant properties of cotton fabrics, and can be widely used in clothing, home furnishings, medical and other fields.

[0149] The above-mentioned novel polymer flame retardant of the present application can be directly used as a flame retardant polymer additive for PBAT, PLA, and PP plastics after copolymerization of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate, and can well improve the flame retardant properties of PBAT, PLA, and PP plastics, and can be widely used in construction, electronics, automobiles, homes, packaging, aerospace and other fields.

[0150] The above-mentioned novel polymer flame retardant of the present application can be directly used as a flame retardant polymer additive for EP plastics after copolymerization of 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate, and can well improve the flame retardant properties of EP plastics, and can be widely used in the fields of construction, electronics, automobiles, homes, packaging, aerospace, etc.

[0151] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multifunctional polymer flame retardant, characterized in that: The structural formula of the polymer flame retardant is as follows:

2. A method for preparing the multifunctional polymer flame retardant according to claim 1, characterized in that: The following steps are involved: Step S1, in a nitrogen atmosphere, subjecting the reaction materials including hydroxyethyl methacrylate and diphenylphosphinyl chloride to a substitution reaction to obtain 2-diphenylphosphinoyloxyethyl 2-methylprop-2-enoate; Wherein, the structural formula of the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is as follows: Step S2, in a nitrogen atmosphere, subjecting the reaction materials including hydroxyethyl methacrylate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to a substitution reaction to obtain 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)ethyl methacrylate; Among them, the structural formula of ethyl 2-((6-oxydibenzo[c,e][1,2]oxaphosphazene-6-yl)oxy)methacrylate is as follows: Step S3, in a nitrogen atmosphere, copolymerizing the reaction raw materials including hydroxyethyl methacrylate and sodium vinyl sulfonate to obtain a product system a of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and sodium vinyl sulfonate to obtain a product system b of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and hydroxyethyl methacrylate to obtain a product system c of a novel polymer flame retardant; copolymerizing the reaction raw materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, hydroxyethyl methacrylate and sodium vinyl sulfonate to obtain a product system d of a novel polymer flame retardant; Step S4, in a nitrogen atmosphere, copolymerizing the reaction materials including 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate and 2-((6-oxydibenzo[c,e][1,2]oxaphosphazen-6-yl)oxy)ethyl methacrylate to obtain a product body e of a novel polymer flame retardant.

3. The preparation method according to claim 2, characterized in that: The molar ratio of the hydroxyethyl methacrylate to the diphenylphosphinyl chloride is 1.01 to 1.03:1; the substitution reaction is first carried out at a temperature of 5°C to -5°C, and then at room temperature, and the total time of the substitution reaction is 10 to 14 hours.

4. The preparation method according to claim 2, characterized in that: The molar ratio of the hydroxyethyl methacrylate to the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 1.01-1.03:1; the substitution reaction is first carried out at a temperature of 5°C to -5°C, and then at room temperature, and the total time of the substitution reaction is 20-26 hours.

5. The preparation method according to claim 2 or 3, characterized in that: The substitution reaction raw materials also include a catalyst, which is 4-dimethylaminopyridine; the molar ratio of the hydroxyethyl methacrylate, the diphenylphosphinyl chloride and the catalyst is 1.01-1.03:1:0.01-0.

05.

6. The preparation method according to claim 2, characterized in that: The copolymerization reaction is firstly carried out at a temperature of 40°C to 45°C, and then at a temperature of 60°C to 65°C, and the total time of the copolymerization reaction is 14 to 18 hours.

7. The preparation method according to claim 2 or 5, characterized in that: The copolymerization reaction raw materials also include a catalyst, which is azobisisobutyronitrile; the molar ratio of the 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate, the hydroxyethyl methacrylate, the sodium vinyl sulfonate and the catalyst is 1:1:1:0.04-0.

06.

8. The preparation method according to claim 2, characterized in that: The reaction raw material and the substitution reaction raw material each independently include a solvent, the solvent is dichloromethane, and the volume ratio of the substitution reaction raw material to the solvent is 1:2-3.

9. The preparation method according to claim 2, characterized in that: The reaction raw materials and the copolymerization reaction raw materials also independently include a solvent, and the solvent is any one or more combinations of dichloromethane, methanol, and ethanol, and the volume ratio of the copolymerization reaction raw materials to the solvent is 1:2-3.

10. The preparation method according to claim 2, characterized in that: The system of the substitution reaction product 2-diphenylphosphoryloxyethyl 2-methylprop-2-enoate is washed once and twice, the washing liquid used in the first washing is a polar solution, and the polar solution is distilled water; The washing liquid used in the secondary washing is a polar solution, and the polar solution is a saturated sodium chloride solution; The system of the substitution reaction product 2-((6-oxydibenzo[c,e][1,2]oxaphosphazenitrile-6-yl)oxy)ethyl methacrylate is washed once, twice and three times, wherein the washing liquid used in the first washing is a non-polar solution, and the non-polar solution is a 3% NaOH solution; The washing liquid used in the secondary washing is a polar solution, and the polar solution is distilled water; The washing liquid used in the three washings is a polar solution, and the polar solution is a saturated sodium chloride solution; The product system is separated and dried to remove water, and the solution left by the separation is the lower layer solution; preferably, the solvent used for the drying and removing water is any one or more combinations of anhydrous sodium sulfate and anhydrous magnesium sulfate; The product system is subjected to reduced pressure distillation at 25° C. to 40° C. to obtain a distilled product.

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