[go: up one dir, main page]

WO2018164709A1 - Procédé de préparation de polysilazanes - Google Patents

Procédé de préparation de polysilazanes Download PDF

Info

Publication number
WO2018164709A1
WO2018164709A1 PCT/US2017/047435 US2017047435W WO2018164709A1 WO 2018164709 A1 WO2018164709 A1 WO 2018164709A1 US 2017047435 W US2017047435 W US 2017047435W WO 2018164709 A1 WO2018164709 A1 WO 2018164709A1
Authority
WO
WIPO (PCT)
Prior art keywords
methyl
formula
dichloro
silane
mixture
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2017/047435
Other languages
English (en)
Inventor
Stefan BOSSMAN
Hongwang Wang
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Purple Solutions LLC
Original Assignee
Purple Solutions LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Purple Solutions LLC filed Critical Purple Solutions LLC
Publication of WO2018164709A1 publication Critical patent/WO2018164709A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
    • C08G77/60—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which all the silicon atoms are connected by linkages other than oxygen atoms
    • C08G77/62—Nitrogen atoms

Definitions

  • the present disclosure generally relates to the synthesis of polysilazanes. More specifically, the present disclosure relates to the synthesis of polysilazanes from chlorosilanes and ammonia, and to the removal of ammonium salts from the reaction product.
  • Polysilazanes which have a Si-N-Si bonding configuration, are increasingly important because they can be pyrolyzed to yield ceramic materials, such as silicon carbide and silicon nitride, and because they can be used in coating compositions which cure at room temperature under ambient conditions. To be effective, the polysilazanes should be substantially free of co-product contamination and of low molecular weight species.
  • Polysilazanes are usually synthesized by an ammonolysis process wherein ammonia or a primary amine reacts with a halide-substituted silane.
  • Preparing silazane products by known ammonolysis methods leads to unwanted co-products, such as ammonium chloride precipitates, which cause coating composition to be cloudy and which interfere with the pyro lysis reaction in ceramics manufacture.
  • Increased additions of inert solvent to the reaction mixture are used to remove the ammonium chloride precipitates by decreasing the viscosity of the reaction mixture, improving agitation of the reaction mixture, and reducing the heat of reaction and/or heat of crystallization due to precipitating ammonium chloride.
  • Another problem encountered during the production of polysilazanes is the formation of a high proportion of low molecular weight species. These low molecular weight silazanes can evaporate during curing or pyrolysis, resulting in a reduced weight yield of the finished product relative to the stalling polysilazane material and resultant gaps in the finished coating or ceramic.
  • the present disclosure provides methods for forming and purifying polysilazanes and their intermediates.
  • the synthesis occurs in anhydrous liquid ammonia, which is then allowed to evaporate after the first stage of the reaction. Without wishing to be bound by theory, evaporating the ammonia increases the concentration of the other reagents in the reaction vessel, thereby promoting polymerization among the reaction intermediates and yielding polysilazanes with a controlled proportion of low molecular weight species.
  • the synthesis reaction still produces ammonium salts by reaction of the chlorosilane starting material with the anhydrous liquid ammonia solvent, it has been discovered that ammonium scavengers can convert these ammonium salts to ammonia gas.
  • the ammonia gas dissipates and the residual ammonium scavengers have surprisingly little impact on formulations using the polysilazanes.
  • the present disclosure provides a method for preparing a compound comprising Formula (II).
  • the method comprises (a) contacting one or more compounds comprising Formula (I) with anhydrous liquid ammonia under ambient pressure at a temperature below about -33 °C.
  • a compound comprising Formula (II) and ammonium chloride are formed in this reaction.
  • the amount of anhydrous liquid ammonia ranges between one and two times the stoichiometric amount of total silicon-chloride bonds in the one or more compounds comprising Formula (I), according to the following reaction scheme:
  • R 1 and FT 2 are independently chosen from hydrogen, alkyl, alkenyl, and phenyl, wherein R 1 and R 2 may be optionally substituted with one or more sulfonic acids, carboxylic acids, amines, or amides; and
  • n is greater than 2.
  • Step (a) may use anhydrous liquid ammonia as the only solvent.
  • Each R 1 and R 2 may be independently hydrogen, methyl, or vinyl.
  • the number n may be greater than 2.5.
  • R 1 may be hydrogen.
  • the one or more compounds comprising Formula (I) may be selected from the group consisting of dichloro(methyl)silane, dichloro(methyl)(vinyl)silane, dichlorodimethylsilane, and combinations thereof.
  • the one or more compounds comprising Formula (I) may consist of a molar ratio ranging between about 10:90 to about 30:70 dichloro(methyl)silane to dichloro(methyl)(vinyl)silane, such as a molar ratio of about 20:80 dichloro(methyl)silane to dichloro(methyl)(vinyl)silane, or between about 60 wt.% and about80 wt.% dichlorodimethylsilane, and between about 40 wt.% and about 20 wt.% dichloro(methyl)silane.
  • the one or more compounds comprising Formula (I) may be dichloro(methyl)silane.
  • the method may further comprise contacting the compound of Formula (II) with a primary alkylamine NH 2 R 3 , wherein R 3 is alkyl, in the presence of a solvent to form a mixture.
  • the mixture is then heated to reflux for about 0.5 to 4 hours to produce a compound comprising Formula (III),
  • the solvent may be selected from the group consisting of aliphatic hydrocarbons, methyl acetate, isopropyl acetate, ieri-butyl acetate, such as an aliphatic hydrocarbon comprising n-heptane.
  • the primary alkylamine may be methylamine.
  • the present disclosure also provides a method of using an ammonium scavenger to remove an ammonium salt from a polysilazane to provide a purified polysilazane.
  • the method comprises (a) mixing a polysilazane containing an ammonium salt with a volume ratio of about 10: 1 to about 20: 1 solvent.
  • the mixture of step (a) is contacted with an ammonium scavenger to convert the ammonium salt to ammonia, wherein the ammonium scavenger is a compound comprising Formula (IV),
  • R 4 is hydrogen or alkyleneamine
  • L is alkylene
  • each R 5 is independently selected alkyl.
  • the purified polysilazane is then separated.
  • R 4 may be alkyleneamine.
  • the alkyleneamine may be ethyleneamine.
  • L may be propylene.
  • R 5 may be selected from the group consisting of methyl, ethyl, and propyl.
  • the ammonium scavenger may be selected from the group consisting of 3- (aminopropyl)triethoxysilane, 3-(aminopropyl)methoxysilane, 3-(aminopropyl)tripropoxysilane, and N-[3-(trimethoxysilyl)propyl]ethylenediamine).
  • the weight ratio of the ammonium scavenger to the mixture of step (a) may range between about 1: 1 and about 20: 1, such as about 2.5: 1, or about 10: 1.
  • the ammonium salt may be ammonium chloride.
  • the polysilazane may be any compound comprising Formula (II), as defined herein.
  • the method may further comprise separating the ammonium salt from the mixture of step (a) before step (b), for example by filtering the mixture of step (a), by centrifuging the mixture of step (a), or by washing the mixture of step (a) with an about 1: 1 to about 20: 1 volume ratio of an aqueous proton acceptor to the mixture of step (a).
  • the aqueous proton acceptor may be selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, aqueous ammonia, and combinations thereof.
  • the volume ratio of the aqueous proton acceptor to the mixture of step (a) may range between about 1:5 to about 1: 15, such as about 1: 10.
  • the concentration of the aqueous proton acceptor may range between about 0.5 N to about 10 N, such as about 2 N.
  • the method may further comprise using an ammonium scavenger to remove the ammonium salt from a polysilazane comprising the compound of Formula (II) to provide a purified polysilazane as disclosed herein.
  • the present disclosure further provides a method for preparing a polysilazane.
  • the method comprises (a) contacting a mixture of Formula (I) selected from the group consisting of dichloro(methyl)silane, dichloro(methyl)silane/dichloro(methyl)(vinyl)silane,
  • R 1 and FT 2 are hydrogen, methyl, or vinyl
  • n is greater than 2.
  • reaction mixture from step (a) is then allowed to attain ambient temperature over the duration of between about 5 and about 7 hours to evaporate the anhydrous liquid ammonia.
  • composition comprising a compound comprising Formula (II),
  • R 1 and R 2" are independently chosen from hydrogen, alkyl, alkenyl, and phenyl, wherein
  • R 1 and R 2" may be optionally substituted with one or more sulfonic acids, carboxylic acids, amines, or amides; and n is 2 or greater;
  • R >4 is hydrogen or alkyleneamine
  • L is alkylene
  • each R 5 is independently selected alkyl.
  • compositions comprising Formula (II), (I I)
  • R 1 and 2 are independently chosen from hydrogen, alkyl, alkenyl, and phenyl, wherein
  • R 1 and R 2" may be optionally substituted with one or more sulfonic acids, carboxylic acids, amines, or amides;
  • n is greater than 2;
  • composition is substantially free of ammonium salts.
  • Figure 1 depicts the Fourier transform infrared (FTIR) spectrum for
  • Figure 2 depicts the FTIR spectrum for methyl(vinyl)silanediamine.
  • Figure 3 depicts the FTIR spectrum for methylsilanediamine after reaction with liquid water/ammonia.
  • Figure 4 depicts the FTIR spectrum for a mixture of methy 1( vinyl) silanediamine and diamino(methyl)silanol after washing with water.
  • Figure 5 depicts the FTIR spectrum for a polysilazane (dichloro(methyl)silane (DMS):dichloro(methyl)(vinyl)silane (DVMS) 20:80 (mol/mol)) after three consecutive washings of the methyl acetate solution of the polysilazane with 10: 1 v/v 2N NaOH (aq).
  • Figure 6 depicts the FTIR spectrum for a polysilazane (100% DMS).
  • Figure 7 depicts the FTIR spectrum for poly(methyl)silazane formed from the reaction of sodium amide and dichloro(methyl)silane.
  • the present disclosure provides a method for preparing polysilazanes, including compounds comprising Formula (II).
  • the method comprises (a) contacting one or more compounds comprising Formula (I) with anhydrous liquid ammonia under ambient pressure at a temperature below about -33 °C.
  • the reaction mixture from step (a) is then allowed to attain ambient temperature to evaporate the anhydrous liquid ammonia.
  • the present disclosure also provides a method of using an ammonium scavenger to remove the ammonium salt from a polysilazane, such as a compound of Formula (II), to provide a purified polysilazane.
  • Polysilazanes usually do not vaporize due to the strong molecular interactions. Heat promotes crosslinking of the polysilazanes to form an even higher molecular weight structures. For example, at temperatures of 100-300 °C, hydrogen gas evolves and ammonia promotes further crosslinking. Once temperatures reach 700-1200 °C, the multi-dimensional amorphous network with Si, C and N atoms is formed, resulting in SiCN ceramic. "Pyrolysis" of polysilazanes produces ceramic materials with low viscosity in high yield, making polysilazanes an excellent choice for precursors for other ceramic matrices. As provided in the present disclosure, polymers combined with low molecular weight components offer added value for the generation of resistant and fast-curing coatings, because new chains can be formed that can improve and enhance the resulting material properties.
  • the present disclosure provides a method for preparing a compound comprising Formula (II).
  • the method comprises (a) contacting one or more compounds comprising Formula (I) with anhydrous liquid ammonia under ambient pressure at a temperature below about -33 °C.
  • a compound comprising Formula (II) and ammonium chloride are formed in this reaction.
  • the amount of anhydrous liquid ammonia ranges between one and two times the stoichiometric amount of total silicon-chloride bonds in the one or more compounds comprising Formula (I).
  • the method further comprises (b) allowing the reaction mixture from step (a) to attain ambient temperature to evaporate the anhydrous liquid ammonia.
  • the method may further comprise using an ammonium scavenger to remove the ammonium salt from a polysilazane comprising the compound of Formula (II) to provide a purified polysilazane, as described below in Section (II).
  • Step A involves contacting one or more compounds comprising Formula (I) with anhydrous liquid ammonia under ambient pressure at a temperature below about -33 °C.
  • Chlorosilanes (including SiC ) with more than two Si-Cl bonds may increase the networking in the resulting polysilazane. Chlorosilanes with less than two Si-Cl bonds would terminate polysilazane chains and decrease the degree of polymerization.
  • R 1 and R 2 may be independently chosen from hydrogen, alkyl, alkenyl, and phenyl. Each R 1 and R 2 may be optionally substituted with one or more sulfonic acids, carboxylic acids, amines, or amides. Alternatively each R 1 and R 2 may be independently hydrogen, methyl, or vinyl. R 1 is hydrogen. In particular, R 1 and R2 may be hydrogen, methyl, or vinyl. Phenylated dichlorosilanes (wherein R 1 and/or R 2 is phenyl) when present may increase the temperature stability of the compounds of Formula (II) produced from the methods disclosed herein.
  • the one or more compounds comprising Formula (I) may be selected from the group consisting of dichloro(methyl)silane, dichloro(methyl)(vinyl)silane,
  • dichlorodimethylsilane and combinations thereof. Certain mixtures of compounds of Formula (I) may be specified, such as those selected from the group consisting of dichloro(methyl)silane, dichloro(methyl)silane/ dichloro(methyl)(vinyl)silane, dichloro(methyl)silane/
  • dichlorodimethylsilane and dichloro(methyl)silane/ dichloro(methyl)(vinyl)silane/
  • dichlorodimethylsilane may include dichloro(methyl)silane, singly or in combination with other compounds comprising Formula (I).
  • the molar ratio of the compounds comprising Formula (I) can and will vary.
  • the one or more compounds comprising Formula (I) may consist of a molar ratio ranging between about 10:90 to about 30:70 dichloro(methyl)silane to
  • the one or more compounds comprising Formula (I) may consist of between about 60 wt.% and about 80 wt.% dichlorodimethylsilane, and between about 40 wt.% and about 20 wt.% dichloro(methyl)silane.
  • Step A a compound comprising Formula (II) and ammonium chloride are formed, as depicted in the reaction scheme below:
  • R 1 and R 2 may be independently chosen from hydrogen, alkyl, alkenyl, and phenyl. Each R 1 and R 2 may be optionally substituted with one or more sulfonic acids, carboxylic acids, amines, or amides. In particular, each R 1 and R 2 may be independently hydrogen, methyl, or vinyl. Alternatively, R 1 may be hydrogen.
  • the number n may range from about 2 to about 500, such as from about 10 to about 100, of from about 5 to about 10, from about 10 to about 25, from about 25 to about 50, from about 50 to about 75, from about 75 to about 100, from about 100 to about 200, from about 200 to about 300, from about 300 to about 400, or from about 400 to about 500.
  • the number n may be less than about 500.
  • the number n may be greater than 2.
  • the number n may be greater than 2.5, such as greater than 4, greater than 5, greater than 6, greater than 7, greater than 8, greater than 9, greater than 10, greater than 15, greater than 20, greater than 25, greater than 30, greater than 35, greater than 40, greater than 45, or greater than 50.
  • the term "about” refers to the average value for n in a given sample of compounds comprising Formula (II).
  • the reaction mixture has a solvent comprising anhydrous ammonia.
  • Step A may use anhydrous liquid ammonia as the only solvent, but the solvent may comprise additional non-aqueous solvents, depending on the compounds of Formula (I).
  • Water causes unwanted decomposition of the polymerized material due to hydrolysis at the silicon atoms of the Si-N bonds. This reaction produces silanols, which continue react with other silicon centers until siloxanes are formed.
  • the additional solvent may be a polar protic solvent, a polar aprotic solvent, a non-polar solvent, or combinations thereof.
  • polar protic solvents include, but are not limited to alcohols such as methanol, ethanol, isopropanol, n-propanol, isobutanol, n- butanol, s-butanol, t-butanol, and the like; diols such as propylene glycol; organic acids such as formic acid, acetic acid, and so forth; amines such as trimethylamine, or triethylamine, and the like; amides such as formamide, acetamide, and so forth; and combinations of any of the above.
  • Non-limiting examples of suitable polar aprotic solvents include acetonitrile, dichloromethane (DCM), diethoxymethane, N,N-dimethylacetamide (DMAC), ⁇ , ⁇ -dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ⁇ , ⁇ -dimethylpropionamide, l,3-dimethyl-3,4,5,6-tetrahydro- 2(lH)-pyrimidinone (DMPU), l,3-dimethyl-2-imidazolidinone (DMI), 1,2-dimethoxyethane (DME), dimethoxymethane, bis(2-methoxyethyl)ether, 1,4-dioxane, N-methyl-2-pyrrolidinone (NMP), ethyl formate, formamide, hexamethylphosphoramide, N-methylacetamide, N- methylformamide, methylene chloride, nitrobenzene, nitromethane, pro
  • non-polar solvents include, but are not limited to, alkane and substituted alkane solvents (including cycloalkanes), aromatic hydrocarbons, esters, ethers, combinations thereof, and the like.
  • Specific non-polar solvents that may be employed include, for example, benzene, butyl acetate, t-butyl methylether, chlorobenzene, chloroform, chloromethane, cyclohexane, dichloromethane, dichloroethane, diethyl ether, ethyl acetate, diethylene glycol, fluorobenzene, heptane, hexane, isopropyl acetate, methyltetrahydrofuran, pentyl acetate, n-propyl acetate, tetrahydrofuran, toluene, and combinations thereof.
  • the solvent in addition to anhydrous liquid ammonia, may comprise an aliphatic solvent, such as n-heptane.
  • suitable aliphatic hydrocarbons and mixtures thereof include aromatic hydrocarbons, such as benzene, toluene, and xylene.
  • the solvent may also be chosen form methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, isobutyl acetate, tert-butyl acetate, and mixtures thereof.
  • anhydrous liquid ammonia is used as both a reagent and a solvent, it is present within the reaction mixture in a stoichiometric excess.
  • the amount of anhydrous liquid ammonia may be restricted to between about 1 and about 2 times the stoichiometric amount of total silicon-chlorine bonds in the one or more compound comprising Formula (I).
  • the volume ratio of the solvent to the compound comprising Formula (I) will range from about 0.5: 1 to about 100: 1.
  • the volume ratio of the solvent to the compound comprising Formula (I) may range from about 0.5:1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the volume ratio of the solvent to the compound comprising Formula (I) may range from about 5: 1 to about 20: 1, such as between about 10: 1 and about 20: 1.
  • the reaction of Step A will be conducted at a temperature that ranges between about -200 °C and about -30 °C.
  • the temperature of the reaction may range between about -200 °C and about -180 °C, between about -180 °C and about -160 °C, between about -160 °C and about -140 °C, between about -140 °C and about -120 °C, between about -120 °C and about -100 °C, between about -100 °C and about -80 °C, between about -80 °C and about -60 °C, or between about -60 °C and about -30 °C.
  • the reaction may be conducted at temperature that ranges between about -60 °C and about -30 °C, from about -40 °C to about -30°C, or at about -33 °C.
  • the temperature of the reaction may be below about -33 °C.
  • the reaction typically is performed under ambient pressure.
  • the reaction may also be conducted under an inert atmosphere, for example under nitrogen, argon, or helium.
  • the reaction may be conducted under an atmosphere of gaseous ammonia.
  • the reaction is allowed to proceed for a sufficient period of time until the reaction is complete, as determined by any method known to one skilled in the art, such as chromatography (e.g., HPLC).
  • the duration of the reaction may range from about 5 minutes to about 10 hours.
  • the duration of the reaction may range from about 5 minutes to about 30 minutes, from about 30 minutes to about 2 hours, from about 2 hours to about 4 hours, or from about 4 hours to about 10 hours.
  • the reaction may be allowed to proceed for about 0.5 hour to about 2 hours.
  • a "completed reaction” generally means that the reaction mixture contains a significantly diminished amount of the compound comprising Formula (I).
  • the amount of the compound comprising Formula (I) remaining in the reaction mixture at the end of the reaction may be less than about 10%, less than about 5%, or less than about 2%.
  • the compound comprising Formula (II) may have a yield of at least about 60%.
  • the compound comprising Formula (II) may have a yield of at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 99%.
  • Step B involves allowing the reaction mixture from Step A to attain ambient temperature to evaporate the anhydrous liquid ammonia. In allowing the temperature to rise, the reaction mixture need not be actively heated. Rather the reaction mixture can be left to equilibrate under ambient conditions until it is warm enough for the ammonia to evaporate.
  • the reaction of Step B may be conducted at a temperature that ranges from about -30 °C to about 100°C.
  • the temperature of the reaction may range between about -30 °C and about -20 °C, between about -20 °C and about 0 °C, between about 0 °C and about 20 °C, between about 20 °C and about 40 °C, between about 40 °C and about 60 °C, between about 60 °C and about 80 °C, or between about 80 °C and about 100 °C.
  • the reaction may be conducted at temperature that ranges between about 10 °C and about 40 °C, or between about 20 °C and about 30°C. Specifically, the temperature of the reaction may be about room temperature.
  • the reaction generally will be conducted under inert atmosphere, for example under nitrogen, argon or helium.
  • the reaction is allowed to proceed for a sufficient period of time until the reaction is complete, as determined by any method known to one skilled in the art.
  • the reaction may be allowed to proceed for a time that ranges from about 1 hour to about 30 hours.
  • the duration of the reaction may range from about 1 hour to about 4 hours, from about 4 hours to about 10 hours, from about 10 hours to about 18 hours, or from about 18 hours to about 30 hours.
  • the reaction may be allowed to proceed between about 5 and about 7 hours to evaporate the anhydrous liquid ammonia.
  • the method may comprise a Step C, which involves contacting the compound of
  • the compound of Formula (II) may be as defined herein.
  • the primary alkylamine has a general formula of NH 2 R 3 , wherein R 3 is alkyl.
  • R 3 may be methyl, ethyl, propyl, or butyl.
  • R 3 may be methyl.
  • the primary alkylamine may be methylamine, ethylamine, propylamine, or butylamine.
  • the primary alkylamine may be methylamine.
  • R may be as defined above under the description of primary alkylamine.
  • R may be as defined above under the description of Formula (I), or any embodiments thereof.
  • the number n may be as defined above under the description of Formula (I), or any embodiments thereof.
  • the weight ratio of the primary alkylamine to the compound comprising Formula (II) will range from about 0.5:1 to about 100: 1.
  • the weight ratio of the primary alkylamine to the compound comprising Formula (II) may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the weight ratio of the primary alkylamine to the compound comprising Formula (II) may range from about 5: 1 to about 20: 1, such as between about 10: 1 and about 20: 1.
  • the solvent may be a polar protic solvent, a polar aprotic solvent, a non-polar solvent, or combinations thereof.
  • polar protic solvents include, but are not limited to alcohols such as methanol, ethanol, isopropanol, n-propanol, isobutanol, n-butanol, s- butanol, t-butanol, and the like; diols such as propylene glycol; organic acids such as formic acid, acetic acid, and so forth; amines such as trimethylamine, or triethylamine, and the like; amides such as formamide, acetamide, and so forth; and combinations of any of the above.
  • Non-limiting examples of suitable polar aprotic solvents include acetonitrile, dichloro methane (DCM), diethoxymethane, ⁇ , ⁇ -dimethylacetamide (DM AC), ⁇ , ⁇ -dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ⁇ , ⁇ -dimethylpropionamide, l,3-dimethyl-3,4,5,6-tetrahydro-2(lH)- pyrimidinone (DMPU), l,3-dimethyl-2-imidazolidinone (DMI), 1,2-dimethoxyethane (DME), dimethoxymethane, bis(2-methoxyethyl)ether, 1,4-dioxane, N-methyl-2-pyrrolidinone (NMP), ethyl formate, formamide, hexamethylphosphoramide, N-methylacetamide, N-methylformamide, methylene chloride, nitrobenzene, nitromethane,
  • non-polar solvents include, but are not limited to, alkane and substituted alkane solvents (including cycloalkanes), aromatic hydrocarbons, esters, ethers, combinations thereof, and the like.
  • Specific non-polar solvents that may be employed include, for example, benzene, butyl acetate, t-butyl methylether, chlorobenzene, chloroform, chloromethane, cyclohexane, dichloromethane, dichloroethane, diethyl ether, ethyl acetate, diethylene glycol, fluorobenzene, heptane, hexane, isopropyl acetate, methyltetrahydrofuran, pentyl acetate, n- propyl acetate, tetrahydrofuran, toluene, and combinations thereof.
  • the solvent may be selected from the group consisting of aliphatic hydrocarbons, methyl acetate, isopropyl acetate, ieri-butyl acetate.
  • the solvent may be an aliphatic hydrocarbon comprising n-heptane.
  • the volume ratio of the solvent to the compound comprising Formula (II) will range from about 0.5: 1 to about 100: 1.
  • the volume ratio of the solvent to the compound comprising Formula (II) may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the volume ratio of the solvent to the compound comprising Formula (II) may range from about 5: 1 to about 20: 1, such as between about 10: 1 and about 20: 1.
  • the reaction of Step C may be conducted at a temperature that allows the solvent to reflux. Reflux depends on the solvent, pressure of the reaction, and the concentration of reagents, among other factors. In general, the temperature may range from about 30 °C to about 200°C.
  • the temperature of the reaction may range between about 30 °C and about 40 °C, between about 40 °C and about 50 °C, between about 50 °C and about 60 °C, between about 60 °C and about 70 °C, between about 70 °C and about 80 °C, between about 80 °C and about 90 °C, between about 90 °C and about 100 °C, between about 100 °C and about 110 °C, between about 110 °C and about 120 °C, between about 120 °C and about 130 °C, between about 130 °C and about 140 °C, between about 140 °C and about 150 °C, between about 150 °C and about 160 °C, between about 160 °C and about 170 °C, between about 170 °C and about 180 °C, between about 180 °C and about 190 °C, or between about 190 °C and about 200 °C.
  • the reaction generally will be conducted under inert atmosphere, for example under nitrogen, arg
  • the reaction is allowed to proceed for a sufficient period of time until the reaction is complete, as determined by any method known to one skilled in the art.
  • the reaction may be allowed to proceed for a time that ranges from about 10 minutes to about 8 hours.
  • the duration of the reaction may range from about 10 minutes to about 30 minutes, from about 30 minutes to about 1 hour, from about 1 hour to about 2 hours, from about 2 hours to about 3 hours, from about 3 hours to about 4 hours, from about 4 hours to about 5 hours, from about 5 hours to about 6 hours, from about 6 hours to about 7 hours, or from about 7 hours to about 8 hours.
  • the duration of the reaction may range from about 30 minutes to about 4 hours.
  • the compound comprising Formula (III) may have a yield of at least about 60%.
  • the compound comprising Formula (III) may have a yield of at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 99%.
  • the present disclosure provides a method for using an ammonium scavenger to remove an ammonium salt from a polysilazane to provide a purified polysilazane.
  • the method comprises mixing a polysilazane containing an ammonium salt with a volume ratio of about 10: 1 to about 20: 1 solvent, and contacting the mixture of Step A with an ammonium scavenger to convert the ammonium salt to ammonia.
  • Step A of the method involves mixing a polysilazane containing an ammonium salt with a volume ratio of about 10: 1 to about 20:1 solvent.
  • “Silazane” and “polysilazane” are generic terms which include compounds containing one or more silicon-nitrogen bonds in which the nitrogen atom is bonded to at least two silicon atoms, and may or may not contain cyclic units. Therefore, the terms “polysilazane” and “silazane polymer” include oligomers, cyclic, polycyclic, linear polymers or resinous polymers having at least one Si-N group in the compound, or having repeating units of H 2 Si- NH; that is, [H 2 Si-NH] n , with "n” greater than 1.
  • the chemical structure for an inorganic polysilazane is shown below.
  • silazane oligomer is disilazane H 3 Si-NH-SiH 3 .
  • the oligomeric or polymeric silazanes may be amorphous or crystalline in nature.
  • Silazane polymer chains having both large chains and small rings with a wide range of molecular mass are called poly silazanes.
  • Polysilazanes or a mixture of polysilazanes known in the art or commercially available include such products generally known among persons skilled in the art as silazanes, disilazanes, polysilazanes, ureasilazanes, polyureasilazanes, aminosilanes, organosilazanes,
  • a polysilazane with the general formula (CH 3 ) 3 Si-NH-[(CH 3 ) 2 Si-NH] n - Si(CH 3 )3 is designated as polydimethylsilazane.
  • One group of polysilazane, [RiR 2 Si-NH] n is isoelectronic with and close relatives to polysiloxane [RiR 2 Si-0] n .
  • Si-N bond can be found in triethylsilylamine ((H 5 C 2 ) 3 Si-NH 2 ), which is a typical aminosilane.
  • small ring-shaped molecules with a base group of Si-N are called "cyclosilazanes.”
  • triazatrisilane H 9 N 3 S1 3
  • the polysilane may be a compound comprising Formula (II), as disclosed herein.
  • the solvent may be as defined above under the description of Section (I)(c).
  • the solvent may be selected from the group consisting of aliphatic hydrocarbons, methyl acetate, isopropyl acetate, and ieri-butyl acetate.
  • the solvent may be an aliphatic hydrocarbon comprising n-heptane.
  • the volume ratio of the solvent to the polysilazane will range from about 0.5: 1 to about 100: 1.
  • the volume ratio of the solvent to the polysilazane may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the volume ratio of the solvent to the polysilazane may range from about 5: 1 to about 20: 1, such as between about 10:1 and about 20: 1.
  • Step B involves contacting the mixture of Step A with an ammonium scavenger to convert the ammonium salt to ammonia.
  • ammonium scavenger may a compound comprising Formula
  • R 4 is hydrogen or alkyleneamine
  • L is alkylene
  • each R 5 is independently selected alkyl
  • R 4 may be alkyleneamine, such as methyleneamine, ethyleneamine,
  • the alkyleneamine may be ethyleneamine.
  • L may be propylene.
  • R 5 may be selected from the group consisting of methyl, ethyl, and propyl.
  • the ammonium scavenger may be selected from the group consisting of 3- (aminopropyl)triethoxysilane, 3-(aminopropyl)methoxysilane, 3-(aminopropyl)tripropoxysilane, and N- [3 -(trimethoxy silyl)propyl] ethylenediamine) .
  • the weight ratio of the ammonium scavenger to the mixture of Step A will range from about 0.5: 1 to about 100: 1.
  • the weight ratio of ammonium scavenger to the mixture of Step A may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the weight ratio of ammonium scavenger to the mixture of Step A may range from about 1: 1 to about 20: 1, such as between about 10: 1 and about 20: 1.
  • the weight ratio of the ammonium scavenger to the mixture of Step A may be about 2.5: 1.
  • the weight ratio of the ammonium scavenger to the mixture of Step A may be about 10: 1.
  • the solvent may be as defined above under the description of Section (I)(c) and any embodiments thereof.
  • the solvent may be selected from the group consisting of aliphatic hydrocarbons, methyl acetate, isopropyl acetate, and tert-butyl acetate.
  • the solvent may be an aliphatic hydrocarbon comprising n-heptane.
  • the volume ratio of the solvent to the polysilazane will range from about 0.5: 1 to about 100: 1.
  • the volume ratio of the solvent to the polysilazane may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the volume ratio of the solvent to the polysilazane may range from about 5: 1 to about 20: 1, such as between about 10:1 and about 20: 1.
  • the reaction of Step B may be conducted at a temperature that allows the solvent to reflux. Reflux depends on the solvent, pressure of the reaction, and the concentration of reagents, among other factors. In general, the temperature may range from about 30 °C to about 200°C.
  • the temperature of the reaction may range between about 30 °C and about 40 °C, between about 40 °C and about 50 °C, between about 50 °C and about 60 °C, between about 60 °C and about 70 °C, between about 70 °C and about 80 °C, between about 80 °C and about 90 °C, between about 90 °C and about 100 °C, between about 100 °C and about 110 °C, between about 110 °C and about 120 °C, between about 120 °C and about 130 °C, between about 130 °C and about 140 °C, between about 140 °C and about 150 °C, between about 150 °C and about 160 °C, between about 160 °C and about 170 °C, between about 170 °C and about 180 °C, between about 180 °C and about 190 °C, or between about 190 °C and about 200 °C.
  • the reaction generally will be conducted under inert atmosphere, for example under nitrogen, arg
  • the reaction is allowed to proceed for a sufficient period of time until the reaction is complete, as determined by any method known to one skilled in the art.
  • the reaction may be allowed to proceed for a time that ranges from about 10 minutes to about 8 hours.
  • the duration of the reaction may range from about 10 minutes to about 30 minutes, from about 30 minutes to about 1 hour, from about 1 hour to about 2 hours, from about 2 hours to about 3 hours, from about 3 hours to about 4 hours, from about 4 hours to about 5 hours, from about 5 hours to about 6 hours, from about 6 hours to about 7 hours, or from about 7 hours to about 8 hours.
  • the duration of the reaction may range from about 30 minutes to about 4 hours.
  • the purified polysilazane may have a yield of at least about 60%.
  • the purified polysilazane may have a yield of at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, or at least about 99%.
  • the method comprises Step C, which involves separating the purified
  • the separation may occur after Step B, and/or involve separating the ammonium salt from the mixture of Step A before Step B.
  • the separation may comprise filtering.
  • a mixture of Step A may be vigorously stirred and then the ammonium salt may be filtered off, for example using filter frits having pore size of about 500 nm and diatomaceous earth (CeliteTM) .
  • the separation may comprise centrifuging the mixture.
  • One of skill in the art is capable of selecting the suitable centrifugation speed and the duration of effect separation of the ammonium salt from the mixture of Step A or the purified polysilazane from the mixture of Step 3.
  • the separation may comprises washing the mixture of Step A or Step B with an about 1: 1 to about 20: 1 volume ratio of an aqueous proton acceptor to the mixture of Step A or Step B.
  • the proton acceptor has a pKa of between about 7 and about 13, preferably between about 8 and about 10.
  • Representative proton acceptors that may be employed include, but are not limited to, borate salts (such as, for example, Na 3 B0 3 ), di- and tri-basic phosphate salts (such as, for example, Na 2 HP0 4 and Na 3 P0 4 ), bicarbonate salts (such as, for example, NaHC0 3 , KHC0 3 , mixtures thereof, and the like), hydroxide salts (such as, for example, NaOH, KOH, mixtures thereof, and the like), carbonate salts (such as, for example, Na 2 C0 3 , K 2 C0 3 , mixtures thereof, and the like), organic bases (such as, for example, pyridine, triethylamine, diisopropylethylamine, N-methylmorpholine, ⁇ , ⁇ -dimethylaminopyridine, and mixtures thereof), organic buffers (such as, for example
  • aqueous proton acceptor may be selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium
  • the volume ratio of the aqueous proton acceptor to the mixture of Step A or Step B will range from about 0.5: 1 to about 100: 1.
  • the volume ratio of the aqueous proton acceptor to the mixture of Step A or Step B may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the volume ratio of the aqueous proton acceptor to the mixture of Step A or Step B may range from about 1:5 to about 1: 15, such as between about 1: 10.
  • the concentration of the aqueous proton acceptor may range between about 0.5 N and about 10 N, such as between about 0.5 N and about 1 N, between about 1 N and about 2 N, between about 2 N and about 3 N, between about 3 N and about 4 N, between about 4 N and about 5 N, between about 5 N and about 6 N, between about 6 N and about 7 N, between about 7 N and about 8 N, between about 8 N and about 9 N, or between about 9 N and about 10 N.
  • the concentration of aqueous proton acceptor may be about 2 N.
  • compositions comprising combinations of a compound comprising Formula (II) and an ammonium scavenger comprising Formula (IV).
  • the compound of Formula (II) may be as defined above under the description of Section (I), and any embodiments thereof.
  • the ammonium scavenger may be as defined above under the description of Section (II), and any embodiments thereof.
  • the ammonium scavenger may be selected from the group consisting of 3-(aminopropyl)triethoxysilane, 3- (aminopropyl)methoxysilane, 3-(aminopropyl)tripropoxysilane, and N-[3- (trimethoxysilyl)propyl]ethylenediamine).
  • the weight ratio of ammonium scavenger to the compound of Formula (II) will range from about 0.5: 1 to about 100: 1.
  • the weight ratio of ammonium scavenger to the compound of Formula (II) may range from about 0.5: 1 to about 2: 1, from about 2: 1 to about 5: 1, from about 5: 1 to about 25: 1, or from about 25: 1 to about 100: 1.
  • the weight ratio of ammonium scavenger to the compound of Formula (II) may range between about 1:99 and about 20:80.
  • the weight ratio of the ammonium scavenger to the compound of Formula (II) may be about 2.5:97.5.
  • the weight ratio of the ammonium scavenger to the compound of Formula (II) may be about 10:90.
  • the composition may further comprise an ammonium salt, such as ammonium chloride.
  • the amount of ammonium chloride present in the composition may range between about 0.01 wt.% and about 10 wt.% of the total composition, such as between about 0.01 wt.% and about 0.05 wt.% of the total composition, between about 0.05 wt.% and about 0.1 wt.% of the total composition, between about 0.1 wt.% and about 0.5 wt.% of the total composition, between about 0.5 wt.% and about 1 wt.% of the total composition, between about 1 wt.% and about 2 wt.% of the total composition, between about 2 wt.% and about 3 wt.% of the total composition, between about 3 wt.% and about 4 wt.% of the total composition, between about 4 wt.% and about 5 wt.% of the total composition, between about 5 wt.% and about 6 wt.% of the total composition
  • composition comprising
  • R 1 and FT 2 are independently chosen from hydrogen, alkyl, alkenyl, and phenyl, wherein R 1 and R 2 may be optionally substituted with one or more sulfonic acids, carboxylic acids, amines, or amides; and
  • n is greater than 2;
  • composition is substantially free of ammonium salts.
  • the terms “about” and “approximately” designate that a value is within a statistically meaningful range. Such a range can be typically within 20%, more typically still within 10%, and even more typically within 5% of a given value or range. The allowable variation encompassed by the terms “about” and “approximately” depends on the particular system under study and can be readily appreciated by one of ordinary skill in the art.
  • the term “w/w” designates the phrase “by weight,” “weight percent,” or “wt. %,” and is used to describe the concentration of a particular substance in a mixture or solution.
  • ml/kg designates milliliters of composition per kilogram of formula weight.
  • cure refers to a change in state, condition, and/or structure in a material that is usually, but not necessarily, induced by at least one variable, such as time, temperature, moisture, radiation, presence and quantity in such material of a catalyst, enhancer, accelerator or the like.
  • the terms cover partial as well as complete curing.
  • oligomer is meant any molecule or chemical compound which comprises several repeat units, generally from about 2 to 10 repeat units.
  • Polymer or copolymer as used herein, means a molecule or compound which comprises a large number of repeat units, generally greater than about 10 repeat units.
  • the term "monomer” refers to any chemical compound that is capable of forming a covalent bond with itself or a chemically different compound in a repetitive manner.
  • the repetitive bond formation between monomers may lead to a linear, branched, super- branched, or three-dimensional product.
  • monomers may themselves comprise repetitive building blocks, and when polymerized the polymers formed from such monomers are then termed "blockpolymers.”
  • Monomers may belong to various chemical classes of molecules including organic, organometallic or inorganic molecules. The molecular weight of monomers may vary greatly between about 40 Daltons and 20,000 Daltons. However, especially when monomers comprise repetitive building blocks, monomers may have even higher molecular weights.
  • Monomers may also include additional reactive groups
  • Contemplated polymers may also comprise a wide range of functional or structural moieties, including aromatic systems, and halogenated groups. Furthermore, appropriate polymers may have many configurations, including a homopolymer, and a heteropolymer. Moreover, alternative polymers may have various forms, such as linear, branched, super-branched, or three-dimensional. The molecular weight of contemplated polymers spans a wide range, typically between 400 Daltons and 400,000 Daltons or more.
  • Prepolymer refers to polymeric structures formed by the processes in the present disclosure are long term-stable liquids, and possess only moderate odors, which mostly arise from the use of solvents. In the solid form, these polymerized materials may be handled similarly to thermosetting or thermoplastic processes. Molecular weight may vary from about 2,000 g/mol up to as much as 100,000 g/mol, depending on process. The density of the prepolymers is normally around 1 g/cm 3 .
  • the polymerization processes include, but are not limited to, step-growth polymerization, polyaddition, and polycondensation. More specifically, polymerization can be initiated by mechanisms, such as acid- or base-catalysis, or free radical polymerization. It may comprise ring-opening copolymerization, and the formation of inorganic and/or organic polymer networks. The actual mechanisms of polymerization depend on the functional groups of the reacting polymeric and monomeric compounds, as well as inherent steric effects. Conceptually new materials can be formed by adding non-conventional starting materials into the
  • polymerization process such as ammonia
  • the compounds described herein may have asymmetric centers.
  • acyl denotes the moiety formed by removal of the hydroxy group from the group COOH of an organic carboxylic acid, e.g., RC(O)-, wherein R is R 1 , R ⁇ -, R ⁇ N-, or R ⁇ -, R 1 is hydrocarbyl, hetero substituted hydrocarbyl, or heterocyclo, and R is hydrogen, hydrocarbyl, or substituted hydrocarbyl.
  • acyloxy as used herein alone or as part of another group, denotes an acyl group as described above bonded through an oxygen linkage (O), e.g., RC(0)0- wherein R is as defined in connection with the term "acyl.”
  • O oxygen linkage
  • alkyl as used herein describes groups which are preferably lower alkyl containing from one to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include methyl, ethyl, propyl, isopropyl, butyl, hexyl and the like.
  • alkenyl as used herein describes groups which are preferably lower alkenyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain or cyclic and include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, hexenyl, and the like.
  • alkynyl as used herein describes groups which are preferably lower alkynyl containing from two to eight carbon atoms in the principal chain and up to 20 carbon atoms. They may be straight or branched chain and include ethynyl, propynyl, butynyl, isobutynyl, hexynyl, and the like.
  • aromatic as used herein alone or as part of another group denotes optionally substituted homo- or heterocyclic conjugated planar ring or ring system comprising delocalized electrons. These aromatic groups are preferably monocyclic (e.g., furan or benzene), bicyclic, or tricyclic groups containing from 5 to 14 atoms in the ring portion.
  • aromatic encompasses "aryl” groups defined below.
  • aryl or “Ar” as used herein alone or as part of another group denote optionally substituted homocyclic aromatic groups, preferably monocyclic or bicyclic groups containing from 6 to 10 carbons in the ring portion, such as phenyl, biphenyl, naphthyl, substituted phenyl, substituted biphenyl, or substituted naphthyl.
  • substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, alkyl, alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl, carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxy, keto, ketal, phospho, nitro, and thio.
  • halogen or halo as used herein alone or as part of another group refer to chlorine, bromine, fluorine, and iodine.
  • heteroatom refers to atoms other than carbon and hydrogen.
  • heteroaromatic as used herein alone or as part of another group denotes optionally substituted aromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring.
  • the heteroaromatic group preferably has 1 or 2 oxygen atoms and/or 1 to 4 nitrogen atoms in the ring, and is bonded to the remainder of the molecule through a carbon.
  • Exemplary groups include furyl, benzofuryl, oxazolyl, isoxazolyl, oxadiazolyl, benzoxazolyl, benzoxadiazolyl, pyrrolyl, pyrazolyl, imidazolyl, triazolyl, tetrazolyl, pyridyl, pyrimidyl, pyrazinyl, pyridazinyl, indolyl, isoindolyl, indolizinyl, benzimidazolyl, indazolyl, benzotriazolyl, tetrazolopyridazinyl, carbazolyl, purinyl, quinolinyl, isoquinolinyl, imidazopyridyl, and the like.
  • substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, alkyl, alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl, carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxy, keto, ketal, phospho, nitro, and thio.
  • heterocyclo or “heterocyclic” as used herein alone or as part of another group denote optionally substituted, fully saturated or unsaturated, monocyclic or bicyclic, aromatic or non-aromatic groups having at least one heteroatom in at least one ring, and preferably 5 or 6 atoms in each ring.
  • the heterocyclo group preferably has 1 or 2 oxygen atoms and/or 1 to 4 nitrogen atoms in the ring, and is bonded to the remainder of the molecule through a carbon or heteroatom.
  • Exemplary heterocyclo groups include heteroaromatics as described above.
  • substituents include one or more of the following groups: hydrocarbyl, substituted hydrocarbyl, alkyl, alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl, carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxy, keto, ketal, phospho, nitro, and thio.
  • hydrocarbon and “hydrocarbyl” as used herein describe organic compounds or radicals consisting exclusively of the elements carbon and hydrogen. These moieties include alkyl, alkenyl, alkynyl, and aryl moieties. These moieties also include alkyl, alkenyl, alkynyl, and aryl moieties substituted with other aliphatic or cyclic hydrocarbon groups, such as alkaryl, alkenaryl and alkynaryl. Unless otherwise indicated, these moieties preferably comprise 1 to 20 carbon atoms.
  • protecting group denotes a group capable of protecting a particular moiety, wherein the protecting group may be removed, subsequent to the reaction for which the protection is employed, without disturbing the remainder of the molecule.
  • exemplary protecting groups include ethers (e.g., allyl, triphenylmethyl (trityl or Tr), p-methoxybenzyl (PMB), p-methoxyphenyl (PMP)), acetals (e.g., methoxymethyl (MOM),
  • MCM ⁇ -methoxyethoxymethyl
  • THP tetrahydropyranyl
  • EE ethoxy ethyl
  • MTM methylthio methyl
  • MOP 2-methoxy-2-propyl
  • SEM 2-trimethylsilylethoxymethyl
  • esters e.g., benzoate (Bz), allyl carbonate, 2,2,2-trichloroethyl carbonate (Troc), 2-trimethylsilylethyl carbonate), silyl ethers (e.g., trimethylsilyl (TMS), triethylsilyl (TES), triisopropylsilyl (TIPS), triphenylsilyl (TPS), t-butyldimethylsilyl (TBDMS), t-butyldiphenylsilyl (TBDPS) and the like.
  • TTPS trimethylsilyl
  • TES triethylsilyl
  • TIPS triisopropyls
  • exemplary protecting groups include benzyl, p-methoxyphenyl (PMP), 3,4-dimethoxybenxyl (PMB)), n- silyl groups, esters (e.g., benzoate (Bz), carbonyl (e.g. p-methoxybenzyl carbonyl (Moz), tert- butyloxycarbonyl (BOC), 9-fluorenylmethyloxycarbonyl (FMOC)), acetyl, carbamates, n-silyl groups and the like.
  • esters e.g., benzoate (Bz)
  • carbonyl e.g. p-methoxybenzyl carbonyl (Moz)
  • BOC tert- butyloxycarbonyl
  • FMOC 9-fluorenylmethyloxycarbonyl
  • substituted hydrocarbyl moieties described herein are hydrocarbyl moieties which are substituted with at least one atom other than carbon, including moieties in which a carbon chain atom is substituted with a heteroatom such as nitrogen, oxygen, silicon, phosphorous, boron, or a halogen atom, and moieties in which the carbon chain comprises additional substituents.
  • substituents include alkyl, alkoxy, acyl, acyloxy, alkenyl, alkenoxy, aryl, aryloxy, amino, amido, acetal, carbamyl, carbocyclo, cyano, ester, ether, halogen, heterocyclo, hydroxy, keto, ketal, phospho, nitro, and thio.
  • Example 1 Attempted polysilazane synthesis.
  • FTIR Fourier transform infrared
  • Example 2 Further attempted polysilazane synthesis.
  • Example 1 Alternatively, the reaction of Example 1 was conducted using a different combination of starting materials and reaction conditions. This combination of features also stopped before producing the desired polysilazane.
  • Figure 2 depicts the FTIR spectrum for bis-
  • Example 2 (chloro methy lvinylsilaneamine), verifying that the reaction of Example 2 also only produced dimers and stopped before producing the desired polysilazane.
  • the reaction product had the additional problem in that residual ammonium chloride (NH 4 CI) was released during the final networking reactions, resulting in a hardened white coating. Filtration and centrifugation of these reaction products caused gradual polymerization, thereby releasing more NH 4 CI crystals. While reactions were instructive, additional methods needed to be tried to achieve the correct finished product.
  • Example 3. Polysilazane synthesis.
  • Examples 1 and 2 these dimers were not the final product. Rather, the dimers continued to react until the polysilazane was formed. Additionally, in comparison, the amount of liquid ammonia was minimized in the reaction at normal pressure. No other solvents were added to this reaction. The molar ratio of liquid ammonia and organodichlorosilane was at least about 2: 1.
  • Figure 5 depicts the FTIR spectrum of a polysilazane (20:80 (mol/mol) DMS/DMVS) after three consecutive washings of the methyl acetate solution of the polysilazane with 10: 1 v/v 2 N NaOH (aq).
  • the Si-H vibration remaining from residual starting material was discernible.
  • Figure 6 depicts the FTIR spectrum for a polysilazane (100% DMS).
  • the sample was only filtered.
  • the FTIR transitions were 3370 cm “1 for the -NH stretch, 2952 cm “1 for the aliphatic CH (-CH 3 ) stretch, 2112 cm “1 for the Si-H stretch, 1404 cm “1 for -CH 2 -, 1251 cm “1 for Si-CH 3 , 1159 cm “1 for the NH-Si-NH transitions, 883 cm “1 for the Si-NH-Si transitions, and 762 cm “1 for the Si-C stretch.
  • Figure 7 depicts the FTIR spectrum for poly(methyl)silazane formed from the reaction of sodium amide and dichloro(methyl)silane.
  • the FTIR transitions were 3600-3000 cm “1 for the SiO-H stretch, 2960 cm “1 for the aliphatic CH (-CH 3 ) stretch, 2155 cm “1 for the Si-H stretch, 1400 cm “1 for -CH 2 -, 1256 cm “1 for the Si-CH 3 stretch, 1060-1040 cm “1 for the NH-Si-NH transitions, 866 cm “1 for the Si-NH-Si transitions, and 758 cm “1 for the Si-C stretch.
  • Si-OH was formed either via reaction of Si-H with oxygen or with residual water/sodium hydroxide in sodium amide.
  • the Si-Cl bond then reacts with ammonia.
  • n-heptane 2 was diluted with n-heptane a volume ratio of about 10 to 20.
  • the NH 4 CI was only minimally soluble at ambient temperature in the mixture.
  • the biphasic system was vigorously stirred and then the NH 4 CI was filtered using filter frits (pore size of about 500 nm). Alternatively diatomaceous earth or centrifugation was used to separate the biphasic system.
  • the n-heptane solvent was then removed from the mixture under reduced pressure.
  • Figure 4 depicts the FTIR spectrum of a mixture of methy 1( vinyl) silanediamine and
  • the polysilazane having trace amounts of NH 4 C1 was mixed with (3- aminopropyl)triethoxysilane (APTES). Since aliphatic amines were better bases than ammonia, hydrogen chloride was transferred to the -NH 2 group of APTES, which prevented NH 4 CI from precipitating.
  • APTES (3- aminopropyl)triethoxysilane
  • APTES bound the remaining HC1 without forming a precipitate.
  • the reaction product then became completely transparent after adding APTES and remained so after being mixed with other resin components and during curing. In this way, coatings formed from the polysilazanes described herein were clear and without cloudiness formed from ammonium chloride precipitation during curing.
  • Example 5 Reaction of the polysilazane product with primary amines.
  • the polysilazane product was further reacted with primary amines to modify its chemical properties.
  • the purified polysilazane product of Example 4 was boiled with a stoichiometric amount of methylamine in heptane (1 mole methylamine per 1 mole Si). The reaction proceeded for about 1 hour to about 2 hours until no more ammonia evolved. This sequence of reactions led to an about 50% Si-H substitution, which was higher than the substitution observed in Examples 1-4.
  • reaction is as follows: wherein R 2 is as defined herein and R 3 is any alkyl group, for example methyl.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)

Abstract

La présente invention concerne un procédé de préparation de polysilazanes. Le procédé comprend la mise en contact d'un ou de plusieurs chlorosilanes avec de l'ammoniac liquide anhydre sous pression ambiante à une température inférieure à environ -33 °C, la quantité d'ammoniac liquide anhydre se situant entre une et deux fois la quantité stœchiométrique des liaisons silicium-chlorure totales dans les chlorosilanes. Le mélange réactionnel chauffe ensuite à température ambiante pour évaporer l'ammoniac liquide anhydre. La présente invention concerne en outre un procédé d'utilisation d'un piégeur d'ammonium pour éliminer un sel d'ammonium d'un polysilazane pour obtenir un polysilazane purifié.
PCT/US2017/047435 2017-03-09 2017-08-17 Procédé de préparation de polysilazanes Ceased WO2018164709A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201762469339P 2017-03-09 2017-03-09
US62/469,339 2017-03-09

Publications (1)

Publication Number Publication Date
WO2018164709A1 true WO2018164709A1 (fr) 2018-09-13

Family

ID=63448843

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2017/047435 Ceased WO2018164709A1 (fr) 2017-03-09 2017-08-17 Procédé de préparation de polysilazanes

Country Status (1)

Country Link
WO (1) WO2018164709A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210317272A1 (en) * 2018-07-24 2021-10-14 A/G Innovation Partners, Ltd. A system and method for a semi-continuous process for producing polysilazanes
US11273432B2 (en) 2018-05-31 2022-03-15 Arizona Board Of Regents On Behalf Of Arizona State University Beta-diketiminate manganese catalysts for hydrosilylation, hydroboration, and dehydrogenative pnictogen-silicon and pnictogen-boron bond formation

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4975512A (en) * 1987-08-13 1990-12-04 Petroleum Energy Center Reformed polysilazane and method of producing same
US5196556A (en) * 1988-12-03 1993-03-23 Hoechst Aktiengesellschaft Polysubstituted chlorine-containing silazane polymers, process for their preparation, ceramic materials containing silicon nitride which can be manufactured therefrom, and their manufacture
US5268496A (en) * 1992-05-27 1993-12-07 Wacker-Chemie Gmbh Process for the preparation of polysilazanes
US5948316A (en) * 1995-01-20 1999-09-07 The United States Of America As Represented By The Secretary Of The Navy Liquid crystal composition and alignment layer
US6329487B1 (en) * 1999-11-12 2001-12-11 Kion Corporation Silazane and/or polysilazane compounds and methods of making
US20100210808A1 (en) * 2009-02-16 2010-08-19 Eun Chang Jeong Method for preparing polysilazane solution with reducing ammonia substitution of si-h bond
US20140341794A1 (en) * 2012-08-10 2014-11-20 Evonik Industries Ag Process for the coupled preparation of polysilazanes and trisilylamine
US20150307354A1 (en) * 2013-05-27 2015-10-29 Evonik Industries Ag Process for the coupled preparation of trisilylamine and polysilazanes having a molar mass of up to 500 g/mol

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4975512A (en) * 1987-08-13 1990-12-04 Petroleum Energy Center Reformed polysilazane and method of producing same
EP0552852A2 (fr) * 1987-08-13 1993-07-28 Toa Nenryo Kogyo Kabushiki Kaisha Polysilazane polycondensé et son procédé de préparation
US5196556A (en) * 1988-12-03 1993-03-23 Hoechst Aktiengesellschaft Polysubstituted chlorine-containing silazane polymers, process for their preparation, ceramic materials containing silicon nitride which can be manufactured therefrom, and their manufacture
US5268496A (en) * 1992-05-27 1993-12-07 Wacker-Chemie Gmbh Process for the preparation of polysilazanes
US5948316A (en) * 1995-01-20 1999-09-07 The United States Of America As Represented By The Secretary Of The Navy Liquid crystal composition and alignment layer
US6329487B1 (en) * 1999-11-12 2001-12-11 Kion Corporation Silazane and/or polysilazane compounds and methods of making
US20100210808A1 (en) * 2009-02-16 2010-08-19 Eun Chang Jeong Method for preparing polysilazane solution with reducing ammonia substitution of si-h bond
US20140341794A1 (en) * 2012-08-10 2014-11-20 Evonik Industries Ag Process for the coupled preparation of polysilazanes and trisilylamine
US20150307354A1 (en) * 2013-05-27 2015-10-29 Evonik Industries Ag Process for the coupled preparation of trisilylamine and polysilazanes having a molar mass of up to 500 g/mol

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11273432B2 (en) 2018-05-31 2022-03-15 Arizona Board Of Regents On Behalf Of Arizona State University Beta-diketiminate manganese catalysts for hydrosilylation, hydroboration, and dehydrogenative pnictogen-silicon and pnictogen-boron bond formation
US20210317272A1 (en) * 2018-07-24 2021-10-14 A/G Innovation Partners, Ltd. A system and method for a semi-continuous process for producing polysilazanes
US12012486B2 (en) * 2018-07-24 2024-06-18 A/G Innovation Partners, Ltd. System and method for a semi-continuous process for producing polysilazanes

Similar Documents

Publication Publication Date Title
US6787625B2 (en) Polyorganosilsesquioxane and process for preparing the same
CN108892775B (zh) D/t型环状支化硅氧烷的混合物及其转化产物
CN1164597C (zh) 氨基官能硅氧烷的制备
FI127433B (fi) Menetelmä siloksaanimonomeerien syntetisoimiseksi sekä näiden käyttö
KR100751655B1 (ko) 신규한 실라잔 및 폴리실라잔과 그 제조방법
CN102741326B (zh) 具有伯胺官能团的有机改性硅氧烷和具有季铵官能团的有机改性硅氧烷及二者的制备方法
JP3474007B2 (ja) 有機官能基含有オルガノポリシロキサンの製造方法
CN106432738B (zh) 一种含氟聚硅氮烷及其制备方法
CN108070086A (zh) D/t型环状枝化的硅氧烷的混合物及其转化产物
WO2007034987A1 (fr) Méthode de synthèse d'un alkoxysilane contenant une structure de type cétimine
KR100909215B1 (ko) 실리콘-수소 결합의 암모니아 치환을 감소시킨 폴리실라잔 및 폴리실라잔 용액의 제조방법
WO2018164709A1 (fr) Procédé de préparation de polysilazanes
KR100854254B1 (ko) 규소 함유 공중합체, 이의 제조방법 및 이를 포함하는 필름
JPH11246662A (ja) ポリオルガノシロキサンの製造方法
KR101055597B1 (ko) 유기관능성 실록산 혼합물
KR101780102B1 (ko) 아미노알킬 알콕시실란과 아크릴산 무수물의 반응에 의한 (메트)아크릴아미도-관능성 실란의 제조 방법
JP2011516676A (ja) ケイ素−ホウ素−炭素−窒素セラミック及び前駆物質化合物、ＲｎＨａｌ３−ｎＳｉ−Ｘ−ＢＲｍＨａｌ２−ｍの塩フリー重合方法
JPH0822925B2 (ja) 有機シラザン重合体およびそれらからのセラミツク物質の製造
JP5087754B2 (ja) 環状ポリオルガノシロキサンシラザンおよびその製造方法
KR100481911B1 (ko) 폴리오르가노실세스퀴옥산 및 그의 제조방법
EP0392509A1 (fr) 3-(2-Oxo-1-pyrrolidinyl)-propylsilanes et procédé de préparation des composés silanes
JP3296441B2 (ja) ケイ素系ハイブリッド材料
KR100444379B1 (ko) 폴리오르가노실세스퀴옥산 및 그의 제조방법
CN1403463A (zh) 一种α－氯代烃基硅氧烷的制备方法
JPH05105762A (ja) ケイ素系ハイブリツド材料

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17899895

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17899895

Country of ref document: EP

Kind code of ref document: A1