Anti-pollutant compositions for vapor space applications

Abstract

A polymerization inhibitor composition is provided. The polymerization inhibitor composition includes at least a first inhibitor compound including a hydroxylamine, a second inhibitor including a phenylenediamine, and a third inhibitor including a benzoquinone or naphthoquinone. Methods of inhibiting polymerization of a monomer using the disclosed composition are also provided. The method of inhibiting polymerization of a monomer includes adding the disclosed composition to the monomer. In some cases, the monomer is an ethylenically unsaturated monomer. Such ethylenically unsaturated monomers include, but are not limited to, vinyl acetate, acrylonitrile, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof. Methods of preparing the disclosed polymerization inhibitors and compositions are also provided.

Description

[Technical field]

[0001] The present disclosure relates generally to compositions comprising a blend of polymerization inhibitors and methods of using the same to inhibit undesired polymerization in vapor space regions. More particularly, the present disclosure relates to compositions comprising at least one compound having stable nitroxide radicals hydroxylamines, quinones and phenylenediamines useful for inhibiting the polymerization of ethylenically unsaturated monomers. [Background technology]

[0002] Ethylenically unsaturated monomers are typically produced in a three-stage process consisting of (i) reaction, (ii) recovery, and (iii) purification. A distillation operation at high temperature is often included in the recovery and purification stages. The process involves fractional distillation of the monomer. In the top section of the distillation column, the purified monomer vapor condenses into a liquid pool before being transferred to a storage facility. A portion of the condensed monomer stream descends the column. In the vapor space region of the distillation column, the liquid monomer pool has a high potential for generating spontaneous or peroxide-initiated free radicals. Current polymer inhibitor technology is limited to the liquid stream in the bottom section of the process column. Because the inhibitors are typically non-volatile, they are trapped in the bottom section of the distillation column and the inhibitors do not reach the highly reactive monomer pool in the vapor space section. With conventional inhibitors, the pooled monomer is not treated to mitigate undesired polymerization. This causes the reactive monomer to undesirably polymerize by radical polymerization, especially at high temperatures or when in contact with rust on the surfaces of the process equipment, such as the distillation column trays.

[0003] This polymerization is especially severe in the presence of polymerization initiators such as organic peroxides, which are ubiquitous in the recycle stream that has previously been exposed to atmospheric oxygen. Conventional polymerization inhibitors such as 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (HTEMPO) and 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl (OTEMPO) are generally effective. Premature polymerization of these monomers is generally controlled by injecting polymerization inhibitors directly into the liquid hydrocarbon stream to reduce premature polymerization of the monomers. However, these polymerization inhibitors (HTEMPO and OTEMPO) are not volatile. In the field, the process is accelerated when liquid monomer condenses on the trays, far above the bulk liquid that is treated with the non-volatile polymerization inhibitor. This problem becomes severe when the trays are rusted or have residual polymer in the cracks and corners. Equally important, existing polymer in equipment cracks, dead legs and stagnant pools of liquid monomer causes rapid accumulation of contaminating polymer due to the Noris-Stromsdorff effect. Due to accelerated polymerization, the growing polymer contamination can cause mechanical damage and potential release of large amounts of heat, resulting in fires or explosions. Complete suppression of tray corrosion or complete removal of polymer from hard-to-reach locations in the purification column means that undesired polymerization in the vapor space is difficult to prevent. In this regard, there is an urgent need for polymerization inhibitors that are effective in the vapor space section of the distillation column. Summary of the Invention

[0004] A composition for inhibiting monomer polymerization is provided, the composition comprising a first inhibitor compound comprising a hydroxylamine, a second inhibitor compound comprising a phenylenediamine, and a third inhibitor compound comprising a benzoquinone or naphthoquinone.

[0005] In some embodiments, the first inhibitor compound has the following formula (II): [ka] wherein R2 is C1 to C 22Alkyl, C1-C 22 Alkenyl, C1-C 22 Alkynyl, C1-C 22 Cycloalkyl, aryl, -C1~C 22 Alkylene, -C(O)(C1-C 22 Alkyl), -C(O)(C1-C 22 alkenyl), -C(O)(C1-C 22 alkynyl), -C(O)(C1-C 22 -C(O)(cycloalkyl), -C(O)(aryl), or -C(O)(C1-C 22 alkylene), where alkyl, alkylene, cycloalkyl, and aryl are C1 to C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 It is optionally substituted with one or more of alkynyl, or aryl.

[0006] In some embodiments, R2 is -C(O)(C1-C 22 Alkyl), -C(O)(C1-C 22 alkenyl), -C(O)(C1-C 22 alkynyl), -C(O)(C1-C 22 -C(O)(cycloalkyl), -C(O)(aryl), or -C(O)(C1-C 22 alkylene), where alkyl, alkylene, cycloalkyl, and aryl are C1 to C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 It is optionally substituted with one or more of alkynyl, or aryl.

[0007] In some embodiments, the first inhibitor is 2,2,6,6-tetramethylpiperine-1,4-diol; 4-methoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-ethoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-propoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-butoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-pentoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-hexyloxy-2,2,6,6-tetramethylpiperidin-1-ol. 4-Heptyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Octyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Nonyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Decyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Undecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Dodecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Tridecyloxy-2,2,6,6-tetramethylpiperidine -1-ol;4-Tetradecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Pentadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Hexadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Heptadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Octadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Nodecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Decyloxy-2,2,6 ,6-Tetramethylpiperidin-1-ol;4-Eicosyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Henicosyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Docosyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-(Phenoxy)-2,2,6,6-tetramethylpiperidin-1-ol;4-(Benzyloxy)-2,2,6,6-tetramethylpiperidin-1-ol;2,2,6,6-Tetramethyl-4-(naphthalen-2-yloxy)piperidin-1-ol;and any combination thereof;

[0008] In some embodiments, the first inhibitor has the following formula (IIa): [ka] wherein R4 is H, C1-C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 Alkynyl, C1-C 22 Cycloalkyl, aryl, -C1~C 22 Alkylene, -C(O)(C1-C 22 Alkyl), -C(O)(C1-C 22 alkenyl), -C(O)(C1-C 22 alkynyl), -C(O)(C1-C 22 -C(O)(cycloalkyl), -C(O)(aryl), or -C(O)(C1-C 22 alkylene), where alkyl, alkylene, cycloalkyl, and aryl are C1 to C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 It is optionally substituted with one or more of alkynyl, or aryl.

[0009] In some embodiments, the first inhibitor is 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl acetate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl propanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl butyrate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl pentanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl hexanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl heptanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl octanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl nonanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl ... 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl undecanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl dodecanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl 2-ethylhexanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl stearate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl benzoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl palmitoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl behenoate, 1-hydroxy-2,2,6,6-tetramethylpiperidin-4-yl 4-tert-butylbenzoate, or any combination thereof.

[0010] In some embodiments, the second inhibitor compound has the following formula (IV) or formula (V): [ka] In the formula, X1 and X2 are independently C1 to C 22 Alkyl or aryl, where alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0011] In some embodiments, the second inhibitor is selected from the group consisting of 1,2-phenylenediamine, 1,4-phenylenediamine, N,N'-di-methyl-p-phenylenediamine, N,N'-di-sec-butyl-1,4-phenylenediamine, N,N'-di-1,4-dimethylpentyl-1,4-phenylenediamine, N,N'-di-ethyl-1,4-phenylenediamine, N-tert-butyl-N'-phenyl-1,4-phenylenediamine, N,N'-di-phenyl-1,4-phenylenediamine, and any combination thereof.

[0012] In some embodiments, the third inhibitor compound has the following formula (VI) or formula (VII): [ka] wherein X3, X4, X5, and X6 are independently H, C1-C 22 Alkyl or aryl, where alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0013] In some embodiments, the third inhibitor compound has the following formula (VII) or formula (VIII): [ka] In the formula, X5 and X6 are independently H, C1-C 22 Alkyl and aryl, and alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0014] In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 80% by weight, and the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 50% by weight.

[0015] In some embodiments, the composition further comprises an organic solvent.

[0016] In some embodiments, the composition further comprises an ethylenically unsaturated monomer selected from the group consisting of vinyl acetate, acrylonitrile, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, acrylic acid, methacrylic acid, and any combination thereof.

[0017] A method for inhibiting polymerization of a monomer is provided, the method comprising adding to the monomer a composition described herein.

[0018] In some embodiments, the monomer is provided in solution.

[0019] In some embodiments, the solution further comprises one or more additional components selected from an acid, an organic solvent, and water.

[0020] In some embodiments, the monomer is an ethylenically unsaturated monomer.

[0021] In some embodiments, the composition is added to the monomer such that the concentration of the first inhibitor compound is from about 0.1 ppm to about 10,000 ppm.

[0022] In some embodiments, the composition is added to the monomer such that the concentration of the second inhibitor compound is from about 0.1 ppm to about 10,000 ppm.

[0023] In some embodiments, the monomer is selected from the group consisting of vinyl acetate, acrylonitrile, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, acrylic acid, methacrylic acid, and any combination thereof.

[0024] The foregoing has outlined rather broadly the features and technical advantages of the present disclosure in order that the detailed description of the embodiments that follow may be better understood. Additional features and advantages of the present disclosure will be described hereinafter which form the subject of the claims of this application. It should be appreciated by those skilled in the art that the concept and specific aspects disclosed may be readily utilized as a basis for modifying or designing other aspects for carrying out the same purposes of the present disclosure. It should also be appreciated by those skilled in the art that such equivalent aspects do not depart from the spirit and scope of the present disclosure as set forth in the appended claims. [Brief description of the drawings]

[0025] A detailed description of the invention is set forth herein below with specific reference to the drawings.

[0026] [Figure 1] FIG. 1 shows kinetic curves illustrating the effectiveness of a combination of 4-acetate TEMPO and N,N'-di-sec-butyl-1,4-phenylenediamine as a polymerization inhibitor compared to the performance of a 25 ppm dosage of a composition of N,N'-di-sec-butyl-1,4-phenylenediamine and 2,6-di-tert-butylphenol for styrene polymerization at about 135° C. using a static method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Various aspects of the present disclosure are described below. The relationship and function of the various elements of the aspects can be better understood by referring to the following detailed description. However, it should be understood that the aspects are not limited to those explicitly described herein, and in some cases, details that are not necessary for understanding the aspects disclosed herein, such as conventional synthesis and / or compounding, may be omitted.

[0028] The present disclosure relates to compositions comprising a blend of polymerization inhibitors and methods of using the same to inhibit the polymerization of ethylenically unsaturated monomers. The polymerization inhibitor compositions of the present disclosure include a hydroxylamine, a phenylenediamine, and a benzoquinone or naphthoquinone.

[0029] In the presence of polymerizable monomers, a "polymerization inhibitor" inhibits the formation of polymer from those monomers during an induction period. After the induction period has elapsed, formation of polymer occurs at substantially the same rate as it would form in the absence of the polymerization inhibitor.

[0030] Polymerization inhibitors and retarders may generally be considered "polymerization inhibitors," that is compounds capable of inhibiting or reducing the formation of polymer from one or more radically polymerizable compounds.

[0031] The term "fouling" refers to the formation of polymers, prepolymers, oligomers, and / or other materials that become insoluble in the stream and / or precipitate from the stream and deposit on the equipment under the conditions under which the equipment is operated. Similarly, the inhibitors, retarders, and amine stabilizer components and compositions of the present disclosure inhibit or reduce such formation and can therefore be referred to as "anti-fouling."

[0032] Disclosed Compositions The present disclosure relates to a composition for inhibiting monomer polymerization, comprising a first inhibitor compound comprising a hydroxylamine, a second inhibitor compound comprising a phenylenediamine, and a third inhibitor compound comprising a benzoquinone or naphthoquinone. In some embodiments, the composition is for inhibiting monomer polymerization, and the monomer is an ethylenically unsaturated monomer. For example, the composition of the present disclosure is useful for inhibiting the polymerization of ethylenically unsaturated monomers, including but not limited to vinyl acetate, acrylonitrile, acrylates, methacrylates, 1,3-butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof.

[0033] In some embodiments, the first inhibitor compound has the following formula (II): [ka] wherein R2 is H, C1-C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 Alkynyl, C1-C 22 Cycloalkyl, aryl, -C1~C 22 Alkylene, -C(O)(C1-C 22 Alkyl), -C(O)(C1-C 22 alkenyl), -C(O)(C1-C 22 alkynyl), -C(O)(C1-C 22 -C(O)(cycloalkyl), -C(O)(aryl), and -C(O)(C1-C 22 alkylene), where alkyl, alkylene, cycloalkyl, and aryl are C1 to C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 It is optionally substituted with one or more of alkynyl, or aryl.

[0034] The term "aryl" refers to monocyclic, bicyclic (fused), and tricyclic (fused or spiro) hydrocarbon ring systems having a total of 5 to 14 ring carbon atoms, in which at least one ring in the system is aromatic and each ring in the system contains 3 to 7 ring carbon atoms. The term "aryl" can be used interchangeably with the term "aryl ring."

[0035] In certain embodiments, R2 is -C(O)(C1-C 22 Alkyl), -C(O)(C1-C 22 alkenyl), -C(O)(C1-C 22 alkynyl), -C(O)(C1-C 22 -C(O)(cycloalkyl), -C(O)(aryl), and -C(O)(C1-C 22 alkylene), where alkyl, alkylene, cycloalkyl, and aryl are C1 to C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22It is optionally substituted with one or more of alkynyl, or aryl.

[0036] In some embodiments, R2 is H. In some embodiments, R2 is C1-C 22 In some embodiments, R2 is C1-C 22 In some embodiments, R2 is C1-C 22 In some embodiments, R2 is C1-C 22 Cycloalkyl, cycloalkyl is C1-C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 In some embodiments, R2 is aryl, and aryl is optionally substituted with one or more of C1-C6 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 In some embodiments, R2 is optionally substituted with one or more of -C1 to -C6. 22 C1-C alkylene, optionally substituted with aryl. 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 In some embodiments, R2 is optionally substituted with one or more of -C(O)(C1-C 22 In some embodiments, R2 is -C(O)(C1-C 12 In some embodiments, R2 is -C(O)(C1-C6 alkyl). In some embodiments, R2 is -C(O)(methyl). In some embodiments, R2 is -C(O)(ethyl). In some embodiments, R2 is -C(O)(propyl). In some embodiments, R2 is -C(O)(butyl). In some embodiments, R2 is -C(O)(C1-C6 alkyl ... 22 In some embodiments, R2 is -C(O)(C1-C alkenyl). 22 In some embodiments, R2 is -C(O)(C1-C 22Cycloalkyl), where cycloalkyl is C1-C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 In some embodiments, R2 is -C(O)(aryl), and aryl is C1-C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 In some embodiments, R2 is optionally substituted with one or more of -C(O)(C1-C 22 alkylene), wherein the alkylene is optionally substituted with aryl, 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 It is optionally substituted with one or more of alkynyl, or aryl.

[0037] In some embodiments, the compound of formula (II) is selected from the group consisting of 2,2,6,6-tetramethylpiperine-1,4-diol; 4-methoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-ethoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-propoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-butoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-pentoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-hexyloxy-2,2,6,6-tetramethylpiperidin-1-ol. 4-Heptyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Octyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Nonyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Decyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Undecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Dodecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Tridecyloxy-2,2,6,6-tetramethylpiperidine- 1-ol;4-Tetradecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Pentadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Hexadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Heptadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Octadecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Nodecyloxy-2,2,6,6-tetramethylpiperidin-1-ol;4-Decyloxy-2,2,6,6- 4-hexamethyloxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-hexamethyloxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-docomethyloxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-(phenoxy)-2,2,6,6-tetramethylpiperidin-1-ol; 4-(benzyloxy)-2,2,6,6-tetramethylpiperidin-1-ol; or 2,2,6,6-tetramethyl-4-(naphthalen-2-yloxy)piperidin-1-ol.

[0038] In certain embodiments, the compositions of the present disclosure include compounds of formula (I) and (II), respectively, in which R1 and R2 are the same. For example, in some embodiments, the compositions of the present disclosure include compounds in which R1 and R2 are each independently -C(O)(C1-C 22 In certain embodiments, the compositions of the present disclosure include a first inhibitor compound and a second inhibitor compound of formula (I) and (II), respectively, in which R and R are different.

[0039] In some embodiments, the second inhibitor compound having a hydroxylamine is selected from the group consisting of: [ka] is selected from. In some embodiments, the second inhibitor compound having a hydroxylamine is [ka] 4-Acetoxy-2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the second inhibitor compound having a hydroxylamine is [ka] 4-propionoxy-2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the second inhibitor compound having a hydroxylamine is [ka] 4-Butyloxy-2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the second inhibitor compound having a hydroxylamine is [ka] 4-valerooxy-2,2,6,6-tetramethylpiperidin-1-ol.

[0040] The presently disclosed compounds of formula (II) having hydroxylamines have advantages over the corresponding nitroxides (compounds of formula (I)), such as the ability to provide additional polymerization inhibition, as described more fully below. A common synthetic route to prepare hydroxylamines of nitroxides is the reduction of the corresponding nitroxide with a reducing agent, such as: [ka]

[0041] The hydroxylamines of nitroxides have the potential to provide additional polymerization inhibition in the presence of carbon- and oxygen-centered radical initiators, as compared to the corresponding nitroxides, as illustrated below: [ka]

[0042] Nitroxide hydroxylamines are excellent hydrogen donors due to the weak NO-H bond in the compounds and are therefore efficient antioxidants. As antioxidants, nitroxide hydroxylamines react readily with oxygen-centered radicals, such as peroxide radicals, and are converted to their corresponding nitroxides. Nitroxides are generally known as the most effective inhibitors due to their excellent inhibition capabilities by scavenging carbon-centered free radicals at a rate that is mostly diffusion-controlled. This rate is several orders of magnitude faster than phenolic compounds. However, their kinetic advantage is not always favorable. For example, they may lose their advantage when oxygen-centered radicals are present as the predominant free radical. Another problem associated with nitroxides is their consumption through uninhibited and undesired reactions with process stream components or other inhibitor additives. As a result, high nitroxide inhibitor dosages are often required for a given inhibition efficacy, making their use economically unattractive or even infeasible.

[0043] Essentially, each hydroxylamine of a nitroxide is equivalent to one hydrogen donor and one nitroxide polymerization inhibitor when both oxygen- and carbon-centered radicals are present, an attractive incentive offered by the hydroxylamine of a nitroxide: one hydroxylamine of a nitroxide can scavenge one oxygen-centered radical and one carbon-centered radical, whereas the nitroxide can only scavenge carbon-centered radicals.

[0044] In some embodiments, the first inhibitor has the following formula IIa: [ka] wherein R4 is H, C1-C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 Alkynyl, C1-C 22 Cycloalkyl, aryl, -C1~C 22 Alkylene, -C(O)(C1-C 22Alkyl), -C(O)(C1-C 22 alkenyl), -C(O)(C1-C 22 alkynyl), -C(O)(C1-C 22 -C(O)(cycloalkyl), -C(O)(aryl), or -C(O)(C1-C 22 alkylene), where alkyl, alkylene, cycloalkyl, and aryl are C1 to C 22 Alkyl, C1-C 22 Alkenyl, C1-C 22 It is optionally substituted with one or more of alkynyl, or aryl.

[0045] In some embodiments, the first inhibitor has the following formula III: [ka] wherein R3 is -O· or -OH; R4 is C1-C 22 Alkyl or aryl, where alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0046] In some embodiments, R3 is -O. In some embodiments, R3 is -OH.

[0047] In some embodiments relating to formula (IIa) and (III), R4 is C1-C 22 C1-C, optionally substituted with one or more alkyl or aryl. 22 In some embodiments relating to formula (IIa) and (III), R4 is C1-C 22 In some embodiments of formula (IIa) and (III), R4 is C1-C5 alkyl, optionally substituted with one or more of alkyl or aryl. 22 In some embodiments of formula (IIa) and (III), R4 is C1-C4 alkyl, optionally substituted with one or more of alkyl or aryl. 22C1-C, optionally substituted with one or more alkyl or aryl. 10 In some embodiments relating to formula (IIa) and (III), R4 is C1-C 22 In some embodiments, R4 is a C1-C8 alkyl group, optionally substituted with one or more of alkyl or aryl. 22 In some embodiments, R4 is aryl, optionally substituted with one or more of alkyl or aryl. In some embodiments, R4 is methyl. In some embodiments, R4 is propyl. In some embodiments, R4 is butyl. In some embodiments, R4 is a C5 alkyl group. In some embodiments, R4 is a C6 alkyl group. In some embodiments, R4 is a C7 alkyl group. In some embodiments, R4 is a C8 alkyl group. In some embodiments, R9 is a C5 alkyl group. In some embodiments, R4 is a C6 alkyl group. In some embodiments, R9 is a C7 alkyl group. In some embodiments, R4 is a C8 alkyl group. In some embodiments, R9 is a C5 alkyl group. In some embodiments, R4 is a C8 alkyl group. In some embodiments, R9 is a C9 alkyl group. In some embodiments, R4 is a C10 alkyl group. In some embodiments, R4 is a C11 alkyl group. In some embodiments, R4 is a C12 alkyl group. In some embodiments, R4 is a C13 alkyl group. In some embodiments 10 In some embodiments, R is an alkyl group. 22 In some embodiments, R is an alkyl group. 21 In some embodiments, R is an alkyl group. 11 In some embodiments, R4 is a benzyl group.

[0048] Examples of compounds of formula (IIa) or (III) include 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl propanoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl butyrate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl pentanoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl pentanoate; 1-Oxyl-2,2,6,6-tetramethylpiperidin-4-ylhexanoate;1-Oxyl-2,2,6,6-tetramethylpiperidin-4-ylheptanoate;1-Oxyl-2,2,6,6-tetramethylpiperidin-4-yloctanoate;1-Oxyl-2,2,6,6-tetramethylpiperidin-4-ylnonanoate;1-Oxyl-2,2,6,6-tetramethylpiperidine 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl undecanoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl dodecanoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 2-ethylhexanoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl stearate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl benzoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl palmitoate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl behenoate; or 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl 4-tert-butylbenzoate.

[0049] In some embodiments, the compound of formula (IIa) or (III) is 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate; 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl propanoate; or 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl butyrate. In some embodiments, the compound of formula (IIa) or (III) is 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl acetate. In some embodiments, the compound of formula (IIa) or (III) is 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl propanoate. In some embodiments, the compound of formula (IIa) or (III) is 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl butyrate.

[0050] In some embodiments, the second inhibitor compound has the following formula (IV) or formula (V): [ka] In the formula, X1 and X2 are independently C1 to C 22 Alkyl or aryl, where alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0051] In some embodiments, the second inhibitor compound is a phenylenediamine of formula (IV). In some embodiments, the second inhibitor compound is a phenylenediamine of formula (V).

[0052] Examples of phenylenediamines include, but are not limited to, 1,2-phenylenediamine, 1,4-phenylenediamine, N,N'-di-methyl-p-phenylenediamine, N,N'-di-sec-butyl-1,4-phenylenediamine, N,N'-di-1,4-dimethylpentyl-1,4-phenylenediamine, N,N'-di-ethyl-1,4-phenylenediamine, N-tert-butyl-N'-phenyl-1,4-phenylenediamine, and N,N'-di-phenyl-1,4-phenylenediamine.

[0053] In some embodiments, the phenylenediamine is N,N'-di-sec-butyl-1,4-phenylenediamine, N,N'-di-1,4-dimethylpentyl-1,4-phenylenediamine, N,N'-di-ethyl-1,4-phenylenediamine, N-tert-butyl-N'-phenyl-1,4-phenylenediamine, or N,N'-di-phenyl-1,4-phenylenediamine.

[0054] In some embodiments, the phenylenediamine is N,N'-di-sec-butyl-1,4-phenylenediamine.

[0055] In some embodiments, the phenylenediamine is N,N'-di-1,4-dimethylpentyl-1,4-phenylenediamine.

[0056] In some embodiments, the phenylenediamine is N,N'-di-ethyl-1,4-phenylenediamine.

[0057] In some embodiments, the phenylenediamine is N-tert-butyl-N'-phenyl-1,4-phenylenediamine.

[0058] In some embodiments, the phenylenediamine is N,N'-di-phenyl-1,4-phenylenediamine.

[0059] In some embodiments, the third inhibitor compound has the following formula (VI) or formula (VII): [ka] wherein X3, X4, X5, and X6 are independently H, C1-C 22 Alkyl or aryl, where alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0060] In some embodiments, the third inhibitor compound is a benzoquinone of formula (VI). In some embodiments, the third inhibitor compound is a benzoquinone of formula (VII).

[0061] In some embodiments, the third inhibitor compound has the following formula (VII) or formula (VIII): [ka] In the formula, X5 and X6 are independently H, C1-C 22 Alkyl and aryl, and alkyl and aryl are C1 to C 22 It is optionally substituted with one or more alkyl or aryl.

[0062] In some embodiments, X5 and X6 are independently H or C1-C 22 It is an alkyl.

[0063] In some embodiments, X5 and X6 are independently H or C1-C 15 It is an alkyl.

[0064] In some embodiments, X5 and X6 are independently H or C1-C 10 It is an alkyl.

[0065] In some embodiments, X5 and X6 are independently H or C1-C5 alkyl.

[0066] In some embodiments, the third inhibitor compound is a naphthoquinone of formula (VII). In some embodiments, the third inhibitor compound is a naphthoquinone of formula (VIII).

[0067] In some embodiments, X, X, X, and X are independently H or C 22 In some embodiments, at least one of X3, X4, X5, and X6 is C1-C 22 In some embodiments, X3, X4, and X5 are H and X6 is C1-C 22 In some embodiments, X3, X4, and X5 are H and X6 is C1-C 10 In some embodiments, X3, X4, and X5 are H and X6 is tert-butyl.

[0068] Examples of benzoquinones include 2-tert-butyl-1,4-benzoquinone, 2-tert-butyl-5-methylbenzoquinone, 2-sec-butyl-5-methylbenzoquinone, 2-n-butyl-5-methylbenzoquinone, 2-sec-butyl-5-methylbenzoquinone, 2-isopropyl-5-methylbenzoquinone, 2,5-di-sec-butylbenzoquinone, 2,5-di-tert-butylbenzoquinone, 2,5-di-isopropylbenzoquinone, 2,6-di-sec-butyl ... c-Butyl benzoquinone, 2,6-di-tert-butyl benzoquinone, 2,6-di-iso-propyl benzoquinone, 2,6-dimethyl benzoquinone, 2,5-di-methyl benzoquinone, 2,6-di-ethyl benzoquinone, 2,5-di-ethyl benzoquinone, 2,6-di-propyl benzoquinone, 2,6-di-n-butyl benzoquinone, 2,5-di-n-butyl benzoquinone, 2,6-di-tert-butyl benzoquinone, 2,6-di-i so-propyl benzoquinone, 2-n-pentyl benzoquinone, 2,6-di-n-pentyl benzoquinone, 2,6-di-n-pentyl benzoquinone, 2-n-hexyl benzoquinone, 2,6-di-hexyl benzoquinone, 2,6-di-hexyl benzoquinone, 2-n-heptyl benzoquinone, 2,6-di-heptyl benzoquinone, 2,6-di-heptyl benzoquinone, 2-n-octyl benzoquinone, 2,6-di-octyl benzoquinone, 2,6-di-octyl benzoquinone, Examples of benzoquinone include, but are not limited to, 2-n-nonylbenzoquinone, 2,6-di-nonylbenzoquinone, 2,6-di-nonylbenzoquinone, 2-n-decylbenzoquinone, 2,6-di-decylbenzoquinone, 2,6-di-decylbenzoquinone, 2-n-undecylbenzoquinone, 2,6-di-undecylbenzoquinone, 2,6-di-undecylbenzoquinone, 2-n-dodecylbenzoquinone, 2,6-di-dodecylbenzoquinone, and 2,6-di-dodecylbenzoquinone.

[0069] In some embodiments, the benzoquinone is 2-tert-butyl-1,4-benzoquinone.

[0070] Examples of naphthoquinones include 1,4-naphthoquinone, 1,2-naphthoquinone, 1-methyl-1,4-naphthoquinone, 1-ethyl-1,4-naphthoquinone, 1-n-propyl-1,4-naphthoquinone, 1-isopropyl-1,4-naphthoquinone, 1-n-butyl-1,4-naphthoquinone, 1-sec-butyl-1,4-naphthoquinone, 1-tert-butyl-1,4 1-n-naphthoquinone, 1-methyl-1,2-naphthoquinone, 1-ethyl-1,2-naphthoquinone, 1-n-propyl-1,2-naphthoquinone, 1-isopropyl-1,2-naphthoquinone, 1-n-butyl-1,2-naphthoquinone, 1-sec-butyl-1,2-naphthoquinone, and 1-tert-butyl-1,2-naphthoquinone.

[0071] In some embodiments, the composition consists essentially of a first inhibitor compound, a second inhibitor compound, and a third inhibitor compound. In other embodiments, the composition consists of an organic solvent, a first inhibitor, a second inhibitor, and a third inhibitor compound. In some embodiments, the composition does not include 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl.

[0072] In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 80% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 70% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 60% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 50% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 40% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 30% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 20% by weight. In some embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 10% by weight.

[0073] For example, in certain embodiments, the first inhibitor compound is present in the composition at a concentration of about 0.01%, about 0.1%, about 1%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80% by weight.

[0074] In some embodiments, the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 50% by weight. In some embodiments, the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 40% by weight. In some embodiments, the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 30% by weight. In some embodiments, the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 20% by weight. In some embodiments, the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 10% by weight.

[0075] For example, in certain embodiments, the second inhibitor compound is present in the composition at a concentration of about 0.01%, about 0.1%, about 1%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, or about 50% by weight.

[0076] In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 80% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 70% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 60% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 50% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 40% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 30% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 20% by weight. In some embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01% to about 10% by weight.

[0077] For example, in certain embodiments, the third inhibitor compound is present in the composition at a concentration of about 0.01%, about 0.1%, about 1%, about 5%, about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, or about 80% by weight.

[0078] In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 100:1 to about 1:100. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 90:1 to about 1:90. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 80:1 to about 1:80. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 70:1 to about 1:70. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 60:1 to about 1:60. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 50:1 to about 1:50. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 40:1 to about 1:40. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 30:1 to about 1:30. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 20:1 to about 1:20. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 10:1 to about 1:10. In some embodiments, the molar ratio of the first inhibitor compound to the second inhibitor compound is about 1:1.

[0079] In some embodiments, the composition further comprises: 2,2,6,6-tetramethylpiperidine-1-oxyl; 2,2,6,6-tetramethylpiperidin-1-ol; 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl; 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl; 4-oxo-2,2,6,6-tetramethylpiperidin-1-ol; 4-acetoxy The composition further comprises one or more additional compounds selected from the group consisting of bis-2,2,6,6-tetramethylpiperidine-1-oxyl; 4-acetoxy-2,2,6,6-tetramethylpiperidin-1-ol; 4-propionoxy-2,2,6,6-tetramethylpiperidin-1-oxyl; 4-propionoxy-2,2,6,6-tetramethylpiperidin-1-ol; and bis((2,2,6,6-tetramethylpiperidin-1-oxyl)-4-yl)oxalate. In some embodiments, the composition further comprises 2,2,6,6-tetramethylpiperidine-1-oxyl. In some embodiments, the composition further comprises 2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the composition further comprises 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl. In some embodiments, the composition further comprises 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the composition further comprises 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl. In some embodiments, the composition further comprises 4-oxo-2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the composition further comprises 4-acetoxy-2,2,6,6-tetramethylpiperidin-1-oxyl. In some embodiments, the composition further comprises 4-acetoxy-2,2,6,6-tetramethylpiperidin-1-ol. In some embodiments, the composition further comprises 4-propionoxy-2,2,6,6-tetramethylpiperidin-1-oxyl. In some embodiments, the composition further comprises 4-propionoxy-2,2,6,6-tetramethylpiperidin-1-ol.In some embodiments, the composition also includes bis((2,2,6,6-tetramethylpiperidine-1-oxyl)-4-yl) oxalate.

[0080] The composition may optionally include one or more organic solvents. Those skilled in the art will understand that there are many organic solvents that are compatible with the compositions of the present disclosure. For example, in some embodiments, the one or more organic solvents are selected from vinyl acetate, dimethyl phthalate, dimethylformamide, toluene, xylene, highly aromatic naphtha, acetonitrile, ethyl acetate, acetone, dichloromethane, tetrahydrofuran, hexane, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and combinations thereof. In certain embodiments, the composition also includes vinyl acetate. In certain embodiments, the composition also includes dimethyl phthalate. In certain embodiments, the composition also includes dimethylformamide. In certain embodiments, the composition also includes toluene. In certain embodiments, the composition also includes xylene. In certain embodiments, the composition also includes highly aromatic naphtha. In certain embodiments, the composition also includes acetonitrile.

[0081] In some embodiments, the composition further comprises one or more ethylenically unsaturated monomers. Those skilled in the art will appreciate that there are many ethylenically unsaturated monomers that are compatible with the compositions of the present disclosure. For example, in some embodiments, the one or more ethylenically unsaturated monomers are selected from vinyl acetate, acrylonitrile, acrylate esters, methacrylate esters, 1,3-butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof. In certain embodiments, the composition also comprises vinyl acetate. In certain embodiments, the composition also comprises acrylonitrile. In certain embodiments, the composition also comprises an acrylate. In certain embodiments, the composition also comprises a methacrylate. In certain embodiments, the composition also comprises 1,3-butadiene. In certain embodiments, the composition also comprises styrene. In certain embodiments, the composition also comprises isoprene. In certain embodiments, the composition also comprises acrylic acid and (meth)acrylic acid.

[0082] Methods of Using the Disclosed Compositions The present disclosure further relates to a method of inhibiting polymerization of a monomer comprising adding a composition of the present disclosure to the monomer, hi some aspects, an effective amount of a composition of the present disclosure is added to the monomer, where an effective amount is any amount sufficient to inhibit polymerization of the monomer.

[0083] In some aspects, the monomer is an ethylenically unsaturated monomer. In some aspects, the monomer is an ethylenically unsaturated monomer selected from vinyl acetate, acrylonitrile, acrylate esters, methacrylate esters, 1,3-butadiene, styrene, isoprene, (meth)acrylic acid, and combinations thereof are disclosed. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of vinyl acetate. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of acrylonitrile. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of acrylates. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of methacrylates. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of 1,3-butadiene. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of styrene. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of isoprene. In some aspects, the methods disclosed herein are useful for inhibiting the polymerization of (meth)acrylic acid.

[0084] The compositions of the present disclosure can be added to the fluid manually or automatically. The compositions can also be added continuously and / or intermittently. Automatic addition can be accomplished by use of a chemical injection pump. The chemical injection pump can be programmed to add a specific amount of the polymerization inhibitor composition or any of its components to the fluid at specific time intervals. In another aspect, the chemical injection pump can be manually controlled to add a specific amount of the polymerization inhibitor composition or any of its components to the fluid. Adding the polymerization inhibitor composition of the present disclosure to a monomer inhibits the polymerization of the monomer.

[0085] In some embodiments, the monomers are provided as a neat solution, while in other embodiments, the monomers are provided in a solution, hereinafter referred to as a "monomer solution."

[0086] In some embodiments, the monomer solution further comprises one or more additional components selected from an acid, an organic solvent, water, and combinations thereof. For example, in some embodiments, the monomer solution comprises one or more organic solvents selected from vinyl acetate, dimethyl phthalate, dimethylformamide, toluene, xylene, highly aromatic naphtha, acetonitrile, ethyl acetate, acetone, dichloromethane, tetrahydrofuran, hexane, dimethyl sulfoxide, N-methyl-2-pyrrolidone, and combinations thereof.

[0087] In some embodiments, the composition is added to the monomer such that the concentration of the first inhibitor compound is about 0.1 ppm to about 10,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the first inhibitor compound is about 0.1 ppm to about 5,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the first inhibitor compound is about 0.1 ppm to about 1,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the first inhibitor compound is about 0.1 ppm to about 500 ppm.

[0088] In some embodiments, the composition is added to the monomer such that the concentration of the second inhibitor compound is about 0.1 ppm to about 10,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the second inhibitor compound is about 0.1 ppm to about 5,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the second inhibitor compound is about 0.1 ppm to about 1,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the second inhibitor compound is about 0.1 ppm to about 500 ppm.

[0089] In some embodiments, the composition is added to the monomer such that the concentration of the third inhibitor compound is about 0.1 ppm to about 10,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the third inhibitor compound is about 0.1 ppm to about 5,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the third inhibitor compound is about 0.1 ppm to about 1,000 ppm. In some embodiments, the composition is added to the monomer such that the concentration of the third inhibitor compound is about 0.1 ppm to about 500 ppm.

[0090] The disclosed method is useful for inhibiting premature polymerization of monomers during manufacturing processes, particularly during processes conducted under acidic conditions. For example, the disclosed method is useful for preventing polymerization of acrylates, which may include, but are not limited to, acrylonitrile, acrylic acid, methyl methacrylic acid and its esters, and vinyl acetate.

[0091] The methods of the present disclosure are further useful in preventing the premature polymerization of styrene during the manufacturing and purification processes.

[0092] The disclosed method is also useful in butadiene extraction processes. This utility stems from the balanced partition coefficient between the polar organic phase and the organic phase.

[0093] In some embodiments, the compositions disclosed herein are used in the distillation purification of olefins. For example, the compositions can be added to a process stream prior to entering a distillation unit, or the compositions can be added to a process stream during a distillation unit. EXAMPLES

[0094] Example 1: Polymerization inhibition by N,N-di-sec-butylphenylenediamine (PDA) The ability of the disclosed compositions to inhibit the polymerization of polystyrene was evaluated by the following protocol. Styrene was used as a reactive monomer for polymerization kinetics studies and screening of proposed polymerization inhibition products. To prevent polymerization during storage and shipping, styrene was stabilized with tert-butylcatechol (TBC). For each experiment, the stabilizer was removed and freshly washed styrene was used immediately. Styrene was used as a reactive monomer for polymerization kinetics studies and screening of proposed polymerization inhibition products. To prevent polymerization during storage and shipping, styrene was stabilized with TBC. For each experiment, the stabilizer was removed and freshly washed styrene was used immediately.

[0095] As a precaution, styrene that was washed and stored overnight had to be discarded as there was significant polymerization during storage, even under refrigerated conditions below 0. Alumina was used to remove the TBC using a chromatography column. The alumina column was prepared on the day of the scheduled set of experiments.

[0096] A 500 mL round bottom flask was charged with approximately 400 ppm N,N-di-sec-butylphenylenediamine, approximately 300 mL of solvent-free styrene treated with the prototype PDA. A thermocouple was inserted directly into the reaction solution and the reaction temperature of the solution was set at 115 °C. To prevent loss of reaction solution due to evaporation, the flask was equipped with a reflux apparatus before being placed on a heating block. A stream of nitrogen was passed through the reaction solution through a separate port while stirring vigorously during the course of the kinetic study. The time when the solution temperature reached 115 °C was designated as the start of the study, i.e., time 0. A sample of the reaction solution was taken from the reactor, after which the solution was immediately diluted with toluene. The polystyrene concentration in the diluted solution was analyzed using a proprietary procedure. From that point on, samples were taken every 20 minutes and the reaction solution was similarly diluted and analyzed for polystyrene concentration.

[0097] Example 2: Polymerization inhibition with 4-acetoxyTEMPOH

[0098] The polymerization reactor was charged with 300 mL of freshly washed styrene and treated with 400 ppm of 4-acetoxyTEMPOH. Kinetic studies were performed as described in Example 1.

[0099] Example 3: Polymerization inhibition with 2-tert-butylbenzoquinone

[0100] Using the procedure of the above example, the polymerization inhibition performance of 400 ppm of 2-tert-butylbenzoquinone was carried out.

[0101] Example 4: Polymerization inhibition by a synergistic composition of 2-tert-butylbenzoquinone, 4-acetoxyTEMPOH and PDA

[0102] A 300 mL freshly prepared solution of styrene was treated with 52 ppm TBBQ, 174 ppm PDA and 174 ppm 4-acetoxyTEMPOH. The solution was transferred to a polymerization reactor and then a kinetic study was carried out using the procedure of the previous example.

[0103] The samples tested and the results of the assay are shown in Figure 1 and summarized in Table 1 below. [Table 1]

[0104] All of the compositions and methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. The present invention can be embodied in many different forms, and certain preferred embodiments of the present invention are described in detail herein. The present disclosure is an exemplification of the principles of the present invention, and is not intended to limit the invention to the specific embodiments exemplified. In addition, unless expressly stated otherwise, the term "a" is intended to include "at least one" or "one or more." For example, "a compound" is intended to include "at least one a compound" or "one or more compounds."

[0105] Any ranges expressed in either absolute or approximate terms are intended to encompass both, and any definitions used herein are intended to be illustrative, not limiting. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Moreover, all ranges disclosed herein should be understood to encompass any and all subranges subsumed therein, including all fractional and whole values.

[0106] Any composition disclosed herein can comprise, consist of, or consist essentially of any element, component, and / or ingredient disclosed herein, or any combination of two or more of the elements, components, or ingredients disclosed herein.

[0107] Any method disclosed herein may comprise, consist of, or consist essentially of any method steps disclosed herein, or any combination of two or more of the method steps disclosed herein.

[0108] The transitional phrase "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements, components, ingredients, and / or method steps.

[0109] The transitional phrase "consisting of" excludes any element, component, ingredient, and / or method step not specified in the claim.

[0110] The transitional phrase "consisting essentially of" limits the scope of the claim to certain elements, components, ingredients, and / or steps, and those that do not materially affect the basic and novel characteristics of the claimed invention.

[0111] As used herein, the term "about" refers to a cited value that is within error resulting from the standard deviation found in their respective testing measurements; where such error cannot be determined, "about" may refer, for example, to within 5% of the cited value.

[0112] Moreover, the present invention encompasses all possible combinations of any or all of the various aspects described herein. It should also be understood that various changes and modifications to the preferred embodiments of the invention described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present invention and without diminishing its intended advantages. Accordingly, such changes and modifications are intended to be covered by the appended claims.

Claims

1. A composition for inhibiting monomer polymerization, wherein the composition is A first inhibitor compound containing hydroxylamine, A second inhibitory compound containing phenylenediamine, A composition comprising a third inhibitor compound containing benzoquinone or naphthoquinone.

2. The first inhibitor compound is given by the following formula (II): 【Chemistry 1】 which is such that, in the formula, R ２ is C １ to C ２２ alkyl, C １ to C ２２ alkenyl, C １ to C ２２ alkynyl, C １ to C ２２ cycloalkyl, aryl, -C １ to C ２２ alkylene, -C(O)(C １ to C ２２ alkyl), -C(O)(C １ to C ２２ alkenyl), -C(O)(C １ to C ２２ alkynyl), -C(O)(C １ to C ２２ cycloalkyl), -C(O)(aryl), or -C(O)(C １ to C ２２ alkylene), and the alkyl, the alkylene, the cycloalkyl, and the aryl are each optionally substituted with one or more of C １ to C ２２ alkyl, C １ to C ２２ alkenyl, C １ to C ２２ alkynyl, or aryl, the composition according to claim 1.

3. R ２ However, -C(O)(C １ ~C ２２ Alkyl), -C(O)(C １ ~C ２２ Alkenyl), -C(O)(C １ ~C ２２ Alkinyl), -C(O)(C １ ~C ２２ Cycloalkyl), -C(O)(aryl), or -C(O)(C １ ~C ２２ (Alkylene), and the alkyl, the alkylene, the cycloalkyl, and the aryl are C １ ~C ２２ Alkyl, C １ ~C ２２ Alkenil, C １ ~C ２２ The composition according to claim 1 or 2, wherein it is optionally substituted with one or more alkynyls or aryls.

4. The first inhibitor is 2,2,6,6-tetramethylpiperin-1,4-diol; 4-methoxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Ethoxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-propoxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Butoxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Pentoxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Hexyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Heptyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Octyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-nonyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-decyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Undecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-dodecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Tridecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-tetradecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Pentadecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Hexadecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-heptadecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Octadecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Nodecyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-decyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Icosyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-Henicosyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-docosyloxy-2,2,6,6-tetramethylpiperidine-1-ol; 4-(phenoxy)-2,2,6,6-tetramethylpiperidine-1-ol; 4-(benzyloxy)-2,2,6,6-tetramethylpiperidine-1-ol; The composition according to claim 1 or 2, selected from the group consisting of 2,2,6,6-tetramethyl-4-(naphthalene-2-yloxy)piperidine-1-ol and any combination thereof.

5. The first inhibitor is given by the following formula IIa: 【Chemistry 2】 A compound of which, in the formula, R ４ However, H, C １ ~C ２２ Alkyl, C １ ~C ２２ Alkenil, C １ ~C ２２ Alkinyl, C １ ~C ２２ Cycloalkyl, aryl, -C １ ~C ２２ Alkylene, -C(O)(C １ ~C ２２ Alkyl), -C(O)(C １ ~C ２２ Alkenyl), -C(O)(C １ ~C ２２ Alkinyl), -C(O)(C １ ~C ２２ Cycloalkyl), -C(O)(aryl), or -C(O)(C １ ~C ２２ Alkylene) and the alkyl, the alkylene, the cycloalkyl, and the aryl are C １ ~C ２２ Alkyl, C １ ~C ２２ Alkenil, C １ ~C ２２ The composition according to claim 1, wherein it is optionally substituted with one or more alkynyls or aryls.

6. The first inhibitor is 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylacetate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylpropanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylbutyrate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylpentanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylpentanoate. Tramethylpiperidine-4-ylhexanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylheptanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-yloctanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylnonanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-yldecanoate, 1- The composition according to claim 5, selected from the group consisting of hydroxy-2,2,6,6-tetramethylpiperidine-4-ylundecanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-yldodecanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-yl2-ethylhexanoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylstearate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylbenzoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylpalmitoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-ylbehenoate, 1-hydroxy-2,2,6,6-tetramethylpiperidine-4-yl4-tert-butylbenzoate, or any combination thereof.

7. The second inhibitor compound is of formula (IV) or formula (V): 【Transformation 3】 A phenylenediamine in which X １ and X ２ However, independently, C １ ~C ２２ It is alkyl or aryl, and the alkyl and the aryl are C １ ~C ２２ The composition according to claim 1 or 2, wherein it is optionally substituted with one or more alkyl or aryl groups.

8. The composition according to claim 1 or 2, wherein the second inhibitor is selected from the group consisting of 1,2-phenylenediamine, 1,4-phenylenediamine, N,N'-dimethyl-p-phenylenediamine, N,N'-di-sec-butyl-1,4-phenylenediamine, N,N'-di-1,4-dimethylpentyl-1,4-phenylenediamine, N,N'-diethyl-1,4-phenylenediamine, N-tert-butyl-N'-phenyl-1,4-phenylenediamine, N,N'-diphenyl-1,4-phenylenediamine, and any combination thereof.

9. The third inhibitor compound is of formula (VI) or formula (VII): 【Chemistry 4】 The benzoquinone in the formula, X ３ , X ４ , X ５ , and X ６ However, independently, H, C １ -C ２２ It is alkyl or aryl, and the alkyl and the aryl are C １ -C ２２ The composition according to claim 1 or 2, wherein it is optionally substituted with one or more alkyl or aryl groups.

10. The third inhibitor compound is of formula (VII) or formula (VIII): 【Transformation 5】 is a naphthoquinone, wherein X ５ and X ６ are independently H, C １ to C ２２ alkyl, aryl, and the alkyl and the aryl are optionally substituted with one or more of C １ to C ２２ alkyl or aryl, the composition according to claim 1 or 2.

11. The composition according to claim 1 or 2, wherein the first inhibitor compound is present in the composition at a concentration of about 0.01% to about 80% by weight, and the second inhibitor compound is present in the composition at a concentration of about 0.01% to about 50% by weight.

12. The composition according to claim 1 or 2, wherein the composition further comprises an organic solvent.

13. The composition according to claim 1 or 2, wherein the composition further comprises an ethylenically unsaturated monomer selected from the group consisting of vinyl acetate, acrylonitrile, acrylate, methacrylate, 1,3-butadiene, styrene, isoprene, acrylic acid, methacrylic acid, and any combination thereof.

14. A method for suppressing monomer polymerization, wherein the method is A method comprising adding the composition described in claim 1 to the monomer.

15. The method according to claim 14, wherein the monomer is provided in a solution.

16. The method according to claim 15, wherein the solution further comprises one or more additional components selected from an acid, an organic solvent, and water.

17. The method according to any one of claims 14 to 16, wherein the monomer is an ethylenically unsaturated monomer.

18. The method according to any one of claims 14 to 16, wherein the composition is added to the monomer such that the concentration of the first inhibitor compound is about 0.1 ppm to about 10,000 ppm.

19. The method according to any one of claims 14 to 16, wherein the composition is added to the monomer such that the concentration of the second inhibitor compound is about 0.1 ppm to about 10,000 ppm.

20. The method according to any one of claims 14 to 16, wherein the monomer is selected from the group consisting of vinyl acetate, acrylonitrile, acrylate, methacrylate, 1,3-butadiene, styrene, isoprene, acrylic acid, methacrylic acid, and any combination thereof.

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