阅读说明：本技术 一种阻聚剂的制备方法及其应用 (Preparation method and application of polymerization inhibitor ) 是由 杨巍 路竹强 于 2020-07-23 设计创作，主要内容包括：本发明提供了一种阻聚剂的制备方法及其应用,将2,4-二硝基-6-仲丁基苯酚与N,N-二苄基羟胺混合均匀制备后得到Ⅰ类混合基体；将二乙羟胺与2-硫甲醚吩噻嗪混合后在三乙胺的存在下进行混合后交联得到Ⅱ混合基体；将Ⅰ类混合基体与Ⅱ混合基体混合并反应,形成预混物；再向所述预混物中加入去离子水混合均匀制成预混物水溶液；将甲基丙烯酸苄基酯加入预混物水溶液中,并加入氢氧化钠,静止后得到阻聚剂；本发明方法制备工艺简单,制作成本较低；并且本发明方法所制备的阻聚剂稳定性较好,毒性小,环保性能较佳。(The invention provides a preparation method and application of a polymerization inhibitor, wherein 2, 4-dinitro-6-sec-butylphenol and N, N-dibenzylhydroxylamine are uniformly mixed to prepare a type I mixed matrix; mixing diethylhydroxylamine and 2-thiomethylphenothiazine, then mixing in the presence of triethylamine, and then crosslinking to obtain a mixed matrix II; mixing and reacting a class I mixed matrix with a class II mixed matrix to form a premix; adding deionized water into the premix and uniformly mixing to prepare an aqueous solution of the premix; adding benzyl methacrylate into the aqueous solution of the premix, adding sodium hydroxide, and standing to obtain a polymerization inhibitor; the method has simple preparation process and lower preparation cost; the polymerization inhibitor prepared by the method has the advantages of good stability, low toxicity and good environmental protection performance.)

1. The preparation method of the polymerization inhibitor is characterized by comprising the following steps:

the method comprises the following steps: preparation of class I Mixed matrices

Uniformly mixing 2, 4-dinitro-6-sec-butylphenol and N, N-dibenzylhydroxylamine to obtain a class I mixed matrix; wherein the mixing molar ratio of the 2, 4-dinitro-6-sec-butylphenol to the N, N-dibenzylhydroxylamine is 0.5-0.8: 1.3; the reaction temperature in the first step is 28-32 ℃, and the reaction time is 3-4 h;

step two: preparation of class II Mixed matrices

Mixing diethylhydroxylamine and 2-thiomethylphenothiazine, then mixing in the presence of triethylamine, and then crosslinking to obtain a mixed matrix II; wherein the mixing molar ratio of the diethylhydroxylamine to the 2-thiomethylphenothiazine is 2.6-3.2: 1; the reaction temperature of the second step is 85-95 ℃, and the reaction time is 6-14 h;

step three: preparation of the premix

Mixing and reacting a class I mixed matrix with a class II mixed matrix to form a premix; adding deionized water into the premix and uniformly mixing to prepare an aqueous solution of the premix; wherein the mixing molar ratio of the class I mixed matrix to the class II mixed matrix is 2-4.8: 1.6-1.9; the reaction temperature of the second step is 110-160 ℃, and the reaction time is 7-10 h;

step four: preparation of polymerization inhibitor

Adding benzyl methacrylate into the aqueous solution of the premix, adding sodium hydroxide with the molar ratio of 0.03-0.12: 1 to the aqueous solution of the premix, stirring for 15-20 min, and standing to obtain a polymerization inhibitor; wherein the ratio of the addition amount of the benzyl methacrylate to the molar amount of the premix is 0.25-0.45: 13, the reaction temperature in the fourth step is 80-130 ℃, and the static reaction time is 3-7 h.

2. The method of claim 1, wherein an anionic polymerization initiator is added in a molar ratio of 0.03-0.05: 5-8 to the mixture in the first step.

3. The process for preparing a polymerization inhibitor according to claim 2, wherein said anionic polymerization initiator is azobisheptanonitrile or dimethyl azobisisobutyrate.

4. The method for preparing the polymerization inhibitor according to claim 1, wherein a bridging agent is added in the second step, wherein the molar ratio of the bridging agent to the mixture is 0.01-0.08: 3-5.

5. The method of claim 1, wherein the bridging agent is N, N-methylenebisacrylamide or divinylbenzene.

6. Use of the polymerization inhibitor prepared by the method according to any one of claims 1 to 5, wherein the polymerization inhibitor is used in the production of styrene.

7. The use of the polymerization inhibitor prepared by the method according to claim 1, wherein the reaction temperature in the first step is 28-32 ℃ and the reaction time is 3-4 h.

Technical Field

The invention relates to the technical field of chemical products, in particular to a preparation method and application of a polymerization inhibitor.

Background

Styrene is used as a chemical raw material with wide application, and a monomer of the styrene is an easily polymerizable substance and can be polymerized at normal temperature. In the production of styrene, in order to reduce the self-polymerization of styrene, a high-efficiency polymerization inhibitor is generally required to be added in addition to the negative pressure operation to reduce the rectification temperature.

However, dinitrophenol is generally used as a main polymerization inhibitor in the production of styrene in the prior art, but due to high toxicity, dinitrophenol cannot meet the requirements of green environmental protection of new industries.

There is a need for an environmentally friendly polymerization inhibitor for use in styrene production.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method and application of a green environment-friendly polymerization inhibitor.

The technical scheme of the invention is as follows: a preparation method of a polymerization inhibitor specifically comprises the following steps:

the method comprises the following steps: preparation of class I Mixed matrices

Uniformly mixing 2, 4-dinitro-6-sec-butylphenol and N, N-dibenzylhydroxylamine to obtain a class I mixed matrix; wherein the mixing molar ratio of the 2, 4-dinitro-6-sec-butylphenol to the N, N-dibenzylhydroxylamine is 0.5-0.8: 1.3; the reaction temperature in the first step is 28-32 ℃, and the reaction time is 3-4 h;

step two: preparation of class II Mixed matrices

Mixing diethylhydroxylamine and 2-thiomethylphenothiazine, then mixing in the presence of triethylamine, and then crosslinking to obtain a mixed matrix II; wherein the mixing molar ratio of the diethylhydroxylamine to the 2-thiomethylphenothiazine is 2.6-3.2: 1; the reaction temperature of the second step is 85-95 ℃, and the reaction time is 6-14 h;

step three: preparation of the premix

Mixing and reacting a class I mixed matrix with a class II mixed matrix to form a premix; adding deionized water into the premix and uniformly mixing to prepare an aqueous solution of the premix; wherein the mixing molar ratio of the class I mixed matrix to the class II mixed matrix is 2-4.8: 1.6-1.9; the reaction temperature of the second step is 110-160 ℃, and the reaction time is 7-10 h;

step four: preparation of polymerization inhibitor

Adding benzyl methacrylate into the aqueous solution of the premix, adding sodium hydroxide with the molar ratio of 0.03-0.12: 1 to the aqueous solution of the premix, stirring for 15-20 min, and standing to obtain a polymerization inhibitor; wherein the ratio of the addition amount of the benzyl methacrylate to the molar amount of the premix is 0.25-0.45: 13, the reaction temperature in the fourth step is 80-130 ℃, and the static reaction time is 3-7 h.

Further, adding an anionic polymerization initiator into the mixture in a molar ratio of 0.03-0.05: 5-8 in the first step; the initiator is used as a starting reagent to initiate the polymerization reaction of the monomers.

Further, as the anionic polymerization initiator, azobisisoheptonitrile or dimethyl azobisisobutyrate is specifically used.

Further, a bridging agent with the molar ratio of 0.01-0.08: 3-5 to the mixture is added in the second step; the diradical generated after the exposure of the bridging agent can form a bridge bond with a polymer molecular chain to become an insoluble substance with a three-dimensional structure.

Furthermore, the bridging agent is N, N-methylene bisacrylamide or divinylbenzene.

Further, the polymerization inhibitor is used in the production of styrene.

Compared with the prior art, the invention has the beneficial effects that: the method has simple preparation process and lower preparation cost; the polymerization inhibitor prepared by the method has excellent polymerization inhibition effect in the production of styrene, and has better economic benefit; the polymerization inhibitor prepared by the method has the advantages of good stability, low toxicity and good environmental protection performance.

Drawings

FIG. 1 is a chemical structural formula of a class I mixed matrix of the present invention;

FIG. 2 is a chemical structure of a class II mixed matrix of the present invention;

FIG. 3 is a chemical structure of the premix of the present invention;

FIG. 4 is a chemical structural formula of the polymerization inhibitor of the present invention.

Detailed Description