阅读说明：本技术 一种高官能度叠氮胶及其制备方法 (High-functionality azide glue and preparation method thereof ) 是由 李战雄 陈明强 吴优 王雪婷 于 2020-04-09 设计创作，主要内容包括：本发明公开了一种高官能度叠氮胶及其制备方法。以3,3-双(氯甲基)氧杂环丁烷/四氢呋喃为混合单体合成双端烯丙基的氯甲基共聚醚,经叠氮化制得双端为烯丙基的叠氮共聚醚；由多巯基化物与烯丙基醇加成制备一巯基多羟基物中间体；最后由双端烯丙基叠氮共聚醚与一巯基多羟基物中间体发生迈克尔加成反应,制得一种叠氮胶,作为复合固体推进剂粘合剂,可以提供更强的交联特性和更大的交联密度,从而赋予推进剂更高的力学强度。高官能度叠氮胶的制备通过加成反应完成,生产工艺条件非常温和,避免了含叠氮基的含能材料受热所存在的潜在危险性；产品制备工艺简单、操作安全,适合工业放大生产。(The invention discloses high-functionality azide glue and a preparation method thereof. Synthesizing double-end allyl chloromethyl copolyether by using 3, 3-bis (chloromethyl) oxetane/tetrahydrofuran as a mixed monomer, and preparing azide copolyether with allyl at the double ends through azide; preparing a monothiopolyol intermediate by the addition of a polymercapto compound to an allyl alcohol; finally, the double-end allyl azide copolyether and the mercapto polyhydroxy compound intermediate are subjected to Michael addition reaction to prepare the azide glue which is used as a composite solid propellant adhesive and can provide stronger crosslinking characteristic and higher crosslinking density, thereby endowing the propellant with higher mechanical strength. The preparation of the high-functionality azide glue is completed through addition reaction, the production process conditions are very mild, and the potential danger caused by heating of the azide-containing energetic material is avoided; the product has simple preparation process and safe operation, and is suitable for industrial scale-up production.)

1. The high-functionality azide glue is characterized in that the chemical structural formula of the high-functionality azide glue is as follows:

wherein n = 15-25; m = 1-3; r is hydrogen, methyl or。

2. The high-functionality azide glue according to claim 1, wherein the preparation method of the high-functionality azide glue comprises the following steps:

(1) taking 3, 3-bis (chloromethyl) oxetane and tetrahydrofuran as monomers, and carrying out copolymerization reaction in a chloroalkane solvent under the catalysis of Lewis acid to synthesize chloromethyl copolyether;

(2) dissolving chloromethyl copolyether prepared in the step (1) in a ketone solvent, and adding an aqueous solution of sodium azide for azide reaction to prepare double-end allyl azide copolyether;

(3) under the action of a catalyst, dissolving multi-mercapto propionate and allyl alcohol in a ketone solvent, adding the catalyst for catalytic reaction, and preparing a mono-mercapto polyhydroxy compound intermediate;

(4) under the action of a catalyst, double-end allyl azide copolyether and a mercapto polyhydroxy compound intermediate are subjected to Michael addition reaction in a ketone solvent to prepare the high-functionality azide glue.

3. The high-functionality azide glue according to claim 2, wherein in the step (1), the molar ratio of 3, 3-bis (chloromethyl) oxetane to tetrahydrofuran is 1: 0.5-2; the chloralkane solvent is dichloromethane and/or dichloroethane; the Lewis acid is any one of boron trifluoride diethyl etherate complex, titanium tetrachloride or tin tetrachloride.

4. The high-functionality azide glue according to claim 2, wherein the temperature of the copolymerization reaction in the step (1) is-5 to 10 ℃ and the time is 12 to 48 hours.

5. The high-functionality azide glue according to claim 2, wherein in the step (2), the ketone solvent is acetone or butanone; the molar ratio of chloromethyl copolyether to sodium azide is 1: 0.05-0.2; the time of the azide reaction is 6-24 h.

6. The high-functionality azide glue of claim 2, wherein in step (3), the polymercaptopropionate is one of trimethylolpropane tris (3-mercaptopropionate) or pentaerythritol tetrakis (3-mercaptopropionate); the molar ratio of the polymercaptopropionate to the allyl alcohol is 1: 2-3; the catalyst is dimethyl phenyl phosphine, sodium ethoxide or sodium methoxide; the temperature of the catalytic reaction is room temperature, and the time is 12-24 h.

7. The high functionality azido gum of claim 2, wherein in step (3), the chemical structure of the monothiol polyol intermediate is as follows:

wherein R is hydrogen, methyl or；m=1～3。

8. The high-functionality azide glue according to claim 2, wherein the molar ratio of the double-end allyl azide copolyether to the mercapto-polyol intermediate in the step (4) is 1: 1-3; the ketone solvent is acetone or butanone; the Michael addition reaction takes dimethyl phenyl phosphine, sodium ethoxide or sodium methoxide as a catalyst; the temperature of the Michael addition reaction is 0-40 ℃, and the time is 30 minutes-24 hours.

9. Use of the high functionality azide gum of claim 1 in the preparation of solid propellants.

10. Use according to claim 9, characterized in that the high-functionality azide glue acts as a binder.

Technical Field

The invention relates to a high-functionality azide adhesive and a preparation method thereof, in particular to telechelic polyhydroxy azide polyether and a preparation method thereof, and belongs to the technical field of preparation of adhesives for fine chemicals and composite solid propellants.

Background

As early as the later 60 years in the last century, in order to improve the energy of the propellant, the countries consume huge manpower and material resources to research the energetic propellant components. However, the problems of thermal stability, toxicity and compatibility with other components in the propellant are difficult to solve, and the practical stage is not reached. At the end of the last 70 th century, the research on energetic adhesives has focused mainly on polyethers with energetic groups. Wherein when azido (-N) is introduced into the polymer₃) After each one of-N₃The radicals can provide 355.3kJ of positive heat of formation, thus forming a new class of high energy polymers, namely azido polyether gums, often referred to as azido gums.

The azide glue is represented by poly-azide glycidyl ether (GAP), and a large amount of research on GAP is carried out at home and abroad, and some of the research approaches to a practical stage. However, GAP has poor low temperature mechanical properties and poor compatibility with burn rate catalysts that must be added to the solid propellant. And, under the high temperature condition of ultraviolet irradiation, -N₃The group is easy to decompose and the thermal stability is poor. To overcome this disadvantage, energetic materials experts developed a variety of azides and studied their performance as solid propellants. Among them, the copolymer of 3, 3-bis (azidomethyl) butylene oxide (BAMO) and Tetrahydrofuran (THF) has good thermal stability and large heat of normal formation, is compatible with other components in the propellant, and is an ideal energetic adhesive. The number average molecular weight of the peptide is 3000The composite propellant with the BAMO/THF copolyether as the adhesive is researched on the aspects of combustion performance, mechanical property and sensitivity, and the specific impulse of the propellant is 220s^-1About 20% elongation at break at-30 ℃ and is seen to be inferior in low-temperature mechanical properties such as elongation. At present, azide gel is used as an adhesive system to develop an azide propellant, and the main problem is that the propellant has poor mechanical property.

Disclosure of Invention

The invention discloses a telechelic azide glue with high functionality aiming at the problem of unsatisfactory mechanical properties commonly existing in the existing azide propellant, and provides high crosslinking density when the azide glue enters a crosslinking network structure of a composite solid propellant, so that the mechanical strength of the azide propellant is improved.

The technical scheme for realizing the purpose of the invention is as follows: the high-functionality azide glue is telechelic azide side-group copolyether, both ends of a polymer molecule comprise a plurality of hydroxypropyl groups, and the chemical structural formula of the high-functionality azide glue is as follows:

wherein n = 15-25; r is hydrogen, methyl or；m=1～3。

The invention discloses a preparation method of the high-functionality azide glue, which comprises the following steps:

(1) taking 3, 3-bis (chloromethyl) oxetane and tetrahydrofuran as monomers, and carrying out copolymerization reaction in a chloroalkane solvent under the catalysis of Lewis acid to synthesize chloromethyl copolyether;

(2) dissolving chloromethyl copolyether prepared in the step (1) in a ketone solvent, and adding an aqueous solution of sodium azide for azide reaction to prepare double-end allyl azide copolyether;

(3) under the action of a catalyst, dissolving multi-mercapto propionate and allyl alcohol in a ketone solvent, adding the catalyst for catalytic reaction, and preparing a mono-mercapto polyhydroxy compound intermediate;

(4) under the action of a catalyst, double-end allyl azide copolyether and a mercapto polyhydroxy compound intermediate are subjected to Michael addition reaction in a ketone solvent to prepare the high-functionality azide glue.

The invention discloses a preparation method of azide propellant, which comprises the following steps:

(1) taking 3, 3-bis (chloromethyl) oxetane and tetrahydrofuran as monomers, and carrying out copolymerization reaction in a chloroalkane solvent under the catalysis of Lewis acid to synthesize chloromethyl copolyether;

(2) dissolving chloromethyl copolyether prepared in the step (1) in a ketone solvent, and adding an aqueous solution of sodium azide for azide reaction to prepare double-end allyl azide copolyether;

(3) under the action of a catalyst, dissolving multi-mercapto propionate and allyl alcohol in a ketone solvent, adding the catalyst for catalytic reaction, and preparing a mono-mercapto polyhydroxy compound intermediate;

(4) under the action of a catalyst, preparing high-functionality azide glue by Michael addition reaction of double-end allyl azide copolyether and a mercapto polyhydroxy compound intermediate in a ketone solvent;

(5) mixing and curing the azide glue, a curing agent, an oxidant and an auxiliary agent to obtain an azide propellant; the azide gum contains the high functionality azide gum.

In the present invention, the curing agent is an isocyanate curing agent such as isophorone diisocyanate; the oxidant is ammonium perchlorate; the auxiliary agent is bonding agent and aluminum powder.

In the technical scheme, in the step (1), the molar ratio of 3, 3-bis (chloromethyl) oxetane to tetrahydrofuran is 1: 0.5-2; the chloralkane solvent is dichloromethane and/or dichloroethane; the Lewis acid is any one of boron trifluoride diethyl etherate complex, titanium tetrachloride or stannic tetrachloride; the temperature of the copolymerization reaction is-5-10 ℃, preferably 0-5 ℃; the polymerization reaction time is 12-48 h; preferably, the time for quenching reaction is 1-5 h after the polymerization reaction is completed.

In the above technical scheme, in the step (2), the ketone solvent is acetone or butanone; the molar ratio of chloromethyl copolyether to sodium azide is 1: 0.05-0.2; the nitridizing reaction is carried out at room temperature for 6-24 h; the mass concentration of the sodium azide aqueous solution is 10-60%.

In the above technical scheme, in the step (3), the polymercaptopropionate is one of trimethylolpropane tri (3-mercaptopropionate) or pentaerythritol tetrakis (3-mercaptopropionate); the molar ratio of the polymercaptopropionate to the allyl alcohol is 1: 2-3; the catalyst is dimethyl phenyl phosphine, sodium ethoxide or sodium methoxide; the temperature of the catalytic reaction is room temperature, and the time is 12-24 h; the chemical structure of the monothiol polyol intermediate is as follows:

wherein R is hydrogen, methyl or；m=1～3。

In the technical scheme, the molar ratio of the double-end allyl azide copolyether to the mercapto polyhydroxy intermediate in the step (4) is 1: 1-3; the Michael addition reaction takes dimethyl phenyl phosphine, sodium ethoxide or sodium methoxide as a catalyst; the ketone solvent is acetone or butanone; the temperature of the Michael addition reaction is 0-40 ℃, and the time is 30 minutes-24 hours.

The invention discloses an application of the high-functionality azide glue in preparation of a solid propellant, wherein the high-functionality azide glue is used as an adhesive.

Compared with the prior art, the technical scheme provided by the invention has the beneficial effects that:

1. the disclosed high functionality azide gum products as composite solid propellant binders can provide enhanced crosslinking characteristics, thereby imparting higher mechanical strength to the propellant. This is of great importance for polyether system composite solid propellants.

2. The high-functionality azide glue has a telechelic molecular structure, a multifunctional group at the end group has uniform reactivity, the adaptation period of the azide solid propellant is longer, and the azide solid propellant is easy to cure at the later curing period.

3. Because the azide gum belongs to energetic materials, the side group azide group of the azide gum is easy to decompose under the heat. The multifunctional systems at two ends of the azide glue are introduced through addition reaction, and the reaction is carried out at room temperature or even at low temperature, so that potential danger in the process of heating materials is avoided.

4. When the multifunctional polyether is prepared by the traditional method, generally, 1, 4-butanediol, 1,2,3 glycerol or pentaerythritol and the like are used to react with Lewis acid to generate an initiator at the beginning of polymerization reaction, and hydroxyl-Lewis acid ester in the initiator is hydrolyzed to generate a multifunctional group after the reaction is finished. The invention discloses a preparation method of high-functionality azide glue, which is characterized in that telechelic polyfunctional groups are introduced into two ends of the azide glue by an addition method after polymerization is finished, the adjustable range of the functionality of the azide glue is as wide as 3.5-6, and the provided material can meet various requirements of mechanical properties of a composite solid propellant.

5. The main chain of the azide glue molecule disclosed by the invention is of a linear structure, so that the azide glue molecule is favorable for providing good elongation after an adhesive system is stretched after the azide glue molecule enters a composite solid propellant curing network.

Drawings

FIG. 1 is a hydrogen NMR spectrum of a high functionality azido gel prepared in accordance with example one of the present invention;

FIG. 2 is an infrared spectrum of a high functionality azide gel prepared in the first embodiment of the present invention.

Detailed Description

The preparation method of the high-functionality azide glue disclosed by the invention comprises the following steps:

(1) taking 3, 3-bis (chloromethyl) oxetane and tetrahydrofuran as monomers, and carrying out copolymerization reaction in a chloroalkane solvent under the catalysis of Lewis acid to synthesize chloromethyl copolyether;

(2) dissolving chloromethyl copolyether prepared in the step (1) in a ketone solvent, and adding an aqueous solution of sodium azide for azide reaction to prepare double-end allyl azide copolyether;

(3) under the action of a catalyst, dissolving multi-mercapto propionate and allyl alcohol in a ketone solvent, adding the catalyst for catalytic reaction, and preparing a mono-mercapto polyhydroxy compound intermediate;

(4) under the action of a catalyst, double-end allyl azide copolyether and a mercapto polyhydroxy compound intermediate are subjected to Michael addition reaction in a ketone solvent to prepare the high-functionality azide glue.

Specifically, the method comprises the following steps:

(1) cationic ring-opening copolymerization: 3, 3-bis (chloromethyl) oxetane and tetrahydrofuran are taken as mixed monomers according to a certain molar ratio, dissolved in chloroalkane solvent, and synthesized into bis-terminal allyl chloromethyl copolyether under the catalysis of Lewis acid;

(2) nitridizing: dissolving chloromethyl copolyether in a ketone solvent, and adding an aqueous solution of sodium azide for azide to prepare azide copolyether with allyl at both ends;

(3) preparation of monothiol polyol intermediate: under the action of a catalyst, dissolving multi-mercapto propionate and allyl alcohol in a ketone solvent, adding the catalyst for catalytic reaction, and preparing a mono-mercapto polyhydroxy compound intermediate;

(4) addition reaction: under the action of a catalyst, double-end allyl azide copolyether and a mercapto polyhydroxy compound intermediate are dissolved in a ketone solvent according to a certain molar ratio, and the high-functionality azide glue is prepared through Michael addition reaction.

Further, the preparation method of the high-functionality azide glue comprises the following specific steps:

(1) allyl-terminated poly 3, 3-bis (chloromethyl) oxetane/tetrahydrofuran:

under the protection of nitrogen, chloralkane is used as a reaction medium, and 1, 4-butanediol serving as an initiator reacts with Lewis acid to generate cationic active species. Under the condition of low temperature, dropping mixed monomer 3, 3-bis (chloromethyl) oxetane/tetrahydrofuran prepared according to certain ingredients, and reacting for certain time after the dropping. After the reaction solution is heated to room temperature, allyl alcohol is added to quench the cation ring-opening polymerization, and the reaction is quenched for a certain time. Diluting the reaction solution with chloralkane, washing with water, drying, and evaporating off chloralkane as reaction medium to obtain poly (3, 3-bis (chloromethyl) oxetane/tetrahydrofuran, i.e. chloromethyl copolyether.

(2) Preparation of poly 3, 3-bis (azidomethyl) oxetane/tetrahydrofuran:

in the reactor, the ketone solvent, the allyl-terminated poly 3, 3-bis (chloromethyl) oxetane/tetrahydrofuran and the solution of sodium azide dissolved in water are added in turn, and the reaction is carried out at room temperature. After the reaction is stopped, reducing the pressure (0.1 MPa) by a water pump to evaporate the solvent to obtain a viscous turbid material, adding a chloroalkane medium to dissolve the viscous turbid material, washing the viscous turbid material with water, drying the mixture, and evaporating chloroalkane to obtain poly (3, 3-bis (azidomethyl) oxetane/tetrahydrofuran, namely the double-end allyl azido copolyether.

(3) Synthesis of monothiol polyol intermediate:

wherein R' is hydrogen, methyl or(ii) a R is hydrogen, methyl or；m=1～3。

A ketone solvent is used as a medium, a catalyst is added, and the polymercapto propionate and allyl alcohol are added according to a certain feed ratio to generate the monothiol polyol.

(4) And (3) using ketone solvent as a medium, and carrying out Michael addition reaction on allyl groups at two ends and the monothiol polyol generated in the step (3) under the catalysis of a catalyst according to a certain molar ratio to generate the high-functionality azide gum.

Wherein n = 15-25; r is hydrogen, methyl or；m=1～3。

The technical scheme of the invention is further described below by combining the drawings and the examples, and the related mechanical property and combustion performance test is a conventional test method of the solid propellant in the field.