CN102443168B - A kind of porous solid amine and preparation method thereof - Google Patents

Abstract

The invention discloses a porous solid amine and a preparation method thereof. Using epoxy compounds and polyamines as raw materials and boric acid as a buffer to slow down the intensity of the reaction, the porous solid amine material is prepared by cross-linking polymerization. The structure It is similar to a sponge-like solid, with a large number of pores, and there are amine groups in it. It is alkaline, has the ability to absorb acid gases such as carbon dioxide, and can also form chelates with metal ions.

Description

A kind of porous solid amine and preparation method thereof

technical field

The invention relates to the field of compounds, in particular to a porous solid amine and a preparation method thereof.

Background technique

Solid amine is a _CO2 absorbent, mainly used for _CO2 removal in closed compartments such as submarines, spacecraft, and space stations. It can replace the original methods such as ethanolamine or LiOH, and solve problems such as corrosion, leakage, reliability, and reproducibility. Solid amine adsorbents are usually prepared by two methods: (1) loading organic amines on the support by impregnation; (2) distributing amino groups on the surface of the support by grafting. Impregnation is a widely used approach to prepare catalysts and adsorbents (Yue Mingbo, Zhu Jianhua, Acta Catalytica Sinica, 2008, Vol. 29, No. 10, 1051-1057). For example, Liu Yamin and others used the impregnation method to load tetraethylenepentamine on the surface of KIT-6 mesoporous silicon material to synthesize hyperbranched solid amine KIT-6, (Journal of Chemical Industry, Vol. 62, No. 3, 2011, 736-742).

The grafting method uses chemical bonds to graft amino groups to the surface of the carrier, thereby improving the dispersion of amino groups and the thermal stability of the obtained adsorbent. For example, Leal et al. grafted aminopropyl groups onto the surface of silica gel. (Leal O, Bolivar C, Ovalles C, Garcia JJ, Espidel Y. Inorg Chim Acta, 1995, 240(122): 183).

In addition, carbon dioxide solid amine absorbents can be synthesized by polymerization. For example, Zhou Xu, Guo Qiang, etc. prepared macroporous cross-linked copolymers by conventional suspension polymerization, using acrylates as monomers, divinylbenzene (DVB) as cross-linking agent, and adding porogen; The amine undergoes aminolysis to obtain a polyacryloylpolyethylene polyamine resin. (Ship Science and Technology. 2008,30(6):218-222.)

The direct preparation of porous solid amines by cross-linking polymerization has not been reported so far.

Contents of the invention

The object of the present invention is to provide a kind of porous solid amine and preparation method thereof, use epoxy compound, polyamine as raw material, boric acid is the buffer agent that slows down reaction intensity, adopt the method for cross-linking polymerization, prepare porous solid amine.

A porous solid amine of the present invention, the structure of the porous solid amine is similar to a sponge-like solid, there are a large number of pores, there are amine groups in the porous solid amine, and it is alkaline.

A method for preparing the porous solid amine, made from the following raw materials and operating steps:

(1) Raw materials:

A: Epoxyalkylene compounds can be ring-opened and polymerized under the action of amino groups, and polymerized with polyamines to form amine-containing polymer products;

B: polyamine, can polymerize with epoxy compound;

C: boric acid, first react with polyamine with boric acid, then use epoxy compound ring-opening polymerization, can reduce the intensity of this reaction, make it expand and become porous product;

(2) Operation steps:

Set the ratio of raw materials: the molar ratio of polyamine, boric acid and epoxy compound is (1~2):(1~2):(1~2);

Take a clean beaker, weigh boric acid with an electronic balance, then use a measuring cylinder to measure polyamine according to the proportion, add polyamine to the container containing boric acid under stirring, stir until a white paste is formed, cool and stir for a while; Put it in a ventilated place, add the epoxy compound according to the ratio, and continue to stir until the reaction occurs to make a porous solid amine.

Preferably, the polyamine is tetraethylenepentamine, triethylenetetramine, diethylenetriamine or small organic molecules with more than two amino groups. Described epoxy compound is epichlorohydrin, oxirane.

Preferably, the molar ratio of the polyamine, boric acid and epoxy compound is 1:1:1.

Beneficial effects: the present invention prepares a porous solid amine material with a sponge-like solid structure by using epoxy compounds and polyamines as raw materials, boric acid as a buffer to slow down the intensity of the reaction, and cross-linking polymerization. There are a large number of pores, there are amine groups in it, it is alkaline, it has the ability to absorb acid gases such as carbon dioxide, and it can also form chelates with metal ions.

Description of drawings

Fig. 1 is the schematic diagram of the principle of preparing porous solid amine by taking tetraethylenepentamine and epichlorohydrin as examples of the present invention.

detailed description

The invention uses epoxy compounds and polyamines as raw materials, boric acid as a buffer to slow down the intensity of the reaction, and adopts a cross-linking polymerization method to prepare porous solid amine materials. In conjunction with Figure 1, tetraethylenepentamine and epichlorohydrin are taken as examples to illustrate the experimental principle:

In the process of synthesizing solid-state amines, if tetraethylenepentamine and epichlorohydrin are directly contacted and reacted, an explosive reaction will occur and block solids will be formed. First, boric acid is used to react with amine group to reduce the reaction speed of amine based on epoxy compound, and boric acid acts as a buffer in the reaction. Since the reaction is an exothermic reaction, the generated heat vaporizes H ₂ O, water vapor and HCl gas expand rapidly, and the solid amine forms a porous structure. Epichlorohydrin is a reactive cross-linking agent that connects the linear molecules of polytetraethylenepentamine to form a network structure. In addition, its side reactions may include intramolecular ring formation and non-condensation hydrolysis (when water exists), etc.

Example 1:

Set the ratio of raw materials, the molar ratio of tetraethylenepentamine, epichlorohydrin and boric acid is 1:1:1. Take a clean 250mL beaker, weigh 3.0981g of boric acid with an electronic balance, measure 9.5mL of tetraethylenepentamine with a 10mL measuring cylinder, and stir continuously with a glass rod until a white paste is formed (boric acid no longer presents crystalline state), cool Stir for a while. Place in a ventilated place, pour 3.8mL of epichlorohydrin, and continue stirring until the reaction occurs. The rapid expansion of the liquid reactant to a spongy solid accompanied by gas evolution was observed.

Example 2:

Set the ratio of raw materials, the molar ratio of triethylenetetramine: boric acid: epichlorohydrin is 1:1:1.

Take a clean 250mL beaker according to the above ratio of 1:1:1, weigh 3.0981g of boric acid with an electronic balance, measure 7.3mL of triethylenetetramine with a 10mL graduated cylinder, and stir continuously with a glass rod until a white paste ( Boric acid is no longer crystalline), cooled and stirred for a while. Place in a ventilated place, pour 3.8mL epichlorohydrin, and continue stirring until the reaction occurs. The rapid expansion of the liquid reactant to a spongy solid accompanied by gas evolution was observed.

Example 3:

The ratio of raw materials is set, and the molar ratio of diethylenetriamine: boric acid: epichlorohydrin is 1:1:1.

Take a clean 250mL beaker according to the above ratio of 1:1:1, weigh 3.0981g of boric acid with an electronic balance, measure 5.3mL of diethylene triethylene with a 10mL graduated cylinder, and stir continuously with a glass rod until a white paste (boric acid no longer present crystalline state), cooled and stirred for a while. Place in a ventilated place, pour 3.8mL of epichlorohydrin, and continue stirring until the reaction occurs. The rapid expansion of the liquid reactant to a spongy solid accompanied by gas evolution was observed.

The synthesized porous amine solid product can measure its amine group content by an acid-base calibration method, such as oxalic acid (H ₂ C ₂ O ₄ 2H ₂ O) to calibrate the number of amine groups per gram of porous solid amine, as synthesized in Example 1 The number of amine groups contained in each gram of solid amine in the porous solid amine is 1.899×10 ^-3 mol.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and its purpose is to enable those of ordinary skill in the art to understand the content of the present invention and implement it accordingly, and cannot limit the protection scope of the present invention. All equivalent changes or modifications made according to the essence of the present invention shall fall within the protection scope of the present invention.

Claims (4)

1. a porous solid amine, is characterized in that, the structure of described porous solid amine is spongy solid, has a large amount of ducts to exist, has amido to exist, have alkalescence in it;

Described porous solid amine is made up of following raw materials according and operation steps:

(1) raw material:

A: epoxy compounds, can ring-opening polymerization under amino effect, and polyamines aggregates into amino-contained macromolecule product;

B: polyamines, can with synthesis of epoxy compounds;

C: boric acid, first reacts with polyamines with boric acid, then with open loop of epoxy compound polymerization, can reduce the severe degree of this reaction, make it be expanded into porous articles;

(2), operation steps:

Set proportioning raw materials: the mol ratio of polyamines, boric acid and epoxy compounds is as (1 ~ 2): (1 ~ 2): (1 ~ 2); Get clean beaker, take boric acid with electronic balance, then measure polyamines with graduated cylinder by proportioning, under agitation polyamines is joined and fill in the container of boric acid, stir until generate white paste, cooling and stirring a moment; Be placed in ventilation, by proportioning, epoxy compounds added, continue to stir until reaction occurs, obtained porous solid amine.

2. porous solid amine according to claim 1, is characterized in that, described polyamines is tetraethylene pentamine, triethylene tetramine, diethylenetriamine or the organic molecule amino more than two.

3. porous solid amine according to claim 1, is characterized in that, described epoxy compounds is epoxy chloropropane, oxyethane.

4. porous solid amine according to claim 1, is characterized in that, the mol ratio of described polyamines, boric acid and epoxy compounds is 1:1:1.