阅读说明：本技术 一种磺化酚醛树脂型固体酸催化剂的制备方法及在甘油酯化反应中的应用 (Preparation method of sulfonated phenolic resin type solid acid catalyst and application of sulfonated phenolic resin type solid acid catalyst in glycerol esterification reaction ) 是由 姜媛媛 赵怀远 刘皓岚 侯昭胤 于 2019-08-21 设计创作，主要内容包括：本发明公开了一种磺化酚醛树脂型固体酸催化剂的制备方法及在甘油酯化反应中的应用,涉及催化剂的制备技术领域。所述的磺化酚醛树脂型固体酸催化剂的制备方法为采用一步缩聚法将对羟基苯磺酸、苯酚和多聚甲醛进行缩聚反应,制得磺化酚醛树脂型固体酸催化剂。本发明还提供了一种利用上述的制备方法制备得到磺化酚醛树脂型固体酸催化剂,可应用于催化甘油酯化反应中。本发明提供的磺化酚醛树脂型固体酸催化剂的制备方法,工艺简单,安全环保,且制备得到的磺化酚醛树脂型固体酸催化剂稳定性好,催化活性高,可在较低温度条件下催化甘油进行酯化反应,且可循环使用。(The invention discloses a preparation method of a sulfonated phenolic resin type solid acid catalyst and application of the sulfonated phenolic resin type solid acid catalyst in glycerol esterification reaction, and relates to the technical field of preparation of catalysts. The preparation method of the sulfonated phenolic resin type solid acid catalyst comprises the step of carrying out polycondensation reaction on p-hydroxybenzene sulfonic acid, phenol and paraformaldehyde by adopting a one-step polycondensation method to prepare the sulfonated phenolic resin type solid acid catalyst. The invention also provides a sulfonated phenolic resin type solid acid catalyst prepared by the preparation method, which can be applied to catalyzing the esterification reaction of glycerin. The preparation method of the sulfonated phenolic resin type solid acid catalyst provided by the invention has the advantages of simple process, safety and environmental protection, and the prepared sulfonated phenolic resin type solid acid catalyst has good stability and high catalytic activity, can catalyze glycerin to carry out esterification reaction at a lower temperature, and can be recycled.)

1. A preparation method of a sulfonated phenolic resin type solid acid catalyst is characterized in that p-hydroxybenzene sulfonic acid, phenol and paraformaldehyde are subjected to polycondensation reaction by a one-step polycondensation method to prepare the sulfonated phenolic resin type solid acid catalyst.

2. The method for producing a sulfonated phenol resin type solid acid catalyst according to claim 1, comprising:

(1) Dissolving p-hydroxybenzene sulfonic acid, phenol, paraformaldehyde and p-methylbenzene sulfonic acid in a reaction solvent to carry out polycondensation;

(2) Carrying out desolventizing treatment on the product obtained by the polycondensation reaction in the step (1) to obtain a crude polycondensation product;

(3) And (3) washing the crude polycondensation product obtained in the step (2) by using absolute ethyl alcohol, separating, and drying insoluble substances to obtain the sulfonated phenolic resin type solid acid catalyst.

3. The method for preparing a sulfonated phenol resin type solid acid catalyst according to claim 2, wherein the molar ratio of the p-hydroxyphenylsulfonic acid to the phenol in the step (1) is 1 to 9:1, and the ratio of the sum of the molar numbers of the p-hydroxyphenylsulfonic acid to the phenol to the molar number of paraformaldehyde in terms of formaldehyde is 1:1.2 to 1.7.

4. the method for preparing the sulfonated phenol-formaldehyde resin type solid acid catalyst according to claim 2, wherein the molar ratio of the p-toluenesulfonic acid to the phenol in the step (1) is 0.2 to 0.5: 1.

5. The method for preparing the sulfonated phenolic resin type solid acid catalyst according to claim 2, wherein the condensation reaction in the step (1) is performed under the condition of condensing reflux for 4-8 h at 100-150 ℃.

6. The method for preparing a sulfonated phenol resin type solid acid catalyst according to claim 2, wherein the temperature of the solvent removal treatment in the step (2) is 40 to 60 ℃.

7. The method for preparing the sulfonated phenol resin type solid acid catalyst according to claim 2 or 6, wherein the solvent removal treatment in the step (2) further comprises vacuum drying, wherein the temperature of the vacuum drying is 50 to 80 ℃, and the vacuum degree is 0 to 0.8 MPa.

8. The sulfonated phenolic resin type solid acid catalyst is prepared by the method for preparing the sulfonated phenolic resin type solid acid catalyst according to any one of claims 1 to 7.

9. The application of the sulfonated phenolic resin type solid acid catalyst in catalyzing the esterification reaction of glycerol according to claim 8, wherein glycerol and acetic acid are uniformly mixed, and the esterification reaction is carried out under the catalysis of the sulfonated phenolic resin type solid acid catalyst; the molar ratio of the glycerol to the acetic acid is 1: 1-9; the mass ratio of the glycerol to the sulfonated phenolic resin type solid acid catalyst is 60-600: 1.

10. The application of the sulfonated phenolic resin type solid acid catalyst in catalyzing glycerol esterification reaction according to claim 8, wherein the esterification reaction is carried out for 1-8 hours at 50-80 ℃.

Technical Field

the invention relates to the technical field of catalyst preparation, in particular to a preparation method of a sulfonated phenolic resin type solid acid catalyst and application of the sulfonated phenolic resin type solid acid catalyst in glycerol esterification reaction.

Background

The traditional liquid acid (such as sulfuric acid, hydrochloric acid, p-toluenesulfonic acid and the like) has high catalytic activity and low cost, but is easy to corrode equipment, unrecoverable, difficult in product separation, large in waste liquid generation and the like in the use process, and is not in accordance with the concept of green chemistry and sustainable development. Thus, environmentally friendly solid acid catalysts and their preparation and use as substitutes for liquid acids are receiving attention.

Among the various solid acid catalysts, the organic solid acid catalyst is an important species, and among them, the most common is a resin type solid acid catalyst, which has the advantages of water resistance, low active temperature, etc., has the characteristics of high efficiency and stability for acid catalytic reaction at a low temperature, is suitable for various condensation reactions and dehydration reactions, and many resin type solid acid catalysts are now commercially available.

The publication No. CN102614919A discloses a preparation method of a sulfonated crosslinked chitosan resin type solid acid catalyst, which takes chitosan as a raw material, firstly reacts with a crosslinking agent (glutaraldehyde or glyoxal) to prepare crosslinked chitosan, and then sulfonated crosslinked chitosan by concentrated sulfuric acid and chlorosulfonic acid to prepare sulfonated crosslinked chitosan solid acid.

The publication No. CN101786017A discloses a preparation method of a sulfonic group functionalized thiourea resin catalyst, which comprises the steps of firstly selecting a polythiourea resin with free sulfydryl by reacting a polythiol compound with a polyisocyanate compound, and then oxidizing the sulfydryl into a sulfonic group by using hydrogen peroxide to prepare the sulfonic group functionalized thiourea resin catalyst.

Phenolic resin is a traditional resin polymer, has simple preparation method, good acid resistance, thermal stability and mechanical strength, is widely applied to the manufacturing industries of flame-retardant materials, adhesives and grinding wheels, but has only few literature reports in the field of heterogeneous catalysis.

In 2013, Minakawa et al (Organic Letters 22 (2013): 5798-5801; Energy & Fuels 32 (2018): 12567-12576) use p-hydroxybenzene sulfonic acid and formaldehyde as raw materials to carry out polycondensation reaction at 120 ℃ for 6h to prepare a p-hydroxybenzene sulfonic acid-formaldehyde resin solid acid catalyst, and generate sulfonic acid functionalized phenolic resin by means of the polycondensation reaction of active hydrogen at the ortho-position of phenolic hydroxyl in the p-hydroxybenzene sulfonic acid and the formaldehyde. The method has simple preparation process and low raw material cost, and the prepared catalyst has excellent catalytic effect in esterification reaction of alcohol and carboxylic acid, but the catalyst is straight-chain phenolic resin, has poor thermal stability and is easy to dissolve in the reaction process, so that the stability is not high.

The publication No. CN101550223A discloses a sulfonated phenolic resin, a preparation method thereof and an application thereof as a catalyst, wherein the sulfonated phenolic resin is prepared by synthesizing phenolic resin by taking phenol and formaldehyde as raw materials, and then sulfonating the phenolic resin in the presence of concentrated sulfuric acid and fuming sulfuric acid, the sulfonated phenolic resin catalyst is used for catalytic synthesis reaction of trioctyl citrate and tributyl citrate, the esterification rate of the tributyl citrate is 99%, and the esterification rate of the trioctyl citrate is more than 96.0%. The preparation process adopts a two-step method, uses a large amount of solvent, concentrated sulfuric acid and fuming sulfuric acid in the sulfonation process, and has complex process, poor safety and environmental protection.

Disclosure of Invention

The invention provides a preparation method of the sulfonated phenolic resin type solid acid catalyst, which is simple in process, safe and environment-friendly, aiming at the problems in the resin type solid acid catalyst, and the sulfonated phenolic resin type solid acid catalyst prepared by the method has good stability and can be recycled.

The sulfonated phenolic resin type solid acid catalyst with a cross-linking structure is prepared by carrying out polycondensation reaction on p-hydroxybenzene sulfonic acid, phenol and paraformaldehyde through a one-step polycondensation method, and can effectively inhibit the defects of loss, difficult separation, easy decomposition and the like caused by dissolution of the catalyst, so that the stability and the reuse activity of the catalyst are improved.

The polycondensation reaction of hydroxybenzenesulfonic acid, phenol and paraformaldehyde is shown as a formula (I):

A preparation method of a sulfonated phenolic resin type solid acid catalyst comprises the following steps:

(1) Dissolving p-hydroxybenzene sulfonic acid, phenol, paraformaldehyde and p-methylbenzene sulfonic acid in a reaction solvent to carry out polycondensation;

(2) Carrying out desolventizing treatment on a product obtained by the polycondensation reaction in the step (1) to obtain a crude polycondensation product;

(3) And (3) washing the crude polycondensation product obtained in the step (2) by using absolute ethyl alcohol, separating, and drying insoluble substances to obtain the sulfonated phenolic resin type solid acid catalyst.

In the step (1), the molar ratio of the p-hydroxybenzene sulfonic acid to the phenol is 1-9: 1, and the ratio of the sum of the molar numbers of the p-hydroxybenzene sulfonic acid and the phenol to the molar number of the paraformaldehyde calculated by formaldehyde is 1: 1.2-1.7.

The mol ratio of the p-hydroxybenzene sulfonic acid, the phenol and the paraformaldehyde is in the range, so that the sulfonated phenolic resin type solid acid catalyst with a cross-linked structure can be obtained, the cross-linked structure improves the specific surface area of the sulfonated phenolic resin type solid acid catalyst and the utilization efficiency of surface acid sites, increases the thermal stability of the sulfonated phenolic resin type solid acid catalyst, reduces the dissolution and inactivation, and the cross-linked structure ensures that the sulfonated phenolic resin type solid acid catalyst has good hydrophobicity and the acid sites are easy to contact.

The p-toluenesulfonic acid in the step (1) is an initiator of a polycondensation reaction, and the polycondensation reaction is induced, wherein the molar ratio of the p-toluenesulfonic acid to phenol is preferably 0.2-0.5: 1.

The reaction solvent in the step (1) is butanone.

The polycondensation reaction condition in the step (1) is that the condensation reflux is carried out for 4-8 h at the temperature of 100-150 ℃.

the temperature of the solvent removal treatment in the step (2) is preferably 40-60 ℃.

Further preferably, the solvent removal treatment in the step (2) further comprises vacuum drying, wherein the temperature of the vacuum drying is preferably 50-80 ℃, and the vacuum degree is preferably 0-0.8 MPa.

By vacuum drying, the reaction solvent can be further removed and the resin can be sufficiently cured.

The purpose of the washing with absolute ethanol described in step (3) is to remove unreacted monomers and initiator p-toluenesulfonic acid.

The invention also provides a sulfonated phenolic resin type solid acid catalyst prepared by the preparation method of the sulfonated phenolic resin type solid acid catalyst.

The application of the sulfonated phenolic resin type solid acid catalyst in catalyzing the esterification reaction of glycerin comprises the following steps: the glycerol and the acetic acid are uniformly mixed, and esterification reaction is carried out under the catalytic action of a sulfonated phenolic resin type solid acid catalyst.

The molar ratio of the glycerol to the acetic acid is 1: 1-9; the mass ratio of the glycerol to the sulfonated phenolic resin type solid acid catalyst is 60-600: 1.

the esterification reaction is carried out for 1-8 h at 50-80 ℃.

Compared with the prior art, the invention has the main advantages that:

(1) The invention overcomes the problems of complicated and unsafe preparation process of the resin type solid acid catalyst (concentrated sulfuric acid or hydrogen peroxide is used, etc.), easy dissolution of the catalyst, poor stability, etc., and the preparation method of the sulfonated phenolic resin type solid acid catalyst provided by the invention is simple, and the sulfonated phenolic resin type solid acid catalyst prepared by the preparation method has low price, good stability, high catalytic activity and can be recycled.

(2) by utilizing the preparation method of the sulfonated phenolic resin type solid acid catalyst, the prepared sulfonated phenolic resin type solid acid catalyst is used for catalyzing glycerol to perform esterification reaction, the reaction condition is mild, the conversion rate of the glycerol is high, and the selectivity of monoacetic glyceride and diacetic glyceride is good; the conversion rate of the glycerol can reach 84.3 percent, and the sum of the selectivity of the monoacetin and the diacetin reaches 99.9 percent.

(3) The activity of the sulfonated phenolic resin type solid acid catalyst provided by the invention is not obviously reduced after the sulfonated phenolic resin type solid acid catalyst is recycled for 5 times.

Drawings

FIG. 1 is an infrared spectrum of a sulfonated phenol resin type solid acid catalyst prepared in example 1.

FIG. 2 is a photograph showing reaction solutions obtained after the esterification reaction of glycerin catalyzed by the solid acid catalyst of sulfonated phenol-novolac resin type prepared in example 1 and the solid acid catalyst of sulfonated phenol-novolac resin type without phenol prepared in comparative example 1;

In the figure, (a) is a reaction liquid obtained after the sulfonated phenolic resin type solid acid catalyst prepared in example 1 catalyzes the esterification reaction of glycerol; (b) the reaction solution obtained by catalyzing the esterification reaction of glycerin by the phenol-free sulfonated phenolic resin type solid acid catalyst prepared in comparative example 1.

Detailed Description

The invention will be further illustrated with reference to the following specific examples. It is to be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention, and that the starting materials used in the following examples are commercially available.