A supported polyoxometalate catalyst and its preparation method and application

Abstract

The invention discloses a supported polyoxometalate catalyst and its use. The catalyst prepared by the invention is used to realize the environmentally friendly preparation of rubber antioxidant TMQ. The supported polyoxometalate catalyst is used, that is, a composite product prepared by using polyoxometalate and a highly chemically active precursor to prepare TMQ. The supported polyoxometalate catalyst is easy to prepare and has a good catalytic effect. It can reduce the consumption of hydrochloric acid in the preparation of TMQ, thereby avoiding the problems of equipment corrosion, large amount of alkali solution and high cost of three waste treatment.

Description

Technical Field

[0001] The invention belongs to the field of rubber additives, and in particular relates to a supported polyoxometalate catalyst which can be used for catalytically preparing a rubber antioxidant TMQ, and a preparation method and application thereof. Background Art

[0002] Antioxidant TMQ is one of the rubber antioxidants with the largest demand in the domestic and international markets. Its main components are di-, tri- and tetra-polymers of 2,2,4-trimethyl-1,2-dihydroquinoline.

[0003] At present, the preparation of TMQ in China mainly adopts the "one-step method", that is, aniline and acetone are usually used as raw materials, and under the catalysis of hydrochloric acid, it is prepared through a series of steps such as salt formation, condensation, polymerization, neutralization, and distillation.

[0004] The hydrochloric acid catalyst often causes the preparation of TMQ to face problems such as severe equipment corrosion, huge consumption of alkaline water, and high cost of waste treatment.

[0005] In order to overcome the above technical deficiencies, it is of great significance to seek new catalytic materials, reduce hydrochloric acid consumption and alkali consumption, and reduce the generation of high-salt wastewater for the environmentally friendly preparation of TMQ.

[0006] Polyoxometalates usually refer to anionic metal oxygen cluster compounds containing transition metal elements. They have a definite molecular structure, are relatively stable, and have multiple adjustable factors. The properties of polyoxometalates can be systematically regulated by adjusting the anion structure, ligand atoms, central atoms, and counter cations. They can be designed at the molecular level for specific requirements, so they have very broad application prospects in catalyst design and preparation.

[0007] In order to reduce the loss of polyoxometalates and improve catalytic efficiency, they can be combined with carriers such as silica and titanium dioxide to form new composite materials, further increase the specific surface area, increase the catalytic active centers, and improve the catalytic activity to meet special technical requirements.

[0008] Therefore, the present invention considers using a supported polyoxometalate catalyst to catalyze the preparation of TMQ and provides a new environmentally friendly preparation method. Summary of the invention

[0009] The object of the present invention is to provide a supported polyoxometalate catalyst and a preparation method thereof, so as to overcome the problems of equipment corrosion, huge acid and alkali consumption, high-salt wastewater discharge, etc. caused by hydrochloric acid catalysis in the prior art of TMQ preparation.

[0010] The supported polyoxometalate catalyst provided by the present invention is a composite product prepared by using polyoxometalate and a precursor with high chemical activity.

[0011] In the catalyst, the polyoxometalate includes but is not limited to dichromic acid, molybdophosphoric acid, tungstosilicic acid, phosphotungstic acid, pyrovanadic acid and the like and their salts.

[0012] In the catalyst, the highly chemically active precursors include but are not limited to tetraethyl orthosilicate, butyl titanate, sodium silicate, P123 block copolymer, and F127 block copolymer.

[0013] In the catalyst, the composite product prepared from polyoxometalate and a precursor with high chemical activity is prepared by the following method:

[0014] The polyoxometalate and the highly chemically active precursor are weighed and mixed in a solvent, stirred and heated to form a colloid, left to stand for a certain period of time for aging, and the sample is vacuum dried at a certain temperature.

[0015] Furthermore, the solvent refers to a solvent that can completely dissolve the polyoxometalate, including but not limited to water, methanol, ethanol, isopropanol, n-butanol, dichloromethane, chloroform, acetone, acetonitrile, ethyl acetate, N,N-dimethylformamide, and dimethyl sulfoxide.

[0016] Furthermore, the stirring time is 0 to 72 h.

[0017] Furthermore, the heating temperature is 30-100°C.

[0018] Another object of the present invention is to provide a method for green and environmentally friendly preparation of TMQ using the above-mentioned supported polyoxometalate catalyst.

[0019] To achieve the above object, the preparation method provided by the present invention is achieved by the following means:

[0020] The raw materials aniline, acetone and supported polyoxometalate catalyst are added into a solvent, mixed and heated to a reaction temperature, and after a period of reaction, the solvent is removed by distillation to obtain a rubber antioxidant TMQ.

[0021] In the method, the reaction temperature for preparing the rubber antioxidant TMQ is 90-180° C., and the reaction time is 1-20 hours.

[0022] In the method, the weight ratio of aniline to acetone is 1:1-10, and the weight ratio of the supported polyoxometalate catalyst to aniline is 0.0005-0.5:1.

[0023] Beneficial Effects of the Invention

[0024] In the preparation process of rubber antioxidant TMQ, the use of strong acid catalysts is avoided, and the processes of liquid alkali neutralization and water separation are omitted, thereby reducing the generation of wastewater. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] Example 1

[0027] Preparation of supported polyoxometalate catalysts:

[0028] 3 g of phosphotungstic acid and 12 g of ethyl orthosilicate were weighed and mixed in n-butanol, stirred at 40°C for 12 h, allowed to stand for 24 h for aging, and the sample was vacuum dried at 80°C to obtain a supported polyoxometalate catalyst.

[0029] Preparation of rubber antioxidant TMQ:

[0030] 10 g of supported polyoxometalate catalyst, 32 g of aniline and 300 g of acetone were added to 100 g of toluene and reacted at 160 °C for 15 h. After the reaction was completed, the aqueous phase and the phosphorus-supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0031] Example 2

[0032] Preparation of supported polyoxometalate catalysts:

[0033] 5 g of molybdophosphoric acid and 20 g of ethyl orthosilicate were weighed and mixed in isopropanol, stirred at 60°C for 12 h, allowed to stand for 24 h for aging, and the sample was vacuum dried at 50°C to obtain a supported polyoxometalate catalyst.

[0034] Preparation of rubber antioxidant TMQ:

[0035] 10 g of supported polyoxometalate catalyst, 22 g of aniline and 280 g of acetone were added to 88 g of toluene and reacted at 120 °C for 12 h. After the reaction was completed, the aqueous phase and supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0036] Example 3

[0037] Preparation of supported polyoxometalate catalysts:

[0038] 5 g of pyrovanadic acid and 20 g of ethyl orthosilicate were weighed and mixed in ethanol, stirred at 50°C for 10 h, allowed to stand for 24 h for aging, and the sample was vacuum dried at 50°C to obtain a supported polyoxometalate catalyst.

[0039] Preparation of rubber antioxidant TMQ:

[0040] 12 g of supported polyoxometalate catalyst, 32 g of aniline and 300 g of acetone were added to 92 g of toluene and reacted at 160 °C for 15 h. After the reaction was completed, the aqueous phase and supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0041] Example 4

[0042] Preparation of supported polyoxometalate catalysts:

[0043] 7 g of phosphotungstic acid and 12 g of butyl titanate were weighed and mixed in methanol, stirred at 60°C for 12 h, allowed to stand for 24 h for aging, and the sample was vacuum dried at 80°C to obtain a supported polyoxometalate catalyst.

[0044] Preparation of rubber antioxidant TMQ:

[0045] 5 g of supported polyoxometalate catalyst, 16 g of aniline and 150 g of acetone were added to 50 g of toluene and reacted at 140°C for 10 h. After the reaction was completed, the aqueous phase and the supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0046] Example 5

[0047] Preparation of supported polyoxometalate catalysts:

[0048] 3 g of molybdophosphoric acid and 12 g of ethyl orthosilicate were weighed and mixed in n-butanol, stirred at 60° C. for 12 h, allowed to stand for 24 h for aging, and the sample was vacuum dried at 80° C. to obtain a supported polyoxometalate catalyst.

[0049] Preparation of rubber antioxidant TMQ:

[0050] 10 g of supported polyoxometalate catalyst, 24 g of aniline and 260 g of acetone were added to 80 g of toluene and reacted at 120 °C for 14 h. After the reaction was completed, the aqueous phase and supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0051] Example 6

[0052] Preparation of supported polyoxometalate catalysts:

[0053] 3 g of pyrovanadic acid and 12 g of butyl titanate were weighed and mixed in acetone, stirred at 55°C for 18 h, allowed to stand for 24 h for aging, and the sample was vacuum dried at 80°C to obtain a supported polyoxometalate catalyst.

[0054] Preparation of rubber antioxidant TMQ:

[0055] 10 g of supported polyoxometalate catalyst, 28 g of aniline and 270 g of acetone were added to 90 g of toluene and reacted at 130 °C for 10 h. After the reaction was completed, the aqueous phase and the supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0056] Example 7

[0057] Preparation of supported polyoxometalate catalysts:

[0058] Weigh 5 g of potassium dichromate and 20 g of ethyl orthosilicate in ethanol, stir at 70°C for 20 h, let stand for 24 h for aging, and dry the sample at 80°C in vacuum to obtain a supported polyoxometalate catalyst.

[0059] Preparation of rubber antioxidant TMQ:

[0060] 10 g of supported polyoxometalate catalyst, 32 g of aniline and 300 g of acetone were added to 100 g of toluene and reacted at 140 °C for 12 h. After the reaction was completed, the aqueous phase and supported polyoxometalate catalyst were separated and then the organic solvent was distilled off to obtain the product rubber antioxidant TMQ.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations, such as changing the conversion conditions of the biological system and the proportion of the reaction materials such as aniline, etc. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Application of a supported polyoxometalate catalyst in preparing TMQ, It is characterized in that The catalyst is prepared from polyoxometalate and a precursor with high chemical activity. The preparation method of the catalyst is as follows: the polyoxometalate and the precursor with high chemical activity are mixed in a solvent, stirred and heated to form a colloid, left to stand for aging, and vacuum dried. The polyoxometalate includes dichromic acid, molybdophosphoric acid, tungstosilicic acid, phosphotungstic acid, pyrovanadic acid and salts thereof. The precursor with high chemical activity includes tetraethyl orthosilicate, butyl titanate, sodium silicate, P123 block copolymer, and F127 block copolymer. The method for preparing TMQ using the supported polyoxometalate catalyst is as follows: raw materials aniline, acetone and the supported polyoxometalate catalyst are added into a solvent, mixed and heated to a reaction temperature, and the solvent is removed by distillation after the reaction to obtain the rubber antioxidant TMQ.

2. The use of the supported polyoxometalate catalyst in preparing TMQ according to claim 1, It is characterized in that The solvent refers to a solvent that can completely dissolve the polyoxometalate, and is selected from water, methanol, ethanol, isopropanol, n-butanol, dichloromethane, chloroform, acetone, acetonitrile, ethyl acetate, N,N-dimethylformamide, and dimethyl sulfoxide.

3. The use of the supported polyoxometalate catalyst in preparing TMQ according to claim 1, It is characterized in that The stirring time for preparing the catalyst is 0~72 h.

4. The use of the supported polyoxometalate catalyst in preparing TMQ according to claim 1, It is characterized in that The heating temperature for preparing the catalyst is 40~100℃.

5. Use of the supported polyoxometalate catalyst in preparing TMQ according to claim 1, It is characterized in that The reaction temperature for preparing rubber antioxidant TMQ is 90~180℃, and the reaction time is 1~20 h.

6. Use of the supported polyoxometalate catalyst in preparing TMQ according to claim 1, It is characterized in that The weight ratio of aniline to acetone is 1:1-10, and the weight ratio of the supported polyoxometalate catalyst to aniline is 0.0005-0.5:1.