Method for producing diallyl terephthalate by utilizing PET (Polyethylene Terephthalate)

Abstract

The invention relates to the field of organic materials, in particular to a method for producing diallyl terephthalate by utilizing PET (Polyethylene Terephthalate). The method for producing diallyl terephthalate by using PET provided by the invention comprises the following steps: mixing PET, allyl alcohol and a catalyst, and heating for reaction to obtain diallyl terephthalate. According to the method disclosed by the invention, upgraded recovery from waste PET to a high-value optical monomer is realized, meanwhile, the method is a low-cost and high-environmental-benefit diallyl terephthalate synthesis method, and the generation cost of diallyl terephthalate is reduced.

Description

Technical Field

[0001] The invention relates to the field of organic materials, and in particular to a method for producing diallyl terephthalate by utilizing PET. Background Art

[0002] Polyethylene terephthalate (PET) is one of the important general polymer materials after polyethylene, polypropylene, polyvinyl chloride and polystyrene, accounting for about 8% of the total global polymer production, with an annual output of more than 70 million tons. Of this output, about 60% is used for chemical fiber textiles, and about 30% is used for packaging products such as bottles and sheets. The rigid terephthalate structure in the PET molecule gives it excellent mechanical properties and temperature resistance, but it also makes it extremely difficult to degrade in nature, becoming one of the main sources of white pollution. At present, the recycling rate of PET is still low, only about 14%. How to achieve efficient and high value-added recycling of PET has always been a difficult problem.

[0003] Diallyl terephthalate (DAT) is an optical resin monomer with extremely high economic value. The resin obtained by self-polymerization or copolymerization with other monomers has excellent mechanical properties, chemical resistance, heat resistance and optical properties, and is widely used in the manufacture of optical lenses, optical disks, optical fibers, optoelectronic devices, engineering plastics, etc. At present, there are few publicly available methods for synthesizing diallyl terephthalate, and there are roughly two methods. One method is the direct esterification method, which specifically uses benzene or toluene as a water-carrying agent and uses concentrated sulfuric acid to catalyze the reaction of terephthalic acid and acryl alcohol to prepare the target product; the other method is the sodium salt method, which specifically uses sodium terephthalate and acryl chloride to react in the presence of CuCl. Among them, in the direct esterification method, since benzene or toluene azeotropes with water and acryl alcohol, the proportion of acryl alcohol in the azeotrope is relatively large, and acryl alcohol is miscible with water, so the loss of acryl alcohol in the water-carrying process is extremely large. The main disadvantage of the sodium salt method is that sodium terephthalate has very low solubility in water and the reaction rate is very slow. In the alkaline system, allyl chloride hydrolyzes very quickly, so a multiple excess of allyl chloride is required, resulting in a waste of raw materials. In addition, wastewater containing allyl alcohol seriously pollutes the environment. Therefore, both methods are relatively expensive. Summary of the invention

[0004] In view of this, the present invention provides a method for producing diallyl terephthalate using PET, which realizes the upgrading and recycling of waste PET into high-value optical monomers. At the same time, it is a low-cost, high-environmental-benefit method for synthesizing diallyl terephthalate, which reduces the production cost of diallyl terephthalate.

[0005] The invention provides a method for producing diallyl terephthalate by using PET, which comprises the following steps: mixing PET, allyl alcohol and a catalyst, and heating the mixture for reaction to obtain diallyl terephthalate.

[0006] Preferably, the catalyst is at least one of antimony trioxide, sodium antimonate, aluminum trichloride, titanium tetrachloride, tetrabutyl titanate, tetraisopropyl titanate, zinc acetate, zinc chloride, dibutyltin dilaurate, aluminum trichloride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, pyridine, triethylamine, sodium methoxide, phosphoric acid, sulfuric acid, benzoic acid, p-toluenesulfonic acid, and sodium p-toluenesulfonate.

[0007] Preferably, the molar ratio of PET to allyl alcohol is 1:(8-32).

[0008] Preferably, the molar amount of the catalyst is 0.01 mol% to 0.5 mol% of the molar amount of PET.

[0009] Preferably, the temperature of the heating reaction is ≥90°C.

[0010] Preferably, the temperature of the heating reaction is 120-240°C.

[0011] Preferably, the heating reaction time is 1 to 72 hours.

[0012] Preferably, after the heating reaction, the method further comprises: distilling the liquid product obtained from the heating reaction to obtain allyl alcohol and undistilled product respectively; and purifying the undistilled product to obtain diallyl terephthalate.

[0013] Preferably, the distillation temperature is 80-120°C;

[0014] The purification process comprises: first filtering to remove solid impurities, and then purifying and decolorizing by silica gel column chromatography to obtain diallyl terephthalate.

[0015] Preferably, the eluent used in the column chromatography method is dichloromethane.

[0016] The invention provides a synthetic method for producing diallyl terephthalate by using waste PET, and adopts allyl alcohol as an alcoholysis agent of PET to convert PET into diallyl terephthalate. It utilizes PET waste to synthesize high-value optical resin monomers, provides an economical PET waste recycling route, is conducive to improving the recycling rate of PET waste, and overcomes the problem of difficult degradation and low recycling rate of waste PET in the prior art. At the same time, this reaction route utilizes low-cost PET waste to replace high-cost terephthalic acid or terephthalate ester raw materials to produce diallyl terephthalate, which can reduce the production cost of diallyl terephthalate, and overcomes the problem of high production cost of diallyl terephthalate in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0018] Figure 1 is the H NMR spectrum of the liquid product obtained by the alcoholysis reaction in Example 1;

[0019] Figure 2 This is the H NMR spectrum of diallyl terephthalate after purification in Example 1. DETAILED DESCRIPTION

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0021] In this article, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0022] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0023] Herein, when it comes to numerical ranges, unless otherwise specified, the numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0024] In this article, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 120-240℃ means that the units of the left endpoint "120" and the right endpoint "240" are both ℃.

[0025] The invention provides a method for producing diallyl terephthalate by using PET, which comprises the following steps: mixing PET, allyl alcohol and a catalyst, and heating the mixture for reaction to obtain diallyl terephthalate.

[0026] The present invention adopts allyl alcohol as the alcoholysis agent of PET to convert PET into diallyl terephthalate and ethylene glycol, and the reaction route is as follows:

[0027]

[0028] In the present invention, the PET (polyethylene terephthalate) is preferably waste PET. The number average molecular weight of the PET is preferably greater than 5,000.

[0029] In the present invention, the allyl alcohol is an alcoholysis agent for PET, and its source is not particularly limited, and it can be a commercial product or prepared according to a preparation method known in the art. The present invention uses allyl alcohol as an alcoholysis agent for PET, and PET can be converted into high-value diallyl terephthalate.

[0030] In the present invention, the catalyst is preferably at least one of antimony trioxide, sodium antimonate, aluminum trichloride, titanium tetrachloride, tetrabutyl titanate, tetraisopropyl titanate, zinc acetate, zinc chloride, dibutyltin dilaurate, aluminum trichloride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, pyridine, triethylamine, sodium methoxide, phosphoric acid, sulfuric acid, benzoic acid, p-toluenesulfonic acid, and sodium p-toluenesulfonate; more preferably at least one of tetrabutyl titanate, zinc acetate, and potassium carbonate; further preferably at least one of tetrabutyl titanate and potassium carbonate. The present invention has no special restrictions on the source of the catalyst, and it can be a commercial product or prepared according to a preparation method known in the art.

[0031] In the present invention, the molar ratio of PET to allyl alcohol is preferably 1:(8-32), specifically 1:8, 1:9, 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32; more preferably 1:(16-32). Under this preferred ratio range, under the same other conditions, the yield of the alcoholysis reaction product and the yield of the purified product can be further improved.

[0032] In the present invention, the molar amount of the catalyst is preferably 0.01mol% to 0.5mol% of the molar amount of the PET, specifically 0.01mol%, 0.05mol%, 0.10mol%, 0.15mol%, 0.20mol%, 0.25mol%, 0.30mol%, 0.35mol%, 0.40mol%, 0.45mol%, 0.50mol%; more preferably 0.25mol% to 0.5mol%. Under this preferred ratio range, under the same other conditions, the yield of the alcoholysis reaction product and the yield of the purified product can be further improved.

[0033] In the present invention, the temperature of the heating reaction is preferably ≥90°C, more preferably 120-240°C, specifically 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, 220°C, 230°C, 240°C; further preferably 140-240°C, most preferably 180-240°C, under this further preferred and most preferred range, under the same other conditions, the yield of the alcoholysis reaction product and the yield of the purified product can be further improved. In the present invention, the time of the heating reaction is preferably 1-72h, specifically 2h, 8h, 12h, 24h, 36h, 48h, 60h, 72h.

[0034] In the present invention, the heating reaction is preferably accompanied by stirring. The stirring speed is preferably 50 to 2000 rpm, specifically 50 rpm, 100 rpm, 200 rpm, 400 rpm, 800 rpm, 1000 rpm, 1500 rpm. After the reaction is completed, a liquid product containing diallyl terephthalate is obtained.

[0035] In the present invention, the above steps preferably specifically include: adding PET, allyl alcohol and a catalyst into a reactor, sealing the reactor; heating for reaction, accompanied by stirring; after the reaction is completed, cooling, opening the reactor and collecting the product. The reactor is preferably a pressure-resistant reactor.

[0036] In the present invention, after the above-mentioned heating reaction, it is preferred to further perform: distilling the liquid product obtained by the heating reaction to obtain allyl alcohol and undistilled product respectively; and purifying the undistilled product to obtain diallyl terephthalate.

[0037] The present invention recovers excess allyl alcohol by distillation. The distillation can be carried out in an atmospheric distillation apparatus. Specifically, the liquid product obtained by the heating reaction is placed in an atmospheric distillation apparatus for distillation. In the present invention, the distillation temperature is preferably 80 to 120°C, specifically 90°C, 100°C, and 110°C. By distilling the liquid product obtained by the heating reaction, allyl alcohol is evaporated and cooled and collected to obtain a colorless and transparent liquid of allyl alcohol. Then, the undistilled high-boiling point portion (i.e., the undistilled product) in the atmospheric distillation apparatus is collected and purified. In the present invention, the purification preferably includes: first filtering to remove solid impurities, then purifying and decolorizing by silica gel column chromatography, and collecting a colorless and transparent product, i.e., diallyl terephthalate. Wherein, the eluent used in the silica gel column chromatography is preferably dichloromethane.

[0038] The invention provides a synthetic method for producing diallyl terephthalate by using waste PET, and adopts allyl alcohol as an alcoholysis agent of PET to convert PET into diallyl terephthalate. It utilizes PET waste to synthesize high-value optical resin monomers, provides an economical PET waste recycling route, is conducive to improving the recycling rate of PET waste, and overcomes the problem of difficult degradation and low recycling rate of waste PET in the prior art. At the same time, this reaction route utilizes low-cost PET waste to replace high-cost terephthalic acid or terephthalate ester raw materials to produce diallyl terephthalate, which can reduce the production cost of diallyl terephthalate, and overcomes the problem of high production cost of diallyl terephthalate in the prior art.

[0039] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0040] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available or can be prepared by known methods. The instruments are all conventionally selected in the art. The number average molecular weight of the waste PET is greater than 5000.

[0041] Example 1

[0042] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET:allyl alcohol is 1:16, and the amount of catalyst is 0.25 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath equipped with a magnetic stirring device, the reaction temperature is controlled to 90°C, the magnetic stirring speed is 400 rpm, and the reaction is continued for 72 hours. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product was detected by nuclear magnetic resonance hydrogen spectroscopy technology, and the yield of diallyl terephthalate was calculated to be 24%; the resulting nuclear magnetic hydrogen spectrum is as follows Figure 1 shown.

[0043] The above liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 23%. The nuclear magnetic resonance hydrogen spectrum results show that its structure is diallyl terephthalate, such as Figure 2 shown.

[0044] Example 2

[0045] Waste PET, allyl alcohol, potassium carbonate catalyst (wherein, the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25mol% of the molar amount of PET) is added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 100°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 48h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 29%.

[0046] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 28%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0047] Example 3

[0048] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 110°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 48h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 42%.

[0049] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 40%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0050] Example 4

[0051] Waste PET, allyl alcohol, potassium carbonate catalyst (wherein, the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25mol% of the molar amount of PET) is added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 120°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 48h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 51%.

[0052] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 48%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0053] Example 5

[0054] Waste PET, allyl alcohol, potassium carbonate catalyst (wherein, the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25mol% of the molar amount of PET) is added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 130°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 48h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 66%.

[0055] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 63%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0056] Example 6

[0057] Waste PET, allyl alcohol, potassium carbonate catalyst (wherein, the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25mol% of the molar amount of PET) is added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 140°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 48h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 80%.

[0058] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 75%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0059] Example 7

[0060] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to be 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 87%.

[0061] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 83%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0062] Example 8

[0063] Waste PET, allyl alcohol, potassium carbonate catalyst (wherein, the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.25mol% of the molar amount of PET) is added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 220°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 2h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 96%.

[0064] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and purity>99% detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 91%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0065] Example 9

[0066] Waste PET, allyl alcohol, potassium carbonate catalyst (wherein, the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.10mol% of the molar amount of PET) is added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 72%.

[0067] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 69%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0068] Example 10

[0069] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.01 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to be 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8 hours. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 49%.

[0070] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 47%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0071] Embodiment 11

[0072] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.50 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to be 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8 hours. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 93%.

[0073] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 89%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0074] Example 12

[0075] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:4, and the amount of catalyst is 0.25 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8 hours. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 44%.

[0076] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 42%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0077] Embodiment 13

[0078] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:8, and the amount of catalyst is 0.25 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8 hours. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 61%.

[0079] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 58%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0080] Embodiment 14

[0081] Waste PET, allyl alcohol, and potassium carbonate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:32, and the amount of catalyst is 0.25 mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8 hours. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 96%.

[0082] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 90%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0083] Embodiment 15

[0084] Waste PET, allyl alcohol, and zinc acetate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.10mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 69%.

[0085] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 64%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0086] Example 16

[0087] Waste PET, allyl alcohol, and tetrabutyl titanate catalyst (wherein the molar ratio of PET: allyl alcohol is 1:16, and the amount of catalyst is 0.10mol% of the molar amount of PET) are added to a pressure-resistant reactor equipped with a magnetic stirrer, and then the reactor is sealed. The reactor is placed in an oil bath pot equipped with a magnetic stirring device, the reaction temperature is controlled to 180°C, the magnetic stirring speed is 400rpm, and the reaction is continued for 8h. After the reaction is completed, the reactor is fully cooled to room temperature, and then the reactor is opened to collect the liquid product. The liquid product is detected by nuclear magnetic resonance hydrogen spectrum technology, and the yield of diallyl terephthalate is calculated to be 73%.

[0088] The liquid product is placed in an atmospheric distillation apparatus, heated to reflux at 110°C, and the distillate is collected to obtain a colorless transparent liquid of allyl alcohol (recovery rate>98%, and its purity is>99% as detected by nuclear magnetic resonance hydrogen spectrum technology); in addition, the undistilled product in the atmospheric distillation apparatus is collected, solid impurities are removed by filtration, and then the product is purified and decolorized by silica gel column chromatography (eluent is dichloromethane), and a colorless transparent product is collected. The colorless transparent product is detected by nuclear magnetic resonance hydrogen spectrum technology, and its yield is calculated to be 67%, and the nuclear magnetic resonance hydrogen spectrum result shows that its structure is diallyl terephthalate.

[0089] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for producing diallyl terephthalate using PET, characterized in that: The method comprises the following steps: mixing PET, allyl alcohol and a catalyst, and heating the mixture for reaction to obtain diallyl terephthalate.

2. The method according to claim 1, characterized in that The catalyst is at least one of antimony trioxide, sodium antimonate, aluminum trichloride, titanium tetrachloride, tetrabutyl titanate, tetraisopropyl titanate, zinc acetate, zinc chloride, dibutyltin dilaurate, aluminum trichloride, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, pyridine, triethylamine, sodium methoxide, phosphoric acid, sulfuric acid, benzoic acid, p-toluenesulfonic acid, and sodium p-toluenesulfonate.

3. The method according to claim 1, characterized in that The molar ratio of the PET to the allyl alcohol is 1:(8-32).

4. The method according to claim 1, characterized in that: The molar amount of the catalyst is 0.01 mol% to 0.5 mol% of the molar amount of PET.

5. The method according to claim 1, characterized in that The temperature of the heating reaction is ≥90°C.

6. The method according to claim 1 or 5, characterized in that: The temperature of the heating reaction is 120-240°C.

7. The method according to claim 1, characterized in that The heating reaction time is 1 to 72 hours.

8. The method according to claim 1, characterized in that After the heating reaction, the method further comprises: distilling the liquid product obtained from the heating reaction to obtain allyl alcohol and undistilled matter respectively; and purifying the undistilled matter to obtain diallyl terephthalate.

9. The method according to claim 8, characterized in that The distillation temperature is 80-120°C; The purification process comprises: first filtering to remove solid impurities, and then purifying and decolorizing by silica gel column chromatography to obtain diallyl terephthalate.

10. The method according to claim 9, characterized in that The eluent used in the column chromatography method is dichloromethane.

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