Preparation method of plastic additive castor oil-based plasticizer

Abstract

The invention is applicable to the technical field of plasticizer synthesis, and provides a preparation method of a plastic additive castor oil-based plasticizer, which comprises the following steps: adding castor oil, triphenylcarbinol and a magnesium oxide-aluminum oxide composite catalyst into a reaction container, reacting for 1.0-3.0 hours under the conditions that the temperature is 150-180 DEG C, the pressure is 1.0-2.5 kPa and the stirring speed is 300-500 n / min, and filtering to obtain the castor oil-based plasticizer. And taking the supernatant. Wherein the molar ratio of the castor oil to the triphenylcarbinol is 1: (3.5-4.5); the use amount of the magnesium oxide-aluminum oxide composite catalyst is 0.3-1.0 wt% of the total mass of the castor oil and the triphenylcarbinol. The yield of the castor oil-based plasticizer prepared by the preparation method is high, and the obtained castor oil-based plasticizer has the advantages of large molecular weight, large viscosity, high flash point, low volatility, extraction resistance, mobility resistance and the like, and can be used for replacing the existing phthalate plasticizer.

Description

Technical Field

[0001] This application belongs to the technical field of plasticizer synthesis, and particularly relates to a preparation method of a castor oil-based plasticizer for plastic auxiliaries. Background Art

[0002] Plasticizers are additives that increase the flexibility, fluidity, and plasticity of materials, and are commonly used in rubber, plastics, resins, building materials, coatings, etc. They are one of the plastic auxiliaries with the largest production and consumption in the world. Traditional plasticizers are phthalate plasticizers, mainly including dibutyl phthalate (DBP), bis(2-ethylhexyl) phthalate (DOP), diisononyl phthalate, etc. Due to their poor resistance to migration and extraction, they are prone to polluting the environment, food, drugs, etc., and their use has now been restricted.

[0003] Therefore, it is of great significance to develop new plasticizers with advantages such as large molecular weight, high viscosity, high flash point, low volatility, good extraction resistance, and good migration resistance to replace the current phthalate plasticizers. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide a preparation method of a castor oil-based plasticizer for plastic auxiliaries, aiming to solve the problems existing in current phthalate plasticizers, such as poor resistance to migration and extraction, and easy pollution to the environment, food, and drugs.

[0005] The embodiments of this application are implemented as follows. A preparation method of a castor oil-based plasticizer for plastic auxiliaries includes:

[0006] Adding castor oil, triphenylmethanol, and a magnesium oxide-aluminum oxide composite catalyst into a reaction vessel, reacting at a temperature of 150 - 180 °C, a pressure of 1.0 - 2.5 kPa, and a stirring rate of 300 - 500 n / min for 1.0 - 3.0 h, and after filtration, taking the upper layer liquid to obtain the castor oil-based plasticizer;

[0007] Among them, the molar ratio of the castor oil to the triphenylmethanol is 1: (3.5 - 4.5); the dosage of the magnesium oxide-aluminum oxide composite catalyst is 0.3 - 1.0 wt% of the total mass of the castor oil and the triphenylmethanol.

[0008] The preparation method of the castor oil-based plasticizer provided by the embodiments of the present application involves adding castor oil, triphenylmethanol, and a magnesium oxide-aluminum oxide composite catalyst into a reaction vessel, reacting under the conditions of a temperature of 150 - 180 °C, a pressure of 1.0 - 2.5 kPa, and a stirring rate of 300 - 500 n / min for 1.0 - 3.0 h, and then obtaining the product by filtration and taking the upper layer liquid. The castor oil-based plasticizer prepared by the preparation method of the present application has a high yield, and the obtained castor oil-based plasticizer has the advantages of a large molecular weight, high viscosity, high flash point, low volatility, good extraction resistance, and good migration resistance, and can be used to replace the current phthalate plasticizers. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 XRD pattern of the magnesium oxide-aluminum oxide composite catalyst provided in Example 2 and Comparative Example 1 of the present application;

[0010] Figure 2 Infrared spectrum of the castor oil-based plasticizer provided in Example 2 of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0011] In order to make the objectives, technical solutions, and advantages of the present application more clear and understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0012] The embodiments of the present application provide a preparation method of a castor oil-based plasticizer for plastic additives, including:

[0013] Adding castor oil, triphenylmethanol, and a magnesium oxide-aluminum oxide composite catalyst into a reaction vessel, reacting under the conditions of a temperature of 150 - 180 °C, a pressure of 1.0 - 2.5 kPa, and a stirring rate of 300 - 500 n / min for 1.0 - 3.0 h, and then obtaining the castor oil-based plasticizer by filtration and taking the upper layer liquid. The equation for the transesterification reaction of castor oil and triphenylmethanol under the action of the catalyst in the present application is as follows:

[0014]

[0015] Among them, the molar ratio of the castor oil to the triphenylmethanol is 1: (3.5 - 4.5), preferably 1:4.

[0016] Among them, the dosage of the magnesium oxide-aluminum oxide composite catalyst is 0.3 - 1.0 wt% of the total mass of the castor oil and the triphenylmethanol, preferably 1.0 wt%.

[0017] Preferably, castor oil, triphenylmethanol, and a magnesium oxide-aluminum oxide composite catalyst are added into a reaction vessel, and the reaction is carried out for 3.0 h under the conditions of a temperature of 170 °C, a pressure of 2.5 kPa, and a stirring rate of 300 n / min. After filtration, the upper layer liquid is taken to obtain the castor oil-based plasticizer.

[0018] Among them, the magnesium oxide-aluminum oxide composite catalyst is obtained by reacting magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl laurate, deionized water, and carbon dioxide at a temperature of 30 - 80 °C and a pressure of 7 - 10 MPa for 15 - 60 min. After washing the obtained product to neutrality, it is dried and calcined.

[0019] Among them, the molar ratio of magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl laurate, deionized water, and carbon dioxide is 1:(0.8 - 1.0):(0.3 - 0.5):(10.0 - 20.0):(4.5 - 5.0), preferably 1:0.9:0.4:15:4.8.

[0020] Preferably, the magnesium oxide-aluminum oxide composite catalyst is obtained by reacting magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl laurate, deionized water, and carbon dioxide at a temperature of 50 °C and a pressure of 8.5 MPa for 30 min. After washing the obtained product to neutrality, it is dried and calcined.

[0021] Optionally, magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl laurate, and deionized water are added to a supercritical reaction kettle according to a molar ratio of 1:(0.8 - 1.0):(0.3 - 0.5):(10.0 - 20.0):(4.5 - 5.0), and stirred at a stirring rate of 80 - 120 r / min for 30 - 60 min at room temperature. Then, carbon dioxide gas is introduced into the reaction kettle. Magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl laurate, deionized water, and carbon dioxide are then heated to 30 - 80 °C, and the pressure in the kettle is 7 - 10 MPa, and the reaction is carried out for 15 - 60 min. During the reaction process, as carbon dioxide participates in the reaction and is consumed, the pressure in the kettle drops, and nitrogen is introduced for pressure compensation; the obtained product is filtered, washed with deionized water until the pH of the filtrate is 7.0, then dried at 100 - 120 °C for 12 - 24 h, and finally calcined at 550 - 600 °C for 1 - 3 h to obtain the magnesium oxide-aluminum oxide composite catalyst.

[0022] Among them, the structural formula of N-acryloyl-N-propyl laurate (C 18 H 36 O 3 N 2 ) is as follows:

[0023]

[0024] The ammonium N - acryloyl - N - propyllaurate used in the specific embodiments of this application is all prepared by the following preparation method: α - chlorododecanoic acid and ammonium hydroxide are added to the reaction kettle in a molar ratio of 1:1, and an acid - base neutralization reaction is carried out at 30 °C to generate ammonium α - chlorododecanoate; ammonium α - chlorododecanoate, N - propylacrylamide and deionized water are added to the reaction vessel in a molar ratio of 1:1.2:17, and then a nano - cesium oxide - alumina composite catalyst is added, and the catalyst is 0.5 wt% of the total mass of ammonium α - chlorododecanoate and N - propylacrylamide; a reaction for removing HCl is carried out at 100 °C. After the reaction is completed, the catalyst is removed by filtration, and the filtrate is allowed to stand and separate into layers, and the upper layer liquid is ammonium N - acryloyl - N - propyllaurate. The reaction equation is as follows:

[0025]

[0026] The preparation method of the castor oil - based plasticizer is described in detail below with specific examples as follows. The experimental methods used in the following examples are all conventional methods unless otherwise specified; the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0027] Example 1

[0028] A preparation method of a castor oil - based plasticizer includes the following steps:

[0029] According to the molar ratio of Mg(OH) 2 :Al(OH) 3 :ammonium N - acryloyl - N - propyllaurate:H 2 O:CO 2 =1:0.8:0.5:10:5.0, 5.83 g of magnesium hydroxide, 6.24 g of aluminum hydroxide, 16.4 g of ammonium N - acryloyl - N - propyllaurate and 18.0 g of deionized water are added to a supercritical reaction kettle, stirred at a stirring rate of 80 r / min at room temperature for 30 min, then 11.2 L of carbon dioxide gas is introduced into the reaction kettle to make the pressure in the kettle 7 MPa, and the temperature is raised to 30 °C and reacted for 30 min to obtain a reaction product; during the reaction, the pressure in the kettle is maintained at 7 MPa by introducing nitrogen; the reaction product is filtered and washed with deionized water until the pH of the filtrate is 7.0, then the solid product is dried at 110 °C for 24 h, and finally calcined at 600 °C for 3 h to obtain a magnesium oxide - alumina composite catalyst, and the yield is 99.6%;

[0030] Castor oil, triphenylmethanol, and a magnesium oxide-aluminum oxide composite catalyst were added into a reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:3.5, and the dosage of the magnesium oxide-aluminum oxide composite catalyst was 0.3 wt% of the total mass of castor oil and triphenylmethanol. After reacting for 2 h under the conditions of a temperature of 180 °C, a pressure of 2 kPa, and a stirring rate of 500 n / min, heating, stirring, and pressure relief were stopped, and it was cooled to room temperature. The catalyst and unreacted triphenylmethanol were removed by filtration. The filtrate was layered, and the upper layer liquid was taken to obtain the castor oil-based plasticizer. The yield of the castor oil-based plasticizer was 99.5%.

[0031] Example 2

[0032] A preparation method of a castor oil-based plasticizer, comprising the following steps:

[0033] According to the molar ratio of Mg(OH) 2 :Al(OH) 3 :N-acryloyl-N-propyl lauric acid ammonium:H 2 O:CO 2 =1:0.9:0.4:15:4.8, 5.83 g of magnesium hydroxide, 7.02 g of aluminum hydroxide, 13.12 g of N-acryloyl-N-propyl lauric acid ammonium, and 27.0 g of deionized water were added into a supercritical reaction kettle, and stirred at a stirring rate of 120 r / min at room temperature for 45 min. Then, 10.75 L of carbon dioxide gas was introduced into the reaction kettle to make the pressure in the kettle 8.5 MPa, and the temperature was raised to 50 °C and reacted for 30 min to obtain a reaction product; during the reaction process, nitrogen gas was introduced to keep the pressure in the kettle at 8.5 MPa; the reaction product was filtered and washed with deionized water until the pH of the filtrate was 7.0. Then, the solid product was dried at 120 °C for 12 h and finally calcined at 580 °C for 3 h to obtain the magnesium oxide-aluminum oxide composite catalyst, and the yield was 99.8%;

[0034] Castor oil, triphenylmethanol, and the magnesium oxide-aluminum oxide composite catalyst were added into a reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:4, and the dosage of the magnesium oxide-aluminum oxide composite catalyst was 1.0 wt% of the total mass of castor oil and triphenylmethanol. After reacting for 3.0 h under the conditions of a temperature of 170 °C, a pressure of 2.5 kPa, and a stirring rate of 300 n / min, heating, stirring, and pressure relief were stopped, and it was cooled to room temperature. The catalyst and unreacted triphenylmethanol were removed by filtration. The filtrate was layered, and the upper layer liquid was taken to obtain the castor oil-based plasticizer. The yield of the castor oil-based plasticizer was 99.9%.

[0035] Example 3

[0036] A preparation method of a castor oil-based plasticizer, comprising the following steps:

[0037] According to a molar ratio of Mg(OH) 2 :Al(OH) 3 :ammonium N - acryloyl - N - propyllaurate:H 2 O:CO 2 =1:1:0.3:20:4.5, 5.83 g of magnesium hydroxide, 7.8 g of aluminum hydroxide, 9.84 g of ammonium N - acryloyl - N - propyllaurate and 36.0 g of deionized water were added to a supercritical reactor, stirred at a stirring rate of 100 r / min for 60 min at room temperature, then 10.08 L of carbon dioxide gas was introduced into the reactor to make the pressure in the reactor 10 MPa, heated to 80 °C and reacted for 15 min to obtain a reaction product; during the reaction, the pressure in the reactor was maintained at 10 MPa by introducing nitrogen; the reaction product was filtered and washed with deionized water until the pH of the filtrate was 7.0, then the solid product was dried at 100 °C for 12 h, and finally calcined at 550 °C for 2 h to obtain a magnesium oxide - aluminum oxide composite catalyst, and the yield was 99.6%;

[0038] Castor oil, triphenylmethanol and the magnesium oxide - aluminum oxide composite catalyst were added into a reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:4.5, and the dosage of the magnesium oxide - aluminum oxide composite catalyst was 0.5 wt% of the total mass of castor oil and triphenylmethanol. At a temperature of 150 °C, a pressure of 1.0 kPa and a stirring rate of 400 n / min, after reacting for 1.0 h, heating was stopped, stirring was carried out, the pressure was released, cooled to room temperature, the catalyst and unreacted triphenylmethanol were removed by filtration, the filtrate was layered, and the upper layer liquid was taken to obtain the castor oil - based plasticizer, and the yield of the castor oil - based plasticizer was 99.7%.

[0039] Example 4

[0040] A preparation method of a castor oil - based plasticizer, comprising the following steps:

[0041] According to a molar ratio of Mg(OH) 2 :Al(OH) 3 :ammonium N - acryloyl - N - propyllaurate:H 2 O:CO 2= 1:0.85:0.45:18:4.6, 5.83 g of magnesium hydroxide, 6.63 g of aluminum hydroxide, 14.76 g of N - acryloyl - N - propyl laurate, and 32.4 g of deionized water were added to a supercritical reactor. Stir at a rate of 110 r / min for 50 min at room temperature, then introduce 10.3 L of carbon dioxide gas into the reactor to make the pressure in the reactor 8 MPa, heat up to 50 °C and react for 45 min to obtain the reaction product; during the reaction process, the pressure in the reactor was maintained at 8 MPa by introducing nitrogen gas; the reaction product was filtered and washed with deionized water until the pH of the filtrate was 7.0, then the solid product was dried at 120 °C for 12 h, and finally calcined at 580 °C for 3 h to obtain the magnesium oxide - aluminum oxide composite catalyst, with a yield of 99.7%;

[0042] Castor oil, triphenylmethanol, and the magnesium oxide - aluminum oxide composite catalyst were added to the reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:3.8, and the dosage of the magnesium oxide - aluminum oxide composite catalyst was 0.8 wt% of the total mass of castor oil and triphenylmethanol. At a temperature of 160 °C, a pressure of 1.8 kPa, and a stirring rate of 450 n / min, after reacting for 2.5 h, stop heating, stirring, relieve the pressure, cool to room temperature, filter to remove the catalyst and unreacted triphenylmethanol, the filtrate is layered, and the upper layer liquid is taken to obtain the castor oil - based plasticizer, with a yield of the castor oil - based plasticizer of 99.6%.

[0043] Example 5

[0044] A preparation method of a castor oil - based plasticizer, comprising the following steps:

[0045] According to the molar ratio of Mg(OH) 2 :Al(OH) 3 :N - acryloyl - N - propyl laurate:H 2 O:CO 2 = 1:0.95:0.35:17:4.8, 5.83 g of magnesium hydroxide, 7.41 g of aluminum hydroxide, 11.48 g of N - acryloyl - N - propyl laurate, and 30.6 g of deionized water were added to a supercritical reactor. Stir at a rate of 115 r / min for 55 min at room temperature, then introduce 10.8 L of carbon dioxide gas into the reactor to make the pressure in the reactor 9 MPa, heat up to 65 °C and react for 55 min to obtain the reaction product; during the reaction process, the pressure in the reactor was maintained at 9 MPa by introducing nitrogen gas; the reaction product was filtered and washed with deionized water until the pH of the filtrate was 7.0, then the solid product was dried at 110 °C for 24 h, and finally calcined at 600 °C for 2 h to obtain the magnesium oxide - aluminum oxide composite catalyst, with a yield of 99.6%;

[0046] Castor oil, triphenylmethanol, and a magnesium oxide-aluminum oxide composite catalyst were added into a reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:4.3, and the dosage of the magnesium oxide-aluminum oxide composite catalyst was 0.7 wt% of the total mass of castor oil and triphenylmethanol. At a temperature of 175 °C, a pressure of 2.0 kPa, and a stirring rate of 500 n / min, after reacting for 3.0 h, heating was stopped, stirring was carried out, the pressure was released, and it was cooled to room temperature. The catalyst and unreacted triphenylmethanol were removed by filtration. The filtrate was separated into layers, and the upper layer liquid was taken to obtain the castor oil-based plasticizer. The yield of the castor oil-based plasticizer was 99.5%.

[0047] Comparative Example 1

[0048] A preparation method of a castor oil-based plasticizer includes the following steps:

[0049] According to the molar ratio in Example 2, Mg(OH) 2 :Al(OH) 3 :N-acryloyl-N-propyl lauric acid ammonium:H 2 O:CO 2 =1:0.9:0.4:15:4.8, 5.83 g of magnesium hydroxide, 7.02 g of aluminum hydroxide, 13.12 g of N-acryloyl-N-propyl lauric acid ammonium, and 27.0 g of deionized water were added into a supercritical reaction kettle. It was stirred at a stirring rate of 120 r / min at room temperature for 45 min, and then the temperature was raised to 50 °C. Carbon dioxide gas with a flow rate of 0.25 L / min was continuously introduced into the reaction kettle for 43 min. The amount of carbon dioxide introduced was 10.75 L. The carbon dioxide was bubbled in from the bottom of the kettle through a gas pipe and discharged from the top of the kettle. The pressure in the kettle was maintained at 0.1 MPa. The product was filtered and washed with deionized water until the pH of the filtrate was 7.0. Then the solid product was dried at 120 °C for 12 h and finally calcined at 580 °C for 3 h to obtain the magnesium oxide-aluminum oxide composite catalyst, and the yield was 99.5%;

[0050] Castor oil, triphenylmethanol, and the magnesium oxide-aluminum oxide composite catalyst were added into a reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:4, and the dosage of the magnesium oxide-aluminum oxide composite catalyst was 1.0 wt% of the total mass of castor oil and triphenylmethanol. At a temperature of 170 °C, a pressure of 2.5 kPa, and a stirring rate of 300 n / min, after reacting for 3.0 h, heating was stopped, stirring was carried out, the pressure was released, and it was cooled to room temperature. The catalyst and unreacted triphenylmethanol were removed by filtration. The filtrate was separated into layers, and the upper layer liquid was taken to obtain the castor oil-based plasticizer. The yield of the castor oil-based plasticizer was 65.2%.

[0051] Comparative Example 2

[0052] A preparation method of a castor oil-based plasticizer, comprising the following steps:

[0053] According to the molar ratio of CsOH:Ca(OH) 2 :N-butyryl-N-butyldodecylammonium acid:H 2 O:CO 2 =1:0.7:1.6:35:2.8, add 8.5 g of cesium hydroxide, 1.6 g of calcium hydroxide, 17.2 g of N-butyryl-N-butyldodecylammonium acid and 18.9 g of deionized water to a supercritical reactor, stir at a stirring rate of 100 r / min for 60 min at room temperature, then introduce 1.88 L of carbon dioxide gas into the reactor to make the pressure in the reactor 8 MPa, heat up to 70 °C and react for 45 min to obtain a reaction product; during the reaction process, keep the pressure in the reactor at 8 MPa by introducing nitrogen; filter the reaction product and wash it with deionized water until the pH of the filtrate is 7.0, then dry the solid product at 100 °C for 20 h, and finally calcine it at 600 °C for 2 h to obtain a cesium oxide-calcium oxide composite catalyst, with a yield of 99.8%.

[0054] Add castor oil, triphenylmethanol and the cesium oxide-calcium oxide composite catalyst into a reaction vessel. The molar ratio of castor oil to triphenylmethanol is 1:4, and the dosage of the cesium oxide-calcium oxide composite catalyst is 1.0 wt% of the total mass of castor oil and triphenylmethanol. After reacting for 3.0 h under the conditions of a temperature of 170 °C, a pressure of 2.5 kPa, and a stirring rate of 300 n / min, stop heating, stirring, relieve the pressure, cool to room temperature, filter to remove the catalyst and unreacted triphenylmethanol, the filtrate is layered, and the upper layer liquid is taken to obtain the castor oil-based plasticizer, with a yield of the castor oil-based plasticizer of 90.3%.

[0055] Comparative Example 3

[0056] A preparation method of a castor oil-based plasticizer, comprising the following steps:

[0057] According to the molar ratio in Example 2, without adding an aluminum source, and keeping the molar ratios of other raw materials unchanged, prepare a nano-magnesium oxide catalyst: the molar ratio is Mg(OH) 2 :N-acryloyl-N-propyl laurate:H 2 O:CO 2= 1:0.4:15:4.8, 5.83 g of magnesium hydroxide, 13.12 g of N - acryloyl - N - propyl laurate, and 27.0 g of deionized water were added to a supercritical reactor. Stir at a rate of 120 r / min at room temperature for 45 min, then introduce 10.75 L of carbon dioxide gas into the reactor to make the pressure in the reactor 8.5 MPa, heat up to 50 °C and react for 30 min to obtain a reaction product; during the reaction process, the pressure in the reactor was maintained at 8.5 MPa by introducing nitrogen gas; the reaction product was filtered and washed with deionized water until the pH of the filtrate was 7.0, then the solid product was dried at 120 °C for 12 h, and finally calcined at 580 °C for 3 h to obtain a nano - magnesium oxide catalyst, and the yield was 99.9%;

[0058] Castor oil, triphenylmethanol, and the nano - magnesium oxide catalyst were added to the reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:4, and the dosage of the nano - magnesium oxide catalyst was 1.0 wt% of the total mass of castor oil and triphenylmethanol. After reacting for 3.0 h under the conditions of a temperature of 170 °C, a pressure of 2.5 kPa, and a stirring rate of 300 n / min, heating, stirring, and pressure relief were stopped, and it was cooled to room temperature. The catalyst and unreacted triphenylmethanol were removed by filtration. The filtrate was layered, and the upper layer liquid was taken to obtain the castor oil - based plasticizer, and the yield of the castor oil - based plasticizer was 89.3%.

[0059] Comparative Example 4

[0060] A preparation method of a castor oil - based plasticizer, comprising the following steps:

[0061] According to the molar ratio in Example 2, without adding a magnesium source, and keeping the molar ratios of other raw materials unchanged, a nano - aluminum oxide catalyst was prepared: the molar ratio was Al(OH) 3 : N - acryloyl - N - propyl laurate: H 2 O: CO 2 = 0.9:0.4:15:4.8, 7.02 g of aluminum hydroxide, 13.12 g of N - acryloyl - N - propyl laurate, and 27.0 g of deionized water were added to a supercritical reactor. Stir at a rate of 120 r / min at room temperature for 45 min, then introduce 10.75 L of carbon dioxide gas into the reactor to make the pressure in the reactor 8.5 MPa, heat up to 50 °C and react for 30 min to obtain a reaction product; during the reaction process, the pressure in the reactor was maintained at 8.5 MPa by introducing nitrogen gas; the reaction product was filtered and washed with deionized water until the pH of the filtrate was 7.0, then the solid product was dried at 120 °C for 12 h, and finally calcined at 580 °C for 3 h to obtain a nano - aluminum oxide catalyst, and the yield was 99.8%;

[0062] Castor oil, triphenylmethanol and nano-alumina catalyst were added into a reaction vessel. The molar ratio of castor oil to triphenylmethanol was 1:4, and the amount of nano-alumina catalyst was 1.0 wt% of the total mass of castor oil and triphenylmethanol. After 3.0 h of reaction at a temperature of 170°C, a pressure of 2.5 kPa, and a stirring rate of 300 n / min, heating was stopped, stirring was performed, the pressure was released, and the mixture was cooled to room temperature. The catalyst and unreacted triphenylmethanol were removed by filtration, and the filtrate was separated into layers. The upper layer was taken to obtain a castor oil-based plasticizer, and the yield of the castor oil-based plasticizer was 85.0%.

[0063] Figure 1 The XRD patterns of the magnesium oxide-aluminum oxide composite catalysts prepared in Example 2 and Comparative Example 1 are shown in FIG. Figure 1 It can be seen that the intensity of each characteristic peak in Example 2 is significantly stronger than that in Comparative Example 1, and the characteristic peaks are sharp, indicating that its crystallinity is high.

[0064] Figure 2 The infrared spectrum of the castor oil-based plasticizer obtained by the reaction of Example 2. The infrared spectrum of the castor oil-based plasticizers obtained in other examples of the present application are the same as Figure 2 According to the literature on the positions of characteristic peaks of infrared spectra of different compound groups, 3423.58 cm -1 The absorption peak of hydroxyl group -OH is at 3007.73 cm -1 The C=C absorption peaks are at 2926.54 and 2854.99 cm -1 The stretching vibration peak of CH in methyl and methylene is at 1744.19 cm -1 Ester The vibration peak of -1 and 1460.54 cm -1 The absorption peak of benzene ring C=C is 724.06 cm -1 and 681.20cm -1 The absorption peak of benzene ring = CH is at the center. Combined with the structural formula of triphenylmethyl ricinoleate, benzene ring, ester group, carbon-carbon double bond, hydroxyl group, methyl group and methylene group all appear in the infrared spectrum, which fully proves that triphenylmethyl ricinoleate has been successfully prepared.

[0065] The surface base content, grain size and specific surface area of ​​the catalysts prepared by testing Examples 1-4 and Comparative Examples 1-4 were as follows: 2 -TPD characterization was used to measure the surface alkali content of the composite catalyst, BET characterization was used to obtain the specific surface area of ​​the catalyst, and SEM characterization was used to obtain the grain size. The results are shown in Table 1:

[0066] Table 1

[0067]

[0068] As can be seen from the test results in Table 1, compared with Comparative Example 1, the magnesium oxide-aluminum oxide composite catalysts prepared in Examples 1-4 of the present application have the advantages of small grain size, large specific surface area, large total base amount, large weak base amount, and high yield. This is because supercritical carbon dioxide fluid has high solubility and high diffusivity, which is conducive to the full and rapid contact and reaction between reactants, and the product has a high degree of dispersion, avoiding the agglomeration phenomenon between nanoparticles, thereby inhibiting the increase in grain size and increasing the number of basic active sites exposed on the surface. In Comparative Example 1, in the method of introducing carbon dioxide under normal pressure, the solubility of carbon dioxide in water is low, normal pressure carbon dioxide gas has no solubility for salt substances, and the raw materials magnesium hydroxide and aluminum hydroxide are not easily soluble in water. Therefore, carbon dioxide does not play any role in the whole operation process, and finally, only the raw materials magnesium hydroxide and aluminum hydroxide are calcined at high temperature to obtain the magnesium oxide-aluminum oxide composite catalyst. At the same time, as can also be seen from the test results in Table 1, the magnesium oxide-aluminum oxide composite catalysts prepared in Examples 1-4 of the present application have weak base and medium strong base sites on the surface, while the cesium oxide-calcium oxide composite catalyst prepared in Comparative Example 2 has weak base and strong base sites on the surface. The total base amount of the composite catalyst in Examples 1-4 is higher than that in Comparative Example 2, and the grain size is smaller and the specific surface area is larger than that in Comparative Example 2.

[0069] It can be known from the comparison between the examples and Comparative Example 1 that the magnesium oxide-aluminum oxide composite catalyst prepared by the supercritical carbon dioxide method has the advantages of small grain size, large specific surface area, large total base amount, and large weak base amount, which is conducive to catalyzing the transesterification reaction of castor oil and triphenylmethanol to obtain a higher yield of castor oil-based plasticizer and has excellent catalytic performance; the total base amount and weak base amount of the cesium oxide-calcium oxide composite catalyst prepared in Comparative Example 2 are less, and the specific surface area is smaller, so the catalytic performance is weaker than that of the examples.

[0070] For the nano-magnesium oxide and nano-aluminum oxide prepared in Comparative Example 3 and Comparative Example 4, the yield of castor oil-based plasticizer is low due to the small total base amount; for the magnesium oxide-aluminum oxide composite catalyst prepared in the examples, due to the synergistic effect of magnesium oxide and aluminum oxide, some strong base sites and all weak base sites on the pure nano-magnesium oxide and nano-aluminum oxide are converted into medium strong base sites, and the total base amount increases, so the catalytic performance is excellent and the yield of castor oil-based plasticizer is high.

[0071] Furthermore, a performance comparison was made between the castor oil-based plasticizer: triphenylmethyl ricinoleate prepared in Example 2 of the present application and the most widely used general-purpose plasticizer dioctyl phthalate: The viscosity and flash point were measured using a viscosity and flash point tester respectively, the migration amount was detected according to the GB / T 21911 standard, and the volatilization loss and extraction loss of the plasticizer were measured by the hot air method. The results are shown in Table 2:

[0072] Table 2

[0073]

[0074] As can be seen from the measurement data in Table 2, the castor oil-based plasticizer prepared by the embodiments of the present application has the advantages of large molecular weight, high viscosity, high flash point, low volatility, extraction resistance, migration resistance, etc.

[0075] The above embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

[0076] The foregoing is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A method for preparing a plastic additive castor oil-based plasticizer, characterized in that: include: Castor oil, triphenylmethanol and magnesium oxide-aluminum oxide composite catalyst are added into a reaction container, reacted for 1.0-3.0 h at a temperature of 150-180° C., a pressure of 1.0-2.5 kPa and a stirring rate of 300-500 n / min, filtered and the upper layer liquid is taken to obtain a castor oil-based plasticizer; Wherein, the molar ratio of castor oil to triphenylmethanol is 1: (3.5-4.5); the amount of the magnesium oxide-aluminum oxide composite catalyst is 0.3-1.0 wt% of the total mass of castor oil and triphenylmethanol.

2. The method for preparing a plastic additive castor oil-based plasticizer according to claim 1, characterized in that: The amount of the magnesium oxide-aluminum oxide composite catalyst used is 1.0 wt% of the total mass of castor oil and triphenylmethanol.

3. The method for preparing a plastic additive castor oil-based plasticizer according to claim 1, characterized in that: The molar ratio of castor oil to triphenylmethanol is 1:

4.

4. The method for preparing a castor oil-based plasticizer as a plastic additive according to claim 1, characterized in that: The temperature was 170 °C, the pressure was 2.5 kPa, and the stirring rate was 300 n / min.

5. The method for preparing a plastic additive castor oil-based plasticizer according to claim 1, characterized in that: The magnesium oxide-aluminum oxide composite catalyst is prepared by reacting magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl ammonium laurate, deionized water and carbon dioxide for 15-60 min at a temperature of 30-80° C. and a pressure of 7-10 MPa, washing the obtained product to neutrality, drying and calcining the product.

6. The method for preparing the plastic additive castor oil-based plasticizer according to claim 5, characterized in that: The molar ratio of the magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl ammonium laurate, deionized water and carbon dioxide is 1:(0.8-1.0):(0.3-0.5):(10.0-20.0):(4.5-5.0).

7. The method for preparing a plastic additive castor oil-based plasticizer according to claim 6, characterized in that: The molar ratio of the magnesium hydroxide, aluminum hydroxide, N-acryloyl-N-propyl ammonium laurate, deionized water and carbon dioxide is 1:0.9:0.4:15:4.

8.

8. The method for preparing a plastic additive castor oil-based plasticizer according to claim 5, characterized in that: The reaction was carried out at a temperature of 50°C and a pressure of 8.5 MPa for 30 min.

9. The method for preparing a castor oil-based plasticizer as a plastic additive according to claim 5, characterized in that: The drying temperature is 100-120℃ and the drying time is 12-24 h.

10. The method for preparing the plastic additive castor oil-based plasticizer according to claim 5, characterized in that: The calcination temperature is 550-600°C and the calcination time is 1-3 h.

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