Polyhydroxy ester plasticizer as well as preparation method and application thereof
By preparing polyhydroxy ester plasticizers through esterification, the environmental problems of phthalate plasticizers are solved, and the performance and processing stability of non-toxic and environmentally friendly PVC materials are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGDONG UNIV OF TECH
- Filing Date
- 2025-12-10
- Publication Date
- 2026-04-10
AI Technical Summary
Existing phthalate plasticizers are environmentally unfriendly and prone to migration, which leads to reduced performance of PVC materials and restricts their use.
A method for preparing polyhydroxy ester plasticizers is adopted, which involves reacting dipentaerythritol, tripentaerythritol, bis(trimethylol)propane or tri(trimethylol)propane with acid anhydrides or carboxylic acids through esterification reaction to prepare polyhydroxy ester plasticizers. After treatment with specific catalysts and dehydrating agents, non-toxic and environmentally friendly plasticizers are obtained.
Polyhydroxy ester plasticizers have good compatibility and mechanical properties with resins, low migration, and improve the processing stability and optical properties of PVC materials, reduce production costs, and expand the range of applications.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of polymer material application, and particularly relates to a polyhydroxy ester plasticizer and a preparation method and application thereof. BACKGROUND
[0002] The addition of plasticizers to polymeric resins can effectively change the modulus, tensile strength, elongation at break, impact strength, flexibility and other properties of the resin material. Plasticizers can significantly change the glass transition temperature of the polymeric resin and improve the processability of the polymeric resin material.
[0003] PVC is one of the three most important general-purpose plastics in the world. According to the different amounts of plasticizers added, PVC products are divided into hard PVC and soft PVC.
[0004] Phthalate esters are commonly used plasticizers, and the market share of phthalate ester plasticizers in PVC materials is about 70%. Phthalate ester plasticizers have the characteristics of high migration rate, and phthalate ester plasticizers have certain toxicity to the nervous system and reproductive system and are difficult to be biodegraded. In many countries and regions, the use of phthalate ester plasticizers has been restricted and banned.
[0005] With the rapid development of the PVC plastic product industry in China, the market demand for plasticizers continues to grow, and China has become the largest plasticizer producer and consumer in Asia. Under this background, developing safe, environmentally friendly and alternative traditional phthalate ester plasticizers has become the clear direction of the industry development and the inevitable requirement of social sustainable development. SUMMARY
[0006] In order to overcome the environmental unfriendly problem of widely using phthalate ester plasticizers and the shortcoming and deficiency of reducing the performance of PVC materials caused by easy migration in the prior art, the primary purpose of the present application is to provide a preparation method of a polyhydroxy ester plasticizer.
[0007] Another purpose of the present application is to provide a polyhydroxy ester plasticizer prepared by the above preparation method.
[0008] Still another purpose of the present application is to provide an application of the above polyhydroxy ester plasticizer.
[0009] The purposes of the present application are achieved by the following technical solutions. A method for preparing a polyhydroxy ester plasticizer, according to the following steps: using dipentaerythritol, tripentaerythritol, di (trimethylol) propane or tri (trimethylol) propane as a substrate reactant, and reacting with an acid anhydride R1-C (O) -O-C (O) -R2 or a carboxylic acid R3-C (O) -OH to obtain a polyhydroxy ester plasticizer; wherein R1, R2, R3 are linear alkanes or branched alkanes with carbon atom number of 2-18, R1, R2, R3 can be the same or different.
[0010] The substrate reactant is calculated by the amount of hydroxyl group, the carboxylic acid is calculated by the amount of anhydride group, and the acid anhydride is calculated by the amount of anhydride group. The molar ratio of substrate reactant to acid anhydride is 1:0.5-3, preferably 1:0.5-2; the molar ratio of substrate reactant to carboxylic acid is 1:1-4, preferably 1:1-3.
[0011] The esterification reaction is specifically carried out according to the following steps: (1) adding the substrate reactant and the acid anhydride to the reaction kettle and adding the catalyst to obtain the reaction mixture; or adding the substrate reactant and the carboxylic acid to the reaction kettle and adding the catalyst, and then adding the water-carrying agent to obtain the reaction mixture; (2) carrying out the esterification reaction of the reaction mixture obtained in step (1) at a temperature of 60-250°C for 20 min-48 h in a nitrogen atmosphere.
[0012] The catalyst in step (1) is one or more of triethylamine, 4-dimethylaminopyridine, concentrated sulfuric acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, Amberlyst acidic ion exchange resin, dibutyltin dilaurate, tetrabutyl titanate or molecular sieve; preferably one or more of 4-dimethylaminopyridine, p-toluenesulfonic acid, trifluoromethanesulfonic acid and Amberlyst-36 acidic ion exchange resin; the amount of catalyst is 0.2-20 wt% of the substrate reactant; the water-carrying agent is benzene, toluene, xylene, cyclohexane, n-heptane, chloroform, preferably toluene and cyclohexane; the amount of water-carrying agent is 10-800% of the substrate reactant.
[0013] The esterification reaction in step (2) is carried out at a temperature of 70-150°C for 40 min-8 h.
[0014] After the esterification reaction is completed, the obtained product is first washed with an alkaline aqueous solution, and then separated into liquid and liquid after washing. After separation, water is absorbed in the organic phase by adding a water removal agent, and the obtained organic liquid is filtered to obtain a polyhydroxy ester plasticizer.
[0015] The basic aqueous solution is an aqueous solution of sodium carbonate, sodium hydroxide, potassium hydroxide, sodium bicarbonate, ammonia or sodium sulfide; the basic aqueous solution is an aqueous solution with a mass concentration of 0.2-50%, and the amount of the basic aqueous solution is 50-1500 wt% of the obtained product; the water removing agent is one or more of anhydrous magnesium sulfate, anhydrous sodium sulfate, calcium oxide, calcium chloride, molecular sieves, silica gel, activated alumina, phosphorus pentoxide, anhydrous copper sulfate, anhydrous calcium chloride, calcium chloride and calcium sulfate.
[0016] A polyhydroxy ester plasticizer prepared by the preparation method.
[0017] Application of the polyhydroxy ester plasticizer in preparing resin products.
[0018] The application is mixing 1-300 parts by weight of the polyhydroxy ester plasticizer and 100 parts by weight of a thermoplastic resin, and other resins, auxiliaries, fillers, etc. can be used according to actual needs or to improve other properties, and the corresponding resin products can be obtained by combining conventional preparation processes.
[0019] The polyhydroxy ester plasticizer can be directly used as a plasticizer for polyvinyl chloride (PVC), and soft or hard PVC materials can be prepared with PVC resin.
[0020] The present application has the following advantages and effects relative to the prior art: (1) The polyhydroxy ester plasticizer prepared by the present application has good compatibility with resins and resin-containing polymers, and the resin material has good mechanical properties, optical properties, thermal stability, and also shows a lower tendency to migrate.
[0021] (2) The present application develops a new plasticizer without benzene ring, avoids the use of harmful plasticizers that are banned or limited at home and abroad, has the characteristics of non-toxic, environmental protection, green and safe process, and has a broad application prospect.
[0022] (3) The initial weight loss temperature of the polyhydroxy ester plasticizer prepared by the present application is obviously improved compared with the commercially available plasticizer, and the maximum weight loss rate temperature is also higher, thereby improving the processing window period of the PVC material. Due to the improvement of stability, the use of stabilizers can be reduced, thereby reducing the production cost, and further improving the service life of the processing equipment. BRIEF DESCRIPTION OF DRAWINGS
[0023] Figure 1 The infrared spectrum of the polyhydroxy ester plasticizer H4C4 obtained in Example 1.
[0024] Figure 2 The nuclear magnetic hydrogen spectrum of the polyhydroxy ester plasticizer H4C4 obtained in Example 1.
[0025] Figure 3 The infrared spectrum of the polyhydroxy ester plasticizer H4C7 obtained in Example 2.
[0026] Figure 4 The nuclear magnetic hydrogen spectrum of the polyhydroxy ester plasticizer H4C7 obtained in Example 2.
[0027] Figure 5 The infrared spectrum of the existing polyhydroxy ester plasticizer H3C7 obtained in Comparative Example 1.
[0028] Figure 6 The nuclear magnetic hydrogen spectrum of the existing polyhydroxy ester plasticizer H3C7 obtained in Comparative Example 1.
[0029] Figure 7 The stability TG, DTG diagrams of Example 1, Example 2, Comparative Example 1, and the commercially available plasticizer DOP. DETAILED DESCRIPTION
[0030] The present application will be further described in conjunction with specific examples, but should not be construed as a limitation of the present application.
[0031] The preparation method of one of the polyhydroxy ester plasticizers in the following examples is as follows: esterification reaction of a double pentaerythritol, a triple pentaerythritol, a double (trihydroxymethyl) propane, or a triple (trihydroxymethyl) propane as a substrate reactant with an acid anhydride R1-C(O)-O-C(O)-R2 or a carboxylic acid R3-C(O)-OH to obtain a polyhydroxy ester plasticizer; wherein R1, R2, and R3 are linear alkanes or branched alkanes with a carbon atom number of 2-18, and R1, R2, and R3 can be the same or different.
[0032] The substrate reactant is calculated in terms of the amount of hydroxyl group, the carboxylic acid is calculated in terms of the amount of acid anhydride group, and the acid anhydride is calculated in terms of the amount of carbon-oxygen double bond acyl carbonyl bond. The feeding molar ratio of the substrate reactant to the acid anhydride is 1:0.5-4, preferably 1:0.5-3; and the feeding molar ratio of the substrate reactant to the carboxylic acid is 1:0.5-5, preferably 1:1-3.
[0033] The double pentaerythritol has the following structural formula:
[0034] The double (trihydroxymethyl) propane has the following structural formula:
[0035] The triple pentaerythritol has the following structural formula:
[0036] The triple (trihydroxymethyl) propane has the following structural formula:
[0037] The reaction formula of the esterification reaction of the substrate reactant (for example, bis (trimethylol) propane) with an acid anhydride R1-C(O)-O-C(O)-R2 is as follows:
[0038] The reaction formula of the esterification reaction of the substrate reactant (for example, bis (trimethylol) propane) with a carboxylic acid R3-C(O)-OH is as follows:
[0039] The esterification reaction is specifically performed according to the following steps: (1) the substrate reactant and the acid anhydride are added to a reaction kettle and a catalyst is added to obtain a reaction mixture; or the substrate reactant and the carboxylic acid are added to a reaction kettle and a catalyst is added, and then a water-carrying agent is added to obtain a reaction mixture; (2) the reaction mixture obtained in step (1) is subjected to an esterification reaction at a temperature of 60-250°C (preferably 70-150°C) for 20 min-24 h (preferably 40 min-8 h) in a nitrogen atmosphere.
[0040] The catalyst is one or more of triethylamine, 4-dimethylaminopyridine, concentrated sulfuric acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, Amberlyst acidic ion exchange resin, dibutyltin dilaurate, tetrabutyl titanate or molecular sieve catalyst, preferably one or more of 4-dimethylaminopyridine, p-toluenesulfonic acid and Amberlyst-36 acidic ion exchange resin; the amount of the catalyst used is 0.5-20% by weight of the substrate reactant; the water-carrying agent is benzene, toluene, xylene, cyclohexane, n-heptane or chloroform, preferably toluene or cyclohexane; the amount of the water-carrying agent used is 10-800% of the substrate reactant.
[0041] Under the above reaction conditions, the reaction product can be efficiently obtained. Generally, a small amount of unreacted substance and catalyst will exist in the prepared polyhydroxy ester plasticizer, but no by-product will be produced.
[0042] After the esterification reaction is completed, the obtained product is first washed with an alkaline aqueous solution, then separated into two phases, a water-removing agent is added to the organic phase to fully absorb the water, and the organic liquid is obtained by filtration, which is the polyhydroxy ester plasticizer.
[0043] The basic aqueous solution is an aqueous solution of sodium carbonate, sodium hydroxide, potassium hydroxide, sodium bicarbonate, ammonia or sodium sulfide; the basic aqueous solution is an aqueous solution with a mass concentration of 0.5-50%, preferably an aqueous solution of sodium carbonate or sodium bicarbonate with a mass concentration of 5-30%; the amount of the basic aqueous solution is 50-1500 wt% of the obtained product; the water removing agent is one or more of anhydrous magnesium sulfate, anhydrous sodium sulfate, calcium oxide, calcium chloride, molecular sieve, silica gel, activated alumina, phosphorus pentoxide, anhydrous copper sulfate, anhydrous calcium chloride, calcium chloride and calcium sulfate, preferably anhydrous magnesium sulfate, anhydrous sodium sulfate or molecular sieve.
[0044] After the water removing agent sufficiently absorbs the water in the compound, the water removing agent is filtered to obtain the desired polyhydroxy ester plasticizer.
[0045] The polyhydroxy ester plasticizer prepared by the present application can be used alone as a plasticizer, or two or more can be mixed as a plasticizer. For further improvement, the polyhydroxy ester plasticizer can be further mixed with a commonly used commercially available plasticizer to be used as a polyhydroxy ester plasticizer composition.
[0046] Commonly used commercially available plasticizers include dioctyl phthalate (DOP), diisodecyl phthalate (DIDP), dibutyl phthalate (DBP), diisononyl phthalate (DINP), trioctyl trimellitate (TOTM), tricresyl phosphate (TCP), triphenyl phosphate (TPP), trioctyl phosphate (TOP), diisononyl cyclohexane 1,2-dicarboxylate (DINCH), chlorinated paraffin (CP), and commercially available plasticizers more suitable for compounding with polyhydroxy ester plasticizers include epoxy soybean oil (ESO), epoxidized soybean oil (ESBO), epoxy butyl oleate (EBO), epoxidized linseed oil (ELO), acetyl tri-butyl citrate (ATBC), triethyl citrate (TEC), dioctyl adipate (DOA), dioctyl sebacate (DOS), etc.
[0047] Suitable thermoplastic resins are preferably polyvinyl chloride (PVC), homo- or copolymers based on ethylene, propylene, butadiene, vinyl acetate, glycidyl acrylate, glycidyl methacrylate, ethyl acrylate, butyl acrylate or methacrylate with alkoxy groups of branched or linear alcohols with 1 to 10 carbon atoms, acrylonitrile or cyclic olefins, chlorosulfonated polyethylene, polyvinylidene fluoride (PVDC), polyacrylate (in particular polymethyl methacrylate (PMMA)), polyalkyl methacrylate (PAMA), polyurea, silylated polymers, fluoropolymers (in particular polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl acetate (PVAc), polyvinyl alcohol (PVA)), polyvinyl acetal (in particular polyvinyl butyral (PVB), polystyrene polymers, in particular polystyrene (PS), expandable polystyrene (EPS), acrylonitrile-styrene-acrylate (ASA), styrene-acrylonitrile (SAN), acrylonitrile-butadiene-styrene (ABS), styrene-maleic anhydride copolymer (SMA)), styrene-methacrylic acid copolymer, polyolefins (in particular polyethylene (PE) or polypropylene (PP)), thermoplastic polyolefins (TPO), polyethylene-vinyl acetate (EVA), polycarbonate, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyoxymethylene (POM), polyamide (PA), polyethylene glycol (PEG), polyurethane (PU), thermoplastic polyurethane (TPU), polysulfide (PSu), biopolymers (in particular polylactic acid (PLA), polyhydroxybutyrate (PHB), polyhydroxyvalerate (PHV), polyesters), starch, cellulose and cellulose derivatives (in particular nitrocellulose (NC), ethyl cellulose (EC), cellulose acetate (CA), cellulose acetate / butyrate (CAB)), rubber and silicone.
[0048] Preferred thermoplastic resins are polyvinyl chloride, copolymers of vinyl chloride with vinyl acetate or with butyl acrylate, polyalkyl methacrylate (PAMA), polyvinyl butyral (PVB), chlorosulfonated polyethylene, polyurethane, polysulfide, polylactic acid (PLA), polyhydroxybutyrate (PHB) and nitrocellulose.
[0049] It is particularly preferred according to the present application that PVC or a copolymer composition containing vinyl chloride is used as the thermoplastic resin.
[0050] The present application also provides a resin composition comprising said polyol ester plasticizer or composition and a resin, wherein the resin can be one or more.
[0051] The resin composition can further include a filler; the amount of the filler can be 0 to 400 parts by weight, preferably 10 to 200 parts by weight, and more preferably 50 to 200 parts by weight, based on 100 parts by weight of the resin.
[0052] The content of the polyhydroxy ester-based plasticizer can be 2 to 150 parts by weight, based on 100 parts by weight of the resin.
[0053] The filler can be a conventional filler known in the art without specific limitation. For example, a mixture of one or more selected from the group consisting of silicon dioxide, magnesium carbonate, calcium carbonate, hard carbon, talc, magnesium hydroxide, titanium dioxide, magnesium oxide, calcium hydroxide, aluminum hydroxide, aluminum silicate, magnesium silicate, and barium sulfate can be used.
[0054] The resin composition can further include other additives, such as a stabilizer, an antioxidant, a flame retardant, etc., as needed.
[0055] Example 1 The present example provides a method for preparing a polyhydroxy ester-based plasticizer according to the following operation steps: 50 g of bis (trihydroxymethyl) propane, 82 g of butyric anhydride, and 2.8 g of p-methylbenzenesulfonic acid are added to a three-necked flask, nitrogen is introduced, and the reaction is carried out under stirring at 100°C, after 6 hours of reaction, the product is washed with a 10% sodium bicarbonate aqueous solution four times, 30 g of anhydrous magnesium sulfate is added to the organic matter, and the moisture is absorbed by shaking, and a colorless, clear, and transparent oil is obtained after filtration, which is the polyhydroxy ester-based plasticizer, named H4C4, and the infrared and nuclear magnetic hydrogen spectrum thereof is tested as shown in Figure 1 and Figure 2 , the chemical structure thereof is determined, and the thermal stability of the synthetic product is tested by thermogravimetry as shown in Figure 7 .
[0056] Example 2 The present example provides a method for preparing a polyhydroxy ester-based plasticizer according to the following operation steps: 50 g of bis (trihydroxymethyl) propane, 82 g of butyric anhydride, and 2.8 g of p-methylbenzenesulfonic acid are added to a three-necked flask, nitrogen is introduced, and the reaction is carried out under stirring at 100°C, after 6 hours of reaction, the product is washed with a 10% sodium bicarbonate aqueous solution four times, 30 g of anhydrous magnesium sulfate is added to the organic matter, and the moisture is absorbed by shaking, and a colorless, clear, and transparent oil is obtained after filtration, which is the polyhydroxy ester-based plasticizer, named H4C4, and the infrared and nuclear magnetic hydrogen spectrum thereof is tested as shown in Figure 3 and Figure 4 , the chemical structure thereof is determined, and the thermal stability of the synthetic product is tested by thermogravimetry as shown in Figure 7 .
[0057] Comparative Example 1 A plasticizer was provided according to the following procedure: Into a three-necked flask, 40 g of trimethylolpropane, 140 g of n-heptanoic acid, 5 g of 4-dimethylaminopyridine and 150 mL of toluene were added, and the reaction was carried out under stirring at 120°C with nitrogen protection. The reaction was terminated when no more water was added to the water trap. The product was washed twice with 10% sodium bicarbonate aqueous solution, and 25 g of anhydrous magnesium sulfate was added to the organic phase to absorb the water therein. After filtration, a yellowish clear transparent oil was obtained, which was a polyhydroxy ester plasticizer, named H3C7. The infrared and nuclear magnetic hydrogen spectrum of the product were tested, as shown in Figure 5 and Figure 6 The thermal stability of the composition was tested by thermogravimetry, and the results are shown in Figure 7 .
[0058] The plasticizers obtained in Examples 1-2 and Comparative Example 1 were used to prepare resin compositions according to the formulations shown in Table 1: Table 1 Formulation table of resin compositions (in parts by weight)
[0059] Examples 3, 4, 5 and Comparative Examples 2, 3, 4, 5, 6 are examples of preparing resin compositions. The PVC S-1000 resin and calcium-zinc stabilizer were weighed according to the formulations shown in Table 1, and were added into a preheated high-speed mixer. The stirring was started (at a speed of 1000-1500 rpm), and when the temperature of the material reached 100°C, the plasticizer (H4C4, H4C7, DOP or ESO) was added into the mixer and the mixing was continued for 8-12 minutes. The mixed material was then discharged. The granules were prepared in a twin-screw extruder. The granules were plasticized in a plasticizer, and the melt was molded into a 0.2 mm sheet for testing its performance.
[0060] The Shore A hardness was determined according to the standard ASTM D2240.
[0061] The resistance of the plasticizer to extraction in different solvents was evaluated using the procedure described in the standard ASTM D1239.
[0062] The universal testing machine was used to test according to the standard GB / T 1040.2-2006.
[0063] The haze and light transmittance were tested according to the standardized method of GB / T 2410-2008.
[0064] The test results are shown in Table 2.
[0065] Table 2 Performance test results
[0066] From the comparison of the Shore A hardness data of Comparative Example 5 and other examples in Table 2, it can be seen that the multi-hydroxy ester plasticizer prepared by the present application can soften PVC as well as the commonly used plasticizers ESO and DOP, which proves that it has good plasticizing effect. From the comparison of the light transmittance and haze data of Comparative Example 5 and other examples, it can be seen that the multi-hydroxy ester plasticizer prepared by the present application has good compatibility with PVC as well as the commonly used plasticizers ESO and DOP, and can improve the optical properties of PVC and expand the application range. From the dissolution rate data of Example 3, Example 4, Comparative Example 2 and Comparative Example 6 in Table 2, it can be seen that the migration rate of the multi-hydroxy ester plasticizer is lower than that of DOP and H3C7. From the data of Comparative Example 5 and Comparative Example 4, it can be seen that the dissolution rate of the multi-hydroxy ester plasticizer compounded with the commonly used environmentally friendly plasticizer ESO is lower. From the comparison of the initial weight loss temperature, it can be seen that the multi-hydroxy ester plasticizer can improve the thermal stability of PVC material. This will further expand the application range.
[0067] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement methods, which are all included in the protection scope of the present application.
Claims
1. A process for the preparation of polyol ester plasticizers, characterized in that According to the following steps: using dipentaerythritol, tripentaerythritol, di (trimethylol) propane or tri (trimethylol) propane as a substrate reactant, and esterifying with an anhydride R1-C (O) -O-C (O) -R2 or a carboxylic acid R3-C (O) -OH to obtain a polyhydroxy ester plasticizer; wherein R1, R2, R3 are linear alkanes or branched alkanes with carbon atom number of 2-18, and R1, R2, R3 can be the same or different.
2. The method for preparing a polyhydroxy ester plasticizer according to claim 1, characterized in that: The substrate reactant is calculated by the amount of hydroxyl, the carboxylic acid is calculated by the amount of anhydride group, and the anhydride is calculated by the amount of carbon-oxygen double bond acyl carbonyl bond. The molar ratio of substrate reactant to anhydride is 1:0.5-3, and the molar ratio of substrate reactant to carboxylic acid is 1:1-4.
3. The method for preparing a polyhydroxy ester plasticizer according to claim 1, characterized in that: The substrate reactant is calculated by the amount of hydroxyl, the carboxylic acid is calculated by the amount of anhydride group, and the anhydride is calculated by the amount of carbon-oxygen double bond acyl carbonyl bond. The molar ratio of substrate reactant to anhydride is 1:0.5-2, and the molar ratio of substrate reactant to carboxylic acid is 1:1-2.
4. The method for preparing a polyhydroxy ester plasticizer according to claim 1, characterized in that: The esterification reaction is specifically carried out according to the following steps: (1) The substrate reactant and the anhydride are added to the reaction kettle and a catalyst is added to obtain a reaction mixture; or the substrate reactant and the carboxylic acid are added to the reaction kettle and a catalyst is added, and then a water-carrying agent is added to obtain a reaction mixture; (2) The reaction mixture obtained in step (1) is subjected to esterification reaction at a temperature of 60-250°C for 20 min-48 h in a nitrogen atmosphere.
5. The method for preparing a polyhydroxy ester plasticizer according to claim 4, characterized in that: The catalyst in step (1) is one or more of triethylamine, 4-dimethylaminopyridine, concentrated sulfuric acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, Amberlyst acidic ion exchange resin, dibutyltin dilaurate, tetrabutyl titanate or molecular sieve catalyst; the amount of catalyst is 0.5-20 wt% of the substrate reactant; the water-carrying agent is benzene, toluene, xylene, cyclohexane, n-heptane or chloroform; the amount of water-carrying agent is 10-800% of the substrate reactant; The esterification reaction in step (2) is carried out at a temperature of 70-150°C for 40 min-8 h.
6. The method for preparing a polyhydroxy ester plasticizer according to claim 4, characterized in that: The catalyst in step (1) is one or more of 4-dimethylaminopyridine, p-toluenesulfonic acid and Amberlyst-36 acidic ion exchange resin; the water-carrying agent is toluene and cyclohexane.
7. The method of claim 1, wherein the polyol ester plasticizer is prepared by the process comprising: reacting a polyol with a carboxylic acid in the presence of a catalyst to form a polyol ester plasticizer. After the esterification reaction is completed, the obtained product is washed with an alkaline aqueous solution first, then separated into two layers, a water-removing agent is added to the organic phase to absorb water, and then filtered to obtain an organic liquid, which is a polyhydroxy ester plasticizer.
8. The method for preparing a polyhydroxy ester plasticizer according to claim 7, characterized in that: The alkaline aqueous solution is an aqueous solution of sodium carbonate, sodium hydroxide, potassium hydroxide, sodium bicarbonate, ammonia or sodium sulfide; the alkaline aqueous solution is an aqueous solution with a mass concentration of 0.2-50%, and the amount of alkaline aqueous solution is 50-1500 wt% of the obtained product; the water-removing agent is one or more of anhydrous magnesium sulfate, anhydrous sodium sulfate, calcium oxide, calcium chloride, molecular sieve, silica gel, activated alumina, phosphorus pentoxide, anhydrous copper sulfate, anhydrous calcium chloride, calcium chloride and calcium sulfate.
9. A polyol ester plasticizer prepared by the process of any one of claims 1 to 8.
10. Use of the polyol ester plasticizer of claim 9 in the preparation of a resinous article.