A plasticizer and preparation method thereof

Abstract

The invention provides a plasticizer and a preparation method thereof, belonging to the technical field of PVC plasticizing and processing. The plasticizer comprises phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin, wherein the mass ratio of phosphorus-doped epoxy fatty acid-chlorobenzyl ester to chlorinated paraffin is (3-3.5): (1-1.2); the preparation method of phosphorus-doped epoxy fatty acid-chlorobenzyl ester comprises the following steps: A1, adding rapeseed oil and o-chlorobenzyl alcohol into a three-necked bottle, then adding sodium methoxide, reacting at 50-60°C for 3-4h, distilling under reduced pressure, removing residual o-chlorobenzyl alcohol, and obtaining an alcoholysis product; A2, heating the alcoholysis product to 55-65°C, firstly dripping peracetic acid, keeping the temperature for 2-3h after the dripping is completed, then dripping phosphoric acid, stirring and reacting at 70-80°C for 2-3h after the dripping is completed, washing with water until neutral, distilling under reduced pressure, removing residual water, and obtaining the phosphorus-doped epoxy fatty acid-chlorobenzyl ester. The plasticizer of the invention is used in PVC plasticizing processing and can effectively improve the flame retardant performance of PVC plasticizing processing materials.

Description

Technical Field

[0001] The invention belongs to the technical field of PVC plasticizing and processing, and specifically relates to a plasticizer and a preparation method thereof. Background Art

[0002] Polyvinyl chloride, abbreviated as PVC in English, is a high molecular weight polymer formed by the polymerization of vinyl chloride monomer in the presence of initiators such as peroxides and azo compounds, or under the action of light or heat according to the free radical polymerization mechanism. The molecular weight of industrially produced PVC is generally in the range of 50,000-110,000, with a large polydispersity, and the molecular weight increases with the decrease of polymerization temperature; it has no fixed melting point, begins to soften at 80-85°C, becomes viscoelastic at 130°C, and begins to change into a viscous flow at 160-180°C; it has good mechanical properties and excellent dielectric properties. PVC was once the world's largest-volume general-purpose plastic and is widely used. It is widely used in building materials, industrial products, daily necessities, floor coverings, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, fibers, etc.

[0003] Plasticizer is an additive added to polymers to increase their plasticity, flexibility and fluidity during processing. Vegetable oil-based plasticizers are modified by functional group reactions on glycerol fatty acid esters, the main component of natural vegetable oils, which can improve the compatibility of natural vegetable oils with PVC. Among them, epoxidized vegetable oil-based plasticizers not only plasticize PVC, but also quickly absorb HCl produced by light and heat degradation, stabilize the active chlorine atoms on the PVC chain, and act as a stabilizer.

[0004] The biggest feature of PVC is its flame retardancy, so it is widely used in fireproof materials. In the prior art, during the plasticizing process of PVC, an epoxidized vegetable oil-based plasticizer can be added to improve the processability. Therefore, how to improve the existing epoxidized vegetable oil-based plasticizer to further improve the flame retardancy of PVC plasticizing materials is a topic worth studying. Summary of the invention

[0005] In order to solve the problems existing in the background technology, the present invention provides a plasticizer and a preparation method thereof, wherein the plasticizer can effectively improve the flame retardant properties of PVC plasticized processing materials.

[0006] In order to achieve the above-mentioned object, in a first aspect, the present invention provides a plasticizer, comprising phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin, wherein the mass ratio of the phosphorus-doped epoxy fatty acid-chlorobenzyl ester to the chlorinated paraffin is (3-3.5): (1-1.2);

[0007] The preparation method of the phosphorus-doped epoxy fatty acid-chlorobenzyl ester is as follows:

[0008] A1. Add rapeseed oil and o-chlorobenzyl alcohol into a three-necked flask, then add sodium methoxide, react at 50-60° C. for 3-4 hours, and distill under reduced pressure to remove the residual o-chlorobenzyl alcohol to obtain an alcoholysis product;

[0009] A2. Heat the alcoholysis product to 55-65°C, first add peracetic acid dropwise, keep warm for 2-3h, then add phosphoric acid dropwise, stir and react at 70-80°C for 2-3h, then wash with water until neutral, and remove residual water by vacuum distillation to obtain phosphorus-doped epoxy fatty acid-chlorobenzyl ester.

[0010] Furthermore, in A1, the mass ratio of the rapeseed oil to o-chlorobenzyl alcohol is 1:(1-1.5).

[0011] Furthermore, in A1, the mass of the sodium methoxide is 0.5-1% of the total mass of rapeseed oil and o-chlorobenzyl alcohol.

[0012] Furthermore, in A2, the mass of the peracetic acid is 30-40% of the mass of the alcoholysis product.

[0013] Furthermore, in A2, the mass of the phosphoric acid is 10-12% of the mass of the alcoholysis product.

[0014] Furthermore, the plasticizer is used for plasticizing and processing PVC materials, and the specific method is: adding the plasticizer to the PVC resin, and the mass of the plasticizer is 35-45% of the mass of the PVC resin.

[0015] Furthermore, the mass of the plasticizer is 40% of the mass of the PVC resin.

[0016] In a second aspect, the present invention provides a method for preparing the above-mentioned plasticizer, comprising the following steps: uniformly mixing the phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin to obtain the plasticizer.

[0017] This application has the following beneficial effects:

[0018] The plasticizer of the present invention comprises phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin. Phosphorus and chlorine are introduced in the preparation of phosphorus-doped epoxy fatty acid-chlorobenzyl ester, and chlorinated paraffin also contains chlorine. The two are coordinated, and phosphorus and chlorine, two flame retardant elements, coexist. Phosphorus serves as a solid phase covering layer, and chlorine and hydrogen chloride serve as a gas phase covering layer. The synergistic effect can effectively and synergistically inhibit the evaporation combustion and decomposition combustion process of the flame, thereby synergistically improving the flame retardant performance (limiting oxygen index).

[0019] At the same time, the molecular structure of chlorinated paraffin contains a relatively long alkyl chain, which can interact with the PVC molecular chain and the phosphorus-doped epoxy fatty acid-chlorobenzyl ester molecular chain to regulate the intermolecular force. This appropriate intermolecular force can not only maintain the strength and stability of the material, but also increase the flexibility and activity of the molecular chain to a certain extent, so that the material can better deform when stretched; chlorinated paraffin also has good lubricity, which can reduce the melt viscosity of the material during processing, making the material easier to flow and mix. When used in combination with phosphorus-doped epoxy fatty acid-chlorobenzyl ester, it can improve the dispersion and uniformity of the material during processing, reduce the risk of material breakage due to local stress concentration, and thus synergistically improve the elongation at break. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 , a comparative trend chart of limiting oxygen index test data of plasticizers obtained from Examples 1 to 5 and Comparative Examples 1 to 3 in the test examples of the present invention used for PVC plasticizing processing samples;

[0021] Figure 2 , a comparative trend chart of the elongation at break test data of the plasticizers obtained in Examples 1 to 5 and Comparative Examples 1 to 3 in the test examples of the present invention used for PVC plasticizing processing samples. DETAILED DESCRIPTION

[0022] The present application is further described in detail below with reference to the embodiments.

[0023] Unless otherwise specified, the raw materials used in the examples and comparative examples of the present application are all commercially available.

[0024] Embodiment 1: A plasticizer comprises phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin.

[0025] The preparation method of the plasticizer is as follows: phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin are mixed at a mass ratio of 3.2:1.1 to obtain the plasticizer. The chlorinated paraffin (52#) is purchased from Shandong AVIC Technology Service Co., Ltd.

[0026] The preparation method of phosphorus-doped epoxy fatty acid-chlorobenzyl ester is as follows:

[0027] A1. Add rapeseed oil and o-chlorobenzyl alcohol in a mass ratio of 1:1.2 into a three-necked flask, then add sodium methoxide as a catalyst, the mass of which is 0.8% of the total mass of rapeseed oil and o-chlorobenzyl alcohol, react at 55°C for 3.5h, and distill under reduced pressure to remove the residual o-chlorobenzyl alcohol to obtain an alcoholysis product.

[0028] A2. Heat the alcoholysis product to 60°C, first add peracetic acid dropwise, the mass of which is 35% of the mass of the alcoholysis product, and keep warm for 2.5 hours. Then add phosphoric acid dropwise, the mass of which is 11% of the mass of the alcoholysis product. After the addition is complete, stir and react at 75°C for 2.5 hours, then wash with water until neutral, and distill under reduced pressure to remove residual water to obtain phosphorus-doped epoxy fatty acid-chlorobenzyl ester.

[0029] Among them, o-chlorobenzyl alcohol was purchased from Hubei Xinrunde Chemical Co., Ltd. Sodium methoxide was purchased from Jinan Century Tongda Chemical Co., Ltd.

[0030] Example 2: The difference between this example and Example 1 is that: a method for preparing a plasticizer comprises the following steps: mixing phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin in a mass ratio of 3:1 to obtain.

[0031] Example 3: The difference between this example and Example 1 is that: a method for preparing a plasticizer comprises the following steps: mixing phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin in a mass ratio of 3.5:1.2 to obtain.

[0032] Example 4: The difference between this example and Example 1 is that the preparation method of phosphorus-doped epoxy fatty acid-chlorobenzyl ester is as follows:

[0033] A1. Add rapeseed oil and o-chlorobenzyl alcohol in a mass ratio of 1:1 into a three-necked flask, then add sodium methoxide, the mass of which is 0.5% of the total mass of rapeseed oil and o-chlorobenzyl alcohol, react at 50°C for 4h, and distill under reduced pressure to remove the residual o-chlorobenzyl alcohol to obtain an alcoholysis product.

[0034] A2. The alcoholysis product is heated to 55°C, and peracetic acid is first added dropwise, the mass of which is 30% of the mass of the alcoholysis product. After the addition is completed, the temperature is kept for 3 hours, and phosphoric acid is then added dropwise, the mass of which is 10% of the mass of the alcoholysis product. After the addition is completed, the reaction is stirred at 70°C for 3 hours, and then washed with water until neutral, and distilled under reduced pressure to remove residual water to obtain phosphorus-doped epoxy fatty acid-chlorobenzyl ester.

[0035] Example 5: The difference between this example and Example 1 is that the preparation method of phosphorus-doped epoxy fatty acid-chlorobenzyl ester is as follows:

[0036] A1. Add rapeseed oil and o-chlorobenzyl alcohol in a mass ratio of 1:1.5 into a three-necked flask, then add sodium methoxide, the mass of which is 1% of the total mass of rapeseed oil and o-chlorobenzyl alcohol, react at 60°C for 3h, and distill under reduced pressure to remove the residual o-chlorobenzyl alcohol to obtain an alcoholysis product.

[0037] A2. The alcoholysis product is heated to 65°C, and peracetic acid is first added dropwise, the mass of which is 40% of the mass of the alcoholysis product. After the addition is completed, the temperature is kept for 2 hours, and phosphoric acid is then added dropwise, the mass of which is 12% of the mass of the alcoholysis product. After the addition is completed, the reaction is stirred at 80°C for 2 hours, and then washed with water until neutral, and distilled under reduced pressure to remove residual water to obtain phosphorus-doped epoxy fatty acid-chlorobenzyl ester.

[0038] Comparative Example 1: The difference between this comparative example and Example 1 is that chlorinated paraffin is deleted, and phosphorus-doped epoxy fatty acid-chlorobenzyl ester is replaced by epoxy fatty acid benzyl ester (o-chlorobenzyl alcohol is replaced by benzyl alcohol; and phosphoric acid is deleted.

[0039] Specifically, the preparation method of epoxy fatty acid benzyl ester is as follows:

[0040] A1. Add rapeseed oil and benzyl alcohol in a mass ratio of 1:1.2 into a three-necked flask, then add sodium methoxide as a catalyst, the mass of which is 0.8% of the total mass of rapeseed oil and benzyl alcohol, react at 55°C for 3.5h, and distill under reduced pressure to remove the residual benzyl alcohol to obtain an alcoholysis product.

[0041] A2. Heat the alcoholysis product to 60°C, add peracetic acid dropwise, the mass of peracetic acid being 35% of the mass of the alcoholysis product. After the addition is complete, keep warm for 2.5 hours, then wash with water until neutral, and remove the residual water by vacuum distillation to obtain epoxy fatty acid benzyl ester.

[0042] Comparative Example 2: The difference between this comparative example and Example 1 is that chlorinated paraffin is deleted.

[0043] Comparative Example 3: The difference between this comparative example and Example 1 is that phosphorus-doped epoxy fatty acid-chlorobenzyl ester is deleted.

[0044] Test example: Test object: Plasticizers obtained from Examples 1 to 5 and Comparative Examples 1 to 3.

[0045] Test items: 1. Flame retardant properties-limiting oxygen index; 2. Plasticizing properties-elongation at break.

[0046] Test method: Each test object plasticizer is used for plasticizing and processing PVC materials. The specific method is: PVC resin, plasticizer and heat stabilizer are fully mixed in a high-speed mixer. The mass of plasticizer is 40% of the mass of PVC resin, and the mass of heat stabilizer (calcium stearate) is 1.8% of the mass of PVC resin. After mixing evenly, melt blend in a twin-screw extruder, extrusion granulation, and then the obtained granules are dried at a temperature of 80℃ for 6h, and injection molded into standard specimens by an injection molding machine for testing. The limiting oxygen index test refers to the standard GB / T2406-2008; the elongation at break test refers to the standard GB / T 1040-2006.

[0047] Test results: See Table 1.

[0048] Table 1. Test data of the experimental example

[0049] Limiting oxygen index / % Elongation at break / % Example 1 47.3 283.9 Example 2 46.9 286.4 Example 3 47.8 279.5 Example 4 47.2 277.4 Example 5 47.7 284.8 Comparative Example 1 37.1 259.5 Comparative Example 2 44.3 243.2 Comparative Example 3 39.6 202.5

[0050] Result analysis: Analyze Example 1-Example 5 and combine the data in Table 1 and Figure 1-Figure 2 It can be seen that the plasticizers prepared in the present invention (Example 1-Example 5) are used in PVC plasticizing processing, which can make the limiting oxygen index of PVC plasticizing processing materials as high as 46.9% or more, and the elongation at break as high as 277.4% or more.

[0051] Analyze Example 1 and Comparative Examples 1-3 and combine the data in Table 1 and Figure 1-Figure 2 By comparing Comparative Example 1 and Comparative Example 2, it can be seen that replacing epoxy fatty acid benzyl ester with phosphorus-doped epoxy fatty acid-chlorobenzyl ester can improve the flame retardant properties (limiting oxygen index) of PVC plasticized materials, but at the same time it will also lead to a decrease in the elongation at break of the PVC plasticized materials.

[0052] This is because phosphorus and chlorine are introduced in the preparation of phosphorus-doped epoxy fatty acid-chlorobenzyl ester. The two flame retardant elements, phosphorus and chlorine, coexist in one body. Phosphorus serves as a solid covering layer, and chlorine and hydrogen chloride serve as a gaseous covering layer. They can effectively and synergistically inhibit the evaporation combustion and decomposition combustion process of the flame, thereby achieving the purpose of flame retardancy and fire prevention and improving flame retardant properties.

[0053] But at the same time, because of the introduction of phosphorus and chlorine, on the one hand, it will increase the polar interactions, hydrogen bonds or other secondary interactions between molecules, making the relative movement between molecular chains more difficult. During the stretching process, the molecular chains are not easy to slide and stretch, resulting in a decrease in the elongation at break; on the other hand, it will promote the regular arrangement of PVC molecular chains, thereby improving the crystallinity of the material. The existence of the crystalline region will limit the movement of the molecular chains, because the molecular chains in the crystalline part are arranged tightly and orderly, and it is difficult to undergo large deformation during stretching. When the material is stretched by external force, the crystalline region will act as a physical cross-linking point, hindering the stretching and slippage of the molecular chains, thereby reducing the elongation at break of the material.

[0054] By comparing Comparative Example 1 and Comparative Example 3, it can be seen that in terms of improving the flame retardant properties (limiting oxygen index) of PVC plasticized processing materials, the effect of chlorinated paraffin is greater than that of epoxy fatty acid benzyl ester; in terms of improving the elongation at break of PVC plasticized processing materials, the effect of epoxy fatty acid benzyl ester is greater than that of chlorinated paraffin.

[0055] By comparison with Example 1, it can be seen that the phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin are used in combination, and there is a synergistic effect between the two, which can synergistically improve the flame retardant properties (limiting oxygen index) and elongation at break of PVC plasticized processing materials.

[0056] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0057] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A plasticizer, characterized in that It comprises phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin, wherein the mass ratio of the phosphorus-doped epoxy fatty acid-chlorobenzyl ester to the chlorinated paraffin is (3-3.5): (1-1.2); The preparation method of the phosphorus-doped epoxy fatty acid-chlorobenzyl ester is as follows: A1. Add rapeseed oil and o-chlorobenzyl alcohol into a three-necked flask, then add sodium methoxide, react at 50-60° C. for 3-4 hours, and distill under reduced pressure to remove the residual o-chlorobenzyl alcohol to obtain an alcoholysis product; the mass ratio of the rapeseed oil to the o-chlorobenzyl alcohol is 1:(1-1.5); the mass of the sodium methoxide is 0.5-1% of the total mass of the rapeseed oil and the o-chlorobenzyl alcohol; A2. The alcoholysis product is heated to 55-65° C., and peracetic acid is first added dropwise. After the addition is completed, the temperature is kept for 2-3 hours. Phosphoric acid is then added dropwise. After the addition is completed, the mixture is stirred and reacted at 70-80° C. for 2-3 hours. The mixture is then washed with water until neutral, and the residual water is removed by vacuum distillation to obtain phosphorus-doped epoxy fatty acid-chlorobenzyl ester. The mass of the peracetic acid is 30-40% of the mass of the alcoholysis product; the mass of the phosphoric acid is 10-12% of the mass of the alcoholysis product.

2. The plasticizer according to claim 1, characterized in that The plasticizer is used for plasticizing and processing PVC materials. The specific method is: adding the plasticizer into the PVC resin, and the mass of the plasticizer is 35-45% of the mass of the PVC resin.

3. The plasticizer according to claim 2, characterized in that The mass of the plasticizer is 40% of the mass of the PVC resin.

4. A method for preparing a plasticizer according to any one of claims 1 to 3, characterized in that: The method comprises the following steps: uniformly mixing the phosphorus-doped epoxy fatty acid-chlorobenzyl ester and chlorinated paraffin to obtain the product.

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