A plasticizer and preparation method thereof

Abstract

The present invention provides a plasticizer and a preparation method thereof. The plasticizer comprises paraffin oil and bio-based oil. The bio-based oil has the following structural formula: wherein R 1 , R 2 , R 3 C 5 H 31‑n or any one of, wherein n=0, 2, 4 or 6. The present invention combines paraffin oil and bio-based oil to prepare a new type of plasticizer, which has good compatibility with rubber and can improve the comprehensive performance of rubber.

Description

Technical Field

[0001] The present invention relates to the technical field of rubber additives, and more particularly to a plasticizer and a preparation method thereof. Background Art

[0002] Petroleum-based plasticizers are one of the most commonly used plasticizers in rubber processing. They have good plasticizing effects and low costs. However, petroleum-based plasticizers are derived from the petroleum refining process. On the one hand, the raw material source is limited and requires a lot of energy to produce. On the other hand, petroleum-based plasticizers pollute the environment and have potential carcinogenic risks. Therefore, the production and use of petroleum-based plasticizers are subject to corresponding restrictions. Bio-based plasticizers are gaining more and more attention.

[0003] Cashew nut oil is a product obtained during the processing of cashew nuts. It has a wide source and is easy to extract. Its main component is cardanol, which can be used as a bio-based plasticizer in rubber processing. However, since cashew nut oil contains only one benzene ring and has a low aromatic content, its affinity with rubber is poor, so it still needs further improvement and development. Summary of the invention

[0004] In view of the various deficiencies of the prior art, in order to solve the above problems, a plasticizer and a preparation method are proposed, and the following technical solutions are provided:

[0005] A plasticizer includes paraffin oil and bio-based oil, wherein the bio-based oil has the following structural formula:

[0006]

[0007] Among them, R1, R2, and R3 are C5H 31-n or Any of , where n=0, 2, 4 or 6.

[0008] Furthermore, R1 and R2 are R3 is C 15 H 31-n .

[0009] Furthermore, in terms of mass percentage, the paraffin oil is 30-60%, and the bio-based oil is 40-70%.

[0010] Furthermore, in terms of mass percentage, the paraffin oil is 50% and the bio-based oil is 50%.

[0011] In addition, the present invention also provides a method for preparing a plasticizer, comprising the following steps: stirring and mixing paraffin oil and bio-based oil.

[0012] Furthermore, the preparation process of bio-based oil is as follows: citric acid is dissolved in ethanol or chloroform, a catalyst and cardanol are added to the solution containing citric acid for esterification reaction to obtain a product between cardanol and citric acid, and the product between cardanol and citric acid is reacted with an oxidant in a solvent to obtain bio-based oil.

[0013] Furthermore, the molar ratio of the citric acid to the cardanol is 1:2-3, and the molar ratio of the cardanol to the oxidant is 3:1-3.

[0014] Furthermore, the catalyst is copper sulfate, aluminum sulfate or ferric chloride.

[0015] Furthermore, the oxidant is benzoic acid peroxide or hydrogen peroxide.

[0016] Furthermore, the temperature for the reaction of the product of cardanol and citric acid with the oxidant in the solvent is 60-70° C., and the time for the reaction of the product of cardanol and citric acid with the oxidant in the solvent is 2-5 hours.

[0017] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are:

[0018] 1. The present invention combines paraffin oil and bio-based oil to prepare a new type of plasticizer, which has good compatibility with rubber and can improve the comprehensive performance of rubber.

[0019] 2. The plasticizer of the present invention contains part of bio-based oil, which can replace part of the amount of paraffin oil, and the bio-based oil contains three benzene rings, which increases the high aromatic content of the plasticizer and improves the compatibility and affinity between the bio-based plasticizer and rubber; the bio-based oil also contains epoxy groups and alkyl chains containing carbon-carbon double bonds, which further improve the compatibility between the plasticizer and rubber, while improving the processing performance and mechanical properties, and can replace part of the petroleum-based plasticizer in the rubber processing process. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the embodiments of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making any creative work should all fall within the scope of protection of this application.

[0021] A plasticizer includes paraffin oil and bio-based oil, wherein the bio-based oil has the following structural formula:

[0022]

[0023] Among them, R1, R2, and R3 are C5H31-n or Any of , where n=0, 2, 4 or 6.

[0024] The plasticizer of the present invention contains paraffin oil and bio-based oil, and has good compatibility with rubber and can improve the comprehensive performance of rubber. In addition, the bio-based oil has a benzene ring, an epoxy group and an alkyl chain containing a carbon-carbon double bond, and the three structures exist at the same time to form a synergistic effect, so that the compatibility of the plasticizer with rubber is improved, and the processing performance and mechanical properties are improved. The bio-based oil can be mixed with the paraffin oil and used in the rubber processing process.

[0025] First, the effects of R1, R2, and R3 on plasticizers were investigated.

[0026] Example 1

[0027] According to the mass percentage, the paraffin oil is 50%, and the bio-based oil is 50%. The paraffin oil and the bio-based oil are mixed to obtain a plasticizer. The R1 and R2 of the bio-based oil are respectively R3 is C 15 H 31-n The plasticizer is used as a plasticizer for natural rubber, and the specific formula is as follows: 100 parts of natural rubber, 50 parts of carbon black N330, 10 parts of plasticizer, 1.5 parts of antioxidant 4010NA, 5 parts of zinc oxide, 2 parts of stearic acid, 2.2 parts of sulfur, and 0.2 parts of accelerator TT. According to the above formula, the natural rubber compound is obtained after mixing and vulcanization.

[0028] Example 2

[0029] According to the mass percentage, the paraffin oil is 50%, and the bio-based oil is 50%. The paraffin oil and the bio-based oil are mixed to obtain a plasticizer. The R1 of the bio-based oil is R2 and R3 are C 15 H 31-n The plasticizer is used as a plasticizer for natural rubber, and the specific formula is as follows: 100 parts of natural rubber, 50 parts of carbon black N330, 10 parts of plasticizer, 1.5 parts of antioxidant 4010NA, 5 parts of zinc oxide, 2 parts of stearic acid, 2.2 parts of sulfur, and 0.2 parts of accelerator TT. According to the above formula, the natural rubber compound is obtained after mixing and vulcanization.

[0030] Example 3

[0031] According to the mass percentage, the paraffin oil is 50% and the bio-based oil is 50%. The paraffin oil and the bio-based oil are mixed to obtain a plasticizer. The R1, R2 and R3 of the bio-based oil are respectively The plasticizer is used as a plasticizer for natural rubber, and the specific formula is as follows: 100 parts of natural rubber, 50 parts of carbon black N330, 10 parts of plasticizer, 1.5 parts of antioxidant 4010NA, 5 parts of zinc oxide, 2 parts of stearic acid, 2.2 parts of sulfur, and 0.2 parts of accelerator TT. According to the above formula, the natural rubber compound is obtained after mixing and vulcanization.

[0032] Comparative Example 1

[0033] Paraffin oil is used as a plasticizer for natural rubber, and the specific formula is as follows: 100 parts of natural rubber, 50 parts of carbon black N330, 10 parts of plasticizer, 1.5 parts of antioxidant 4010NA, 5 parts of zinc oxide, 2 parts of stearic acid, 2.2 parts of sulfur, and 0.2 parts of accelerator TT. According to the above formula, natural rubber compound is obtained after mixing and vulcanization.

[0034] The natural rubber compounds prepared in Examples 1-3 and Comparative Example 1 were subjected to various performance tests, and the specific test results are shown in Tables 1 and 2 below.

[0035] Table 1 Mechanical properties test results of natural rubber compounds prepared in Examples 1-3 and Comparative Example 1

[0036]

[0037] Table 2 Processing properties and rheological test results of styrene-butadiene rubber compounds prepared in Examples 1-3 and Comparative Example 1

[0038]

[0039]

[0040] The benzene ring, alkyl chain and epoxy group in the plasticizer are the key factors affecting the processing and performance of rubber. It can be seen from Table 1 above that the difference in R1, R2 and R3 leads to differences in the various properties of the obtained rubber. Specifically, the present invention further explores the structures of R1, R2 and R3. When R1 and R2 are respectively R3 is C 15 H 31-n That is to say, while having three benzene rings, the epoxy group and an alkyl chain containing a carbon-carbon double bond work together. At this time, the mechanical properties and wear resistance are optimal. As shown in Table 1, the tensile strength reaches 25MPa and the elongation at break reaches 471%. When R1 is R2 and R3 are C 15 H 31-n, the epoxy structure is relatively reduced compared with that of Example 1, and the carbon-carbon double bonds are increased. At this time, the compatibility of the bio-based plasticizer with the rubber is good, but the processing performance is deteriorated, and the scorch time T10 is shortened. Too short a scorch time will reduce the processing performance of the rubber. When R1, R2 and R3 of the bio-based oil in the plasticizer are respectively At this time, there is no alkyl chain containing carbon-carbon double bonds in the bio-based oil, and the compatibility of the plasticizer with the rubber is poor, but the processing performance is good. Therefore, according to the test results in Tables 1 and 2, it can be seen that the different R1, R2 and R3 will have different effects on the processing performance and mechanical properties of the rubber compound. When R1 and R2 are respectively R3 is C 15 H 31-n When the rubber is heated to 400 ℃ and the temperature is maintained at 400 ℃, the three benzene rings, the epoxy group and an alkyl chain containing a carbon-carbon double bond cooperate with each other. The presence of the benzene ring structure improves the processing performance of the rubber, and an alkyl chain containing a carbon-carbon double bond has a better effect on the physical and mechanical properties of the rubber. The appropriate epoxy group further improves the processing performance and increases the scorch time.

[0041] In addition, paraffin oil is used as a plasticizer in Comparative Example 1. From the data in Tables 1 and 2 above, it can be seen that the combination of paraffin oil and bio-based oil can further improve the compatibility with rubber compared with pure paraffin oil. At the same time, the processing performance and mechanical properties are also improved accordingly.

[0042] Specifically, the ratio between paraffin oil and bio-based oil is also an important factor affecting the effect of plasticizer. According to the mass percentage, the paraffin oil is 30-60%, and the bio-based oil is 40-70%. Within this ratio range, the bio-based oil can make up for the disadvantage of low aromatic content of paraffin oil, and can have good compatibility with rubber. After many experiments, it was found that when the bio-based oil is less than 30%, the reduction in benzene ring content cannot give full play to the advantages of the bio-based oil itself. When the bio-based oil exceeds 70%, the amount of paraffin oil is reduced, and the two cannot fully cooperate. The effect of its plasticizer in rubber is lower than the effect of 50% bio-based oil and 50% paraffin oil.

[0043] The invention also provides a method for preparing a plasticizer, which comprises the following steps: stirring and mixing paraffin oil and bio-based oil.

[0044] The preparation process of bio-based oil is as follows: dissolving citric acid in ethanol or chloroform, adding a catalyst and cardanol to the solution containing citric acid for esterification reaction to obtain a product between cardanol and citric acid, and reacting the product between cardanol and citric acid with an oxidant in a solvent to obtain a bio-based plasticizer. Specifically, the molar ratio of cardanol to the oxidant is 3:1-3, and the oxidant is benzoic acid peroxide or hydrogen peroxide.

[0045] For example, when the oxidant is used in excess molar amount relative to cardanol, R1, R2 and R3 are When the molar ratio of the oxidant to the cardanol is 1:3, R1 is R2 and R3 are C 15 H 31-n When the molar ratio of the oxidant to the cardanol is 2:3, R1 and R2 are R3 is C 15 H 31-n .

[0046] 1.92 g of citric acid was dissolved in 100 ml of chloroform, and then 0.0192 g of ferric chloride catalyst and 6.05 g of cardanol were added, and the reaction was carried out at 40° C. for 8 hours to obtain the product between cardanol and citric acid. The product between cardanol and citric acid was reacted with hydrogen peroxide in dichloromethane at a reaction temperature of 50° C. for 5 hours to obtain the bio-based oil in Example 1, and the amount of hydrogen peroxide used was 0.45 g.

[0047] 1.92 g of citric acid was dissolved in 100 ml of chloroform, and then 0.0192 g of ferric chloride catalyst and 6.05 g of cardanol were added, and the reaction was carried out at 40° C. for 8 hours to obtain the product between cardanol and citric acid. The product between cardanol and citric acid was reacted with hydrogen peroxide in dichloromethane at a reaction temperature of 50° C. for 5 hours to obtain the bio-based oil in Example 2, and the amount of hydrogen peroxide used was 0.227 g.

[0048] 1.92 g of citric acid was dissolved in 100 ml of chloroform, and then 0.0192 g of ferric chloride catalyst and 6.05 g of cardanol were added, and the reaction was carried out at 40° C. for 8 hours to obtain the product between cardanol and citric acid. The product between cardanol and citric acid was reacted with hydrogen peroxide in dichloromethane at a reaction temperature of 50° C. for 5 hours to obtain the bio-based oil in Example 3, and the amount of hydrogen peroxide used was 0.68 g.

[0049] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing a plasticizer, characterized in that: The following steps are involved: The paraffin oil and the bio-based oil are stirred and mixed. The preparation process of the bio-based oil is as follows: citric acid is dissolved in ethanol or chloroform, a catalyst and cardanol are added to the solution containing the citric acid for esterification reaction to obtain a product between cardanol and citric acid, and the product between cardanol and citric acid is reacted with an oxidant in a solvent to obtain the bio-based oil; In terms of mass percentage, the paraffin oil is 30-60%, and the bio-based oil is 40-70%; The molar ratio of the citric acid to the cardanol is 1:2-3, and the molar ratio of the cardanol to the oxidant is 3:1-3.

2. The method for preparing a plasticizer according to claim 1, characterized in that: Calculated by mass percentage, the paraffin oil accounts for 50% and the bio-based oil accounts for 50%.

3. The method for preparing a plasticizer according to claim 1, characterized in that: The catalyst is copper sulfate, aluminum sulfate or ferric chloride.

4. The method for preparing a plasticizer according to claim 1, characterized in that: The oxidant is benzoic acid peroxide or hydrogen peroxide.

5. The method for preparing a plasticizer according to claim 1, characterized in that: The temperature for reacting the product of cardanol and citric acid with the oxidant in the solvent is 60-70° C., and the time for reacting the product of cardanol and citric acid with the oxidant in the solvent is 2-5 hours.

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