Method for preparing hydrogenated bio-based itaconate rubber through emulsion hydrogenation

Abstract

The invention provides a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, which comprises the following steps: adding bio-based itaconate latex into a hydrogenation reaction kettle, heating to the temperature required by hydrogenation reaction, adding a reducing agent, then adding a mixed aqueous solution of a catalyst and an oxidizing agent, reacting for a certain period of time, and filtering to obtain the hydrogenated bio-based itaconate rubber. The hydrogenated bio-based itaconate latex is obtained. The method is emulsion hydrogenation, an organic solvent and a noble metal catalyst are not used, and the hydrogenation degree can reach 90% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of rubber materials, and in particular relates to a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation. Background Art

[0002] Bio-based itaconate rubber is a new generation of high-performance bio-based rubber prepared by free radical emulsion polymerization with bio-based itaconate as the main monomer. Against the backdrop of global energy shortage and the gradual implementation of the dual carbon strategy, the market for bio-based itaconate rubber has broad room for development.

[0003] Bio-based itaconate rubber contains carbon-carbon unsaturated bonds in its molecular chain, which limits its application in the fields of shoe materials, conveyor belts, oil pipelines, etc. In order to improve the heat resistance, anti-aging performance and use temperature of polymers with unsaturated bonds, hydrogenation is often used to achieve significant improvements in polymer performance and expand the application field of polymers.

[0004] Patent CN11729222 discloses a solution method for hydrogenating bio-based itaconate rubber using a homogeneous noble metal complex catalyst composition. The hydrogenated polymer is a novel polymer material with a hydrogenation degree of more than 90% and excellent heat resistance and anti-aging properties. However, the solution method hydrogenation process has a high pressure and uses an organic solvent. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, which method is emulsion hydrogenation, avoids the use of organic solvents and precious metal catalysts, and the degree of hydrogenation can be as high as more than 90%.

[0006] The present invention provides a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, comprising the following steps:

[0007] In a hydrogenation reactor, add bio-based itaconate latex, heat it to the temperature required for hydrogenation reaction, add a reducing agent, then add a mixed aqueous solution of a catalyst and an oxidant, react for a certain time, and obtain hydrogenated bio-based itaconate latex.

[0008] Preferably, the bio-based itaconate latex is an itaconate-diene copolymer, wherein the mass content of itaconate is 5 to 95%, and the mass content of diene is 5 to 95%;

[0009] The solid content of the bio-based itaconate latex is 10-30%.

[0010] Preferably, the itaconate-diene copolymer is prepared by emulsion polymerization of itaconate and diene;

[0011] Itaconate esters have the structure of Formula I:

[0012]

[0013] The R1 and R2 are independently selected from C1 to C10 alkyl groups;

[0014] The diene is selected from one or more of 1,3-butadiene, isoprene, myrcene and farnesene.

[0015] Preferably, the reducing agent is selected from hydrazine or a compound that generates hydrazine.

[0016] Preferably, the oxidizing agent is hydrogen peroxide and / or peracetic acid.

[0017] Preferably, the catalyst is selected from one or more of boric acid, CuSO 4 and FeSO 4. The above catalysts are cheap and readily available.

[0018] Preferably, the molar ratio of the reducing agent, the oxidizing agent, the catalyst and the carbon-carbon double bonds in the bio-based itaconate latex is (0.5-8):(0.5-9):(0.01-1):1.

[0019] Preferably, the temperature of the hydrogenation reaction is 10 to 95°C;

[0020] The hydrogenation reaction time is 2 to 15 hours.

[0021] The present invention provides a hydrogenated bio-based itaconate rubber prepared by emulsion hydrogenation, which is prepared by the method described in the above technical scheme.

[0022] The present invention provides a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, comprising the following steps: adding bio-based itaconate latex into a hydrogenation reactor, heating to a temperature required for hydrogenation reaction, adding a reducing agent, and then adding a mixed aqueous solution of a catalyst and an oxidant, reacting for a certain time, and obtaining hydrogenated bio-based itaconate latex. The method is emulsion hydrogenation, avoids the use of organic solvents and precious metal catalysts, and the degree of hydrogenation can be as high as 90% or more. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an infrared spectrum of the bio-based itaconate rubber latex 6610 before hydrogenation in Example 1 of the present invention;

[0024] Figure 2 This is the infrared spectrum of the hydrogenated bio-based itaconate rubber prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0025] The present invention provides a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, comprising the following steps:

[0026] In a hydrogenation reactor, add bio-based itaconate latex, heat it to the temperature required for hydrogenation reaction, add a reducing agent, then add a mixed aqueous solution of a catalyst and an oxidant, react for a certain time, and obtain hydrogenated bio-based itaconate latex.

[0027] The hydrogenation method for preparing hydrogenated bio-based itaconate rubber has mild conditions, a simple process, is environmentally friendly and has low cost; the degree of hydrogenation of the prepared hydrogenated bio-based itaconate rubber reaches more than 90%.

[0028] The bio-based itaconate latex used in the present invention is an itaconate-diene copolymer, wherein the mass content of itaconate is 5-95%, preferably 20-80%, more preferably 35-70%; the mass content of diene is 5-95%, preferably 20-80%, more preferably 30-65%;

[0029] The itaconate-diene copolymer is prepared by emulsion polymerization of itaconate and diene; the itaconate and diene are prepared by low-temperature emulsion polymerization;

[0030] Itaconate esters have the structure of Formula I:

[0031] Said R1 and R2 are independently selected from C1-C10 alkyl groups; preferably CH3CH2-, CH3CH2CH2- or CH3CH2CH2CH2-.

[0032] The diene is selected from one or more of 1,3-butadiene, isoprene, myrcene and farnesene, preferably 1,3-butadiene.

[0033] The solid content of the bio-based itaconate latex in the present invention is 10-30%.

[0034] In a specific embodiment, the bio-based itaconate latex is bio-based itaconate rubber latex IBR6610 (diethyl itaconate-butadiene copolymer latex, butadiene content 40%, solid content 22%); or bio-based itaconate latex 7410 (diethyl itaconate-butadiene copolymer latex, butadiene content 30%, solid content 22%); or bio-based itaconate latex 6600 (dibutyl itaconate-butadiene copolymer latex, butadiene content 40%, solid content 22%).

[0035] In the present invention, the reducing agent is selected from hydrazine or a compound that generates hydrazine, preferably one or more of hydrazine hydrate, hydrazine acetate, hydrazine sulfate and hydrazine sulfonate, more preferably hydrazine hydrate.

[0036] The oxidant in the present invention and the reducing agent constitute a redox system. The oxidant can be any oxidant used together with the reducing agent of the above type to constitute a redox system, preferably hydrogen peroxide and / or hydrogen peroxide, more preferably hydrogen peroxide.

[0037] The catalyst in the present invention is selected from one or more of boric acid, CuSO4 and FeSO4.

[0038] The molar ratio of the reducing agent, the oxidizing agent, the catalyst and the carbon-carbon double bond in the bio-based itaconate latex described in the present invention is (0.5-8):(0.5-9):(0.01-1):1.

[0039] The temperature of the hydrogenation reaction in the present invention is 10-95° C.; the time of the hydrogenation reaction is 2-15 hours.

[0040] The hydrogenated bio-based itaconate rubber prepared by the method provided by the present invention has a hydrogenation degree of more than 90%, has excellent aging resistance, and can be applied in the fields of shoe materials, sealing products, conveyor belts, oil pipelines, etc.

[0041] In the present invention, the unsaturation of the hydrogenated bio-based itaconate rubber is determined by iodine titration, the test method is GB-1776-81, and the calculation formula of hydrogenation degree is as follows:

[0042] Degree of hydrogenation = [(unsaturation of polymer before hydrogenation - unsaturation of polymer after hydrogenation) / unsaturation of polymer before hydrogenation] x 100%.

[0043] In order to further illustrate the present invention, a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation provided by the present invention is described in detail below in conjunction with examples, but they should not be construed as limiting the scope of protection of the present invention.

[0044] The bio-based itaconate rubber latex in the embodiment of the present invention is homemade in the laboratory.

[0045] Example 1

[0046] Step 1: In a polymerization reaction device, add 1200g of deionized water, 8g of potassium disproportionate rosin acid, 1.6g of potassium chloride, 0.1g of ferrous sulfate, 0.35g of sodium formaldehyde sulfoxylate, 0.5g of disodium ethylenediaminetetraacetic acid, 0.12g of sodium dithionite, 240g of diethyl itaconate, and 0.4g of n-dodecyl mercaptan, then close the polymerization device, first evacuate and then fill with nitrogen, and do this 3 times; then, add 160g of butadiene and 0.3g of p-menthane hydrogen peroxide, react for 8h at 6°C and 0.4MPa pressure, then add 3.2g of terminator isopropylhydroxylamine to terminate the reaction, and obtain bio-based itaconate rubber latex 6610.

[0047] Step 2: Add 200g of bio-based itaconate rubber latex 6610 (solid content 22%) and 60g of hydrazine hydrate (85%) to a 1L hydrogenation reactor, stir for 30 minutes, heat to 70°C, mix 100g of hydrogen peroxide solution (30%) and 6g of boric acid solution, and slowly add them to the reactor under stirring for 10 hours. The hydrogenated latex is demulsified and dried with ethanol to obtain hydrogenated bio-based itaconate rubber. By comparing the infrared spectra of the 6610 samples before and after hydrogenation (see Figure 1 and Figure 2 ), 968cm in the hydrogenated sample -1 The absorption peak at the wavelength (C=C double bond) becomes significantly weaker, indicating that the double bonds in the sample undergo hydrogenation reaction. The degree of hydrogenation tested by iodine titration is 87.5%.

[0048] Example 2

[0049] Different from Example 1, 120 g of bio-based itaconate latex 6610 was added in step 2, and the reaction temperature was 60°C.

[0050] The degree of hydrogenation of hydrogenated bio-based itaconate rubber 6610 was measured to be 91.4%.

[0051] Example 3

[0052] Step 1: In a polymerization reaction device, add 1500g of deionized water, 10g of potassium disproportionate rosin acid, 1.6g of potassium chloride, 0.08g of ferrous sulfate, 0.25g of sodium formaldehyde sulfoxylate, 0.5g of disodium ethylenediaminetetraacetic acid, 0.12g of sodium dithionite, 280g of diethyl itaconate, and 0.4g of n-dodecyl mercaptan, then close the polymerization device, first evacuate and then fill with nitrogen, and do this 3 times; then, add 120g of butadiene and 0.3g of p-menthane hydrogen peroxide, react for 8h at 5°C and 0.3MPa pressure, then add 3.2g of terminator isopropylhydroxylamine to terminate the reaction, and obtain bio-based itaconate rubber latex 7410.

[0053] Step 2: Different from Example 1, bio-based itaconate latex 7410 (solid content 15%) was used.

[0054] The degree of hydrogenation of hydrogenated bio-based itaconate rubber 7410 was measured to be 92.5%.

[0055] Example 4

[0056] Step 1: In a polymerization reaction device, add 1200g of deionized water, 8g of potassium disproportionate rosin acid, 1.6g of potassium chloride, 0.1g of ferrous sulfate, 0.35g of sodium formaldehyde sulfoxylate, 0.5g of disodium ethylenediaminetetraacetic acid, 0.12g of sodium dithionite, 240g of dibutyl itaconate, and 0.4g of n-dodecyl mercaptan, then close the polymerization device, first evacuate and then fill with nitrogen, and do this 3 times; then, add 140g of butadiene and 0.3g of hydrogen peroxide p-menthane, react for 8h at 5°C and 0.5MPa pressure, then add 3.2g of terminator isopropylhydroxylamine to terminate the reaction, and obtain bio-based itaconate rubber latex 6600.

[0057] Step 2: Different from Example 1, bio-based itaconate latex 6600 (solid content 22%) was used.

[0058] The degree of hydrogenation of hydrogenated bio-based itaconate rubber 6600 was measured to be 88.7%.

[0059] Example 5

[0060] The difference from Example 2 is that copper sulfate is used as the catalyst.

[0061] The degree of hydrogenation of the tested hydrogenated bio-based itaconate rubber 6610 was 92.0%.

[0062] Comparative Example 1

[0063] 100g of bio-based itaconate rubber IBR6610 (diethyl itaconate-butadiene copolymer, butadiene content of 40%) was dissolved in 1250ml of chlorobenzene, added to a 2L autoclave, and replaced with nitrogen three times; 0.13g of catalyst and 1.6g of triphenylphosphine were added to the autoclave, and hydrogen was introduced for reaction at a reaction temperature of 100°C, a hydrogen pressure of 4.0MPa, and a reaction time of 10 hours. The hydrogenated rubber solution was flocculated and dried by water vapor to obtain hydrogenated bio-based itaconate rubber (referred to as HIBR-2#). The hydrogenation degree of HIBR-2# was tested by iodine titration and was 92.2%.

[0064] The conditions and degree of hydrogenation of the above embodiments and comparative examples of the present invention are summarized in Table 1:

[0065] Table 1

[0066]

[0067] As can be seen from the above embodiments, the present invention provides a method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, comprising the following steps: adding bio-based itaconate latex to a hydrogenation reactor, heating to the temperature required for the hydrogenation reaction, adding a reducing agent, and then adding a mixed aqueous solution of a catalyst and an oxidant, reacting for a certain time to obtain hydrogenated bio-based itaconate latex. The method is emulsion hydrogenation, avoids the use of organic solvents and precious metal catalysts, and the degree of hydrogenation can be as high as 90% or more.

[0068] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing hydrogenated bio-based itaconate rubber by emulsion hydrogenation, comprising the following steps: In a hydrogenation reactor, add bio-based itaconate latex, heat it to the temperature required for hydrogenation reaction, add a reducing agent, then add a mixed aqueous solution of a catalyst and an oxidant, react for a certain time, and obtain hydrogenated bio-based itaconate latex.

2. The method according to claim 1, characterized in that The bio-based itaconate latex is an itaconate-diene copolymer, wherein the itaconate content is 5 to 95% and the diene content is 5 to 95%; The solid content of the bio-based itaconate latex is 10-30%.

3. The method according to claim 2, characterized in that The itaconate-diene copolymer is prepared by emulsion polymerization of itaconate and diene; Itaconate esters have the structure of Formula I: The R1 and R2 are independently selected from C1 to C10 alkyl groups; The diene is selected from one or more of 1,3-butadiene, isoprene, myrcene and farnesene.

4. The method according to claim 1, characterized in that: The reducing agent is selected from hydrazine or a compound that generates hydrazine.

5. The method according to claim 1, characterized in that The oxidant is hydrogen peroxide and / or peracetic acid.

6. The method according to claim 1, characterized in that The catalyst is selected from one or more of boric acid, CuSO4 and FeSO4.

7. The method according to claim 1, characterized in that The molar ratio of the reducing agent, the oxidizing agent, the catalyst and the carbon-carbon double bond in the bio-based itaconate latex is (0.5-8):(0.5-9):(0.01-1):

1.

8. The method according to claim 1, characterized in that The temperature required for the hydrogenation reaction is 10 to 95°C; The reaction time is 2 to 15 hours.

Images