A functionalized bio-based, narrow distribution liquid ethylene propylene rubber and its preparation and use

Abstract

This invention relates to the field of rubber technology, and provides a functionalized bio-based narrow-distribution liquid ethylene propylene rubber, its preparation and application. The preparation method includes: oxidatively degrading bio-based eucommia gum followed by hydrogenation to obtain the liquid ethylene propylene rubber, wherein the number average molecular weight of the liquid ethylene propylene rubber is 0.19 × 10⁻⁶. 4 ~6.50×10 4 The molecular weight distribution is 1-4. Simultaneously, oxygen-containing functional groups such as hydroxyl and carbonyl groups are introduced into the molecular chain of this liquid ethylene propylene rubber. Using this liquid ethylene propylene rubber as an environmentally friendly reactive plasticizer for ethylene propylene rubber, it can participate in cross-linking during the vulcanization process, exhibiting good compatibility. It can significantly shorten vulcanization time, improve the processing performance of ethylene propylene rubber, and enhance mechanical properties. The preparation method of this invention has a simple process flow, controllable product molecular weight, and uses bio-based Eucommia ulmoides gum as raw material, resulting in low price and environmental friendliness that aligns with the concept of sustainable development.

Description

Technical Field

[0001] This invention relates to the field of liquid rubber technology, to a liquid ethylene propylene rubber and its preparation method, and more particularly to a functionalized bio-based narrow-distribution liquid ethylene propylene rubber and its preparation and application. Background Technology

[0002] Petroleum-based synthetic rubber is one of the three major synthetic materials, widely used in industry, agriculture, transportation, national defense, and daily life. However, fossil fuels are non-renewable resources, and their overexploitation causes environmental pollution and contributes to the greenhouse effect through excessive industrial carbon emissions. Therefore, exploring sustainable new energy pathways is crucial to address the global energy crisis and align with the green era.

[0003] Ethylene propylene rubber (EPR) is the world's third largest petroleum-based synthetic rubber. Its corresponding liquid EPR exhibits good flowability at room temperature, low viscosity, and high-temperature shear stability. Compared to high molecular weight EPR, liquid EPR can be injection molded, is easier to process, and can be used in lubricants, rubber processing plasticizers, plastic toughening modifiers, gaskets, and sealants. Currently, my country still relies heavily on imports for liquid EPR, which is expensive.

[0004] Liquid rubber is mainly prepared by synthesis and thermal decomposition. The synthesis method involves copolymerizing monomers under the action of a catalyst. For example, isoprene is polymerized using neodymium neodecanoate / diisobutylaluminum hydride / dichlorodimethylsilane rare earth catalyst. In the literature (Zeng Jian, Li Shiqi, Huang Guangsu, et al. Polymer Materials Science and Engineering, 2017, 33(07):1-5.), the molecular weight Mn of polyisoprene can be strictly controlled to be 3500-18600, and the molecular weight distribution of polyisoprene is narrow, with a PDI of 1.09-1.4. However, currently only a few companies, such as Exxon and Lion, use the synthesis method to prepare liquid ethylene propylene rubber. Moreover, the liquid ethylene propylene rubber prepared by this method will have residual catalyst, making post-processing difficult. Direct pyrolysis uses high-molecular-weight solid rubber as raw material and prepares liquid rubber of different molecular weights through molecular chain breakage under the action of mechanical force, heat, oxygen, light or chemical action. For example, in reference 2 (Su Zhizhong, Tan Feng. Special Rubber Products, 2000, 21(5):5), the shear force of a two-roll mill is used to degrade natural rubber into liquid natural rubber with a molecular weight of about 40,000. However, this method has poor molecular weight control and a wide molecular weight distribution, and is rarely used at present. In addition, patent CN100549148C mixes high-molecular-weight ethylene propylene rubber with base oil and adds it to the degradation vessel for degradation by hot melting and stirring. The degraded ethylene propylene rubber dissolves in the base oil and exists as a viscosity index modifier. It cannot be separated to obtain liquid ethylene propylene rubber, which limits its application range.

[0005] It can be seen that, whether it is the synthesis method or the cracking method, the raw materials used are petroleum resources themselves or products synthesized from petroleum resources, which does not conform to the concept of green and environmentally friendly.

[0006] Therefore, this invention is proposed. Summary of the Invention

[0007] This invention provides a functionalized bio-based narrow-distribution liquid ethylene propylene rubber and its preparation method, addressing the shortcomings of existing liquid ethylene propylene rubbers, such as difficulty in controlling molecular weight and limited application range. Using bio-based Eucommia ulmoides gum as raw material, the molecular weight is controlled through oxidative degradation to obtain low-molecular-weight Eucommia ulmoides gum. Then, the low-molecular-weight Eucommia ulmoides gum undergoes complete double bond saturation to generate functionalized bio-based narrow-distribution liquid ethylene propylene rubber. The prepared functionalized bio-based narrow-distribution liquid ethylene propylene rubber contains oxygen-containing functional groups in its molecular chain, which can further interact with other functional groups to generate functional materials, thus having a wide range of applications. The liquid ethylene propylene rubber prepared by this invention can also be used as an environmentally friendly reactive plasticizer for ethylene propylene rubber, significantly shortening the vulcanization time, increasing the vulcanization rate, improving the processing performance and mechanical properties of ethylene propylene rubber.

[0008] The present invention provides a method for preparing liquid ethylene propylene rubber, comprising: oxidizing and degrading bio-based eucommia gum and then performing a hydrogenation reaction to obtain the liquid ethylene propylene rubber.

[0009] This invention uses bio-based Eucommia ulmoides gum as raw material and prepares a viscous, flowable liquid ethylene propylene rubber at room temperature through oxidative degradation and hydrogenation. Moreover, its molecular chain contains oxygen-containing functional groups such as hydroxyl and carbonyl groups.

[0010] Moreover, the experiment found that the oxidative degradation process can achieve the controlled degradation of bio-based Eucommia ulmoides gum, resulting in low molecular weight Eucommia ulmoides gum. More importantly, when the Eucommia ulmoides gum obtained by this method is further subjected to a hydrogenation reaction, the molecular weight of the resulting liquid ethylene propylene rubber can remain basically unchanged compared to the Eucommia ulmoides gum after oxidative degradation, and the molecular weight distribution can be further reduced.

[0011] The method for preparing liquid ethylene propylene rubber according to the present invention includes: preparing a solution of bio-based eucommia gum, adding a degrading agent to carry out an oxidative degradation reaction until the number average molecular weight of the bio-based eucommia gum is 0.19 × 10⁻⁶. 4 ~6.50×10 4 The molecular weight distribution is 1–4;

[0012] Preferably, the bio-based Eucommia ulmoides gum has a number average molecular weight of 1×10⁻⁶. 5 ~3×10 5 Preferably 2×10 5 .

[0013] According to the preparation method of liquid ethylene propylene rubber provided by the present invention, the amount of the degrading agent is 0.5-30% of the mass of bio-based Eucommia ulmoides gum, preferably 1-20%;

[0014] Preferably, the concentration of the adhesive solution is 2-20%, more preferably 4-10%;

[0015] More preferably, the temperature of the oxidative degradation reaction is 20–150°C, and the time is 2–24 h.

[0016] The experiment revealed that the dosage of the degrading agent, reaction temperature, and reaction time all had a certain impact on the molecular weight of the low molecular weight Eucommia ulmoides gum obtained by oxidative degradation. Within an appropriate range, increasing the dosage of the degrading agent, raising the reaction temperature, and extending the reaction time would gradually reduce the molecular weight. However, due to the potential for bimolecular binding caused by excessive reactive free radicals, exceeding the appropriate range would result in an increase in molecular weight. Therefore, to obtain low molecular weight Eucommia ulmoides gum, it is necessary to use an appropriate amount of degrading agent and suitable reaction temperature and time.

[0017] When preparing the bio-based Eucommia ulmoides gum solution according to the present invention, the bio-based Eucommia ulmoides gum solution can be prepared by dissolving the bio-based Eucommia ulmoides gum solution in an organic solvent under heating conditions to prepare a solution with a certain mass fraction; wherein, the dissolution temperature is 30-80℃, preferably 40-60℃, and more preferably, the solvent used is a good solvent for Eucommia ulmoides gum, preferably one or more of benzene, toluene, xylene, chloroform, petroleum ether, and n-hexane.

[0018] The method for preparing liquid ethylene propylene rubber according to the present invention includes: the degradation agent being an organic / inorganic peroxide;

[0019] Preferably, the degrading agent is one or more of the following: hydrogen peroxide (generally 30% hydrogen peroxide), ammonium persulfate, potassium persulfate, sodium peroxide, potassium peroxide, potassium hydrogen persulfate, benzoic acid peroxide, neodecanoic acid peroxide, cyclohexanone peroxide, benzoyl peroxide, tert-butyl benzoyl peroxide, dicumyl peroxide, di(2-ethylhexyl) percarbonate, tert-amyl peroxide, tert-butyl peroxide, cumene peroxide, and methyl ethyl ketone peroxide.

[0020] More preferably, the degrading agent with a high content of active oxygen is selected, including hydrogen peroxide, cyclohexanone peroxide, benzoyl peroxide, tert-butyl peroxide, or methyl ethyl ketone peroxide.

[0021] To avoid residual degradation agents and their decomposition products affecting the hydrogenation process, after oxidative degradation, the organic solvent is removed by ethanol flocculation to collect low molecular weight Eucommia gum. At this stage, the Eucommia gum is still crystalline and in powder form. The dried Eucommia gum is then redispersed in an organic solvent for hydrogenation.

[0022] The method for preparing liquid ethylene propylene rubber according to the present invention includes: the temperature of the oxidative degradation reaction is 20-150°C and the time is 2-24 hours.

[0023] The method for preparing liquid ethylene propylene rubber according to the present invention includes: adding a hydrogenation catalyst to a rubber solution prepared from Eucommia ulmoides gum after oxidative degradation to carry out the hydrogenation reaction to obtain the liquid ethylene propylene rubber;

[0024] The hydrogenation catalyst is one or more of the following: group VIII transition metal complex catalyst, diimide type catalyst, Ziegler type catalyst, Grubbs type catalyst, and Hoveyda-Grubbs type catalyst; to maintain a low molecular weight and molecular weight distribution, the Hoveyda-Grubbs II catalyst is preferred.

[0025] Preferably, the amount of the hydrogenation catalyst is 0.01-10% of the mass of the oxidized and degraded Eucommia ulmoides gum, and more preferably 0.1-5%.

[0026] Eucommia gum after oxidative degradation was collected by ethanol flocculation precipitation and drying. At this point, the gum was still crystalline and in powder form. The gum was then redissolved in an organic solvent (such as toluene, xylene, or n-hexane) to prepare a solution with a specific mass fraction. This solution was transferred to a high-pressure reactor, where double bond addition (i.e., hydrogenation) occurred under the action of a hydrogenation catalyst to form an alternating ethylene-propylene structure. After the reaction was complete, the product could be collected by rotary evaporation. This product, due to the complete saturation of the double bonds in the gum, formed liquid ethylene-propylene rubber, which was non-crystalline, viscous at room temperature, and flowable. The reaction mechanism of the double bond addition is as follows:

[0027]

[0028] The experiment found that the molecular weight of the liquid ethylene propylene rubber obtained by hydrogenation remained basically unchanged and the molecular weight distribution could be further reduced. At the same time, due to the introduction of oxygen-containing functional groups such as hydroxyl and carbonyl groups in the molecular chain of the liquid ethylene propylene rubber during the oxidative degradation process, these oxygen-containing functional groups were retained after hydrogenation, and can be further functionalized to prepare functional materials and expand the application range.

[0029] The method for preparing liquid ethylene propylene rubber according to the present invention includes: the reaction conditions for the hydrogenation reaction are: hydrogen pressure 1-10 MPa, preferably 1-5 MPa, room temperature to 150°C, preferably 50-130°C, reaction time 1-12 h, preferably 2-8 h, and rotation speed 50-800 r / min, preferably 200-400 r / min.

[0030] The present invention also provides liquid ethylene propylene rubber prepared by the method described above.

[0031] The liquid ethylene propylene rubber provided by the present invention has a number-average molecular weight of 0.19 × 10⁻⁶. 4 ~6.5×10 4 The molecular weight distribution is 1–4.

[0032] The present invention also provides the application of the liquid ethylene propylene rubber as described above, including: the application of the liquid ethylene propylene rubber as an environmentally friendly reactive plasticizer in the ethylene propylene rubber processing process.

[0033] According to the application of the liquid ethylene propylene rubber provided by the present invention, the number average molecular weight of the liquid ethylene propylene rubber is 2000 to 30000.

[0034] Preferably, the process of plasticizing the ethylene propylene rubber with liquid propylene rubber is carried out on a two-roll mill, and the vulcanization formula is 20-100 parts carbon black, 1-20 parts zinc oxide, 1-15 parts stearic acid, 0.5-10 parts antioxidant, and 2-10 parts crosslinking agent.

[0035] The process of plasticizing the ethylene propylene rubber with liquid ethylene propylene rubber on a two-roll mill is as follows: First, adjust the roll gap of the two-roll mill to an appropriate roll gap, and plasticize the ethylene propylene rubber (such as Lanxess 6950 from Germany) on the two-roll mill. Then, zinc oxide, stearic acid, antioxidant, and carbon black are added sequentially along the central axis of the rolls and mixed evenly. Next, plasticizer is added. After the liquid ethylene propylene rubber is mixed evenly, crosslinking agent is added. After thorough mixing, the mixture is finally sheeted.

[0036] When the liquid ethylene propylene rubber is used as a plasticizer in the processing of the aforementioned ethylene propylene rubber, it can reduce the interaction forces between rubber molecular chains, reduce Mooney viscosity, improve the mixing process and the plasticity of the rubber compound, thereby improving the vulcanization processing performance. Co-crosslinking can be carried out in the aforementioned vulcanization process, and the physical and mechanical properties of the vulcanized rubber are improved at the same time. Compared with traditional plasticizers, it has better solvent extraction resistance.

[0037] More preferably, the vulcanization is carried out on a flat vulcanizer, with a vulcanization pressure of 15 MPa, a vulcanization temperature of 60–200°C, preferably 100–180°C, and a vulcanization time of 10–120 min, preferably 10–50 min.

[0038] This invention provides a functionalized bio-based narrow-distribution liquid ethylene propylene rubber and its preparation method. It is prepared by a two-step method using bio-based eucommia gum as raw material. The specific process includes: firstly, degrading the bio-based eucommia gum to generate low molecular weight eucommia gum, and then further hydrogenating the low molecular weight eucommia gum to fully saturate the double bonds, so that the molecular chain forms a strictly alternating ethylene propylene structure, that is, functionalized bio-based narrow-distribution liquid ethylene propylene rubber.

[0039] The low molecular weight Eucommia ulmoides gum has a low number-average molecular weight and a narrow molecular weight distribution. After hydrogenation, it generates a functionalized bio-based narrow-distribution liquid ethylene propylene rubber with essentially unchanged molecular weight and a further reduction in molecular weight distribution, resulting in a number-average molecular weight of 0.19 × 10⁻⁶. 4 ~6.5×10 4 Furthermore, liquid ethylene propylene rubber with a molecular weight distribution of 1 to 4, and the introduction of oxygen-containing functional groups such as hydroxyl and carbonyl groups into the molecular chain of this liquid ethylene propylene rubber, can be further functionalized to prepare functional materials and expand the application range.

[0040] The liquid ethylene propylene rubber is used in the processing of ethylene propylene rubber. During the vulcanization process, it can also participate in co-crosslinking, which can reduce the Mooney viscosity of ethylene propylene rubber, improve processing performance, and enhance the mechanical properties of ethylene propylene rubber.

[0041] The preparation method of this invention features a simple process, controllable molecular weight of the product, and uses bio-based Eucommia ulmoides gum as a raw material, resulting in low cost and environmental friendliness, aligning with the concept of sustainable development. Furthermore, the prepared liquid ethylene propylene rubber can also be used as an environmentally friendly reactive plasticizer for ethylene propylene rubber. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 The infrared spectra of Eucommia ulmoides gum, low molecular weight Eucommia ulmoides gum after oxidative degradation, and liquid ethylene propylene rubber obtained in step (2) of Example 1 provided by the present invention are shown.

[0044] Figure 2 This is a molecular weight distribution diagram of the oxidatively degraded Eucommia ulmoides gum in step (1) of Example 12 provided by the present invention and the liquid ethylene propylene rubber obtained in step (2).

[0045] Figure 3 This is a comparison of the extraction performance of vulcanized rubber in Examples 18-21 and Comparative Examples 3-7 provided by the present invention. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0047] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0048] The following is combined Figures 1-3 This invention describes a liquid ethylene propylene rubber, its preparation method, and its application.

[0049] Example 1

[0050] A method for preparing liquid ethylene propylene rubber includes the following steps:

[0051] (1) Using petroleum ether as solvent, 10% of the number-average molecular weight of Eucommia ulmoides gum with a molecular weight of 200,000 was prepared at 40°C. 250g of the solution was transferred to a three-necked flask and 0.5g of benzoyl peroxide (degrading agent) was added at 40°C. After oxidative degradation for 10h, the low molecular weight Eucommia ulmoides gum was collected by flocculation and precipitation with ethanol. The number-average molecular weight and molecular weight distribution of the low molecular weight Eucommia ulmoides gum are shown in Table 1.

[0052] (2) The eucommia gum obtained in step (1) was dissolved in toluene at 40°C to prepare a 6% mass fraction solution. 200g of the solution was added to the reactor, followed by 12mg of Hoveyda-Grubbs II catalyst. After sealing, N2 and H2 were pumped out five times each. Finally, H2 was introduced to stabilize the pressure at 3MPa. The hydrogenation reaction was carried out at a reaction temperature of 110°C and a reaction time of 5h. After the reaction was completed, the liquid ethylene propylene rubber was collected by rotary evaporation. The molecular weight and molecular weight distribution of the liquid ethylene propylene rubber are shown in Table 1.

[0053] Infrared spectroscopy was performed on the bio-based eucommia gum from step (1), the oxidatively degraded eucommia gum, and the liquid ethylene propylene rubber obtained in step (2). The test results are as follows: Figure 1 As shown, compared to bio-based Eucommia ulmoides gum, the 877 cm⁻¹ infrared spectrum of liquid ethylene propylene rubber shows a higher density. -1 798cm -1 The crystallization peak disappeared at 1664 cm⁻¹ -1 The double bonds in the eucommia gum disappear; at 3424 cm⁻¹ -1 1720cm -1 1082cm-1 The presence of stretching vibration peaks of -OH, -C=O, and -COC- at the specified locations indicates that oxygen-containing functional groups are introduced during the degradation process.

[0054] Example 2

[0055] It is basically the same as Example 1, except that the temperature of oxidative degradation in step (1) is 60°C.

[0056] Example 3

[0057] It is basically the same as Example 1, except that the temperature of oxidative degradation in step (1) is 80°C.

[0058] Example 4

[0059] It is basically the same as Example 1, except that the temperature of oxidative degradation in step (1) is 100°C.

[0060] Example 5

[0061] It is basically the same as Example 1, except that the temperature of oxidative degradation in step (1) is 120°C.

[0062] Example 6

[0063] It is basically the same as Example 1, except that the temperature of oxidative degradation in step (1) is 140°C.

[0064] Example 7

[0065] It is basically the same as Example 3, except that the amount of degradation agent added in step (1) is 0.25g.

[0066] Example 8

[0067] It is basically the same as Example 3, except that the amount of degradation agent added in step (1) is 1g.

[0068] Example 9

[0069] It is basically the same as Example 3, except that the amount of degradation agent added in step (1) is 1.5g.

[0070] Example 10

[0071] It is basically the same as Example 3, except that the catalytic degradation time in step (1) is 2 hours.

[0072] Example 11

[0073] It is basically the same as Example 3, except that the catalytic degradation time in step (1) is 4 hours.

[0074] Example 12

[0075] It is basically the same as Example 3, except that the catalytic degradation time in step (1) is 6 hours.

[0076] The molecular weight and molecular weight distribution of the liquid ethylene propylene rubber are shown in Table 1 and... Figure 2 ,from Figure 2 It can be seen that the molecular weight distribution of the liquid ethylene propylene rubber generated after hydrogenation is further reduced, while the molecular weight change is not significant. Therefore, this invention can indirectly and effectively control the molecular weight and molecular weight distribution of liquid ethylene propylene rubber by adjusting the molecular weight of Eucommia ulmoides gum.

[0077] Example 13

[0078] It is basically the same as Example 3, except that the catalytic degradation time in step (1) is 12h.

[0079] Example 14

[0080] It is basically the same as Example 1, except that the oxidative degradation time in step (1) is 14 hours.

[0081] Example 15

[0082] It is basically the same as Example 3, except that the catalyst in step (2) is a group VIII transition metal complex catalyst: RhCI(PPh3)3.

[0083] Example 16

[0084] It is basically the same as Example 3, except that the catalyst in step (2) is a Ziegler-type catalyst: nickel naphthenate and triisobutylaluminum in a molar ratio of 1:4.

[0085] Example 17

[0086] It is basically the same as Example 3, except that the catalyst in step (2) is a diimide type catalyst: p-toluenesulfonyl hydrazine.

[0087] Comparative Example 1

[0088] It is basically the same as Example 3, except that no degradation agent is added in step (1), and the amount of Hoveyda-GrubbsⅡ catalyst added in step (2) is adjusted to 15mg.

[0089] Comparative Example 2

[0090] The results were essentially the same as in Example 3, except that the amount of degrading agent added was 5g. The resulting Eucommia gum underwent cross-linking, forming a gel.

[0091] Table 1

[0092]

[0093]

[0094] As shown in Table 1, the molecular weight of Eucommia ulmoides gum can be controlled by adjusting the reaction temperature, reaction time, and amount of degrading agent. Specifically, as the amount of degrading agent increases, more active groups are introduced, thus gradually reducing the molecular weight. However, when excessive degrading agent is added, as shown in Comparative Example 2, free radicals on the molecular chain can undergo bimolecular bonding, leading to gel formation. With increasing reaction temperature, molecular motion accelerates, increasing the reactivity of the degrading agent, which is beneficial to the degradation process. However, excessively high temperatures, as shown in Example 6, can also result in excessive generation of active free radicals, leading to a slight increase in molecular weight. As the reaction time increases, the molecular weight of Eucommia ulmoides gum gradually decreases. When the reaction time is extended to 14 hours, the molecular weight increases, indicating that degradation and cross-linking occur simultaneously during the reaction process. Degradation is dominant in the early stages, while degradation efficiency gradually weakens and cross-linking efficiency increases in the later stages, resulting in an increase in molecular weight. In conclusion, to obtain low molecular weight Eucommia ulmoides gum, it is necessary to simultaneously control the reaction temperature, reaction time, and amount of degrading agent.

[0095] From Table 1 and Figure 2 It can be seen that the molecular weight of low molecular weight Eucommia gum remains basically unchanged after hydrogenation, while the molecular weight distribution can be further reduced. This is because the Hoveyda-Grubbs II catalyst is an olefin metathesis catalyst. Compared with other catalysts, it can also carry out intermolecular and intramolecular cross metathesis reactions during catalytic hydrogenation, thereby further reducing the molecular weight distribution.

[0096] Example 18

[0097] The application of liquid ethylene propylene rubber as an environmentally friendly reactive plasticizer for ethylene propylene rubber is as follows: First, adjust the roll gap of the two-roll mill to an appropriate roll gap, and plasticize EPDM6950 (Lanxess 6950 from Germany) on the two-roll mill. Then, add 8 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant 4010NA, and 80 parts of carbon black N330 along the central axis of the rolls and mix evenly. Then, add 5 parts of the liquid ethylene propylene rubber (plasticizer) prepared in Example 7. After the liquid ethylene propylene rubber is mixed evenly, add 2 parts of crosslinking agent DCP. After thorough mixing, finally sheet out.

[0098] After the rubber compound is sheeted, it is left to stand for 12 hours, then re-milled on a two-roll mill. 5-7g of the compound is weighed and its vulcanization curve is plotted on a high-speed vulcanizing apparatus to determine the scorch time (t). 10 ) and vulcanization time (t) 90Then, vulcanization was carried out on a flat vulcanizing apparatus at a temperature of 160℃ for a time of t. 90 .

[0099] Example 19

[0100] It is basically the same as Example 18, except that the liquid ethylene propylene rubber is 10 parts.

[0101] Example 20

[0102] It is basically the same as Example 18, except that the liquid ethylene propylene rubber is 15 parts.

[0103] Example 21

[0104] It is basically the same as Example 18, except that the liquid ethylene propylene rubber is 20 parts.

[0105] Comparative Example 3

[0106] It is basically the same as Example 18, except that the plasticizer is 0 parts.

[0107] Comparative Example 4

[0108] It is basically the same as Example 18, except that it uses traditional petroleum-based small molecule naphthenic oil as plasticizer, and the amount added is 5 parts.

[0109] Comparative Example 5

[0110] It is basically the same as Example 18, except that traditional petroleum-based small molecule naphthenic oil is used as a plasticizer, and the amount added is 10 parts.

[0111] Comparative Example 6

[0112] It is basically the same as Example 18, except that traditional petroleum-based small molecule naphthenic oil is used as a plasticizer, and the amount added is 15 parts.

[0113] Comparative Example 7

[0114] It is basically the same as Example 18, except that a traditional petroleum-based small molecule naphthenic oil is used as a plasticizer, and the amount added is 20 parts.

[0115] The processing performance and mechanical properties of Examples 18-21 and Comparative Example 3 were tested, as shown in the table below.

[0116]

[0117] As shown in the table above, without the addition of plasticizer, the Mooney viscosity of ethylene propylene rubber is 94.03, and the scorch time (t) is... 10 The ratio of vulcanization time (t) is 1:47 (min:s). 90The ratio of liquid ethylene propylene rubber to capacities is 22:28 (min:s). With the addition of the liquid ethylene propylene rubber prepared in this invention, on the one hand, the Mooney viscosity of the rubber compound can be significantly reduced; when 20 parts of liquid ethylene propylene rubber are added, the Mooney viscosity is 57.07, improving the processing performance of the rubber compound. This is because the addition of liquid ethylene propylene rubber reduces the interaction forces between molecular chains and between molecular chains and fillers, resulting in a gradual decrease in the Mooney viscosity and torque of the rubber compound. On the other hand, compared with traditional naphthenic oil plasticizers, the vulcanization time is shortened; when 10 parts of naphthenic oil are added, the vulcanization time is reduced. 90 The ratio is 20:45 (min:s), while when 10 parts of liquid ethylene propylene rubber are added, t 90 The ratio is 18:17 (min:s), which shortens the vulcanization time while maintaining a longer scorch time, ensuring processing safety.

[0118] As shown in the table above, the introduction of plasticizers also affects the mechanical properties of vulcanized rubber. With the introduction of plasticizers, the tensile strength of the vulcanized rubber initially increases and then decreases. This is because the addition of plasticizers allows for a more uniform distribution of fillers in the system, thereby improving tensile strength. However, when the amount of plasticizer exceeds 10 parts, the distance between rubber molecular chains increases, weakening intermolecular forces and thus reducing tensile strength. On the other hand, plasticizers fill the spaces between rubber molecular chains, promoting chain movement and increasing chain flexibility. Consequently, with the increase of plasticizers, the hardness of the rubber compound gradually decreases, while the elongation at break gradually increases.

[0119] To investigate the effects of liquid ethylene propylene rubber and naphthenic oil as plasticizers on the pull-out resistance of vulcanizates, the vulcanizates were immersed in n-hexane solvent and the mass loss rate was calculated. Figure 3 As shown, naphthenic oil does not participate in the vulcanization process and only plays a physical plasticizing role. Therefore, with the increase of naphthenic oil content, the mass loss rate of vulcanized rubber in n-hexane solvent increases sharply. Liquid ethylene propylene rubber, as a reactive plasticizer, can co-crosslink with ethylene propylene rubber, so the mass loss rate of vulcanized rubber in n-hexane solvent is low, and the plasticizer is not easily extracted.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for the production of liquid ethylene-propylene rubber, characterized in that, include: The liquid ethylene propylene rubber is obtained by oxidative degradation of bio-based eucommia gum followed by hydrogenation. The degrading agent is a peroxide; The amount of the degradation agent used is 1-6% of the mass of the bio-based Eucommia ulmoides gum.

2. The process for the preparation of liquid ethylene-propylene rubber according to claim 1, characterized in that, include: After the bio-based gutta-percha is prepared into a glue solution, a degradation agent is added to perform an oxidative degradation reaction until the number average molecular weight of the bio-based gutta-percha is 0.19×10 4 ~6.50×10 4 and the molecular weight distribution is 1~4.

3. The method for preparing liquid ethylene propylene rubber according to claim 1, characterized in that, The bio-based gutta-percha has a number average molecular weight of 1 x 10 5 3 x 10 5 .

4. The process for the preparation of liquid ethylene-propylene rubber according to claim 3, characterized in that, The bio-based gutta-percha has a number average molecular weight of 2 x 10 5 .

5. The process for the preparation of liquid ethylene-propylene rubber according to any one of claims 1 to 4, characterized in that, The concentration of the adhesive solution is 2-20%.

6. The process for the preparation of liquid ethylene-propylene rubber according to claim 5, characterized in that, The concentration of the adhesive solution is 4-10%.

7. The method for preparing liquid ethylene propylene rubber according to any one of claims 1 to 4 and 6, characterized in that, The degrading agent is one or more of the following: hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium peroxide, potassium peroxide, potassium hydrogen persulfate, benzoic acid peroxide, neodecanoic acid peroxide, cyclohexanone peroxide, benzoyl peroxide, tert-butyl peroxide, dicumyl peroxide, di(2-ethylhexyl) percarbonate, tert-amyl peroxide, tert-butyl peroxide, cumene peroxide, and methyl ethyl ketone peroxide.

8. The process for preparing liquid ethylene-propylene rubber according to claim 5, characterized by, The degrading agent is one or more of the following: hydrogen peroxide, ammonium persulfate, potassium persulfate, sodium peroxide, potassium peroxide, potassium hydrogen persulfate, benzoic acid peroxide, neodecanoic acid peroxide, cyclohexanone peroxide, benzoyl peroxide, tert-butyl peroxide, dicumyl peroxide, di(2-ethylhexyl) percarbonate, tert-amyl peroxide, tert-butyl peroxide, cumene peroxide, and methyl ethyl ketone peroxide.

9. The process for the preparation of liquid ethylene-propylene rubber according to any one of claims 1 to 4, 6, 8, characterized in that, include: The oxidative degradation reaction is carried out at a temperature of 20~150℃ for a time of 2~24h.

10. The process for preparing liquid ethylene-propylene rubber according to claim 5, characterized by, include: The oxidative degradation reaction is carried out at a temperature of 20~150℃ for a time of 2~24h.

11. The process for preparing liquid ethylene-propylene rubber according to claim 7, characterized by, include: The oxidative degradation reaction is carried out at a temperature of 20~150℃ for a time of 2~24h.

12. The method for preparing liquid ethylene propylene rubber according to any one of claims 1-4, 6, 8, 10-11, characterized in that, include: The hydrogenation catalyst is added to the syrup prepared from the oxidatively degraded Eucommia ulmoides gum to carry out the hydrogenation reaction to obtain the liquid ethylene propylene rubber; The hydrogenation catalyst is one or more of the following: group VIII transition metal complex catalyst, diimide type catalyst, Ziegler type catalyst, Grubbs type catalyst, and Hoveyda-Grubbs type catalyst.

13. The process for the preparation of liquid ethylene-propylene rubber according to claim 12, characterized in that, The amount of hydrogenation catalyst used is 0.01~10% of the mass of the oxidized and degraded Eucommia ulmoides gum.

14. The process for the preparation of liquid ethylene-propylene rubber according to claim 13, characterized in that, The amount of hydrogenation catalyst used is 0.1-5% of the mass of the oxidized and degraded Eucommia ulmoides gum.

15. The process for preparing liquid ethylene-propylene rubber according to claim 5, characterized by, include: The hydrogenation catalyst is added to the syrup prepared from the oxidatively degraded Eucommia ulmoides gum to carry out the hydrogenation reaction to obtain the liquid ethylene propylene rubber; The hydrogenation catalyst is one or more of the following: group VIII transition metal complex catalyst, diimide type catalyst, Ziegler type catalyst, Grubbs type catalyst, and Hoveyda-Grubbs type catalyst.

16. The process for the preparation of liquid ethylene propylene rubber according to claim 15, characterized in that, The amount of hydrogenation catalyst used is 0.01~10% of the mass of the oxidized and degraded Eucommia ulmoides gum.

17. The process for the preparation of liquid ethylene propylene rubber according to claim 16, characterized in that, The amount of hydrogenation catalyst used is 0.1-5% of the mass of the oxidized and degraded Eucommia ulmoides gum.

18. The process for preparing liquid ethylene-propylene rubber according to claim 7, characterized by, include: The hydrogenation catalyst is added to the syrup prepared from the oxidatively degraded Eucommia ulmoides gum to carry out the hydrogenation reaction to obtain the liquid ethylene propylene rubber; The hydrogenation catalyst is one or more of the following: group VIII transition metal complex catalyst, diimide type catalyst, Ziegler type catalyst, Grubbs type catalyst, and Hoveyda-Grubbs type catalyst.

19. The process for the preparation of liquid ethylene propylene rubber according to claim 18, characterized in that, The amount of hydrogenation catalyst used is 0.01~10% of the mass of the oxidized and degraded Eucommia ulmoides gum.

20. The process for the preparation of liquid ethylene propylene rubber according to claim 19, characterized in that, The amount of hydrogenation catalyst used is 0.1-5% of the mass of the oxidized and degraded Eucommia ulmoides gum.

21. The process for preparing liquid ethylene-propylene rubber according to claim 9, characterized by, include: The hydrogenation catalyst is added to the syrup prepared from the oxidatively degraded Eucommia ulmoides gum to carry out the hydrogenation reaction to obtain the liquid ethylene propylene rubber; The hydrogenation catalyst is one or more of the following: group VIII transition metal complex catalyst, diimide type catalyst, Ziegler type catalyst, Grubbs type catalyst, and Hoveyda-Grubbs type catalyst.

22. The process for the preparation of liquid ethylene propylene rubber according to claim 21, characterized in that, The amount of hydrogenation catalyst used is 0.01~10% of the mass of the oxidized and degraded Eucommia ulmoides gum.

23. The process for the preparation of liquid ethylene propylene rubber according to claim 22, characterized in that, The amount of hydrogenation catalyst used is 0.1-5% of the mass of the oxidized and degraded Eucommia ulmoides gum.

24. The process for preparing liquid ethylene propylene rubber according to claim 12, characterized in that, include: The hydrogenation reaction conditions are: hydrogen pressure 1~10MPa, room temperature~150℃, and reaction time 1~12h.

25. The process for preparing liquid ethylene-propylene rubber according to any one of claims 13 to 23, characterized in that, include: The hydrogenation reaction conditions are: hydrogen pressure 1~10MPa, room temperature~150℃, and reaction time 1~12h.

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