Functionalized rubber, functionalized rubber nanocomposite and preparation method and application thereof

Abstract

The invention provides functionalized rubber, a functionalized rubber nano composite material as well as a preparation method and application of the functionalized rubber nano composite material. The functionalized rubber is obtained by carrying out click reaction on a sulfydryl reagent and rubber containing double bonds in the presence of a side reaction inhibitor, and the obtained functionalized rubber and a rubber additive are mixed and vulcanized to obtain the functionalized rubber nano composite material. According to the method, the defects that in the rubber functionalization process, many side reactions exist, the click reaction is difficult to control and the like are overcome, the side reactions such as carbon-carbon crosslinking in the reaction process are effectively inhibited, the click rate is increased, the prepared high-performance functionalized rubber is low in Mooney viscosity and good in processability, and the method is easy to operate and easy to apply and popularize.

Description

Technical Field

[0001] The invention relates to the technical field of rubber materials, and more particularly to a functionalized rubber, a functionalized rubber nanocomposite material, and a preparation method and application thereof. Background Art

[0002] Fillers have high surface energy and high polarity, and are not compatible with non-polar rubbers. In addition, the surface of fillers contains a large number of hydroxyl groups, which will form hydrogen bonds between fillers, and are prone to agglomeration in rubber composites, resulting in poor dispersibility. In order to solve the above problems, people have improved the dispersibility of fillers in rubber matrices by modifying the surface of fillers and functionalizing rubber.

[0003] At present, bifunctional silane bis(3-triethoxysilylpropyl) tetrasulfide (Si69) in silane coupling agent is widely used in the "green tire" industry. The triethoxy group in Si69 undergoes hydrolysis and condensation reaction with the hydroxyl group on the surface of the filler, which can effectively improve the dispersion of the filler in the rubber, but Si69 will produce volatile organic compounds during the chemical reaction. Another method is rubber functionalization, which introduces polar functional groups to make the rubber molecular chain have higher polarity. According to the position of the functional group introduced into the rubber molecular chain, rubber functionalization modification can be divided into chain end functionalization and chain functionalization. Rubber chain functionalization can be introduced by double bond epoxidation, introduction of a third polar comonomer, hydrosilylation and thiol-ene click chemistry reaction. Among them, the thiol-ene click chemistry reaction has the advantages of fast reaction rate, simple reaction conditions, high product yield and strong selectivity, so it has received high attention in the field of rubber functionalization. However, since the thiol-ene click chemistry reaction is prone to side reactions, such as carbon-carbon crosslinking, the occurrence of side reactions. Justynska J et al. introduced thiol reagents into 1,2-polybutadiene using azobisisobutyronitrile as an initiator under an inert atmosphere at 70°C. The results showed that there was almost no C=C bond in the product after the click reaction, but the click rate was far less than 100%. It was speculated that the thiol click reaction occurred a carbon-carbon cross-linking reaction, leading to intramolecular cyclization (Justynska J, Hordyjewicz Z, Schlaad H. Toward a toolbox of functional block copolymers via free-radical addition of mercaptans [J]. Polymer, 2005, 46 (26): 12057-12064.). The researchers used methods such as changing the reaction conditions and optimizing the degree of functionalization to inhibit the occurrence of side reactions, which was beneficial to the improvement of the comprehensive properties of rubber. Romani F et al. used initiators to graft thioglycolic acid and its fatty acid esters into styrene-butadiene rubber. By changing experimental conditions such as reaction temperature, initiator type, and solvent, they optimized the degree of functionalization and minimized the formation of insoluble cross-linked polymers (Romani F, Passaglia E, Aglietto M, et al. Functionalization of SBR copolymer by free radical addition of thiols [J]. Macromolecular Chemistry and Physics, 1999, 200 (3): 524-530.).

[0004] In the prior art, the preparation of functionalized rubber by thiol click requires the generation of thiol free radicals, which react with double bonds to graft functional groups onto rubber. The initiation reaction and grafting rate are difficult to control, resulting in other cross-linking side reactions in the rubber, low click efficiency, and uneven grafting. The occurrence of side reactions seriously affects the dispersion of fillers and the interaction between fillers and rubber. The thiol reagents remaining in the rubber after the reaction will also have an adverse effect on the scorch of the rubber, which will make it difficult to improve the performance of the functionalized rubber. Summary of the invention

[0005] In order to solve the technical problems existing in the prior art, the present invention provides a functionalized rubber, a functionalized rubber nanocomposite material, and a preparation method and application thereof.

[0006] The prior art uses thermal initiation, light initiation or initiator initiation during functionalization, which will cause side reactions such as carbon-carbon crosslinking in the rubber matrix. The present invention adds a side reaction inhibitor during the thiol clicking rubber process, which effectively inhibits the side reactions occurring during the reaction, reduces side reactions such as carbon-carbon crosslinking, and improves the click rate.

[0007] The present invention provides a simple and efficient method for preparing high-performance functionalized rubber, which is simple to operate, significantly improves material performance, and solves the shortcomings of many side reactions and difficult-to-control click reactions in the rubber functionalization process. The high-performance functionalized rubber finally obtained has an improved click rate, low Mooney viscosity, and good processing performance.

[0008] One of the purposes of the present invention is to provide a functionalized rubber obtained by a click reaction between a mercapto reagent and a rubber containing double bonds in the presence of a side reaction inhibitor.

[0009] In a preferred embodiment of the present invention, the mercapto reagent carries at least one of a siloxane group, an amine group, a carboxyl group, an ester group, and a hydroxyl functional group and a mercapto functional group; preferably at least one of 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, mercaptopropylmethyldimethoxysilane, 3-mercaptopropionic acid, mercaptosuccinic acid, ethyl mercaptoacetate, methyl mercaptoacetate, mercaptoethanol, 3-mercaptopropanol, and mercaptoethylamine;

[0010] The rubber is a rubber with double bonds in the main chain or side chain, preferably at least one of nitrile rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, silicone rubber, EPDM rubber, natural rubber, butadiene rubber, butadiene rubber, and butyl rubber; the styrene-butadiene rubber is preferably solution-polymerized styrene-butadiene rubber;

[0011] The side reaction inhibitor is at least one of hydroquinone, diphenylamine, 5,5-dimethyl-1-pyrroline-N-oxide, 2,2,6,6-tetramethylpiperidinyl oxide, methyl methacrylate, tea polyphenols, gallic acid, dopamine, butylated hydroxytoluene, divinyl ether, 1,1-diphenylethylene, 2,2-diphenyl-1-trinitrophenylhydrazine, p-benzoquinone, tetramethylbenzoquinone, p-aminobenzoic acid, iodine, ascorbic acid, α-tocopherol, hydroquinone, β-carotene, gentisic acid, and N-tert-butyl-α-phenylimine.

[0012] The side reaction inhibitor captures the carbon free radicals generated by the click reaction to prevent the occurrence of carbon-carbon cross-linking side reactions. The addition of the side reaction inhibitor can also promote the click of the thiol reagent, thereby effectively inhibiting the cross-linking side reaction.

[0013] In a preferred embodiment of the present invention,

[0014] The molar ratio of the mercapto reagent to the double bonds of the rubber is (0.005-0.9):1, preferably (0.005-0.1):1;

[0015] The molar ratio of the side reaction inhibitor to the double bonds of the rubber is (0.005-0.9):1, preferably (0.02-0.1):1.

[0016] A second object of the present invention is to provide a method for preparing a functionalized rubber, comprising:

[0017] The thiol reagent and the rubber containing double bonds undergo a click reaction in the presence of a side reaction inhibitor to obtain the functionalized rubber.

[0018] In a preferred embodiment of the present invention,

[0019] The high performance functionalized rubber is obtained by one of the following methods:

[0020] Method 1: Add the thiol reagent and the side reaction inhibitor to the rubber containing double bonds to carry out click reaction;

[0021] Method 2: Add the side reaction inhibitor to the rubber containing double bonds and mix them, then add the thiol reagent to carry out the click reaction.

[0022] In a preferred embodiment of the present invention,

[0023] The click reaction is carried out in a solution or a solid phase; when carried out in a solution, the concentration of the rubber in the solution is preferably 1 to 50 wt%, more preferably 15 to 30 wt%, and the solvent is a good solvent for rubber commonly used in the prior art, such as cyclohexane, etc.;

[0024] The initiation mode of the click reaction is at least one of thermal initiation, photoinitiation, and initiator initiation; thermal initiation is related to temperature, and thiol free radicals are generated at a certain temperature; photoinitiation mainly uses ultraviolet light or natural light to generate thiol free radicals through light initiation; the initiator is mainly a free radical initiator, which generates thiol free radicals by taking hydrogen from the thiol group; preferably,

[0025] When the initiation method is thermal initiation,

[0026] The temperature of the heat-induced click reaction is 30 to 170° C., preferably 60 to 160° C.; and / or,

[0027] The heat-induced click reaction time is 1 to 360 minutes; preferably 5 to 60 minutes; and / or,

[0028] When the initiation method is light initiation,

[0029] The photoinitiator is at least one of the following raw materials: 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzil, bis(2,4,6-trimethylbenzoyl)diphenylphosphine oxide, benzoin ethyl ether, thioxanthone (TX) / triethylamine (Et3N); and / or,

[0030] The light intensity is 2-15W, preferably 5-15W; and or,

[0031] The illumination time is 1 to 24 hours; preferably 8 to 24 hours; and / or,

[0032] The amount of the photoinitiator is 1 to 10 wt % of the rubber mass, preferably 3 to 8 wt %; and / or,

[0033] When the initiation mode is initiated by an initiator,

[0034] The initiator is a free radical initiator, preferably at least one of cyclohexanone peroxide, dibenzoyl peroxide (LPO), tert-butyl hydroperoxide, azobisisobutyronitrile and azobisisoheptanenitrile; and / or,

[0035] The amount of the initiator is 0.01 to 8 wt % of the rubber mass, preferably 0.01 to 2 wt %.

[0036] The third object of the present invention is to provide a functionalized rubber obtained by the above preparation method.

[0037] A fourth object of the present invention is to provide a functionalized rubber nanocomposite material prepared from raw materials including the above-mentioned functionalized rubber.

[0038] The fifth object of the present invention is to provide a method for preparing a functionalized rubber nanocomposite material, comprising: mixing the functionalized rubber with a rubber additive and vulcanizing the mixture to obtain the functionalized rubber nanocomposite material.

[0039] The sixth object of the present invention is to provide an application of a functionalized rubber or a functionalized rubber nanocomposite material in rubber products, preferably in tires.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] When the prior art is functionalized, side reactions such as carbon-carbon crosslinking will occur in the rubber matrix, resulting in low click efficiency and uneven grafting. The occurrence of side reactions seriously affects the dispersion of fillers and the interaction between fillers and rubber. The mercapto reagents remaining in the rubber after the reaction will also have an adverse effect on the scorch of the rubber, which will make it difficult to improve the performance of the functionalized rubber.

[0042] The present invention provides a simple and efficient method for preparing high-performance functionalized rubber. By adding a side reaction inhibitor to the mercapto click rubber reaction, side reactions such as carbon-carbon crosslinking occurring during the reaction are effectively inhibited, and the click rate is improved. The prepared high-performance functionalized rubber has low Mooney viscosity and good processing performance, and the shortcomings of many side reactions and difficult control of click reactions in the rubber functionalization process are solved. The method is simple to operate and easy to promote and apply.

[0043] The high-performance functionalized rubber prepared by the present invention can be compounded with fillers, additives, etc. to obtain a high-performance rubber nanocomposite material. Compared with the composite material prepared from the functionalized rubber without using the side reaction inhibitor, the composite material has lower rolling resistance, higher anti-skid performance, better filler dispersion performance, lower compression heat rise, longer scorch time, and better wear resistance, and can be applied to tires. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 The internal mixer torque-time diagram of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1-2 and Comparative Examples 1-2;

[0045] Figure 2 The infrared spectra of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1-2 and Comparative Examples 1-2 and the raw material solution-polymerized styrene-butadiene rubber;

[0046] Figure 3 The infrared spectra of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1 to 2 and Comparative Examples 1 to 2 and the raw solution-polymerized styrene-butadiene rubber are at 993 cm -1 、910cm -1 Magnified image of the place;

[0047] Figure 4The infrared spectra of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1 to 2 and Comparative Examples 1 to 2 and the raw solution-polymerized styrene-butadiene rubber are at 1166 cm -1 、1103cm -1 、1080cm -1 Magnified image of the place;

[0048] Figure 5 The Mooney viscosity diagram of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1-2 and Comparative Examples 1-2. DETAILED DESCRIPTION

[0049] The present invention is described in detail below in conjunction with specific drawings and embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the content of the present invention still fall within the scope of protection of the present invention.

[0050] The raw materials used in the examples and comparative examples are all conventional commercially available raw materials. Table 1 shows the sources and material descriptions of some raw materials.

[0051] Table 1 Raw materials and suppliers

[0052]

[0053]

[0054] Test method:

[0055] Fourier transform infrared spectroscopy (FTIR): The functionalized rubber was dissolved in cyclohexane, precipitated with ethanol, washed three times, and dried. The functional group changes of the sample were characterized by using the American FTS-3000 Fourier transform infrared spectrometer in total reflection mode (ATR). Test conditions: Scanning range 4000cm -1 Up to 400cm -1 , resolution 4cm -1 .

[0056] Mooney viscosity test: This experiment used MV-3000VS (High-speed Railway Testing Instrument Co., Ltd.) to conduct Mooney viscosity test according to ASTM D1646 standard. At 100°C, the preheating time was set to 1 min and the rotation time was set to 4 min.

[0057] Internal mixer processing analysis: This experiment used MIX-300C (China Harpu Electric Technology Co., Ltd.) with a rotor speed of 60r / min.

[0058] The Payne effect of rubber was tested by RPA2000 rubber process analyzer (RPA2000, Alpha Corporation, USA). For the blend, the strain scan at 1 Hz and 60°C was 0.28%-200%; for the vulcanizate, the strain range at 10 Hz and 60°C was 0.28-42%.

[0059] The dynamic mechanical properties were characterized by a VA3000 dynamic mechanical thermal analysis (DMTA) system (Metravib, France), and the test conditions were set at 3°C / min and 10 Hz, and the tensile strain was 0.1%.

[0060] Abrasion test: The wear resistance of vulcanized rubber was tested using an MZ-4061 Arkon abrasion tester (Jiangsu Mingzhu Testing Machine Co., Ltd.) according to GB / T1689-201451 standard.

[0061] Vulcanization performance test: The vulcanization performance of the composite material was studied at 150°C using an MR-C3 rotorless rheometer that complies with ASTM D5289 standard.

[0062] Compression fatigue temperature rise test: The test was carried out on the sample by RH-2000N compression heating tester (Gotech Testing Machine Co., Ltd.) at a temperature of 55°C in accordance with ISO 4666-3:2010 standard in pure compression mode at 30Hz. The static pressure during measurement was 10% and the pre-compression was 4.45mm.

[0063] The parts in the following examples and comparative examples are all parts by weight.

[0064] Example 1

[0065] 137.5 parts of solution polymerized styrene butadiene rubber (each 137.5 g contains 100 g of rubber and 37.5 g of oil, and the following specifications of solution polymerized styrene butadiene rubber are the same), 3.77 parts of 3-mercaptopropyltriethoxysilane and 2.47 parts of 2,2,6,6-tetramethylpiperidinoxide are added to an internal mixer for mixing at a temperature of 90°C for 5 minutes. The molar ratio of 3-mercaptopropyltriethoxysilane to the double bonds in the solution polymerized styrene butadiene rubber is 0.02:1, the molar ratio of 2,2,6,6-tetramethylpiperidinoxide to the double bonds in the solution polymerized styrene butadiene rubber is 0.02:1, the temperature is 90°C, and mixing is carried out for 5 minutes to obtain functionalized solution polymerized styrene butadiene rubber.

[0066] According to the formula, 100 parts of the prepared functionalized solution-polymerized styrene-butadiene rubber, 3 parts of zinc oxide, 2 parts of stearic acid, 80 parts of white carbon black, 2 parts of antioxidant, and 1.5 parts of paraffin wax were added in sequence on an open mill and mixed, and then heat-treated in an internal mixer for 5 minutes. After cooling, 2 parts of accelerator CZ, 2 parts of accelerator D, and 1.5 parts of sulfur were added in the open mill to prepare a rubber mix. The rubber mix was vulcanized at 150°C and 15MPa to obtain a high-performance functionalized rubber nanocomposite material.

[0067] Example 2

[0068] The difference from Example 1 is that the temperature of the click reaction is different, and the click temperature for mixing in the internal mixer is 150°C;

[0069] Except for the above differences, other conditions in Example 2 are the same as those in Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, a high-performance functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0070] Example 3

[0071] The difference from Example 1 is that the mercapto reagent is different, the mercapto reagent is replaced by 2.85 parts of mercaptopropylmethyldimethoxysilane, and the molar ratio of mercaptopropylmethyldimethoxysilane to the double bonds in the solution-polymerized styrene-butadiene rubber is 0.02:1;

[0072] Except for the above differences, other conditions in Example 3 are the same as those in Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, a high-performance functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0073] Example 4

[0074] The difference from Example 1 is that the amount of the mercapto reagent is different, and the amount of the side reaction inhibitor is different; specifically, the mercapto reagent is 0.94 parts of 3-mercaptopropyltriethoxysilane, and the molar ratio of 3-mercaptopropyltriethoxysilane to the double bonds in the solution polymerized styrene butadiene rubber is 0.005:1; the side reaction inhibitor is 12.34 parts of 2,2,6,6-tetramethylpiperidinyl oxide, and the molar ratio of 2,2,6,6-tetramethylpiperidinyl oxide to the double bonds in the solution polymerized styrene butadiene rubber is 0.1:1;

[0075] Except for the above differences, other conditions in Example 4 are the same as those in Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, a high-performance functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0076] Example 5

[0077] The difference from Example 1 is that the amount of the mercapto reagent is different, and the amount of the side reaction inhibitor is different; specifically, the mercapto reagent is 18.83 parts of 3-mercaptopropyltriethoxysilane, and the molar ratio of 3-mercaptopropyltriethoxysilane to the double bonds in the solution polymerized styrene butadiene rubber is 0.1:1; the side reaction inhibitor is 12.34 parts of 2,2,6,6-tetramethylpiperidinyl oxide, and the molar ratio of 2,2,6,6-tetramethylpiperidinyl oxide to the double bonds in the solution polymerized styrene butadiene rubber is 0.1:1;

[0078] Except for the above differences, other conditions in Example 5 are the same as those in Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, a high-performance functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0079] Example 6

[0080] The difference from Example 1 is that the temperature and time of the click reaction are different, the click temperature for mixing in the internal mixer is 60° C., and the click time is 60 min; the side reaction inhibitor and the amount used are different, the side reaction inhibitor is 1.58 parts of methyl methacrylate, and the molar ratio of methyl methacrylate to the double bond in the solution polymerized styrene-butadiene rubber is 0.02:1;

[0081] Except for the above differences, other conditions in Example 6 are the same as those in Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, a high-performance functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0082] Example 7

[0083] The difference from Example 1 is that the temperature and time of the click reaction are different. The click temperature for mixing in the internal mixer is 60° C. and the click time is 60 min. The side reaction inhibitor and the amount used are different. The side reaction inhibitor is 3.48 parts of butylated hydroxytoluene, and the molar ratio of the side reaction inhibitor to the double bond in the solution polymerized styrene-butadiene rubber is 0.02:1.

[0084] Except for the above differences, other conditions in Example 7 are the same as those in Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, a high-performance functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0085] Example 8

[0086] 2.67 parts of 3-mercaptopropyltriethoxysilane, 1.75 parts of 2,2,6,6-tetramethylpiperidinoxide, and 3 parts of benzoin ethyl ether were added to 500 parts of cyclohexane solution containing 100 parts of butadiene rubber (the molar number of vinyl per 100g of rubber is 0.56 mol), wherein the molar ratio of vinyl in 3-mercaptopropyltriethoxysilane is 0.02:1, and the molar ratio of vinyl in 2,2,6,6-tetramethylpiperidinoxide to butadiene rubber is 0.02:1. Use low-power 15W black light, cover with argon, and irradiate the mixture at room temperature for about 24 hours. Ethanol is dripped into the solution to precipitate the polymer. After filtration, all products are redissolved and reprecipitated three times in cyclohexane. Functionalized butadiene rubber is obtained after drying in an oven.

[0087] According to the formula, 100 parts of functionalized butadiene rubber, 3 parts of zinc oxide, 2 parts of stearic acid, 80 parts of white carbon black, 2 parts of antioxidant, and 1.5 parts of paraffin wax were added and mixed in an open mill, and then heat treated in an internal mixer for 5 minutes. After cooling, 2 parts of accelerator CZ, 2 parts of accelerator D, and 1.5 parts of sulfur were added in the open mill to prepare a rubber mix. The rubber mix was vulcanized at 150°C and 15MPa to obtain a high-performance functionalized rubber nanocomposite material.

[0088] Example 9

[0089] 137.5 parts of solution polymerized styrene butadiene rubber, 3.77 parts of 3-mercaptopropyltriethoxysilane, and 1.11 parts of divinyl ether were added into an internal mixer for mixing at 90°C and hot clicking for 5 minutes. The molar ratio of 3-mercaptopropyltriethoxysilane to the double bonds in the solution polymerized styrene butadiene rubber was 0.02:1, and the molar ratio of divinyl ether to the double bonds in the solution polymerized styrene butadiene rubber was 0.02:1. After uniform mixing, functionalized solution polymerized styrene butadiene rubber was obtained.

[0090] According to the formula, 100 parts of the prepared functionalized solution-polymerized styrene-butadiene rubber, 3 parts of zinc oxide, 2 parts of stearic acid, 80 parts of white carbon black, 2 parts of antioxidant, and 1.5 parts of paraffin wax were added in sequence on an open mill and mixed, and then heat-treated in an internal mixer for 5 minutes. After cooling, 2 parts of accelerator CZ, 2 parts of accelerator D, and 1.5 parts of sulfur were added in the open mill to prepare a rubber mix. The rubber mix was vulcanized at 150°C and 15MPa to obtain a high-performance functionalized rubber nanocomposite material.

[0091] Example 10

[0092] 137.5 parts of solution polymerized styrene butadiene rubber and 2.47 parts of 2,2,6,6-tetramethylpiperidinyl oxide (the molar ratio of 2,2,6,6-tetramethylpiperidinyl oxide to the double bonds in the solution polymerized styrene butadiene rubber is 0.02:1) are blended, and then 3.77 parts of 3-mercaptopropyltriethoxysilane (the molar ratio of 3-mercaptopropyltriethoxysilane to the double bonds in the solution polymerized styrene butadiene rubber is 0.02:1) are added into an internal mixer for mixing at a temperature of 90°C and hot-clicked for 5 minutes. After mixing evenly, functionalized solution polymerized styrene butadiene rubber is obtained.

[0093] According to the formula, 100 parts of the prepared functionalized solution-polymerized styrene-butadiene rubber, 3 parts of zinc oxide, 2 parts of stearic acid, 80 parts of white carbon black, 2 parts of antioxidant, and 1.5 parts of paraffin wax were added in sequence on an open mill and mixed, and then heat-treated in an internal mixer for 5 minutes. After cooling, 2 parts of accelerator CZ, 2 parts of accelerator D, and 1.5 parts of sulfur were added in the open mill to prepare a rubber mix. The rubber mix was vulcanized at 150°C and 15MPa to obtain a high-performance functionalized rubber nanocomposite material.

[0094] Embodiment 11

[0095] 137.5 parts of solution polymerized styrene butadiene rubber were added to a three-necked flask containing 687.5 parts of cyclohexane and dissolved at 40°C. Then, 0.01 parts of dodecyl peroxide initiator, 3.77 parts of 3-mercaptopropyltriethoxysilane (the molar ratio of 3-mercaptopropyltriethoxysilane to the double bonds in the solution polymerized styrene butadiene rubber was 0.02:1) and 2.47 parts of 2,2,6,6-tetramethylpiperidinoxide (the molar ratio of 2,2,6,6-tetramethylpiperidinoxide to the double bonds in the solution polymerized styrene butadiene rubber was 0.02:1) were added to the completely dissolved solution polymerized styrene butadiene rubber / cyclohexane solution. The reaction was carried out at 40°C for 1 hour, and ethanol was dripped into the solution to precipitate the polymer. After filtration, all products were redissolved and reprecipitated in cyclohexane three times. Functionalized solution polymerized styrene butadiene rubber was obtained after drying in an oven.

[0096] According to the formula, 100 parts of the prepared functionalized solution-polymerized styrene-butadiene rubber, 3 parts of zinc oxide, 2 parts of stearic acid, 80 parts of white carbon black, 2 parts of antioxidant, and 1.5 parts of paraffin wax were added in sequence on an open mill and mixed, and then heat-treated in an internal mixer for 5 minutes. After cooling, 2 parts of accelerator CZ, 2 parts of accelerator D, and 1.5 parts of sulfur were added in the open mill to prepare a rubber mix. The rubber mix was vulcanized at 150°C and 15MPa to obtain a high-performance functionalized rubber nanocomposite material.

[0097] Comparative Example 1

[0098] The difference from Example 1 is that 2,2,6,6-tetramethylpiperidinoxide is not added when preparing the functionalized solution-polymerized styrene-butadiene rubber;

[0099] The other conditions of Comparative Example 1 are the same as those of Example 1. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, the functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0100] Comparative Example 2

[0101] The difference from Example 2 is that 2,2,6,6-tetramethylpiperidinoxide is not added when preparing the functionalized solution-polymerized styrene-butadiene rubber;

[0102] The other conditions of Comparative Example 2 are the same as those of Example 2. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, the functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0103] Comparative Example 3

[0104] The difference from Example 8 is that 2,2,6,6-tetramethylpiperidinoxide was not added when preparing the functionalized butadiene rubber;

[0105] The other conditions of Comparative Example 3 are the same as those of Example 8. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, the functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0106] Comparative Example 4

[0107] The difference from Example 11 is that 2,2,6,6-tetramethylpiperidinoxide is not added when preparing the functionalized solution-polymerized styrene-butadiene rubber;

[0108] The other conditions of Comparative Example 4 are the same as those of Example 11. After obtaining the functionalized solution-polymerized styrene-butadiene rubber, the functionalized rubber nanocomposite material is obtained according to the same formula and preparation method.

[0109] Table 2 Test results of functionalized rubber nanocomposites prepared in Examples 1 to 11 and Comparative Examples 1 to 4

[0110]

[0111] Table 2 shows the performance test results of the high performance functionalized rubber nanocomposites of Examples 1 to 11 and the functionalized rubber nanocomposites of Comparative Examples 1 to 4. It can be seen from the table that:

[0112] Compared with Comparative Example 1, Example 2 compared with Comparative Example 2, Example 8 compared with Comparative Example 3, and Example 11 compared with Comparative Example 4, the scorch time and DMA-tanδ(0℃) were improved, and RPA-ΔG'(60℃), RPA-tanδ(7%) and compression fatigue temperature rise were reduced. Compared with the samples without the side reaction inhibitor, the samples with the side reaction inhibitor added had a longer scorch time, better white carbon black dispersion, lower rolling resistance, and improved wet skid resistance, proving that after the side reaction inhibitor was added, the cross-linking side reaction was suppressed, and the thiol reagent was easier to click into the rubber.

[0113] Examples 1, 8, and 11 studied the effects of different initiation methods of click reaction on functionalized rubber. Compared with Comparative Examples 1, 3, and 4, the dispersion, anti-slip performance, and rolling resistance of white carbon black in the rubber nanocomposite material were improved. It was proved that whether thermal initiation, photoinitiation, or initiator initiation was used, the side reaction inhibitor could promote the click of thiol reagents and inhibit the occurrence of cross-linking side reactions.

[0114] Figure 1 The internal mixer torque-time diagram of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1-2 and Comparative Examples 1-2 is shown in FIG. Figure 1 It can be seen that the torque of the internal mixer of Example 1 and Comparative Example 1 is gradually decreasing, while the torque of Comparative Example 2 is first increased and then decreased. After the side reaction inhibitor is added, the torque of Example 2 is also gradually reduced. This is because the click reaction temperature in Comparative Example 2 is high, and the cross-linking side reaction occurs rapidly, resulting in an increase in torque. Under the action of shear force, the rubber is shredded, resulting in a decrease in torque. After the side reaction inhibitor is added, the torque no longer increases significantly, which shows that the added side reaction inhibitor has the effect of inhibiting the cross-linking side reaction.

[0115] Figure 2 The infrared spectra of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1 to 2 and Comparative Examples 1 to 2 and the raw material solution-polymerized styrene-butadiene rubber are shown in FIG. Figures 2 to 4 It can be seen that for solution-polymerized styrene-butadiene rubber, 2920 cm -1 The peak at 910 cm is the stretching vibration peak of methylene. -1 and 993cm -1 The peak near 968cm is due to the bending vibration of 1,2 vinyl groups. -1 The peak near 1166cm is attributed to the 1,4 double bond. -1 The corresponding CH 2 CH 3 New peak, 1103cm -1 With 1080cm -1The peaks near 910cm are caused by the asymmetric stretching vibration of Si-O in 3-mercaptopropyltriethoxysilane. New absorption peaks appear in the functionalized SSBR, indicating that 3-mercaptopropyltriethoxysilane has been successfully grafted into SSBR. In addition, as the click temperature of 3-mercaptopropyltriethoxysilane increases, the peaks at 910cm -1 The peak intensity gradually weakens at 2920cm -1 、1103cm -1 、1080cm -1 The peak at gradually strengthened, indicating that the thiol click rate gradually increased with the increase of click temperature. This proves that the side reaction inhibitor has a promoting effect on thiol click.

[0116] Figure 5 The Mooney viscosity diagram of the functionalized solution-polymerized styrene-butadiene rubber prepared in Examples 1 to 2 and Comparative Examples 1 to 2 is shown in FIG. Figure 5 It can be seen that in Example 1 and Comparative Example 1, the higher the click temperature, the more serious the cross-linking side reaction, resulting in an increase in Mooney viscosity. Compared with Comparative Example 1, the Mooney viscosity of Example 1 is lower. Compared with Comparative Example 2, the Mooney viscosity of Example 2 is lower, which is because after the side reaction inhibitor is added, the cross-linking side reaction is effectively inhibited, thereby reducing the Mooney viscosity.

[0117] In Examples 1 to 11, whether the high-performance functionalized rubber is prepared by heat initiation, light initiation or initiator initiation, the side reactions such as carbon-carbon crosslinking occurring during the reaction process can be effectively suppressed, thereby improving the click rate. The obtained high-performance functionalized rubber has a low Mooney viscosity and good processing performance; the high-performance rubber nanocomposite material obtained after compounding with fillers, additives, etc. has low rolling resistance, high anti-slip performance, good filler dispersion performance, low compression heat rise, long scorch time, and good wear resistance, and can be used in tires.

Claims

1. A functionalized rubber obtained by a click reaction of a mercapto reagent and a rubber containing double bonds in the presence of a side reaction inhibitor.

2. The functionalized rubber according to claim 1, wherein: the mercapto reagent has at least one of siloxanyl, amino, carboxyl, ester, and hydroxyl functional groups and a mercapto functional group; preferably at least one of 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, mercaptopropylmethyldimethoxysilane, 3-mercaptopropionic acid, mercaptosuccinic acid, ethyl mercaptoacetate, methyl mercaptoacetate, mercaptoethanol, 3-mercaptopropanol, and mercaptoethylamine; and / or, the rubber is a rubber with double bonds in the main chain or side chain, preferably at least one of nitrile rubber, isoprene rubber, styrene-butadiene rubber, chloroprene rubber, silicone rubber, ethylene-propylene-diene monomer rubber, natural rubber, butadiene rubber, cis-1,4-polybutadiene rubber, and butyl rubber; and / or, the side reaction inhibitor is at least one of hydroquinone, diphenylamine, 5,5-dimethyl-1-pyrroline-N-oxide, 2,2,6,6-tetramethylpiperidine-N-oxide, methyl methacrylate, tea polyphenols, gallic acid, dopamine, dibutylhydroxytoluene, divinyl ether, 1,1-diphenylethylene, 2,2-diphenyl-1-picrylhydrazyl, p-benzoquinone, tetramethyl-p-benzoquinone, p-aminobenzoic acid, iodine, ascorbic acid, α-tocopherol, hydroquinone, β-carotene, gentisic acid, and N-tert-butyl-α-phenylnitrone.

3. The functionalized rubber according to claim 1, wherein: the molar ratio of the mercapto reagent to the double bonds of the rubber is (0.005 - 0.9):1, preferably (0.005 - 0.1):1; and / or, the molar ratio of the side reaction inhibitor to the double bonds of the rubber is (0.005 - 0.9):1, preferably (0.02 - 0.1):

1.

4. A method for preparing a functionalized rubber according to any one of claims 1 to 3, comprising: performing a click reaction of the mercapto reagent and the rubber containing double bonds in the presence of a side reaction inhibitor to obtain the functionalized rubber.

5. The method for preparing a functionalized rubber according to claim 4, wherein: the high-performance functionalized rubber is obtained by one of the following methods: Method 1: Simultaneously adding the mercapto reagent and the side reaction inhibitor to the rubber containing double bonds for a click reaction; Method 2: Adding the side reaction inhibitor to the rubber containing double bonds for mixing, and then adding the mercapto reagent for a click reaction.

6. The method for preparing a functionalized rubber according to claim 4, wherein: the click reaction is carried out in solution or in the solid phase; when carried out in solution, the concentration of the rubber in the solution is preferably 1 - 50 wt%, more preferably 15 - 30 wt%; and / or, the initiation mode of the click reaction is at least one of thermal initiation, photoinitiation, and initiator initiation; preferably, when the initiation mode is thermal initiation, the temperature of the thermally initiated click reaction is 30 - 170 °C, preferably 60 - 160 °C; and / or, the time of the thermally initiated click reaction is 1 - 360 min; preferably 5 - 60 min; and / or, When the initiation method is photo-initiation, the photoinitiator is at least one of the following raw materials: 2-hydroxy-2-methyl-1-phenyl-1-propanone, benzil, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, benzoin ethyl ether, thioxanthone / triethylamine; and / or, the light intensity is 2 to 15 W, preferably 5 - 15 W; and / or, the light irradiation time is 1 to 24 h; preferably 8 to 24 h; and / or, the dosage of the photoinitiator is 1 to 10 wt% of the mass of the rubber, preferably 3 to 8 wt%; and / or, When the initiation method is initiator-initiation, the initiator is a free radical initiator, preferably at least one of cyclohexanone peroxide, benzoyl peroxide, tert-butyl hydroperoxide, azobisisobutyronitrile, azobisisoheptonitrile; and / or, the dosage of the initiator is 0.01 to 8 wt% of the mass of the rubber, preferably 0.01 to 2 wt%.

7. A functionalized rubber obtained by the preparation method according to any one of claims 4 to 6.

8. A functionalized rubber nanocomposite prepared from raw materials including the functionalized rubber according to any one of claims 1 to 3, 7.

9. A method for preparing a functionalized rubber nanocomposite, comprising: Mixing the functionalized rubber with rubber additives and then vulcanizing to obtain the functionalized rubber nanocomposite.

10. An application of the functionalized rubber according to any one of claims 1 to 3, 7 or the functionalized rubber nanocomposite according to claim 8 in rubber products, preferably in tires.

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