Low-temperature-resistant rare earth butadiene rubber and preparation method thereof

Abstract

The invention relates to the technical field of rubber, and discloses low-temperature-resistant rare earth butadiene rubber and a preparation method thereof. Phosphorus-containing quaternary ammonium salt modified polyurethane, polyethoxylene ether modified phenolic resin, rare earth butadiene rubber and sulfur are added into an internal mixer to be mixed and then vulcanized, and the low-temperature-resistant rare earth butadiene rubber is obtained. In the phosphorus-containing quaternary ammonium salt modified polyurethane, silicon-oxygen bonds enable the rubber to maintain stability at low temperature, so that the low-temperature-resistant effect of the rubber is improved; polyurethane and a rubber molecular chain form an interpenetrating polymer network, so that the mechanical property of the rubber is improved; due to the soft segment chain of polyurethane, the rubber has better toughness at low temperature, and the low temperature resistance of the rubber is improved; an ether bond in polyoxyethylene ether has flexibility and stability, so that the rubber is not easy to crystallize or cure at low temperature; phosphorus, silicon and sulfur elements are used together to generate a synergistic flame-retardant effect, so that the flame retardance of the rubber is improved; the phenolic resin plays a reinforcing role in the rubber, so that the mechanical property of the rubber is improved.

Description

Technical Field

[0001] The invention relates to the technical field of rubber, in particular to low-temperature resistant rare earth butadiene rubber and a preparation method thereof. Background Art

[0002] Cis-1,4-polybutadiene rubber is a synthetic rubber with a regular structure formed by the polymerization of butadiene, referred to as cis-1,4-butadiene rubber. It has the advantages of good elasticity, wear resistance, and good low-temperature resistance. It is not only widely used in the tire industry, but also plays an important role in the modification process of plastics. It is an important raw material for manufacturing tires and other rubber products. However, the poor flame retardant and mechanical properties have hindered the further development and application of cis-1,4-butadiene rubber. For example, patent CN117070006B discloses a low-temperature resistant and anti-crystallization cis-1,4-butadiene rubber composition and its preparation method, as well as rubber sealing products, which improves the low-temperature resistance of rare earth cis-1,4-butadiene rubber materials, and the raw material cost is also low, but its flame retardant and mechanical properties need to be improved. Summary of the invention

[0003] 1. Technical issues to be resolved In view of the deficiencies in the prior art, the present invention provides a low-temperature resistant rare earth butadiene rubber and a preparation method thereof, which improves the flame retardant properties and mechanical properties of the rubber and has good low-temperature resistance.

[0004] (II) Technical solution To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a low-temperature resistant rare earth butadiene rubber, comprising the following weight components: 10-15 weight parts of phosphorus-containing quaternary ammonium salt modified polyurethane, 8-12 weight parts of polyoxyethylene ether modified phenolic resin, 20-24 weight parts of rare earth butadiene rubber, and 2-5 weight parts of sulfur.

[0005] Preferably, the method for preparing the phosphorus-containing quaternary ammonium salt modified polyurethane comprises the following steps: (1) Add 6-10 parts by weight of epoxypropyltrimethoxysilane to an isopropanol solvent, stir to dissolve, then add 3-6 parts by weight of tetramethylethylenediamine and 2-5 parts by weight of acetic acid, heat and reflux for 7-9 hours under nitrogen replacement conditions, and after the reaction is completed, remove isopropanol by rotary evaporation to obtain a silane quaternary ammonium salt; (2) Under a nitrogen atmosphere, silane quaternary ammonium salt and triethylamine catalyst are added to a dichloromethane solvent, stirred to dissolve, and phenylphosphoryl dichloride is added dropwise thereto. After the addition is complete, the reaction is carried out at 8-12° C. for 10-12 hours. After the reaction is completed, the reaction is washed and dried to obtain a phosphorus-modified quaternary ammonium salt chain extender; (3) Add 4-6 parts by weight of toluene diisocyanate, 7-12 parts by weight of polycaprolactone diol, and 0.2-0.5 parts by weight of dibutyltin dilaurate into a reactor, introduce nitrogen protection, carry out prepolymerization at 78-82°C, react for 2-3 hours, cool to 65-70°C, add 3-5 parts by weight of phosphorus-modified quaternary ammonium salt chain extender to carry out chain extension reaction, the reaction time is 1.5-2 hours, after the reaction is completed, cool, wash and dry to obtain phosphorus-containing quaternary ammonium salt modified polyurethane.

[0006] Preferably, the heating temperature in step (1) is 75-80°C.

[0007] Preferably, in step (2), the mass ratio of silane quaternary ammonium salt, triethylamine and phenylphosphoryl dichloride is 2.8-3:0.04-0.06:1.

[0008] Preferably, the preparation method of the polyoxyethylene ether modified phenolic resin comprises the following steps: S1. 6-8 parts by weight of 3-butene-1-ol and 0.3-0.6 parts by weight of sodium hydroxide catalyst are added to an autoclave, heated to 75-80°C, low-boiling substances and water in the system are removed in vacuo, nitrogen is replaced, heated to 160-170°C, 3-5 parts by weight of ethylene oxide are added, and the induction reaction is started. When the pressure drops to 0.1-0.15MPa, 7-10 parts by weight of ethylene oxide are added and reacted for 1.5-2h. After the reaction is completed, the reaction is cooled to 70-80°C, and the ethylene oxide gas in the reaction system is removed in vacuo to obtain an alkenyl-containing polyoxyethylene ether; S2. Add 8-12 parts by weight of alkenyl polyoxyethylene ether to N,N-dimethylformamide solvent, stir and disperse, add 4-7 parts by weight of 2-chloro-3-mercaptopyridine and 0.4-0.6 parts by weight of benzoin dimethyl ether photoinitiator, irradiate with 365nm ultraviolet light at 35-38°C, centrifuge after completion, wash and dry to obtain intermediate 1; S3. Add 7-11 parts by weight of phenolic resin to n-butanol solvent, stir and dissolve at 58-60°C, add 0.2-0.4 parts by weight of catalyst, stir at 75-80°C for 45-60 minutes, cool to 40-45°C, add 3-6 parts by weight of intermediate 1 dropwise thereto, and after the addition is completed, heat to 80-85°C and react for 5-6 hours. After the reaction is completed, cool, filter and rotary evaporate to obtain polyoxyethylene ether modified phenolic resin.

[0009] Preferably, the ultraviolet light irradiation time in S2 is 2.5-3h.

[0010] Preferably, the catalyst in S3 is potassium hydroxide.

[0011] Preferably, the preparation method of the low-temperature resistant rare earth butadiene rubber is: adding phosphorus-containing quaternary ammonium salt-modified polyurethane, polyethoxylated ether-modified phenolic resin, and rare earth butadiene rubber into an internal mixer and mixing for 5-10 minutes, then adding sulfur and continuing to mix for 2-5 minutes, taking out the mixed rubber, and vulcanizing it in a flat vulcanizer under the conditions of 4.8-5MPa and 140-160°C to obtain the low-temperature resistant rare earth butadiene rubber.

[0012] 3. Beneficial technical effects The invention provides a method for obtaining low-temperature resistant rare earth butadiene rubber by adding phosphorus-containing quaternary ammonium salt modified polyurethane, polyethoxylated ether modified phenolic resin and rare earth butadiene rubber into an internal mixer, mixing them, adding sulfur and continuing to mix, taking out the mixed rubber, and vulcanizing it in a flat vulcanizer.

[0013] Tetramethylethylenediamine and epoxypropyltrimethoxysilane undergo a ring-opening addition reaction under acetic acid conditions to obtain a silane quaternary ammonium salt and introduce hydroxyl groups at both ends. The hydroxyl groups in the silane quaternary ammonium salt react with the chlorine in phenylphosphoryl dichloride to obtain a phosphorus-modified quaternary ammonium salt chain extender. Toluene diisocyanate and polycaprolactone diol are prepolymerized and further reacted with the phosphorus-modified quaternary ammonium salt chain extender to obtain a phosphorus-modified quaternary ammonium salt polyurethane. The hydroxyl groups in 3-butene-1-ol undergo a ring-opening polymerization reaction with ethylene oxide to obtain an alkenyl-containing polyethoxylated ether. The alkenyl groups in the alkenyl-containing polyethoxylated ether undergo a click reaction with the mercapto groups in 2-chloro-3-thiopyridine to obtain an intermediate 1. The chlorine in the intermediate 1 undergoes a substitution reaction with the hydroxyl groups in the phenolic resin to obtain a polyethoxylated ether-modified phenolic resin.

[0014] In the polyurethane modified by phosphorus-containing quaternary ammonium salt, phosphoric acid produced by thermal decomposition of phosphorus can promote the dehydration of rubber into carbon, thereby forming a protective barrier to prevent the combustion of rubber. At the same time, the formation of carbon will be accompanied by the release of water vapor, thereby effectively absorbing heat and reducing the oxygen content, playing a flame retardant role; silicon element can promote the formation of a dense carbon layer on the rubber surface at high temperature, isolating the contact between oxygen and rubber, and preventing the spread of flames; the bond energy of silicon-oxygen bonds is relatively high, the molecular chain is flexible, and it is not easy to break at low temperatures. Rubber containing silicon-oxygen bonds can still maintain structural stability at low temperatures, thereby improving the low-temperature resistance of rubber; polyurethane has high hardness and strength. When it is added to rubber, the polyurethane molecular chains can intersperse and interweave with the rubber molecular chains to form an interpenetrating polymer network, which improves the mechanical properties of the rubber; The soft segment chain contained in the urethane is easier to rotate, which increases the flexibility of the rubber and makes it still have good toughness in a low temperature environment, thereby improving the low temperature resistance of the rubber; in the polyoxyethylene ether modified phenolic resin, the molecular chain of the polyoxyethylene ether contains a large number of ether bonds, which have high flexibility and stability, making the rubber difficult to crystallize or solidify in a low temperature environment, thereby improving the low temperature resistance of the rubber; the sulfur element can decompose into non-combustible gases such as hydrogen sulfide and sulfur dioxide during the combustion process, diluting the oxygen concentration in the combustion area, thereby inhibiting the spread of flames; the combined use of phosphorus, silicon and sulfur elements produces a synergistic flame retardant effect, thereby improving the flame retardancy of the rubber; the phenolic resin can interact with the rubber molecular chain to form a stable network structure, play a reinforcing role, and improve the mechanical properties of the rubber. DETAILED DESCRIPTION

[0015] The preparation process of rare earth butadiene rubber comprises the following steps: Step 1: add 0.6 parts by weight of neodymium neodecanoate, 0.3 parts by weight of triisobutylaluminum and 0.2 parts by weight of diisobutylaluminum hydride into a catalyst preparation kettle, add n-hexane to dilute it, put the diluted catalyst into an aging kettle, and age it at 60° C. for 50 minutes; Step 2: adopting the "four-pot continuous polymerization + one-pot termination" process, adding 16 parts by weight of butadiene and n-hexane into a dryer and drying them, and then pumping them into the first polymerization kettle, and then adding aged neodymium neodecanoate, triisobutylaluminum and diisobutylaluminum hydride. After the polymerization reaction for 50 minutes, the glue enters the second polymerization kettle to continue the reaction for 40 minutes, and then enters the third polymerization kettle to continue the reaction for 28 minutes, and enters the fourth polymerization kettle to continue the reaction for 15 minutes. The outlet pipeline of the fourth polymerization kettle enters the termination kettle together with ethanol for termination treatment; wherein the temperature of the four polymerization kettles is controlled at 40°C, and the pressure is controlled at 0.3MPa. Finally, the glue enters the glue preparation kettle, and after being mixed and matched according to the Mooney viscosity value, it is filtered through a glue filter to obtain a rare earth butadiene rubber glue; Step 3: adding hot water at 60° C. into three series-connected coagulation kettles, adding 0.5 parts by weight of zinc oxide dispersant, spraying rare earth cis-1,1-butadiene rubber solution into the coagulation kettle, fully coagulating to form rare earth cis-1,1-butadiene rubber particles, and distilling off cyclohexane solvent and butadiene; Step 4: The rare earth cis-1,4-dimethylbutyl rubber particles and circulating hot water are pumped into a buffer tank, and then separated by a first vibrating screen to obtain rubber particles and sent to a rubber washing tank. Water at 80°C is added to wash the rubber particles. The washed rubber particles and water are separated by a second vibrating screen to obtain rubber particles containing 50% water. The water content of the rubber particles is reduced to 8% by extrusion through an extruder, and finally enters an expansion dryer to remove water from the rubber particles to obtain rare earth cis-1,4-dimethylbutyl rubber. Example 1

[0016] (1) Add 6 parts by weight of glycidyltrimethoxysilane to isopropanol solvent, stir to dissolve, add 3 parts by weight of tetramethylethylenediamine and 2 parts by weight of acetic acid, heat and reflux at 75° C. for 7 hours under nitrogen replacement conditions, and after the reaction is completed, remove isopropanol by rotary evaporation to obtain silane quaternary ammonium salt; (2) Under a nitrogen atmosphere, silane quaternary ammonium salt and triethylamine catalyst are added to a dichloromethane solvent, stirred to dissolve, and phenylphosphoryl dichloride is added dropwise thereto, wherein the mass ratio of silane quaternary ammonium salt, triethylamine and phenylphosphoryl dichloride is 2.8:0.04:1. After the addition is completed, the mixture is reacted at 8°C for 10 hours. After the reaction is completed, the mixture is washed and dried to obtain a phosphorus-modified quaternary ammonium salt chain extender; (3) Add 4 parts by weight of toluene diisocyanate, 7 parts by weight of polycaprolactone diol, and 0.2 parts by weight of dibutyltin dilaurate into a reactor, introduce nitrogen protection, carry out prepolymerization at 78°C, react for 2 hours, cool to 65°C, add 3 parts by weight of phosphorus-modified quaternary ammonium salt chain extender to carry out chain extension reaction, the reaction time is 1.5 hours, after the reaction is completed, cool, wash and dry to obtain phosphorus-modified quaternary ammonium salt polyurethane; (4) 6 parts by weight of 3-butene-1-ol and 0.3 parts by weight of sodium hydroxide catalyst are added to an autoclave, the temperature is raised to 75° C., low-boiling substances and water in the system are removed under vacuum, and after nitrogen replacement, the temperature is raised to 160° C., 3 parts by weight of ethylene oxide are added to start an induction reaction, and when the pressure drops to 0.1 MPa, 7 parts by weight of ethylene oxide are added to react for 1.5 hours. After the reaction is completed, the autoclave is cooled to 70° C., and the ethylene oxide gas in the reaction system is removed under vacuum to obtain an alkenyl-containing polyoxyethylene ether; (5) Add 8 parts by weight of alkenyl-containing polyoxyethylene ether to N,N-dimethylformamide solvent, stir and disperse, then add 4 parts by weight of 2-chloro-3-mercaptopyridine and 0.4 parts by weight of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 35° C. for 2.5 h, centrifuge after irradiation, wash and dry to obtain intermediate 1; (6) Add 7 parts by weight of phenolic resin to n-butanol solvent, stir and dissolve at 58° C., add 0.2 parts by weight of potassium hydroxide catalyst, stir at 75° C. for 45 min, cool to 40° C., drop 3 parts by weight of intermediate 1 thereinto, raise the temperature to 80° C. to react for 5 h, cool, filter and rotary evaporate to obtain polyoxyethylene ether modified phenolic resin after the reaction is completed; (7) 10 parts by weight of phosphorus-containing quaternary ammonium salt-modified polyurethane, 8 parts by weight of polyoxyethylene ether-modified phenolic resin, and 20 parts by weight of rare earth butadiene rubber were added to an internal mixer and mixed for 5 minutes. Then, 2 parts by weight of sulfur were added and mixed for another 2 minutes. The mixed rubber was taken out and vulcanized in a flat vulcanizer at 4.8 MPa and 140°C to obtain low-temperature resistant rare earth butadiene rubber. Example 2

[0017] (1) Add 10 parts by weight of glycidyltrimethoxysilane to an isopropanol solvent, stir to dissolve, then add 6 parts by weight of tetramethylethylenediamine and 5 parts by weight of acetic acid, and heat under reflux at 80° C. for 9 hours under nitrogen replacement conditions. After the reaction is completed, remove the isopropanol by rotary evaporation to obtain a silane quaternary ammonium salt; (2) Under a nitrogen atmosphere, silane quaternary ammonium salt and triethylamine catalyst are added to a dichloromethane solvent, stirred to dissolve, and phenylphosphoryl dichloride is added dropwise thereto, wherein the mass ratio of silane quaternary ammonium salt, triethylamine and phenylphosphoryl dichloride is 3:0.06:1. After the addition is completed, the mixture is reacted at 12°C for 12 hours. After the reaction is completed, the mixture is washed and dried to obtain a phosphorus-modified quaternary ammonium salt chain extender; (3) Add 6 parts by weight of toluene diisocyanate, 12 parts by weight of polycaprolactone diol, and 0.5 parts by weight of dibutyltin dilaurate into a reactor, introduce nitrogen protection, carry out prepolymerization at 82° C., cool to 70° C. after reacting for 3 hours, add 5 parts by weight of phosphorus-modified quaternary ammonium salt chain extender to carry out chain extension reaction, the reaction time is 2 hours, after the reaction is completed, cool, wash and dry to obtain phosphorus-modified quaternary ammonium salt polyurethane; (4) 8 parts by weight of 3-butene-1-ol and 0.6 parts by weight of sodium hydroxide catalyst are added to an autoclave, the temperature is raised to 80° C., low-boiling substances and water in the system are removed under vacuum, and after nitrogen replacement, the temperature is raised to 170° C., 5 parts by weight of ethylene oxide are added to start an induction reaction, and when the pressure drops to 0.15 MPa, 10 parts by weight of ethylene oxide are added to react for 2 hours. After the reaction is completed, the autoclave is cooled to 80° C., and the ethylene oxide gas in the reaction system is removed under vacuum to obtain an alkenyl-containing polyoxyethylene ether; (5) Add 12 parts by weight of alkenyl-containing polyoxyethylene ether to N,N-dimethylformamide solvent, stir and disperse, then add 7 parts by weight of 2-chloro-3-mercaptopyridine and 0.6 parts by weight of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 38° C. for 3 h, centrifuge, wash and dry to obtain intermediate 1; (6) Add 11 parts by weight of phenolic resin to n-butanol solvent, stir and dissolve at 60° C., add 0.4 parts by weight of potassium hydroxide catalyst, stir at 80° C. for 60 min, cool to 45° C., drop 6 parts by weight of intermediate 1 thereinto, raise the temperature to 85° C. to react for 5-6 h, cool, filter and rotary evaporate to obtain polyoxyethylene ether modified phenolic resin after the reaction is completed; (7) 15 parts by weight of phosphorus-containing quaternary ammonium salt-modified polyurethane, 12 parts by weight of polyoxyethylene ether-modified phenolic resin, and 24 parts by weight of rare earth butadiene rubber were added to an internal mixer and mixed for 10 minutes. Then, 5 parts by weight of sulfur were added and mixed for another 5 minutes. The mixed rubber was taken out and vulcanized in a flat vulcanizer at 5 MPa and 160°C to obtain low-temperature resistant rare earth butadiene rubber. Example 3

[0018] (1) Add 8 parts by weight of glycidyltrimethoxysilane to isopropanol solvent, stir to dissolve, then add 4 parts by weight of tetramethylethylenediamine and 3 parts by weight of acetic acid, and heat under reflux at 78° C. for 8 hours under nitrogen replacement conditions. After the reaction is completed, remove isopropanol by rotary evaporation to obtain silane quaternary ammonium salt; (2) Under a nitrogen atmosphere, silane quaternary ammonium salt and triethylamine catalyst were added to a dichloromethane solvent, stirred and dissolved, and phenylphosphoryl dichloride was added dropwise thereto, wherein the mass ratio of silane quaternary ammonium salt, triethylamine and phenylphosphoryl dichloride was 2.9:0.05:1. After the addition was completed, the reaction was carried out at 10°C for 11 hours. After the reaction was completed, the reaction was washed and dried to obtain a phosphorus-modified quaternary ammonium salt chain extender; (3) Add 5 parts by weight of toluene diisocyanate, 10 parts by weight of polycaprolactone diol, and 0.3 parts by weight of dibutyltin dilaurate into a reactor, introduce nitrogen protection, carry out prepolymerization at 80° C., react for 2.5 hours, cool to 68° C., add 4 parts by weight of phosphorus-modified quaternary ammonium salt chain extender to carry out chain extension reaction, the reaction time is 1.8 hours, after the reaction is completed, cool, wash and dry to obtain phosphorus-modified quaternary ammonium salt polyurethane; (4) 7 parts by weight of 3-butene-1-ol and 0.4 parts by weight of sodium hydroxide catalyst are added to an autoclave, the temperature is raised to 78° C., low-boiling substances and water in the system are removed under vacuum, and after nitrogen replacement, the temperature is raised to 165° C., 4 parts by weight of ethylene oxide are added to start an induction reaction, and when the pressure drops to 0.12 MPa, 9 parts by weight of ethylene oxide are added to react for 1.8 hours. After the reaction is completed, the autoclave is cooled to 75° C., and the ethylene oxide gas in the reaction system is removed under vacuum to obtain an alkenyl-containing polyoxyethylene ether; (5) Add 10 parts by weight of alkenyl-containing polyoxyethylene ether to N,N-dimethylformamide solvent, stir and disperse, then add 5 parts by weight of 2-chloro-3-mercaptopyridine and 0.5 parts by weight of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 36° C. for 2.8 h, centrifuge after irradiation, wash and dry to obtain intermediate 1; (6) Add 9 parts by weight of phenolic resin to n-butanol solvent, stir and dissolve at 59° C., add 0.3 parts by weight of potassium hydroxide catalyst, stir at 77° C. for 48 min, cool to 43° C., dropwise add 4 parts by weight of intermediate 1, raise the temperature to 82° C. and react for 5.5 h. After the reaction, cool, filter and rotary evaporate to obtain polyoxyethylene ether modified phenolic resin; (7) 13 parts by weight of phosphorus-containing quaternary ammonium salt-modified polyurethane, 10 parts by weight of polyoxyethylene ether-modified phenolic resin, and 22 parts by weight of rare earth butadiene rubber were added to an internal mixer and mixed for 8 minutes. Then, 3 parts by weight of sulfur were added and mixed for another 3 minutes. The mixed rubber was taken out and vulcanized in a flat vulcanizer at 4.9 MPa and 150°C to obtain low-temperature resistant rare earth butadiene rubber. Example 4

[0019] (1) Add 6 parts by weight of glycidyltrimethoxysilane to isopropanol solvent, stir to dissolve, add 3 parts by weight of tetramethylethylenediamine and 2 parts by weight of acetic acid, heat and reflux at 75° C. for 7 hours under nitrogen replacement conditions, and after the reaction is completed, remove isopropanol by rotary evaporation to obtain silane quaternary ammonium salt; (2) Under a nitrogen atmosphere, silane quaternary ammonium salt and triethylamine catalyst are added to a dichloromethane solvent, stirred to dissolve, and phenylphosphoryl dichloride is added dropwise thereto, wherein the mass ratio of silane quaternary ammonium salt, triethylamine and phenylphosphoryl dichloride is 2.8:0.04:1. After the addition is completed, the mixture is reacted at 8°C for 10 hours. After the reaction is completed, the mixture is washed and dried to obtain a phosphorus-modified quaternary ammonium salt chain extender; (3) Add 6 parts by weight of toluene diisocyanate, 12 parts by weight of polycaprolactone diol, and 0.5 parts by weight of dibutyltin dilaurate into a reactor, introduce nitrogen protection, carry out prepolymerization at 82° C., cool to 70° C. after reacting for 3 hours, add 5 parts by weight of phosphorus-modified quaternary ammonium salt chain extender to carry out chain extension reaction, the reaction time is 2 hours, after the reaction is completed, cool, wash and dry to obtain phosphorus-modified quaternary ammonium salt polyurethane; (4) 8 parts by weight of 3-butene-1-ol and 0.6 parts by weight of sodium hydroxide catalyst are added to an autoclave, the temperature is raised to 80° C., low-boiling substances and water in the system are removed under vacuum, and after nitrogen replacement, the temperature is raised to 170° C., 5 parts by weight of ethylene oxide are added to start an induction reaction, and when the pressure drops to 0.15 MPa, 10 parts by weight of ethylene oxide are added to react for 2 hours. After the reaction is completed, the autoclave is cooled to 80° C., and the ethylene oxide gas in the reaction system is removed under vacuum to obtain an alkenyl-containing polyoxyethylene ether; (5) Add 10 parts by weight of alkenyl-containing polyoxyethylene ether to N,N-dimethylformamide solvent, stir and disperse, then add 5 parts by weight of 2-chloro-3-mercaptopyridine and 0.5 parts by weight of benzoin dimethyl ether photoinitiator, irradiate with 365 nm ultraviolet light at 36° C. for 2.8 h, centrifuge after irradiation, wash and dry to obtain intermediate 1; (6) Add 9 parts by weight of phenolic resin to n-butanol solvent, stir and dissolve at 59° C., add 0.3 parts by weight of potassium hydroxide catalyst, stir at 77° C. for 48 min, cool to 43° C., dropwise add 4 parts by weight of intermediate 1, raise the temperature to 82° C. and react for 5.5 h. After the reaction, cool, filter and rotary evaporate to obtain polyoxyethylene ether modified phenolic resin; (7) 13 parts by weight of phosphorus-containing quaternary ammonium salt-modified polyurethane, 10 parts by weight of polyoxyethylene ether-modified phenolic resin, and 22 parts by weight of rare earth butadiene rubber were added to an internal mixer and mixed for 8 minutes. Then, 3 parts by weight of sulfur were added and mixed for another 3 minutes. The mixed rubber was taken out and vulcanized in a flat vulcanizer at 4.9 MPa and 150°C to obtain low-temperature resistant rare earth butadiene rubber.

[0020] Comparative Example 1 The difference between this comparative example and Example 4 is that no phosphorus-containing quaternary ammonium salt-modified polyurethane is added.

[0021] Comparative Example 2 This comparative example is compared with Example 4, except that no polyoxyethylene ether modified phenolic resin is added.

[0022] The oxygen index meter was used to test the limiting oxygen index of the low-temperature resistant rare earth butadiene rubber, and the horizontal and vertical combustion instrument was used to test the combustion grade of the low-temperature resistant rare earth butadiene rubber. The test results are shown in Table 1.

[0023] Table 1: Flame retardant performance test.

[0024] project Limiting oxygen index (%) Combustion level Example 1 37 V-0 Example 2 35 V-0 Example 3 36 V-0 Example 4 34 V-0 Comparative Example 1 21 V-1 Comparative Example 2 24 V-1 It can be seen from Table 1 that Examples 1-4 of the present invention have better flame retardant effects than Comparative Examples 1-2.

[0025] The tear strength test of low temperature resistant rare earth cis-1,4-butadiene rubber was carried out according to the national standard GB / T529; the tensile stress, tensile strength and elongation at break of low temperature resistant rare earth cis-1,4-butadiene rubber were tested according to GB / T528. The test results are shown in Table 2.

[0026] Table 2: Tests of various mechanical properties.

[0027] project Tear strength (KN / m) 300% tensile stress (Mpa) Tensile strength (Mpa) Elongation at break (%) Example 1 61.3 6.7 28.7 708 Example 2 59.7 7.4 26.4 718 Example 3 62.0 7.2 25.9 712 Example 4 58.7 6.9 27.1 723 Comparative Example 1 27.1 3.6 14.7 547 Comparative Example 2 25.4 4.1 12.4 561 It can be seen from Table 2 that Examples 1-4 of the present invention have better mechanical properties than Comparative Examples 1-2.

[0028] The glass transition temperature of the low temperature resistant rare earth butadiene rubber was tested using a dynamic thermomechanical analyzer. The test results are shown in Table 3.

[0029] Table 3: Glass transition temperature test.

[0030] project Glass transition temperature (℃) Example 1 -85 Example 2 -83 Example 3 -87 Example 4 -82 Comparative Example 1 -61 Comparative Example 2 -59 It can be seen from Table 3 that Examples 1-4 of the present invention have better low temperature resistance than Comparative Examples 1-2.

[0031] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A low-temperature resistant rare earth butadiene rubber, characterized in that: The invention comprises the following components by weight: 10-15 parts by weight of phosphorus-containing quaternary ammonium salt modified polyurethane, 8-12 parts by weight of polyoxyethylene ether modified phenolic resin, 20-24 parts by weight of rare earth butadiene rubber and 2-5 parts by weight of sulfur.

2. The low-temperature resistant rare earth butadiene rubber according to claim 1, characterized in that: The preparation method of the phosphorus-containing quaternary ammonium salt modified polyurethane comprises the following steps: (1) Add 6-10 parts by weight of epoxypropyltrimethoxysilane to an isopropanol solvent, stir to dissolve, then add 3-6 parts by weight of tetramethylethylenediamine and 2-5 parts by weight of acetic acid, heat and reflux for 7-9 hours under nitrogen replacement conditions, and after the reaction is completed, remove isopropanol by rotary evaporation to obtain a silane quaternary ammonium salt; (2) Under a nitrogen atmosphere, silane quaternary ammonium salt and triethylamine catalyst are added to a dichloromethane solvent, stirred to dissolve, and phenylphosphoryl dichloride is added dropwise thereto. After the addition is complete, the reaction is carried out at 8-12° C. for 10-12 hours. After the reaction is completed, the reaction is washed and dried to obtain a phosphorus-modified quaternary ammonium salt chain extender; (3) Add 4-6 parts by weight of toluene diisocyanate, 7-12 parts by weight of polycaprolactone diol, and 0.2-0.5 parts by weight of dibutyltin dilaurate into a reactor, introduce nitrogen protection, carry out prepolymerization at 78-82°C, react for 2-3 hours, cool to 65-70°C, add 3-5 parts by weight of phosphorus-modified quaternary ammonium salt chain extender to carry out chain extension reaction, the reaction time is 1.5-2 hours, after the reaction is completed, cool, wash and dry to obtain phosphorus-containing quaternary ammonium salt modified polyurethane.

3. The low-temperature resistant rare earth butadiene rubber according to claim 2, characterized in that: The heating temperature in step (1) is 75-80°C.

4. The low-temperature resistant rare earth butadiene rubber according to claim 2, characterized in that: In the step (2), the mass ratio of silane quaternary ammonium salt, triethylamine and phenylphosphoryl dichloride is 2.8-3:0.04-0.06:

1.

5. The low-temperature resistant rare earth butadiene rubber according to claim 1, characterized in that: The preparation method of the polyoxyethylene ether modified phenolic resin comprises the following steps: S1. 6-8 parts by weight of 3-butene-1-ol and 0.3-0.6 parts by weight of sodium hydroxide catalyst are added to an autoclave, heated to 75-80°C, low-boiling substances and water in the system are removed in vacuo, nitrogen is replaced, heated to 160-170°C, 3-5 parts by weight of ethylene oxide are added, and the induction reaction is started. When the pressure drops to 0.1-0.15MPa, 7-10 parts by weight of ethylene oxide are added and reacted for 1.5-2h. After the reaction is completed, the reaction is cooled to 70-80°C, and the ethylene oxide gas in the reaction system is removed in vacuo to obtain an alkenyl-containing polyoxyethylene ether; S2. Add 8-12 parts by weight of alkenyl polyoxyethylene ether to N,N-dimethylformamide solvent, stir and disperse, add 4-7 parts by weight of 2-chloro-3-mercaptopyridine and 0.4-0.6 parts by weight of benzoin dimethyl ether photoinitiator, irradiate with 365nm ultraviolet light at 35-38°C, centrifuge after completion, wash and dry to obtain intermediate 1; S3. Add 7-11 parts by weight of phenolic resin to n-butanol solvent, stir and dissolve at 58-60°C, add 0.2-0.4 parts by weight of catalyst, stir at 75-80°C for 45-60 minutes, cool to 40-45°C, add 3-6 parts by weight of intermediate 1 dropwise thereto, and after the addition is completed, heat to 80-85°C and react for 5-6 hours. After the reaction is completed, cool, filter and rotary evaporate to obtain polyoxyethylene ether modified phenolic resin.

6. The low-temperature resistant rare earth butadiene rubber according to claim 5, characterized in that: The ultraviolet light irradiation time in S2 is 2.5-3h.

7. The low-temperature resistant rare earth butadiene rubber according to claim 5, characterized in that: The catalyst in S3 is potassium hydroxide.

8. A method for preparing the low-temperature resistant rare earth butadiene rubber according to any one of claims 1 to 7, characterized in that: The preparation method of the low-temperature resistant rare earth butadiene rubber comprises the following steps: adding phosphorus-containing quaternary ammonium salt-modified polyurethane, polyethoxylated ether-modified phenolic resin and rare earth butadiene rubber into an internal mixer and mixing for 5-10 minutes, then adding sulfur and mixing for 2-5 minutes, taking out the mixed rubber, and vulcanizing it in a flat vulcanizer under the conditions of 4.8-5MPa and 140-160°C to obtain the low-temperature resistant rare earth butadiene rubber.