阅读说明：本技术 一种高强度、高定伸应力的仿生橡胶及其制备方法和应用 (High-strength high-stress-at-definite-elongation bionic rubber and preparation method and application thereof ) 是由 白晨曦 代全权 崔龙 范卫锋 董巍 于 2021-11-11 设计创作，主要内容包括：本申请属于合成橡胶材料技术领域,本发明提供了一种高强度、高定伸应力的仿生橡胶及其制备方法和应用,所述的仿生橡胶由异戊二烯单体和助剂在稀土催化剂催化下反应制成；所述助剂为烷基铝和磷脂经反应得到的改性磷脂物质；所述烷基铝为三烷基铝或氢化烷基铝；所述磷脂选自卵磷脂、磷脂酰肌醇、甘油磷酸酯、甘油磷酰胆碱和长链烷基磷酸酯中的一种或多种。采用本发明方法制得的仿生橡胶具有高强度、高定伸应力等特点,可用于制备航空轮胎胎面。(The invention belongs to the technical field of synthetic rubber materials, and provides a high-strength high-stress-at-elongation bionic rubber, a preparation method and application thereof, wherein the bionic rubber is prepared by reacting an isoprene monomer and an auxiliary agent under the catalysis of a rare earth catalyst; the auxiliary agent is a modified phospholipid substance obtained by reacting alkyl aluminum with phospholipid; the alkyl aluminum is trialkyl aluminum or alkyl aluminum hydride; the phospholipid is selected from one or more of lecithin, phosphatidylinositol, glycerophosphate, glycerophosphorylcholine and long-chain alkyl phosphate. The bionic rubber prepared by the method has the characteristics of high strength, high stress at definite elongation and the like, and can be used for preparing the tread of an aircraft tire.)

1. A bionic rubber with high strength and high stress at definite elongation is characterized in that the bionic rubber is prepared by the reaction of an isoprene monomer and an auxiliary agent under the catalysis of a rare earth catalyst;

the auxiliary agent is a modified phospholipid substance obtained by reacting alkyl aluminum with phospholipid; the alkyl aluminum is trialkyl aluminum or alkyl aluminum hydride; the phospholipid is selected from one or more of lecithin, phosphatidylinositol, glycerophosphate, glycerophosphorylcholine and long-chain alkyl phosphate.

2. The biomimetic rubber according to claim 1, wherein the alkyl aluminum is triisobutyl aluminum, trioctyl aluminum, triethyl aluminum, diisobutyl aluminum hydride, or diethyl aluminum hydride.

3. The biomimetic rubber according to claim 1, wherein the auxiliary is prepared by: under the protective atmosphere, dissolving the alkyl aluminum in hexane, and adding phospholipid for reaction to obtain the product; the molar ratio of the alkyl aluminum to the phospholipid is 1-10: 1.

4. The biomimetic rubber according to any one of claims 1-3, wherein the alkyl aluminum and the phospholipid react at 50-100 ℃ for 1-12 hours to obtain the modified phospholipid material.

5. The bionic rubber as claimed in claim 4, wherein the amount of the auxiliary agent is 0.5-2% of the mass of the isoprene monomer.

6. The biomimetic rubber according to any one of claims 1-3, wherein the rare earth catalyst is prepared by mixing a rare earth compound, an organoaluminum compound and a chloride in a solvent;

the rare earth compound is one or more of rare earth carboxylate, rare earth acidic phosphonate, alkoxy rare earth, chlorinated rare earth electron donor complex and sulfonic rare earth electron donor complex;

the organic aluminum compound is trialkyl aluminum and/or alkyl aluminum hydride;

the chloride is one or more of diisobutylaluminum chloride, diethylaluminum chloride, ethylaluminum sesqui, tert-butyl chloride, benzyl chloride, allyl chloride, chloromethylsilane and silicon tetrachloride.

7. The biomimetic rubber according to claim 6, wherein the rare earth catalyst is obtained by preparing: under the protective atmosphere, a rare earth compound, an organic aluminum compound and a chloride are sequentially added, and the mixture is aged for 15 to 120 minutes at the temperature of between 30 and 80 ℃ to prepare a catalyst solution with a certain concentration.

8. The method for preparing a biomimetic rubber according to any one of claims 1-7, comprising the steps of:

reacting alkyl aluminum with phospholipid to obtain a modified phospholipid substance; the alkyl aluminum is trialkyl aluminum or alkyl aluminum hydride; the phospholipid is selected from one or more of lecithin, phosphatidylinositol, glycerophosphate, glycerophosphorylcholine and long-chain alkyl phosphate;

in the presence of a rare earth catalyst, an isoprene monomer and a modified phospholipid substance are mixed in an organic solvent for reaction to obtain the bionic rubber.

9. The preparation method of the bionic rubber according to claim 8, wherein the bionic rubber is obtained by adding a rare earth catalyst into an isoprene solution, then adding a modified phospholipid substance, and reacting for 2-24 hours at 20-70 ℃.

10. Use of a biomimetic rubber according to any of claims 1-7 in the preparation of an aircraft tire tread.

Technical Field

The application belongs to the technical field of synthetic rubber materials, particularly relates to high-strength and high-stress-at-elongation bionic rubber, and a preparation method and application thereof, and more particularly relates to a method for preparing the bionic rubber for an aircraft tire tread from alkyl aluminum modified phospholipid.

Background

The natural rubber has very good mechanical strength and the like, and is a necessary rubber for preparing aviation tires; the main component of the natural polymer elastomer material is polyisoprene, and the natural polymer elastomer material also comprises non-rubber substances such as protein, fatty acid, ash, saccharides and the like. Natural rubber for aviation tires in China completely depends on import, the markets of military and civil aviation tires are completely monopolized by foreign companies such as Michelin France, Goodyear America and the like for a long time, and the quality of domestic natural rubber cannot meet the requirements of aviation tires at present. Therefore, there is an urgent need to develop a rubber material having excellent properties such as high impact strength and tear resistance to replace natural rubber for aircraft tires.

Among synthetic polymer elastomer materials, rare earth isoprene rubber is called synthetic natural rubber, has the most similar component structure and physical properties to natural rubber, and is the only rubber variety hopefully replacing high-performance natural rubber at present. How to further improve the properties of the rare earth isoprene rubber such as strength and the like so as to be used for preparing aviation tires has important strategic significance for China.

Disclosure of Invention

In view of the above, the application provides a high-strength high-stress-at-elongation bionic rubber, and a preparation method and an application thereof.

The invention provides a high-strength high-stress-at-definite-elongation bionic rubber which is prepared by the reaction of an isoprene monomer and an auxiliary agent under the catalysis of a rare earth catalyst;

the auxiliary agent is a modified phospholipid substance obtained by reacting alkyl aluminum with phospholipid; the alkyl aluminum is trialkyl aluminum or alkyl aluminum hydride; the phospholipid is selected from one or more of lecithin, phosphatidylinositol, glycerophosphate, glycerophosphorylcholine and long-chain alkyl phosphate.

Natural rubber has superior mechanical properties compared to synthetic rubber because natural rubber latex contains about 5% by mass of non-rubber components, mainly biological macromolecules such as proteins, phospholipids and polysaccharides. The non-rubber components are superior to synthetic rubber in performance because they form cross-linking points in rubber molecules through self-assembly aggregation by hydrogen bonding or coordination, thereby promoting the formation of branched and network structures in natural rubber.

The bionic rubber provided by the invention belongs to rare earth isoprene rubber, has tensile strength equivalent to that of natural rubber and high stress at definite elongation, and is beneficial to replacing the natural rubber to prepare an aircraft tire.

The catalyst for preparing the bionic rubber is a rare earth catalyst, and comprises the following components: A. rare earth compound, B, organic aluminum compound, C, chloride; for convenience of description, the components of the catalyst system are sequentially referred to as a component a, a component B, and a component C. In the embodiment of the present invention, the rare earth catalyst may be prepared by mixing a rare earth compound, an organoaluminum compound, and a chloride in a solvent.

Preferably, the rare earth catalyst is obtained by the following preparation: adding rare earth compound (A), organic aluminium compound (B) and chloride (C) into a dry catalyst reactor in sequence under the protection atmosphere of nitrogen, aging at 30-80 deg.C for 15-120 min to obtain a product with a certain concentration of 2 × 10^-5mol/ml catalyst solution. According to the embodiment of the invention, the organic solvent used in the preparation method of the rare earth catalyst is a hydrocarbon solvent, preferably one or more of n-hexane, n-pentane, cyclohexane and n-heptane, and more preferably n-hexane.

The rare earth compound plays a main catalytic role and is selected from one or more of rare earth carboxylate, rare earth acid phosphonate, alkoxy rare earth, chlorinated rare earth electron donor complex and sulfonic rare earth electron donor complex; the rare earth element in the rare earth compound is usually neodymium (Nd), and the rare earth compound can be prepared from commercially available rare earth products.

The rare earth compound (A) according to some embodiments of the present invention is selected from rare earth carboxylates, preferably neodymium neodecanoate Nd (vers)₃Neodymium isooctanoate Nd (EHA)₃Neodymium naphthenate Nd (naph)₃(ii) a Some embodiments select a rare earth acidic phosphorus/phosphonate, preferably neodymium (2-ethylhexyl) phosphonate Nd (P)₂₀₄)₃Or (2-ethylhexyl) neodymium phosphonate, Nd (P) mono-2-ethylhexyl ester₅₀₇)₃. The rare earth compound of some embodiments is selected from alkoxy rare earth, preferably neodymium ethoxide, neodymium n-propoxide, neodymium isopropoxide, etc.; the rare earth compounds of other embodiments are selected from the group consisting of rare earth chloride electron donor complexes, preferably neodymium chloride isopropyl alcohol (NdCl)₃·₃PrⁱOH) or neodymium chloride tributyl phosphate (NdCl)₃3 TBP); other embodiments select a sulfonic acid rare earth electron donor complex, preferably neodymium triflate tributyl phosphate Nd (CF)₃SO₃)₃3TBP, neodymium benzenesulfonate Nd N, N-dimethylformamide (C)₁₈H₂₉SO₃)₃·3C₃H₇NO。

In addition, in the rare earth catalyst system, an organic aluminum compound (B) plays a role in auxiliary catalysis, and specifically comprises the following components: a combination of one or more alkylaluminums of a trialkylaluminum and an alkylaluminum hydride, preferably triisobutylaluminum Al (i-Bu)₃Diisobutylaluminum hydride Al (i-Bu)₂H. Diethyl aluminium hydride AlEt₂H. Trioctylaluminum (oct)₃Or triethylaluminum AlEt₃. The molar ratio of the organoaluminum compound to the rare earth element in the rare earth compound is preferably 10 to 30:1 (which may be expressed as a B: a ═ 10 to 30:1 molar ratio), and more preferably 20 to 30: 1.

The rare earth catalyst of the present invention also includes a chloride, preferably diisobutylaluminum monochloride Al (i-Bu)₂Cl, aluminum diethyl monochloride AlEt₂Cl, aluminum sesquiethyl Al₂Et₃Cl₃T-butyl chloride t-BuCl (chloro-tert-butane), benzyl chloride BzCl, allyl chloride H₂C＝CHCH₂Cl, chloromethylsilane Me_4-nSiCl_n(n is 1, 2 or 3) or silicon tetrachloride SiCl₄. Preferably, the mol ratio of the chloride to the rare earth in the rare earth compound is 2-3: 1.

The preparation of the rare earth isoprene rubber is improved, the alkyl aluminum modified phospholipid compound is used as an auxiliary agent and added into a rare earth catalytic reaction system of isoprene in situ, so that the modified phospholipid compound and a polymer are combined in a molecular form and uniformly dispersed.

In the invention, the auxiliary agent is a modified phospholipid substance obtained by reacting alkyl aluminum with phospholipid. The raw materials for preparing the modified phospholipid material in the embodiment of the invention comprise alkyl aluminum and phospholipid. The alkyl aluminum is trialkyl aluminum or hydrogenated alkyl aluminum, and the alkyl and the metallic aluminum are directly combined to form a metallic aluminum organic matter. Among them, the aluminum alkyl hydride is also called aluminum alkyl hydride. In a particular embodiment of the invention, the aluminum alkyl concerned is triisobutylaluminum Al (i-Bu)₃Diisobutylaluminum hydride Al (i-Bu)₂H. Diethyl aluminium hydride AlEt₂H. Trioctylaluminum (oct)₃Or triethylaluminum AlEt₃。

The phospholipid is one or more of lecithin, phosphatidylinositol, glycerophosphate, glycerophosphorylcholine and long-chain alkyl phosphate (the number of carbon atoms of the long-chain alkyl is more than or equal to 12, for example, 12-18). The phospholipid according to the embodiment of the present invention is selected from any one of the following: (1) lecithin C₄₂H₈₀NO₈P; (2) phosphatidylinositol C₄₅H₈₇O₁₃P; (3) glycerol phosphate ester C₃H₉O₆P; (4) glycerol phosphorylcholine C₈H₂₀NO₆P; (5) dodecyl phosphate C₁₂H₂₇O₄P。

In the embodiment of the invention, the preparation method of the alkyl aluminum modified phospholipid comprises the following steps: dissolving the alkyl aluminum (the alkyl aluminum is used as a modifier) in hexane under the protective atmosphere of nitrogen and the like, and adding phospholipid for reaction to obtain the modified alkyl aluminum; wherein the molar ratio of the alkyl aluminum to the phospholipid is preferably 1-10: 1, and specifically can be 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1 or 10: 1.

Preferably, the alkyl aluminum and the phospholipid react at 50-100 ℃ for 1-12 hours to obtain a modified phospholipid substance which can be marked as an auxiliary agent D. Further, the temperature of the reaction is preferably 60 to 90 ℃, more preferably 65 to 85 ℃.

In the high-strength high-stress-at-elongation bionic rubber provided by the invention, the auxiliary agent isThe amount used is preferably 0.5 to 2% by mass, for example 0.5%, 1% or 2% by mass, based on the isoprene monomer. The rare earth catalyst system described in the above examples may have a ratio of the number of moles of Nd to the mass of added monomeric isoprene, g, of 1.0X 10^-6～6×10^-6mol/g, preferably 2X 10^-6～6×10^-6mol/g。

The embodiment of the invention also provides a preparation method of the bionic rubber in the technical scheme, which comprises the following steps:

reacting alkyl aluminum with phospholipid to obtain a modified phospholipid substance; the alkyl aluminum is trialkyl aluminum or alkyl aluminum hydride; the phospholipid is selected from one or more of lecithin, phosphatidylinositol, glycerophosphate, glycerophosphorylcholine and long-chain alkyl phosphate;

in the presence of a rare earth catalyst, an isoprene monomer and a modified phospholipid substance are mixed in an organic solvent for reaction to obtain the bionic rubber.

In the embodiment of the invention, rare earth catalyst solution and modified phospholipid substance as an auxiliary agent can be respectively prepared; the specific types and dosage ratios of the raw materials such as the alkyl aluminum and the phospholipid are introduced in the above description, and are not described in detail herein.

In the specific embodiment of the invention, the rare earth catalyst is firstly added into the isoprene solution, then the modified phospholipid substance is added, and the reaction is preferably carried out for 2-24 hours at the temperature of 20-70 ℃ to obtain the bionic rubber with high strength and high stress at definite elongation.

According to the preferred embodiment of the invention, the preparation method of the rare earth catalyst for the bionic rubber comprises the following steps:

under the protection of nitrogen, 1L of isoprene hexane solution with the monomer concentration of 10g/100ml is added into a polymerization kettle, then a rare earth catalyst is added, and after 5 minutes of reaction, D is added. The catalyst system had a molar ratio of Nd to the mass of the added monomer g of 1.0X 10^-6～6×10^-6And (3) mol/g, wherein the weight ratio of D to the monomer is 0.5-2%, the reaction is carried out for 2-24 hours at the temperature of 20-70 ℃, then the polymer is precipitated in ethanol, and the polymer is dried in vacuum to constant weight, so that the bionic rubber which is raw rubber is obtained.

The bionic rubber provided by the embodiment of the invention has high strength, the 300% stress at definite elongation can be 2.4-2.7 MPa, and the stress at definite elongation is higher, so that the bionic rubber is beneficial to application in preparing an aircraft tire tread.

The embodiment of the invention provides an aircraft tire tread rubber which is prepared by taking bionic rubber obtained by the preparation method as a raw material and vulcanizing, and meets the performance requirement of an aircraft tire.

The invention has no special limitation on the formula, the process and the like for preparing the vulcanized rubber from the reclaimed rubber, and the preparation method is a conventional operation in the field. The blank rubber is not added with carbon black, and the bionic rubber is interpreted as simulating the rubber of natural rubber. The invention adopts a general formula of tread rubber for comparison, and according to the embodiment of the invention, the formula for testing the performance of the blank rubber is as follows: 100phr of crude rubber, 5phr of zinc oxide, 2phr of stearic acid, 0.7phr of an accelerator NS (the Chinese name IS N-tertiary butyl-2-benzothiazole sulfonamide) and 0.7phr of sulfur IS-HS-80102.5 phr. phr, i.e. represents the parts added per 100 parts (by mass) of rubber.

Detailed Description

In order that the invention may be more readily understood, reference will now be made to the following more particular description of the invention, examples of which are set forth below. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; these embodiments are provided so that this disclosure will be thorough and complete. The various starting materials used in the examples are, unless otherwise indicated, conventional commercial products.

In order to better understand the technical content of the invention, specific examples are provided below to further illustrate the invention. In the following examples, the formulation for testing the performance of the white rubber is as follows: 100phr of crude rubber, 5phr of zinc oxide, 2phr of stearic acid, 0.7phr of accelerator NS and 0.78 phr of sulfur IS-HS-80102.5.

Examples 1 to 5

To a dry catalyst reactor, 10ml of 2X 10 were added in succession under nitrogen protection^-4Rare earth compound in mol/ml, 2X 10 in 30ml^-3The B component hexane solution is prepared by mixing B component aluminum alkyl and rare earth elements in rare earth compoundsThe molar ratio of the elements is 30:1, 20ml of 2X 10 are added^-4And (3) a C component hexane solution of mol/ml, wherein the molar ratio of the C component to the rare earth elements in the rare earth compound is 2:1, adding hexane solution to prepare the solution with the concentration of 2X 10^-5And (3) aging the rare earth catalyst with mol/ml at 80 ℃ for 15 minutes to obtain the catalyst solution for preparing the bionic rubber.

Under the protection of nitrogen, the alkyl aluminum is dissolved in hexane, phospholipid is added, and the reaction is carried out for 1 hour at 100 ℃ to obtain a modified phospholipid substance, which is recorded as D.

Under the protection of nitrogen, 1L of isoprene hexane solution with the monomer concentration of 10g/100ml is added into a polymerization kettle, then a rare earth catalyst is added, and after 5 minutes of reaction, D is added, wherein D is 0.5% of monomer. The molar ratio of Nd in the system to the monomer added is 3X 10^-6And (3) mol/g, reacting for 24 hours at the temperature of 20 ℃, precipitating the polymer in ethanol, washing with ethanol, extruding, and drying in vacuum to constant weight to obtain the bionic rubber.

The specific formulations and experimental results corresponding to examples 1-5 are shown in Table 1; reaction temperatures and the like not listed in Table 1 were kept constant. In Table 1 the properties of the vulcanizates are tested, but without the addition of carbon black, so called blank vulcanizates, the test methods are general (same in the examples below).

TABLE 1 results of polymer experiments obtained in examples 1 to 5

Examples 6 to 9

To a dry catalyst reactor, 10ml of 2X 10 were added in succession under nitrogen protection^-4Rare earth compound in mol/ml, 2X 10 in 20ml^-3And (3) a B component hexane solution in mol/ml, wherein the molar ratio of the B component alkyl aluminum to the rare earth elements in the rare earth compound is 20: 1, 30ml of 2X 10 are added^-4C component hexane in mol/mlA solution wherein the molar ratio of component C to rare earth elements in the rare earth compound is 3:1, adding hexane solution to prepare the solution with the concentration of 2X 10^-5And (3) aging the rare earth catalyst with mol/ml at 30 ℃ for 120 minutes to obtain the catalyst solution for preparing the bionic rubber.

Under the protection of nitrogen, the alkyl aluminum is dissolved in hexane, phospholipid is added, and the reaction is carried out for 12 hours at 50 ℃ to obtain a modified phospholipid material, which is recorded as D.

Under the protection of nitrogen, 1L of isoprene hexane solution with the monomer concentration of 10g/100ml is added into a polymerization kettle, then a rare earth catalyst is added, and after 5 minutes of reaction, D is added, wherein D is 1.0 percent of monomer. The molar ratio of Nd to monomer added in the system is 1X 10^-6And (3) mol/g, reacting for 10 hours at 40 ℃, precipitating the polymer in ethanol, washing with ethanol, extruding, and drying in vacuum to constant weight to obtain the bionic rubber.

The specific formulations and experimental results corresponding to examples 6-9 are shown in Table 2; reaction temperatures and the like not listed in Table 2 were kept constant.

TABLE 2 results of polymer experiments obtained in examples 6 to 9

Examples 10 to 13

To a dry catalyst reactor, 10ml of 2X 10 were added in succession under nitrogen protection^-4Rare earth compound in mol/ml, 2X 10 in 10ml^-3And (3) a B component hexane solution in mol/ml, wherein the molar ratio of the B component alkyl aluminum to the rare earth elements in the rare earth compound is 10:1, 25ml of 2X 10 are added^-4And (3) a C component hexane solution of mol/ml, wherein the molar ratio of the C component to the rare earth elements in the rare earth compound is 2.5: 1, adding hexane solution to prepare the solution with the concentration of 2X 10^-5Aging the rare earth catalyst with mol/ml at 50 ℃ for 60 minutes to obtain the bionic rubberThe catalyst solution of (1).

Under the protection of nitrogen, the alkyl aluminum is dissolved in hexane solution, phospholipid is added, and the reaction is carried out for 6 hours at 80 ℃ to obtain a modified phospholipid substance, which is recorded as D.

Under the protection of nitrogen, 1L of isoprene hexane solution with the monomer concentration of 10g/100ml is added into a polymerization kettle, then a rare earth catalyst is added, and after 5 minutes of reaction, D is added, wherein D is 2.0% of monomer. The molar ratio of Nd in the system to the monomer added is 6X 10^-6And (3) reacting at 70 ℃ for 2 hours in mol/g, precipitating the polymer in ethanol, washing with ethanol, extruding, and drying in vacuum to constant weight to obtain the bionic rubber.

The specific formulations and experimental results corresponding to examples 10-13 are shown in Table 3; reaction temperatures and the like not listed in Table 3 were kept constant.

TABLE 3 results of polymer experiments obtained in examples 10 to 13

According to the embodiments, the bionic rubber prepared by the method has the characteristics of high strength, high stress at definite elongation and the like, and can be used for preparing the tread of the aircraft tire.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.