Alpha, omega double-end functionalized diene rubber as well as preparation method and application thereof

Abstract

The invention provides alpha, omega double-end functionalized diene rubber as well as a preparation method and application thereof, and belongs to the technical field of rubber. The alpha, omega double-end functionalized diene rubber provided by the invention has a chemical structure as shown in a formula I which is described in the specification. The two ends of the alpha, omega double-end functionalized diene rubber provided by the invention both contain polar groups (N, O and S), and through the interaction between the polar groups and a filler (such as carbon black), the dispersity of the filler in a rubber matrix can be effectively improved, motion friction heat generation at the molecular chain end of the diene rubber is passivated, and the mechanical property of the diene rubber is improved. Meanwhile, polar groups at the two ends of the alpha, omega double-end functionalized diene rubber are different in structure and adjustable in number, and the mechanical property of the diene rubber can be improved. In addition, besides head and tail end structures, the content of cis-1, 4 in the main chain structure of the alpha, omega double-end functionalized diene rubber provided by the invention can reach 98.2%. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the technical field of rubber, and in particular relates to an α,ω double-end functionalized diene rubber and a preparation method and application thereof. Background Art

[0002] The main component of natural rubber is high molecular weight cis-1,4 polyisoprene, and there are also about 3-7wt% non-rubber components. High cis-1,4 polyisoprene rubber is closest to the structure of natural rubber and can replace natural rubber in some fields. However, in some special fields such as mining tires, engineering tires, load-bearing tires, aviation tires, tank road wheels and other extreme working conditions, natural rubber must still be used. This is because the proteins, phospholipids and metal ions in the non-rubber components at the end groups of natural rubber are coupled through weak valence bonds such as hydrogen bonds / ionic bonds, giving natural rubber the properties of strain-induced crystallization, self-recovery of trimming modulus and metal adhesion.

[0003] Therefore, in recent years, natural rubber has been mainly synthesized by end functionalization of cis-1,4 polyisoprene rubber. However, due to the limitation of polymerization mechanism, the polar group at the α end is easy to coordinate with the transition metal active center and inactivate it. For example, a prior art prepared a polybutadiene terminated with siloxy groups. The terminal functionalization of this high cis-1,4 diene polymer is mostly limited to the functionalization of the ω end. The structure is quite different from that of natural rubber, which contains multiple polar groups at the head and end, and has the defect of poor mechanical properties. Summary of the invention

[0004] The purpose of the present invention is to provide an α,ω double-end functionalized diene rubber and a preparation method and application thereof. The α,ω double-end functionalized diene rubber provided by the present invention has different polar groups at the α and ω ends, and has similar structure and properties to natural rubber.

[0005] In order to achieve the purpose of the present invention, the present invention provides the following technical solutions:

[0006] An α,ω double-end functionalized diene rubber having a chemical structure shown in formula I:

[0007]

[0008] In Formula I, R is hydrogen or methyl, R 1 is one of hydrogen, methyl and halogen, X is -NMe 2 , -OMe and -SMe; Y is O or S;

[0009] The x≥1, y is 100-2000, and z≥1.

[0010] Preferably, the content of cis-1,4 structure in the α,ω dual-end functionalized diene rubber is 80-98.2%.

[0011] The present invention also provides a method for preparing the α,ω double-end functionalized diene rubber described in the above technical solution, comprising the following steps:

[0012] The neodymium compound, compound A, an alkyl aluminum compound and a chlorine source are mixed, and alkylation reaction and chlorination reaction are performed in sequence to obtain a compound containing an α-terminal active center;

[0013] The neodymium compound is a neodymium carboxylate compound, a neodymium alkoxide compound, and a neodymium phosphonate compound;

[0014] The compound A has the structure shown in A1, A2 or A3:

[0015]

[0016] The chemical structure of the compound containing the α-terminal active center is shown in Formula II:

[0017]

[0018] The α-terminal active center-containing compound and a conjugated diene monomer are mixed and polymerized to obtain a diene rubber molecule main chain compound;

[0019] The diene rubber molecular main chain compound and compound B are mixed and end-capped to obtain the α,ω double-end functionalized diene rubber;

[0020] The compound B has the structures shown in B1 to B6:

[0021]

[0022] Among them, n in B1 to B6 is 2 to 6; R in B5 and B6 1 , R 2 and R 3 is independently one of hydrogen, methyl and halogen.

[0023] Preferably, the carboxylate compound of neodymium is one of neodymium neodecanoate, neodymium isooctanoate and neodymium cyclohexaneate; the alkoxide compound of neodymium is neodymium isopropoxide or neodymium isobutoxide; the phosphonate compound of neodymium is neodymium (2-ethylhexyl) phosphonate or neodymium (2-ethylhexyl) phosphonate mono-2-ethylhexyl ester;

[0024] The alkyl aluminum compound is one or more of triethyl aluminum, triisobutyl aluminum, trihexylaluminum, trioctylaluminum, diisobutylaluminum hydride and diethylaluminum hydride;

[0025] Wherein the chlorine source is dichlorodimethylsilane or sesquiethylaluminum chloride;

[0026] The conjugated diene monomer is butadiene and / or isoprene.

[0027] Preferably, the molar ratio of the compound A, the neodymium compound, the alkyl aluminum compound and the chlorine source is 1-30:1:10-40:1-3;

[0028] The molar ratio of the conjugated diene monomer to the neodymium compound is 100 to 20000:1;

[0029] The molar ratio of compound B to the neodymium compound is 1 to 30:1.

[0030] Preferably, the alkylation reaction and chlorination reaction, polymerization reaction and end-capping reaction are carried out under organic solvent conditions; the organic solvent is a non-polar organic solvent.

[0031] Preferably, the temperature of the alkylation reaction and the chlorination reaction is 40-70°C and the time is 5min-4h;

[0032] The polymerization reaction temperature is 40-100°C and the reaction time is 2-10h;

[0033] The end-capping reaction is carried out at a temperature of 40 to 100° C. and for a time of 2 to 12 hours.

[0034] The present invention also provides the use of the α,ω double-end functionalized diene rubber described in the above technical solution or the α,ω double-end functionalized diene rubber prepared by the preparation method described in the above technical solution in rubber products.

[0035] The present invention provides an α,ω double-end functionalized diene rubber having a chemical structure shown in Formula I: In Formula I, R is hydrogen or methyl, R1 is one of hydrogen, methyl and halogen, and X is -NH 2 , -OH and -SH; Y is O or S; x≥1, y is 100-2000, z≥1. Both ends of the α,ω double-end functionalized diene rubber provided by the present invention contain polar groups (N, O, S), which can effectively improve the dispersibility of the filler in the rubber matrix through the hydrogen bond interaction between the polar groups and the filler (such as carbon black, white carbon black), passivate the friction heat generated by the movement of the diene rubber molecular chain ends, and improve the mechanical properties of the diene rubber. At the same time, the polar group structures at both ends of the α,ω double-end functionalized diene rubber of the present invention are different, and the number can be adjusted, which can further improve the mechanical properties of the diene rubber. In addition, in addition to the head-end structure, the cis-1,4 content in the main chain structure of the α,ω double-end functionalized diene rubber provided by the present invention can reach 98.2%, which is similar to the structure of natural rubber. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 The figure is a physical picture of the high cis-1,4 polyisoprene rubber obtained in Comparative Example 1 and the α,ω double-end functionalized diene rubber obtained in Example 7; wherein the left side is the high cis-1,4 polyisoprene rubber and the right side is the α,ω double-end functionalized diene rubber;

[0038] Figure 2 This is the H NMR spectrum of the α,ω double-end functionalized diene rubber obtained in Example 15;

[0039] Figure 3 This is the MALDI-TOF spectrum of the α,ω double-end functionalized diene rubber obtained in Example 15;

[0040] Figure 4 This is the gel permeation chromatogram of the α,ω double-end functionalized diene rubber obtained in Example 15;

[0041] Figure 5 This is a stress-strain curve of the α,ω dual-end functionalized diene rubber obtained in Example 7;

[0042] Figure 6 Stress-strain curve of the high cis-1,4 polyisoprene rubber obtained in Comparative Example 1. DETAILED DESCRIPTION

[0043] The present invention provides an α,ω double-end functionalized diene rubber having a chemical structure shown in Formula I:

[0044]

[0045] In Formula I, R is hydrogen or methyl, R 1 is one of hydrogen, methyl and halogen, X is -NMe 2 , -OMe and -SMe; Y is O or S;

[0046] The x≥1, y is 100-2000, and z≥1.

[0047] In the present invention, the formula I is the α end, is the polymer backbone, For the ω end.

[0048] In the present invention, R in Formula I1 is one of hydrogen, methyl and halogen; the halogen may be one of fluorine, chlorine, bromine and iodine, and in a specific embodiment, may be fluorine or bromine.

[0049] In the present invention, x≥1, and may be 1-30, and in a specific embodiment, may be 5, 10 or 20; y is 100-2000, and in a specific embodiment, may be 500 or 1000; z≥1, and may be 1-5, and in a specific embodiment, may be 2 or 3.

[0050] In the present invention, the content of cis-1,4 structure in the α,ω double-end functionalized diene rubber is 80-98.2%, and in specific embodiments, it can be 92.2%, 93.5%, 95.6%, 96.4% or 97.6%.

[0051] The present invention also provides a method for preparing the α,ω double-end functionalized diene rubber described in the above technical solution, comprising the following steps:

[0052] The neodymium compound, compound A, an alkyl aluminum compound and a chlorine source are mixed, and alkylation reaction and chlorination reaction are performed in sequence to obtain a compound containing an α-terminal active center;

[0053] The neodymium compound is a neodymium carboxylate compound, a neodymium alkoxide compound, and a neodymium phosphonate compound;

[0054] The compound A has the structure shown in A1, A2 or A3:

[0055]

[0056] The chemical structure of the compound containing the α-terminal active center is shown in Formula II:

[0057]

[0058] The α-terminal active center-containing compound and a conjugated diene monomer are mixed and polymerized to obtain a diene rubber molecule main chain compound;

[0059] The diene rubber molecular main chain compound and compound B are mixed and end-capped to obtain the α,ω double-end functionalized diene rubber;

[0060] The compound B has the structures shown in B1 to B6:

[0061]

[0062] Among them, n in B1 to B6 is 2 to 6; R in B5 and B6 1 , R 2 and R 3is independently one of hydrogen, methyl and halogen.

[0063] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well known to those skilled in the art or are prepared by preparation methods well known to those skilled in the art.

[0064] The present invention sequentially performs alkylation reaction and chlorination reaction on a neodymium compound, a compound A, an alkyl aluminum compound and a chlorine source to obtain a solution containing an α-terminal active center compound. In the present invention, the neodymium carboxylate compound is one of neodymium neodecanoate, neodymium isooctanoate and neodymium cyclohexaneate; the neodymium alkoxide compound is neodymium isopropoxide or neodymium isobutoxide; the neodymium phosphonate compound is neodymium (2-ethylhexyl) phosphonate or neodymium (2-ethylhexyl) phosphonate mono-2-ethylhexyl ester. In the present invention, the neodymium compound is used as a main catalyst to provide metal neodymium atoms in the active center.

[0065] In the present invention, the alkyl aluminum compound is one or more of triethyl aluminum, triisobutyl aluminum, trihexylaluminum and trioctylaluminum, diisobutyl aluminum hydride and diethyl aluminum hydride, and in a specific embodiment, it can be diisobutyl aluminum hydride or triethyl aluminum; the chlorine source is dimethylsilyl dichloride or sesquiethylaluminum chloride; the conjugated diene monomer is a butadiene monomer (Bd) and / or an isoprene monomer (Ip), and in a specific embodiment, when the conjugated diene monomer is a butadiene monomer and an isoprene monomer, the molar ratio of the butadiene monomer to the isoprene monomer is 2 to 8:2 to 8, and in a specific embodiment, it can be 4:6 or 6:4.

[0066] In the present invention, the molar ratio of the compound A, the neodymium compound, the alkyl aluminum compound and the chlorine source is 1-30:1:10-40:1-3. In specific embodiments, it can be 1:1:30:2, 1:8:30:2 or 1:20:20:3.

[0067] In the present invention, the molar ratio of the conjugated diene monomer to the neodymium compound is 100 to 20,000:1. In specific embodiments, the molar ratio may be 600:1, 1,000:1, 2,000:1, 10,000:1 or 15,000:1.

[0068] In the present invention, the molar ratio of compound B to the neodymium compound is 1 to 30:1, and in specific embodiments, it can be 3:1, 5:1, 10:1 or 20:1.

[0069] In the present invention, the alkylation reaction and chlorination reaction, polymerization reaction and end-capping reaction are carried out under organic solvent conditions; the organic solvent is a non-polar organic solvent; the non-polar organic solvent can be one or more of toluene, n-hexane, n-pentane and n-heptane, and in a specific embodiment, it can be toluene.

[0070] In the present invention, the temperature of the alkylation reaction and the chlorination reaction is 40-70°C, in a specific embodiment, it can be 50 or 60°C, and the time is 5min-4h, in a specific embodiment, it can be 20min, 1h or 2h. In the alkylation process of the present invention, one group on the neodymium compound is replaced by the alkyl group in the alkyl aluminum; in the chlorination process, another group on the neodymium compound is replaced by the chlorine of the chlorine-containing compound.

[0071] In the present invention, the polymerization reaction temperature is 40-100°C, and in a specific embodiment, it can be 50, 70 or 90°C; the time is 2-10h, and in a specific embodiment, it can be 3, 4 or 8h;

[0072] In the present invention, the temperature of the end-capping reaction is 40-100° C., and in a specific embodiment, it can be 50, 60, 70 or 90° C., and the time is 2-12 h, and in a specific embodiment, it can be 4, 6 or 10 h.

[0073] The present invention also provides the use of the α,ω double-end functionalized diene rubber described in the above technical solution or the α,ω double-end functionalized diene rubber prepared by the preparation method described in the above technical solution in rubber products.

[0074] In the present invention, the rubber product includes one or more of tires, rubber shoes, rubber hoses and rubber belts; the tire can be an all-steel radial tire.

[0075] In order to further illustrate the present invention, the α,ω dual-end functionalized diene rubber provided by the present invention and its preparation method and application are described in detail below in conjunction with the accompanying drawings and examples, but they should not be construed as limiting the scope of protection of the present invention.

[0076] Examples 1 to 20

[0077] The solution α-1 to 12 containing the α-terminal active center compound is prepared by the following specific steps:

[0078] According to the preparation conditions described in Table 1, a neodymium compound, a compound A, and an alkyl aluminum compound are sequentially added to an ampoule that has been vacuum-baked and filled with nitrogen, and reacted under corresponding conditions to obtain solutions α-1 to 12 containing α-terminal active center compounds;

[0079] Table 1 Preparation conditions of solutions α-1 to 12 containing α-terminal active center compounds

[0080]

[0081]

[0082] Table 2 Structural formula of specific compound B in Examples 1 to 20

[0083]

[0084] The above solutions α1-12 containing the α-terminal active center are used to prepare α,ω dual-terminal functionalized diene rubber, and the specific steps are as follows:

[0085] In a 100mL ampoule bottle that has been dried by vacuum baking and filled with nitrogen, the solution of α1-12 containing α-terminal active centers and conjugated diene monomers are added in sequence, and a polymerization reaction is carried out in a solvent. After the polymerization reaction is completed, a certain proportion of compound B is added to carry out a capping reaction to obtain α, ω dual-end functionalized diene rubber. Among them, the yield of α, ω dual-end functionalized diene rubber is calculated by weight method, the number average molecular weight (Mn) and molecular weight distribution (PDI, Mw / Mn) are characterized by gel permeation chromatography (GPC), and the cis-1,4 content (cis-1,4) is calculated by infrared spectrum and nuclear magnetic spectrum.

[0086] The specific reaction conditions and the molecular weight and microstructure data of the α,ω dual-end functionalized diene rubber are shown in Tables 3 and 4; wherein, [monomer] / [Nd] is the molar ratio of the conjugated diene monomer and the neodymium compound; n-hexane is used as the solvent in Examples 1 to 6, toluene is used as the solvent in Examples 7 to 10, and n-pentane is used as the solvent in Examples 11 to 16; Bd is a butadiene monomer, and Ip is an isoprene monomer; the amount of the ω-terminal compound B added is [B] / [Nd+Al]=3.

[0087] Table 3 Preparation conditions and performance test results of α,ω dual-end functionalized polybutadiene rubber described in Examples 1 to 16

[0088]

[0089] Table 4 Preparation conditions and performance test results of α,ω dual-end functionalized polybutadiene rubber described in Examples 17 to 20

[0090]

[0091] In Table 4, [Ip+Bd] / [Nd]=2000, and the amount of the ω-terminal compound B added is [B] / [Nd+Al]=3. In Examples 17-20, n-hexane was used as the solvent.

[0092] Comparative Example 1

[0093] In a 100 mL ampoule bottle which was dried by vacuum baking and filled with nitrogen, neodymium neodecanoate, diisobutylaluminum hydride and ethylaluminum sesquihydrate were added in a molar ratio of 1:20:2, and the mixture was reacted at 50°C for 40 minutes to obtain a catalyst active center solution; isoprene was added to the catalyst active center solution at a molar ratio of isoprene to neodymium neodecanoate of 10000:1, and the mixture was polymerized in a toluene solvent at 50°C for 4 hours, ethanol was added to precipitate the polymer, and the mixture was dried in a vacuum oven to constant weight to obtain polyisoprene rubber with a yield of 98.0%; the number average molecular weight of the obtained high cis-1,4 polyisoprene rubber was 34.3×10 4 , molecular weight distribution is 2.51, cis-1,4 content is 96.1%, and tensile strength is 8.81MPa.

[0094] Figure 1 It is a physical picture of the high cis-1,4 polyisoprene rubber obtained in Comparative Example 1 and the α,ω double-end functionalized diene rubber obtained in Example 7; wherein, the left side is the high cis-1,4 polyisoprene rubber, and the right side is the α,ω double-end functionalized diene rubber.

[0095] Figure 2 This is the H NMR spectrum of the α,ω double-end functionalized diene rubber obtained in Example 15. Figure 3 is the MALDI-TOF spectrum of the α,ω double-end functionalized diene rubber obtained in Example 15; Figure 2 and 3 The results can prove the structure and number of the first and last functional groups. Figure 2 and 3 As shown, the number at the head end is 1 to 2, and the number at the tail end is 1 to 5.

[0096] The structures of the α,ω dual-end functionalized diene rubbers obtained in Examples 7 and 15 are shown below:

[0097]

[0098] Figure 4 is the gel permeation chromatogram of the α,ω double-end functionalized diene rubber obtained in Example 15; Figure 4 The results show that the α,ω dual-end functionalized diene rubber is monodisperse.

[0099] Figure 5 This is a stress-strain curve of the α,ω dual-end functionalized diene rubber obtained in Example 7; Figure 6 The stress-strain curve of the high cis-1,4 polyisoprene rubber obtained in Comparative Example 1 is shown in FIG. Figures 5-6It can be seen that the tensile strength of the α,ω double-end functionalized diene rubber obtained in the present invention is 14.3 MPa, and the tensile strength of the high cis-1,4 polyisoprene rubber obtained in Comparative Example 1 is 8.81 MPa. The present invention has better mechanical properties.

[0100] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An α,ω double-end functionalized diene rubber, characterized in that: It has the chemical structure shown in Formula I: In Formula I, R is hydrogen or methyl, R1 is one of hydrogen, methyl and halogen, X is one of -NMe2, -OMe and -SMe; Y is O or S; The x≥1, y is 100-2000, and z≥1.

2. The α,ω double-end functionalized diene rubber according to claim 1, characterized in that: The content of cis-1,4 structure in the α,ω double-end functionalized diene rubber is 80-98.2%.

3. The method for preparing the α,ω double-end functionalized diene rubber according to claim 1 or 2, characterized in that: The following steps are involved: The neodymium compound, compound A, an alkyl aluminum compound and a chlorine source are mixed, and alkylation reaction and chlorination reaction are performed in sequence to obtain a compound containing an α-terminal active center; The neodymium compound is a neodymium carboxylate compound, a neodymium alkoxide compound, and a neodymium phosphonate compound; The compound A has the structure shown in A1, A2 or A3: The chemical structure of the compound containing the α-terminal active center is shown in Formula II: The α-terminal active center-containing compound and a conjugated diene monomer are mixed and polymerized to obtain a diene rubber molecule main chain compound; The diene rubber molecular main chain compound and compound B are mixed and end-capped to obtain the α,ω double-end functionalized diene rubber; The compound B has the structures shown in B1 to B6: Among them, n in B1-B6 is 2-6; R1, R2 and R3 in B5 and B6 are independently one of hydrogen, methyl and halogen.

4. The preparation method according to claim 3, characterized in that: The carboxylate compound of neodymium is one of neodymium neodecanoate, neodymium isooctanoate and neodymium cyclohexaneate; the alkoxide compound of neodymium is neodymium isopropoxide or neodymium isobutoxide; the phosphonate compound of neodymium is neodymium (2-ethylhexyl) phosphonate or neodymium (2-ethylhexyl) phosphonate mono-2-ethylhexyl ester; The alkyl aluminum compound is one or more of triethyl aluminum, triisobutyl aluminum, trihexylaluminum, trioctylaluminum, diisobutylaluminum hydride and diethylaluminum hydride; Wherein the chlorine source is dichlorodimethylsilane or sesquiethylaluminum chloride; The conjugated diene monomer is butadiene and / or isoprene.

5. The preparation method according to claim 3, characterized in that: The molar ratio of the compound A, the neodymium compound, the alkyl aluminum compound and the chlorine source is 1-30:1:10-40:1-3; The molar ratio of the conjugated diene monomer to the neodymium compound is 100 to 20000:1; The molar ratio of compound B to the neodymium compound is 1 to 30:

1.

6. The preparation method according to claim 3, characterized in that: The alkylation reaction, chlorination reaction, polymerization reaction and end-capping reaction are carried out under the condition of an organic solvent; the organic solvent is a non-polar organic solvent.

7. The preparation method according to claim 3, characterized in that: The temperature of the alkylation reaction and the chlorination reaction is 40-70°C and the time is 5min-4h; The polymerization reaction temperature is 40-100°C and the reaction time is 2-10h; The end-capping reaction is carried out at a temperature of 40 to 100° C. and for a time of 2 to 12 hours.

8. Use of the α,ω double-end functionalized diene rubber according to claim 1 or 2 or the α,ω double-end functionalized diene rubber prepared by the preparation method according to any one of claims 3 to 7 in rubber products.

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