Use of organophosphorus compounds in the preparation of iron-based catalysts for the polymerization of 1,2-polybutadiene

Abstract

The application of an organic phosphine compound in the preparation of 1,2-polybutadiene with an iron-based catalyst belongs to the field of 1,2-polybutadiene preparation. The organic phosphine compound is used to adjust the melting point and molecular weight of 1,2-polybutadiene. The structural formula of the organic phosphine compound is PR3 or P(Ph-OR1)3, R is one of C1-C 20 alkyl, phenyl and substituted phenyl, and R1 is one of C1-C 20 alkyl, phenyl and substituted phenyl. The use of the organic phosphine compound can prepare 1,2-polybutadiene with a weight average molecular weight of 80,000-1,300,000 and a melting point of 60-140 ℃, which can be adjusted, and the problems of large molecular weight, difficult processing and dark color of 1,2-polybutadiene are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of preparing syndiotactic 1,2-polybutadiene, and particularly relates to an electron donor, i.e. an organic phosphine compound, capable of adjusting the melting point and molecular weight of syndiotactic 1,2-polybutadiene, and application of the organic phosphine compound in preparing syndiotactic 1,2-polybutadiene by using an iron-based catalyst. BACKGROUND

[0002] Under the action of a catalyst, butadiene is subjected to 1,2 addition polymerization to obtain 1,2-polybutadiene having a vinyl side group in the molecular main chain, which has the advantages of good wet skid resistance, aging resistance, low heat generation, etc., and thus can be used to manufacture airplane and automobile tires. In addition, with different microstructures and relative molecular weights, 1,2-polybutadiene is increasingly widely used in many fields such as plastics, coatings, adhesives, functional polymers, etc., and can be used to prepare films, fibers, rubber products and modifiers of rubber products, etc. At present, the catalysts for preparing 1,2-polybutadiene mainly include molybdenum, cobalt, tungsten, cobalt, chromium and alkyl lithium catalytic systems. According to the different arrangement forms of 1,2-structure side groups on both sides of the molecular chain, three kinds of stereopolymer of isotactic, syndiotactic and atactic 1,2-polybutadiene can be generated. Syndiotactic 1,2-polybutadiene has the performance advantages of 1,2-polybutadiene rubber, and also has the characteristics of high modulus and high stiffness. Therefore, it is also one of the three kinds of stereopolymers that are studied more.

[0003] The iron-based catalyst itself is non-toxic, green, environmentally friendly, biocompatible and inexpensive and easy to obtain. Moreover, the iron-based catalyst can be used for polymerization in aliphatic hydrocarbon solvents, without using toxic electron donor reagents such as carbon disulfide and solvents such as dichloromethane and benzene which pollute the environment and are harmful to human health, and has obvious environmental and price advantages compared with the cobalt-based catalyst system. Japan Bridgestone Company has developed an iron-based catalyst using dialkyl phosphite [HP(O)(OR)2] or cyclic phosphite as an electron donor, and a technical scheme for preparing syndiotactic 1,2-polybutadiene using aliphatic hydrocarbon as a solvent (European patents EP0994129A1 and EP0994130A, US patents US627779 and PCT patent WO0149753A1). The dialkyl phosphite is an intermediate for preparing pesticides, and is easy to decompose and release toxic and harmful phosphorus oxide smoke when encountering water, and belongs to the chemical products subject to transportation restrictions. At the same time, the syndiotactic 1,2-polybutadiene thermoplastic elastomer obtained forms a kind of pseudo-gel-like substance, and the anti-aging agent is difficult to uniformly disperse in the polymer, thereby leading to gelation of the polymer.

[0004] In order to solve the problem of gelation, the Chinese patent with publication number CN101434671A discloses the use of iron octoate / diphosphite / trialkyl aluminum system plus 2,6-dihydrocarbyl-4-(dihydrocarbyl aminomethyl) phenol as a catalyst to prepare heat-stable syndiotactic 1,2-polybutadiene thermoplastic elastomer. The polymerization activity of the iron-based catalyst is relatively high, but the melting point of the syndiotactic 1,2-polybutadiene elastomer prepared by the iron-based catalyst is between 150-170℃, and the high melting point will cause problems such as uneven mixing when mixed with other rubbers, and the syndiotactic 1,2-polybutadiene elastomer prepared will also cause the elastomer to gel at high temperatures.

[0005] In view of the above problems, the inventors' team discloses the use of an iron organic compound / azobis nitrile compound / alkyl aluminum / blocking phenol (blocking amine) catalyst system (granted publication number CN114085303B) to solve the problem of easy gelation of iron-based catalysts during polymerization of butadiene, but the 1,2-polybutadiene prepared by this catalyst system still has problems such as large molecular weight, difficult processing, and dark rubber color. SUMMARY

[0006] In view of the problems existing in the prior art, the purpose of the present application is to provide the use of an organic phosphine compound in the preparation of syndiotactic 1,2-polybutadiene by an iron-based catalyst. The iron catalyst is used to introduce an organic phosphine compound electron donor. By adjusting the amount or structure of the organic phosphine compound, the melting point and molecular weight of the syndiotactic 1,2-polybutadiene can be adjusted. A new metal complex is formed by the organic phosphine compound and the active metal center atom. By adjusting the microstructure of the organic phosphine compound, the electron-donating ability to the active metal center is adjusted, thereby obtaining syndiotactic 1,2-polybutadiene with adjustable molecular weight and melting point. The iron catalyst can be used to prepare syndiotactic 1,2-polybutadiene with a melting point range of 60-140℃ at high temperature and high activity without gelation. By effectively adjusting the molecular weight and melting point of the syndiotactic 1,2-polybutadiene, the problems of large molecular weight, difficult processing, and dark rubber color are improved.

[0007] In order to achieve the above-mentioned application purposes, the present application provides the following technical solutions:

[0008] The present application provides the use of an organic phosphine compound in the preparation of syndiotactic 1,2-polybutadiene by an iron-based catalyst. The organic phosphine compound is used to adjust the melting point and molecular weight of the syndiotactic 1,2-polybutadiene. The structural formula of the organic phosphine compound is: PR3 or P(Ph-OR1)3, R is one of C1-C6 alkyl, phenyl, and substituted phenyl, and R1 is one of C1-C6 alkyl, phenyl, and substituted phenyl. 20 20 ​​

[0009] The said syndiotactic 1,2-polybutadiene is a gel-free syndiotactic 1,2-polybutadiene with a weight average molecular weight of 80000-1300000 and a melting point of 60-140℃.

[0010] The preferred organic phosphine compound is selected from one or more of tributylphosphine (TBUP), tri-tert-butylphosphine, trioctylphosphine, triphenylphosphine, tri(2,4-dimethylphenyl)phosphine, tri(p-tolyl)phosphine, tri(4-methoxyphenyl)phosphine, tri-(4-n-butoxyphenyl)phosphine, tri-(4-n-octyloxyphenyl)phosphine, tri-(4-n-dodecyloxyphenyl)phosphine, tri-(4-n-hexadecyloxyphenyl)phosphine, and cyanomethylidene tributylphosphine.

[0011] The present application provides an application of an organic phosphine compound in the preparation of a syndiotactic 1,2-polybutadiene by using an iron-based catalyst, which is an application of an organic phosphine compound in the preparation of a syndiotactic 1,2-polybutadiene by using an iron-based catalyst.

[0012] The said iron-based catalyst comprises an iron-containing organic compound, an azobiscyanophyl compound, and an organic aluminum compound.

[0013] The molar ratio of the iron element in the said iron-containing organic compound, the organic phosphine compound, the azobiscyanophyl compound, and the organic aluminum compound is 1:(0.5-10):(0.5-10):(1-100).

[0014] Preferably, the said iron-containing organic compound is selected from an iron-containing carboxylate and / or an iron-containing complex.

[0015] Preferably, the said iron-containing carboxylate is selected from one or more of iron naphthenate, iron neodecanoate, and iron iso-octoate.

[0016] The said iron-containing complex is iron acetylacetonate.

[0017] Preferably, the said azobiscyanophyl compound is selected from one or more of azobis(isobutyronitrile) (AIBN), azobis(isopentanenitrile), and azobis(isoheptanenitrile) (ABVN).

[0018] Preferably, the said organic aluminum compound is selected from one or more of triethylaluminum (TEA), triisobutylaluminum (TIBA), and diisobutylaluminum hydride (DIBAH).

[0019] The present application also provides an application of an organic phosphine compound in the preparation of a syndiotactic 1,2-polybutadiene by using an iron-based catalyst, which is an application of an organic phosphine compound and an iron-based catalyst in the preparation of a syndiotactic 1,2-polybutadiene, and the specific application process comprises:

[0020] Mixing the organic phosphine compound, the iron-based catalyst, and butadiene to perform a polymerization reaction to obtain the said syndiotactic 1,2-polybutadiene.

[0021] The form of the butadiene is selected from liquid butadiene bulk or butadiene solution;

[0022] The solvent of the butadiene solution is a hydrocarbon organic solvent; as preferred, the mass-volume concentration of the butadiene solution is 8-12 g / 100 ml.

[0023] Preferably, the molar ratio of the iron element in the iron-based catalyst to the butadiene is 1:(1000-100000).

[0024] The polymerization reaction temperature is 30-150℃, and the polymerization reaction time is 10-240 min.

[0025] The present application provides a meso-1,2-polybutadiene molecular weight regulator and a method for preparing meso-1,2-polybutadiene using an iron catalyst system. The iron catalyst system comprises an iron-containing organic compound, an azobiscyan compound and an organic aluminum compound; the molar ratio of the iron element in the iron-containing organic compound, the molecular weight regulator, the azobiscyan compound and the organic aluminum compound is 1:(0.5-10):(0.5-10):(1-1000); and the molecular weight regulator is an organic phosphine compound. The iron-based catalyst of the present application uses a non-toxic iron element as the active component center metal, an azobiscyan compound as a ligand, and an organic aluminum compound as a cocatalyst. By adjusting the structure of the organic phosphine compound and its electron-donating ability to the active metal center atom, the iron-based catalyst can be used to prepare a meso-1,2-polybutadiene elastomer with a melting point of 60-140℃ and adjustable molecular weight at high temperature and high activity. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 DSC graph of meso-1,2-polybutadiene prepared in Examples 4-7;

[0027] Figure 2 GPC graph of meso-1,2-polybutadiene prepared in Examples 4-7. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below with reference to examples.

[0029] The present application provides a meso-1,2-polybutadiene molecular weight regulator, an organic phosphine compound (denoted as A), and a method for preparing meso-1,2-polybutadiene using an iron-based catalyst.

[0030] The iron-based catalyst of the present application comprises an iron-containing organic compound (denoted as B), an azobiscyan compound (denoted as C) and an organic aluminum compound (denoted as D);

[0031] The molar ratio of the iron element in the iron-containing organic compound, the organic phosphine compound, the azobiscyanide compound and the organic aluminum compound is 1: (0.5-10): (0.5-10): (1-1000);

[0032] The organic phosphine compound has a structural formula of PR3 or P(Ph-OR1)3, R is one of C1-C6 alkyl, phenyl and substituted phenyl, R1 is one of C1-C6 alkyl, phenyl and substituted phenyl. 20 20 The organic phosphine compound has a structural formula of PR3 or P(Ph-OR1)3, R is one of C1-C6 alkyl, phenyl and substituted phenyl, R1 is one of C1-C6 alkyl, phenyl and substituted phenyl.

[0033] In the present application, all the components are commercially available products well known to those skilled in the art, unless otherwise specified.

[0034] In the present application, the iron-containing organic compound is preferably selected from iron-containing carboxylate and / or iron-containing complex, the valence of iron in the iron-containing carboxylate is preferably divalent or trivalent; the iron-containing carboxylate is preferably selected from one or more of naphthenic acid iron, neodecanoic acid iron and isooctanoic acid iron; the iron-containing complex is preferably acetylacetone iron; when the iron-containing organic compound is two or more of the above specific selection, the present application does not have any special limitation on the ratio of the above specific substances, and any ratio is acceptable.

[0035] In the present application, the azobiscyanide compound is preferably selected from one or more of AIBN and ABVN; when the azobiscyanide compound is two or more of the above specific selection, the present application does not have any special limitation on the ratio of the above specific substances, and any ratio is acceptable.

[0036] In the present application, the organic aluminum compound is preferably selected from one or more of TEA, TIBA and DIBAH; when the organic aluminum compound is two or more of the above specific selection, the present application does not have any special limitation on the ratio of the above specific substances, and any ratio is acceptable.

[0037] In the present application, the organic phosphine compound is preferably one or more of tributyl phosphine (TBUP), tri-tert-butyl phosphine, trioctyl phosphine, triphenyl phosphine, tri(2,4-dimethylphenyl) phosphine, tri(p-tolyl) phosphine, tri(4-methoxyphenyl) phosphine, tri-(4-n-butoxyphenyl) phosphine, tri-(4-n-octyloxyphenyl) phosphine, tri-(4-n-dodecyloxyphenyl) phosphine, tri-(4-n-hexadecyloxyphenyl) phosphine and cyanomethylene tributyl phosphine; when the organic phosphine compound is two or more of the above specific selection, the present application does not have any special limitation on the ratio of the above specific substances, and any ratio is acceptable.

[0038] ​In the present application, the molar ratio of the iron element in the iron-containing organic compound, the organic phosphine compound, the azobiscyanide compound and the organic aluminum compound is preferably 1:(0.5-10):(0.5-10):(1-100), more preferably 1:(1-8):(1-6):(10-100), and most preferably 1:(3-6):(2-4):(30-60).

[0039] Each component in the catalytic system of the present application is preferably independently packaged before use, and when used, the above-mentioned components are mixed in sequence.

[0040] The present application also provides the use of the organic phosphine compound and the iron-based catalyst as described in the above technical solutions in the field of preparing syndiotactic 1,2-polybutadiene.

[0041] The present application also provides a preparation method of syndiotactic 1,2-polybutadiene, comprising the following steps:

[0042] The molecular weight regulator, the iron-based catalyst and the butadiene are mixed to perform a polymerization reaction to obtain the syndiotactic 1,2-polybutadiene;

[0043] The form of the butadiene is selected from liquid butadiene bulk or butadiene solution;

[0044] The solvent of the butadiene solution is a hydrocarbon organic solvent;

[0045] The molecular weight regulator is the molecular weight regulator as described in the above technical solution.

[0046] In the present application, the form of the butadiene is selected from liquid butadiene bulk or butadiene solution; the solvent of the butadiene solution is preferably a hydrocarbon organic solvent, more preferably an aliphatic hydrocarbon organic solvent or an aromatic hydrocarbon organic solvent; the aliphatic hydrocarbon organic solvent is preferably one or more of hexane, cyclohexane, pentane, heptane and octane; the aromatic hydrocarbon organic solvent is preferably one or more of benzene, toluene and xylene; more preferably hexane or cyclohexane; when the hydrocarbon organic solvent is two or more of the above-mentioned specific choices, the present application does not have any special limitation on the ratio of the above-mentioned specific substances, and any ratio is acceptable.

[0047] In the present application, the ratio of the use amount of butadiene to the hydrocarbon organic solvent in the butadiene solution is preferably 1g:8.4mL.

[0048] In the present application, the mixing is preferably performed in a nitrogen atmosphere.

[0049] In the present application, the molar ratio of iron element in the iron-based catalyst to the butadiene is preferably 1:(1000-100000), more preferably 1:(5000-50000), and most preferably 1:(10000-30000).

[0050] In the present application, the order of mixing is preferably adding the organic phosphine compound A to butadiene, and then adding each component of the iron-based catalyst to the butadiene in any order, more preferably adding A, B, C and D to butadiene in the order of A, B, C and D or B, A, C and D; or mixing two or more components of the catalyst system together in advance, and then adding to the butadiene.

[0051] In the present application, the temperature of the polymerization reaction is preferably 20-150°C, more preferably 20-100°C, and most preferably 50-100°C; and the time is preferably 10-240 min, more preferably 10-160 min, and most preferably 10-120 min.

[0052] After the polymerization reaction is completed, the present application also preferably terminates the reaction by adding an ethanol solution of HCl with a mass concentration of 1%.

[0053] After the termination reaction is completed, the present application also preferably includes filtration and vacuum drying in sequence.

[0054] The present application provides a preparation method of syndiotactic 1,2-polybutadiene, which specifically comprises: under nitrogen protection, adding 40 ml of hexane solution of monomer with a concentration of 8-12 g / 100 ml butadiene to a polymerizer without water and oxygen, and then adding an organic phosphine compound and an iron-based catalyst, wherein the iron-based catalyst comprises the above-mentioned three components of iron-containing organic compound, azobiscyan compound and organic aluminum compound. The molar ratio of the number of moles of monomer butadiene added to the system to the iron content of the catalyst system is 1.0x10 5 ~1x10 3 mol / mol, reacting at 20-100°C for 10-160 min, terminating the reaction with an ethanol solution containing 2,6-di-tert-butyl-p-methylphenol with a mass fraction of 1%, precipitating the polymer in ethanol, washing and extruding, and then vacuum drying to constant weight to obtain polybutadiene.

[0055] In the present application, the syndiotactic 1,2-polybutadiene prepared by the above-mentioned preparation method is preferably used to manufacture shoe soles, tire treads, sponges or foamed treads.

[0056] The catalytic system and its application and the preparation method of syndiotactic 1,2-polybutadiene provided by the present application are described in detail below in conjunction with examples, but they should not be understood as limiting the scope of protection of the present application.

[0057] Note: The gel content in the examples and comparative examples was tested according to the standard of SH / T 1050-2014, and "-" in the table indicates that the test was not performed; [BD] / [Fe] represents the molar ratio of butadiene to iron; [Al] / [Fe] represents the molar ratio of Al and Fe; [P] / [Al] represents the molar ratio of P groups in the organic phosphine compound to Al.

[0058] Examples 1-7

[0059] A butadiene solution containing 40 mL of dry hexane and 4 g of dry butadiene was added to a single-neck reaction flask which had been subjected to an oven drying treatment under a nitrogen atmosphere; then the components of the molecular weight regulator triphenylphosphine, iron acetylacetonate, AIBN and TIBA were added in the amounts shown in Table 1, and after polymerization in a 50°C constant-temperature water bath for 2 hours, the reaction was terminated by adding a 1% mass concentration HCl alcohol solution, the resulting solid product was filtered and vacuum dried at 60°C to constant weight to obtain the 1,2-polybutadiene (the relevant physicochemical parameters of the 1,2-polybutadiene are shown in Table 1);

[0060] Table 1 Raw material usage and physicochemical parameters of syndiotactic 1,2-polybutadiene

[0061]

[0062] Note: [BD] / [Fe] = 20000, [Al] / [Fe] = 25 mol / mol, [AIBN] / [Fe] = 2 mol / mol;

[0063] Figure 1 The DSC graph of the syndiotactic 1,2-polybutadiene described in Examples 4-7 is shown in Figure 1, from which it can be seen that the melting point of the syndiotactic 1,2-polybutadiene shows a decreasing trend; Figure 1

[0064] Figure 2 The GPC spectrum of the syndiotactic 1,2-polybutadiene described in Examples 4-7 is shown in Figure 2, from which it can be seen that the high molecular weight portion of the syndiotactic 1,2-polybutadiene gradually decreases with increasing [P] / [Fe] usage. Figure 2

[0065] Comparative Example 1

[0066] With reference to Examples 1-7, the only difference is that after obtaining the butadiene solution, no organic phosphine compound A is added, but only 0.0037 mmol of iron acetylacetonate, 0.0925 mmol of TIBA and 0.0074 mmol of AIBN are sequentially added, and the mass of the obtained 1,2-polybutadiene is 3.46 g (yield 86.5%, melting point 106.7°C, 1,2-structure content 75.9%, Mw: 137.6 x 10​​4

[0067] Comparing the data of Comparative Example 1 with Examples 1-7, it can be seen that the molecular weight of syndiotactic 1,2-polybutadiene is adjusted by the organic phosphine compound, and the molecular weight of the polymer decreases with the increase of the amount of the organic phosphine compound.

[0068] Example 8

[0069] Referring to Examples 1-7, the difference is that after obtaining the butadiene solution, the amount of the molecular weight adjusting agent triphenylphosphine is 0.0074 mmol, and 0.0037 mmol of iron acetylacetonate, 0.0925 mmol of TEA, and 0.0074 mmol of AIBN are sequentially added, and the mass of the obtained 1,2-polybutadiene is 3.79 g (the yield is 94.8%, the melting point is 122.0°C, the 1,2-structure content is 83.9%, and the weight average molecular weight is 26.3 x 104). 4

[0070] Examples 9-17

[0071] Referring to Example 8, the difference is that the chemical structure of the organic phosphine compound is different, and after obtaining the butadiene solution, 0.0148 mmol of the organic phosphine compound is added, and 0.0074 mmol of iron acetylacetonate, 0.185 mmol of TIBA, and 0.0148 mmol of AIBN are sequentially added. The organic phosphine compounds in Examples 10-18 are shown in Table 2, and the physicochemical parameters of the prepared 1,2-polybutadiene are shown in Table 2:

[0072] Table 2 Amount of raw material and physicochemical parameters of syndiotactic 1,2-polybutadiene

[0073]

[0074] Note: BD] / [Fe] = 5000, [Al] / [Fe] = 25:1, [P] / [Fe] = 2:1 (mol / mol);

[0075] It can be proved by the above examples that by adjusting the structure of the organic phosphine compound, the melting point and the molecular weight of the syndiotactic 1,2-polybutadiene can be adjusted.

[0076] Examples 18-25

[0077] Referring to Examples 1-7, the difference is that the amount of AIBN added after obtaining the butadiene solution is different, and 0.0148 mmol of iron isooctoate, 0.444 mmol of triisobutylaluminum, 0.0296 mmol of tri(p-tolyl)phosphine, and AIBN are sequentially added to obtain the syndiotactic 1,2-polybutadiene. The physicochemical parameters of the syndiotactic 1,2-polybutadiene are shown in Table 3:​​

[0078] Table 3 Raw material amount and physicochemical parameters of syndiotactic 1,2-polybutadiene

[0079]

[0080] Note: [Al] / [Fe]=30:1 (mol / mol), [BD] / [Fe]=5000;

[0081] Examples 26-34

[0082] Reference Examples 1-7, except that the amount of aluminum alkyl added after obtaining the butadiene solution is different, and 0.0148 mmol of iron isopropylate, 0.444 mmol of triethylaluminum, 0.0296 mmol of tributylphosphine and AIBN are sequentially added to obtain the syndiotactic 1,2-polybutadiene; the physicochemical parameters of the syndiotactic 1,2-polybutadiene are shown in Table 3:

[0083] Table 4 Raw material amount and physicochemical parameters of syndiotactic 1,2-polybutadiene

[0084]

[0085]

[0086] Note: [BD] / [Fe]=5000, [P] / [Fe]=2:1 (mol / mol);

[0087] Examples 35-38

[0088] Reference Examples 1-7, except that after obtaining the butadiene solution, 0.0074 mmol of iron neodecanoate, 0.74 mmol of DIBAH, 0.074 mmol of tri(4-methoxyphenyl)phosphine and 0.074 mmol of AIBN are sequentially added, and polymerization is carried out at different constant temperature water bath temperatures to obtain the syndiotactic 1,2-polybutadiene; the physicochemical parameters of the syndiotactic 1,2-polybutadiene are shown in Table 4:

[0089]

[0090] Note: [BD] / [Fe]=10000.

[0091] Example 39

[0092] Reference Examples 1-7 differ in that after obtaining the butadiene solution, 0.00074 mmol of iron isooctoate, 0.074 mmol of TEA, 0.0074 mmol of trioctylphosphine and 0.0074 mmol of ABVN are sequentially added to obtain 0.5 g of the syndiotactic 1,2-polybutadiene (yield of 12.5 wt%, melting point of 86.8°C, 1,2-structure content of 75.4%, crystallinity of 12.7%, weight average molecular weight Mw: 77.6 x 10 4 , gel content of 0).

[0093] Example 40

[0094] Reference Examples 1-7 differ in that after obtaining the butadiene solution, 0.074 mmol of iron isooctoate, 0.74 mmol of TEA, 0.148 mmol of trioctylphosphine and 0.148 mmol of ABVN are sequentially added to obtain 0.5 g of the syndiotactic 1,2-polybutadiene (yield of 92.5 wt%, melting point of 88.9°C, 1,2-structure content of 75.8%, crystallinity of 13.4%, weight average molecular weight Mw: 57.6 x 10 4 , gel content of 0).

[0095] The above only describes the preferred embodiments of the present application, and it should be noted that for those skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. Use of an organic phosphine compound in the preparation of 1,2-polybutadiene with iron-based catalysts, for adjusting the melting point and molecular weight of 1,2-polybutadiene with organic phosphine compound; The organic phosphine compound has a structural formula of PR3 or P(Ph-OR1)3, R is one of C1-C4 alkyl, R1 is one of C1-C4 alkyl, phenyl, and substituted phenyl. 20 The organic phosphine compound has a structural formula of PR3 or P(Ph-OR1)3, R is one of C1-C4 alkyl, R1 is one of C1-C4 alkyl, phenyl, and substituted phenyl. 20 The organic phosphine compound has a structural formula of PR3 or P(Ph-OR1)3, R is one of C1-C4 alkyl, R1 is The iron-based catalysts include an iron-containing organic compound, an azobiscyanophyl compound and an organic aluminum compound; The prepared 1,2-polybutadiene has a weight average molecular weight of 800,000 to 1,300,000 and a melting point of 60 to 140℃, and is a gel-free 1,2-polybutadiene; The molar ratio of the iron element in the iron-containing organic compound, the organic phosphine compound, the azobiscyanophyl compound and the organic aluminum compound is 1:(0.5-10):(0.5-10):(1-100).

2. Use of the organic phosphine compound according to claim 1 in the preparation of 1,2-polybutadiene from an iron-based catalyst, characterized in that, The organic phosphine compound is selected from one or more of tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, tri(4-methoxyphenyl)phosphine, tri(4-n-butoxyphenyl)phosphine, tri(4-n-octyloxyphenyl)phosphine, tri(4-n-dodecyloxyphenyl)phosphine, and tri(4-n-hexadecyloxyphenyl)phosphine.

3. The use of the organic phosphine compound according to claim 1 in the preparation of an iron-based catalyst for the isomerization of 1,2-polybutadiene, characterized in that, The iron-containing organic compound is selected from an iron-containing carboxylate and / or an iron complex; And / or, the azobiscyanophyl compound is selected from one of azobisdiisobutyronitrile, azobisdiisopentyl nitrile, or azobisdiisoheptyl nitrile; And / or, the organic aluminum compound is selected from one or more of triethylaluminum, triisobutylaluminum, diisobutylaluminum hydride.

4. The use of the organophosphorus compound according to claim 3 in the preparation of an iron-based catalyst for the isomerization of 1,2-polybutadiene, characterized in that, The iron-containing carboxylate is selected from one or more of naphthenic acid iron, neodecanoic acid iron and isooctanoic acid iron; The iron complex is acetylacetone iron.

5. The use of the organic phosphine compound according to claim 1 in the preparation of an iron-based catalyst for the polymerization of 1,2-polybutadiene, characterized in that, The organic phosphine compound of claim 2 and the iron-based catalyst of any one of claims 3-4 are used to prepare 1,2-polybutadiene, and the specific process includes: Mixing the organic phosphine compound, the iron-based catalyst and butadiene to perform a polymerization reaction to obtain the 1,2-polybutadiene.

6. The use of the organophosphorus compound according to claim 5 in the preparation of an iron-based catalyst for the isomerization of 1,2-polybutadiene, characterized in that, The form of the butadiene is selected from liquid butadiene bulk or butadiene solution; The solvent of the butadiene solution is a hydrocarbon organic solvent; And / or, the molar ratio of the iron element in the iron-based catalyst to the butadiene is 1:(1000-100000); and / or, the polymerization reaction temperature is 20-150℃, and the polymerization reaction time is 10-240 min.

Images