RU2538956C1 - Method of producing hydrogenated 1,2-polybutadienes - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: disclosed is a method of producing hydrogenated 1,2-polybutadienes, which comprises reacting a polymer with a hydrogenating agent, characterised by that the hydrogenation step is preceded by aluminising 1,2-polybutadiene, where the aluminising agent used is a mixture of diisobutylaluminium hydride in the presence of ZrCl₄ in molar ratio of 1,2-polybutadiene:diisobutylaluminium hydride=1:0.2-4; 1.2-polybutadiene:ZrCl₄=1:0.01-0.02; at 10-55°C for 12-26 hours, followed by hydrogenation of the aluminium derivative of 1,2-polybutadiene with a hydrogenating agent in the form of 5% hydrogen chloride solution; hydrogenation is carried out at room temperature without a catalyst for 2 hours. Atactic or syndiotactic 1,2-polybutadiene with number-average molecular weight Mn of 1000 to 150000 and content of 1,2-polymerisation links in macromolecules of 70-85 mol% is used.

EFFECT: improved quality of the end product, excluding explosive and fire hazardous substances from the process of producing hydrogenated 1,2-polybutadiene.

2 cl, 1 tbl, 18 ex

Description

The invention relates to the field of macromolecular compounds, in particular to the production of polymer products based on 1,2-polybutadiene containing hydrogenated groups in macromolecules.

Hydrogenated polymer products are characterized by a high range of physicomechanical properties, good adhesive properties and can be used in adhesive compositions, sealants, paints, and as modifiers in various compositions of thermoplastics and elastomers.

Hydrogenated 1,2-polybutadiene can be obtained by chemical modification of 1,2-polybutadiene containing double carbon-carbon bonds in macromolecules of the main and side chains, which are synthesized in industry by polymerization of 1,3-butadiene on complex catalysts [RF Patent 2072362, cl. C08F 136/06, C08F 36/06, C08F 136/00, C08F 36/00; publ. 01/27/1997. RF patent 2177008, cl. C08F 136/06, C08F 36/06, C08F 36/04, C08F 4/70; publ. 12/20/2001. RF patent 2283850, cl. C08F 36/06, C08F 136/06; publ. 09/20/2006. U.S. Patent 4,182,813, CL C08F 136/06, C08F 36/00, C08F 4/00; publ. 01/08/1980. RF patent 2139299, cl. C08F 136/06; publ. 10/10/1999].

Known methods for producing hydrogenated derivatives of 1,2-polybutadiene, with hydrogen gas in the presence of metal complexes: US patent 7176262, CL. C08C 19/02; B60C 1/00; C08F 8/04; C08C 19/00; B60C 1/00; C08F 8/00; publ. 02/13/2007, US patent 5206301, class. C08L 23/02; C08F 8/04; C08F 8/46; C08F 2 97/04; C08L 53/00; C08L 53/02; C08L 101/00; publ. 03/27/1993, patent Europe 19800104471, cl. C08F 8/00; C08C 19/02; C08F 8/04; C08F 8/00; C08C 19/00; publ. 09/26/1984, US patent 5945485, class. C08C 19/02; C08F 8/04; C08F 36/00; C08F 36/04; C08F 136/06; C08F 297/02; C08F 297/04; C08L 53/00; C10M 143/12; publ. 08/31/1999. The disadvantage of these methods is the high energy costs, due to the need to carry out the process at high pressure and at elevated temperature. Use of fire and explosion hazard hydrogen.

Closest to the invention in technical essence and the achieved effect is a method of hydrogenation of 1,2-polybutadiene, which consists in the interaction of a solution of 1,2-polybutadiene in cyclohexane with hydrogen in the presence of a titanium catalyst [US Patent 7960481, cl. C08F 8/04; C08C 19/02; publ. 06/14/2011]. Used polybutadiene with a molecular weight of 1000 g / mol, containing 85% of 1,2-units, 15% of 1,4-units of polymerization. Polybutadiene, bis (η ⁵ -cyclopentadienyl) titanium di-n-toluyl in cyclohexane are placed in a reactor equipped with a mechanical stirrer. The molar ratio of polymer: bis (η ⁵ -cyclopentadienyl) titanium di-n-toluyl 1: 0.014. The reaction was carried out at 60-90 ° C and a pressure of 0.7 MPa. At the end of the synthesis, the organic phase was separated and washed twice with water. The polymer was dried in vacuo. The degree of hydrogenation of 1,2-polybutadiene is> 95%.

The disadvantages of this method are the high energy costs, due to the need for the process at high pressure. Use of fire and explosion hazard hydrogen.

The technical task of this invention is to develop a method for producing hydrogenated 1,2-polybutadiene, which improves the quality of the target product, reduces energy costs, eliminates fire and explosion hazard substances from the process of producing hydrogenated 1,2-polybutadiene.

In the proposed method for producing hydrogenated 1,2-polybutadiene, the specified technical problem is achieved by interacting the polymer with a hydrogenating agent, where, in addition to the hydrogenation step, 1,2-polybutadiene is aluminized, where a mixture of diisobutylaluminum hydride is used in the presence of ZrCl ₄ in a molar ratio of 1 , 2-polybutadiene: diisobutylaluminum hydride = 1: 0.2-4; 1,2-polybutadiene: ZrCl ₄ = 1: 0.01-0.02; at a temperature of 10-55 ° C for 12-26 h, hydrogenation of the aluminum derivative 1,2-polybutadiene is carried out by the action of a hydrogenating agent, which is used as a 5% solution of hydrogen chloride, hydrogenation is carried out at room temperature in the absence of a catalyst for 2 hours As the starting 1,2-polybutadiene, an atactic or syndiotactic polymer with a number average molecular weight M _n from 1000 to 150,000 and a content of 1,2- and 1,4-polymerization units of 70-85 mol% and 15-30 mol in the macromolecules is used .%, respectively.

When implementing the proposed method used industrial samples of 1,2-polybutadiene produced by JSC "Efremovskiy Zavod SK" and polymers of the brand JSR RB manufactured by "Japan Synthetic Rubber Co." (Japan). A 1,2-polybutadiene sample was purified by reprecipitation in the chloroform-ethanol system, then the polymer was washed twice with alcohol and dried under vacuum at 60 ° C to constant weight. DIBAG (Aidrich), ZrCl ₄ (Aidrich) were used as starting components.

The invention is illustrated by the following examples.

Example 1. Used purified syndiotactic 1,2-polybutadiene with a number average molecular weight M _n = 150,000, containing 1,2- and 1,4-polymerization units of 86 and 14 mol%, respectively. 3 g (0.056 mol) of syndiotactic 1,2-polybutadiene were loaded into a glass reactor equipped with a stirrer, reflux condenser and dropping funnel, 114.3 ml of toluene was added and mixed until completely dissolved. 12.77 g of DIBAG (0.112 mol) and 0.235 g of ZrCl ₄ (0.799 mmol) were added to the resulting solution. The molar ratio of syndiotactic 1,2-polybutadiene: DIBAG = 1: 2; syndiotactic 1,2-polybutadiene: ZrCU = 1: 0.015. The reaction mass was stirred in an inert atmosphere at room temperature for 20 hours. After completion of the synthesis, the reaction mass was treated with a 5% solution of hydrogen chloride. The polymer was precipitated from the reaction mixture with ethanol, purified by reprecipitation in the chloroform-ethanol system, and dried in vacuum at 40 ° C. Received 3.89 g of hydrogenated syndiotactic 1,2-polybutadiene with a degree of functionalization of 76.8%.

Example 2. Used purified 1,2-polybutadiene with a number average molecular weight M _n = 82000, containing 1,2- and 1,4-polymerization units of 59 and 41 mol%, respectively. 3 g (0.056 mol) of 1,2-polybutadiene were charged into a glass reactor equipped with a stirrer, reflux condenser and dropping funnel, 114.3 ml of toluene was added and mixed until completely dissolved. 12.77 g of DIBAG (0.112 mol) and 0.235 g of ZrCl ₄ (0.799 mmol) were added to the resulting solution. The molar ratio of 1,2-polybutadiene: DIBAG = 1: 2; 1,2-polybutadiene: ZrCl ₄ = 1: 0.015. The reaction mass was stirred in an inert atmosphere at room temperature for 14 hours. After completion of the synthesis, the reaction mass was treated with a 5% solution of hydrogen chloride. The polymer was precipitated from the reaction mixture with ethanol, purified by reprecipitation in the chloroform-ethanol system, and dried in vacuum at 40 ° C. Received 3.22 g of hydrogenated 1,2-polybutadiene with a degree of functionalization of 67.5%.

Examples 3-18. All process operations were carried out in accordance with example 1-2. The experimental results are shown in table 1.

For the hydrogenation process, the molar ratio of 1,2-polybutadiene: DIBAG 1: 0.2-4 is the most optimal. With a decrease in the molar ratio of 1,2-polybutadiene: TEA below 1: 0.2, a decrease in the degree of hydrogenation takes place (Example 3). With an increase in the molar ratio of 1,2-polybutadiene: DIBAG above 1: 4 leads to inappropriate consumption of DIBAG (example 6). The molar ratio of 1,2-polybutadiene: ZrCL ₄ 1: 0.01-0.02 is the most optimal. With a decrease in the molar ratio of 1,2-polybutadiene: ZrCl ₄ 1: 0.01, a decrease in the degree of hydrogenation takes place (Example 7). With an increase in the molar ratio of 1,2-polybutadiene: ZrCl ₄ 1: 0.02, side reactions of rearrangement of the polydiene macrochain are observed (Example 10). The process temperature in the range of 10-55 ° C allows to obtain a modified product with the highest yield and high quality. A decrease in temperature below 10 ° C reduces the hydrogenation rate and leads to a decrease in the yield of the target product (example 11). An increase in temperature above 55 ° C leads to a deterioration in the quality of the target product (example 14). The aluminization time for all experiments is 12-26 hours. Reducing the reaction time below 12 hours leads to a decrease in the degree of hydrogenation of the final product (Example 14). An increase in the reaction time of more than 26 hours leads to an increase in the energy intensity of the process (Example 18).

In the proposed method for producing hydrogenated 1,2-polybutadiene, the indicated technical problem is achieved by hydrogenation of intermediate aluminum derivatives of 1,2-polybutadiene with a 5% solution of hydrogen chloride. As an aluminizing agent, a DIBAG mixture in the presence of ZrCl _{4 is used} . The aluminization process is carried out at a temperature of 10-55 ° C for 12-26 hours, thereby reducing energy costs and increasing the degree of functionalization of the final product.

Thus, the proposed method makes it possible to purposefully obtain polymer products containing hydrogenated groups based on 1,2-polybutadiene with a given degree of functionalization (content of hydrogenated groups) from 16.0 to 96.8%, molecular weight 1000-150000 and content in macromolecules of 1,2-polymerization units 70-85 mol.% depending on the requirements for the polymer.

Table 1 The results of experiments on the synthesis of hydrogenated polybutadiene No. 1,2-PB Process conditions Note m.s. 1,2-PB: DIBAG m.s. 1,2-PB: ZrCl ₄ t, ° C τ _reag , h α,% one but. 1: 2 1: 0.015 25 twenty 76.8 2 from. 1: 2 1: 0.015 25 twenty 67.5 3 A., p. 1: 0.1 1: 0.015 25 twenty 16,0 Declining SG four A., p. 1: 0.2 1: 0.015 25 twenty 38,2 5 A., p. 1: 4 1: 0.015 25 twenty 93.7 6 A., p. 1: 4.1 1: 0.015 25 twenty 96.8 7 A., p. 1: 2 1: 0.005 25 twenty 23,4 Declining SG 8 A., p. 1: 2 1: 0.01 25 twenty 68.6 9 A., p. 1: 2 1: 0.02 25 twenty 69.7 10 A., p. 1: 2 1: 0,025 25 twenty 73.9 Side RI eleven A., p. 1: 2 1: 0.015 5 twenty 37,2 Declining SG 12 A., p. 1: 2 1: 0.015 10 twenty 80.9 13 A., p. 1: 2 1: 0.015 55 twenty 64.6 fourteen A., p. 1: 2 1: 0.015 60 twenty 21.1 Side RI fifteen A., p. 1: 2 1: 0.015 25 10 34.2 Declining SG 16 A., p. 1: 2 1: 0.015 25 12 61.5 17 A., p. 1: 2 1: 0.015 25 26 70.3 eighteen A., p. 1: 2 1: 0.015 25 28 85.9 but. Atactic 1,2-polybutadiene C. - syndiotactic 1,2-polybutadiene τ _reag - the duration of the aluminization reaction

Claims (2)

1. The method of producing hydrogenated 1,2-polybutadiene, which consists in the interaction of the polymer with a hydrogenating agent, characterized in that in addition to the hydrogenation step, aluminization of 1,2-polybutadiene is carried out, where a mixture of diisobutylaluminum hydride in the presence of ZrCl ₄ in a molar ratio is used as an aluminizing agent 1,2-polybutadiene: diisobutylaluminum hydride = 1: 0.2-4; 1,2-polybutadiene: ZrCl ₄ = 1: 0.01-0.02; at a temperature of 10-55 ° C for 12-26 h, then the hydrogenation of the aluminum-derivative 1,2-polybutadiene is carried out by the action of a hydrogenating agent, which is used as a 5% solution of hydrogen chloride, hydrogenation is carried out at room temperature in the absence of a catalyst for 2 hours 2. The method according to claim 1, characterized in that atactic or syndiotactic 1,2-polybutadiene is used with a number average molecular weight M _n from 1000 to 150,000 and a content of 1,2-polymerization units of 70-85 mol% in the macromolecules.