CS232313B1 - Method of selective polymerization of butadiene feom c4 fraction - Google Patents

Description

(54) A process for the selective polymerization of butadiene from C, fractions

Process for the selective polymerization of butadiene C 1 fraction to homopolymers and copolymers in which the ^ j and ^k on. Init tor ^ ^p ^ s oužije, Compounds of the general formula

CH

R * (CH ₂ CH-) N- (CH ₂ ) _n N (R-CH ₂ -CH (Li) -CH 2 -R '

Li wherein R 1 is iso-4-yl, n-alkyl, cycloalkyl or aryl, R is isoaltyl, n-allyl, cycloalkyl and n is 2 to 16.

Polymers having a predetermined molecular weight in the range of from 1000 to 200,000 and a mitarostructure selectable in a range from a high content of 1.4 structures to a high content of 1.2 structures are obtained. The polymerization takes place in a homogeneous liquid phase, optionally in the presence of a liquid. and polar solvates thereof.

In particular, it relates to a process for the selective polymerization of butadiene from fractions to homopolymers, in particular having functional groups and a predetermined molecular weight in the range from 1000 to 200 000 and having a microstructure ranging from a high content of 1.4 structures to a high content of 1. 2 structures in a homogeneous phase, optionally in the presence of polar solvating agents, and in the presence of initiators in which novel types of initiators are used.

It is known that butadiene can be selectively polymerized using organolithium compounds from fractions containing butadiene. The general principles of anionic polymerization also apply to the polymerization of butadiene, for example, according to Japanese patent 73-42717, butadiene or isoprene from the S- or S- fraction is polymerized by means of buutlituium. Polybutadiene is obtained in 100% yield, having similar properties to polybutadiene, obtained by polymerizing pure butadiene.

According to German Patent No. 2,431,258, polybutadienes are obtained by solution polymerization using organolithium polymerization catalysts of the general formula R-Li _K where R can be alkyl, aryl, such as, for example, starting from a fraction containing butadiene obtained by petroleum cracking or butane dehydrogenation. The high content of structure 1.2 is obtained by adding electron donors, e.g. polar compounds, before or during polymerization.

By co-combining the organo compound with the polar compound, a special catalytic complex is obtained according to this DOS, which reacts to a degree with the δ-hydrocarbons contained in the-fraction as impurities than with butadiene. Therefore, this catalyst is deactivated more slowly than in other cases. Thus, smaller amounts of organlithium compound may be used.

However, it is clear from the examples of this DOS that up to 65% of the used compound is consumed for uptake of impurities and that the conversion of butadiene is only 60%. However, the mono-compound compounds prevent the preparation of polymers having a functional group at each end of the chain. The obtained polymers can in principle be functionalized at only one end of the chain. Synthesis of A-B-A block copolymers is also problematic. It is known that these polymers are prepared by anionic polymerization of functional compounds, mostly dihalic, from pure butadiene and, for example, styrene as a comonomer (Faseforsuhag and Textiltecnik 25 (1974) 5, p. 191; U.S. Pat. NSR-DOS 2,425,924, USSR 296 77 z).

It is also known from other works that polybutadienes and polymers of butadiene and styrene can be prepared from low-butadiene hydrocarbon fractions (R.-J. Soimneneld, Am. Chem. Soc. Polym. Chem., Polymer prep. (1975> 1, pp. 346-350), it is important to remove acetylenes and 1,2-butadiene, and polymers are formed only in systems analogous to those from which polybutadlene is obtained from pure butadiene.

The initiators used include the 1,4-diltujumbutao Japanese patent 70.01629, 70.01628, as well as dilishi adducts to the jugged dienes having 1 to 7 palm units (NSR-PS 1 169 674, NSR-DAS 1 170 645). Multifunctional alkali metal compounds are, however, generally not *

soluble in nonpolar solvents. The addition of more monomers leads in some cases to the formation of living oligomers whose better solubility in the hydrocarbon, while allowing for the polymerization of the newly added monomer in the homogeneous phase, but the formation of polymers with a defined relative molecular size remains problematic. Also, the addition of polar solvents improves the solubility of the initiators in the hydrocarbons. Many initiators can only be prepared in the presence of strongly polar solvents. If the polymerization is carried out with pornography of such initiator solutions containing ether, the efficiency of the initiator by ether cleavage is very easily reduced. Thus, in the known processes, the total or partial replacement of the ether with a non-polar solvent is carried out before the polymerization reaction (U.S. Pat. No. 3,377,404, U.S. Pat. No. 3,388,171, NSR-DAS 1,768,188, NSR-DOS 1,817,479). in hydrocarbons, not even in the present! Even with small amounts of polar solvents, there is no need to worry about the corresponding purity of the side reaction reagents. However, the conditions required to remove the ether often result in partial activation of the initiator and increase operating costs.

A further disadvantage of the known method is that the auto-ignition point of diethyl ether is very low, so that it cannot be used on an industrial scale without risk. It is also known that from pure butadiene they can be prepared by anionic polymerization of three- and multi-functional alkali metal initiators, mostly cast iron compounds, star polymers or end-functional polymers having a functionality greater than 2. (US 3,644,322, 3,652,516, 3,752) 368, 3,734,973, 3,862,251, Germany-DOS 2,003,384, 2,063,642, 2,231,958, US 2,408,969, 2,427,955).

According to this method, the organosilane compounds are reacted with polyvinyl aromatic compounds, such as dlvinylbenzene or diisopropylbenzene, to form a multi-metalated compound, and then used as polymerization initiators. more or less star-branched or cross-linked to one another ^, partially or fully crosslinked products may form within the molecule, which are insoluble and are only conditionally useful for ionic polymerization.

These disadvantages and drawbacks are eliminated or mitigated in processes for the selective polymerization of butadiene from C 2 fractions to homopolymers and copolymers with a predetermined molecular weight ranging from 1,000 to 200,000 and with a microstructure selectable ranging from a high content of 1.4 structures to a high content of 1.2 structures, in a homogeneous phase, optionally in the presence of polar polarizing agents, and in the presence of the initiators according to the invention, characterized in that compounds of the general composition are used as initiators

R 'R *

I I

N - (CH ₂ ) n - N __I I CH ₂ <^ '''·<ΌΗ CH ₂ - CH (Li) - 0¾ - R

L 1 where R is L 2 -U 4, L, n-alkyl, cycloalkyl or aryl of 2 to 8 carbon atoms, R 3 is isoalkyl, n-alkyl or cycloalkyl of 3 to 20 carbon atoms, and n is 2 to 6.

The polymerization is preferably carried out in the liquid phase and at a temperature of 263 to 373 K, preferably 303 to 333 K. The polymerization reaction is terminated after 10 minutes to 6 hours, preferably 0.5 to 3 hours.

This results in live homopolymers which do not contain any homogeneous polymers. gel having a low content of vinyl groups, which can be further enriched in vinyl groups by copolymerization with styrene, alpha-methylstyrene, and the like, and the like. so that A-B-A block copolymers are formed. . ,

Statistical copolymers are obtained with the simultaneous addition of C. fraction and vinyl monomers. The homo-polymers may be liquid to solid, depending on the mole ratio of initiator used, and the polymer's low molecular weight may be adjusted to between 5,000 and 200,000 g / mol. By adding water or alcohol, the Li-C linkages of living polymers are reduced and non-functional polymers are obtained. By treating the polymers with ethylene oxide, butyrolactone, carbon dioxide and the like, polymers containing groups (-OH, -COOH, etc.) are obtained at the end of the chains. converted to densely crosslinked polymers.

The stoichiometrically calculated and osmomeerically measured molecular weights as well as the calculated and measured functionalities of the liquid polymers coincide well with each other.

232313 4

The polymerization of butadiene in the liquid C- fraction does not require the addition of additional solvents, as the other C4 components act as a diluent ·

The mitoostructure of the polymers can be varied within wide limits · if the polymerization is carried out in non-polar solvents, butadiene polymers with a structure of 1.4 highly above 70% are obtained · if polar solvents such as diethyl ether, tetrahydrofuran and the like are formed before polymerization high in structure 1.2.

An advantage of the process according to the invention is that it is possible to polymerize butadiene from C4 fractions directly without prior isolation. The initiator bifunctionality allows the preparation of bifunctional living polymers which can be further processed to A-B-A copolymers or polymers with terminal functional groups. The milnrostructure of the polymer can be appropriately changed by changing the polymerization conditions.

The corresponding initiators were obtained by treating the corresponding diamine with an alkyllithium, in particular with lithium or butyl lithium at normal or slightly elevated temperature for 1 to 5 hours.

Example!

To 50 mmol of the iso-C ^Hg 130-04 ^ initiator,

- (CH ₂ ) ₂ -N

CH 2 -CH (LQ-C 1 -iso 4 Hg.

Li dissolved in 250 ml of benzene at 313 K was added 220 ml of C4 fraction containing 980 moles of butadiene 1,3. The polymerization in the glass autoclave was terminated after 2 hours by quenching the reaction by precipitation with methanol, after which the remaining C4 fraction was distilled off. butadiene-free. An easily flowing polymer was obtained in which the molecular weight f-1-400 was determined to be eight-dimeric compared to the calculated value. 1 058 · The calculations of the moleocular polymer content in all examples were carried out without taking into account the diamine incorporates into the polymer and in the functionalization of the polymer regardless of the increase in molecular weight by incorporating a focalcitizing agent

The microstructure was 28 '. % 1.4 cis, 47% 1.4 trans and 25% 1.2 · Polymer yield of tulle - 95% theoretical limit

Example 2

Example 1 was repeated except that a 5 mmmL initiator solution in 50 ml benzene was used. 48 g of a polymer having an average molecular weight of 11,000x were obtained compared to the calculated value of 10,534.

The polymer microstructure was 27% 1.4 cis, 47% 1.4 traos and 26% 1.2.

Example 3

Example 1 was repeated except that after 2 hours of polymerization, the solution was cooled to 268 K and 220 mmol of gamm-buyrolactons were added with stirring. The solution solidified and the syrup-like reddish-brown gel was cooled to room temperature with stirring. se C4 fraction not packedUni buladien ·

Example 4

Example 3 was repeated except that a solution of 25 mmol of initiator in 125 ml of benzene was used and the polymerization was continued for 2.5 h, after which the solution was cooled to 268 K and 105 mmol of ethylene oxide were added with stirring. The solution solidified to a white solid gel, which could be mixed into a bulk. After working up the reaction mixture analogously to Example 3, a polymer having an average molecular weight M ₂₆₀₀ was obtained as compared to a calculated value of ₂₁₁₇ and a functionality of 2.0. The yield was 95% of theory. The microstructure was similar to Example 3 ·

Example 5

Example 4 was repeated except that an initiator was used in which R was n-C ^H H. He obtained a liquid polymer having the same properties as in Example 4.

Example 6

The polymerization of Example 4 was repeated except that 50 mmol of the initiator dissolved in 250 ml / benzene were used and that the fraction was added at 293 K. The polymerization was carried out for 4 h. An easily flowable medium molecular weight polymer was obtained.

600 and calculated 1,058. Functionality was 2.1, infrared spectrometry showed a microstructure of 29% 1.4 cis, 47% 1.4 trans and 24% 1.2 PB. The yield was 95% of theory.

Example 7

5 mmol of the initiator of Example 1 in 60 ml of benzene at 323 K were added with stirring 35 g of butadiene in 145 ml of fraction and 15 g of styrene. The homogeneous solution was stirred for 4 h and methanol was precipitated after distilling off the residue of the butadiene-free fraction. A statistical copolymer with a 33% styrene content was formed. The polybutadiene moiety had 72% 1.4 and 28% 1.2 structures. .

Example 8

3 mmol of the initiator according to Example 1 in 300 ml of pure benzene were added at 333 K 35 g of butadiene 1.3 in 145 ml of the fraction and the polymerization was continued for 3 hours. 15 g of styrene were then added and polymerized for another 5 hours. as in Example 7, 48 g of ABA block copolymer with a styrene content of 32.3% and a polybutadiene structure of 72% 1.4 and 28% 1.2 were obtained.

Example 9

To 50 mmol of the initiator of Example 1 in 120 ml of benzene was added 200 ml of cold tetrahydrofuran and the temperature was lowered to 263 K. Then 980 mmol of butadiene 1.3 contained in 220 ml of the fraction were added and polymerized for 2 hours. precipitated in methanol and the remaining fraction was distilled off. This resulted in a liquid product with an average molecular weight of 1,400 and calculated 1,058, which had a microstructure of 88% 1.2 and 12% 1.4 trans. The yield was 96% of theory.

Examples 10-14

Example 4 was repeated except that an initiator where *

a) R was п-СдН ^, R * was iso ΟθΗ ^? and W was 3

b) R was C ₁₂ H ₂₅ , R 1 was C ₉ and n was 2

c) R was cyclo C ₆ H _H R was N-СдН an bylo2

d) R was iso СдН ₉ , R * was п-СдН ₉ and n was 6

e) R was iso C ₄ H ₉ , R ₄ was C ₈ H ₉ (phenylene was 4

2323136

Polymers having the following properties were obtained:

N calculated M _n measured Structure 1,4 cis% 1,4 trans% 1.2% Yield and) 1 150 2 500 27 Mar: 47 26 95 (b) 1 200 1 300 28 47 25 94 C) 1 105 1 500 27 Mar: 47 26 95 (d) 2 150 4 000 27 Mar: 47 26 96 E) 1 113 1 800 25 47 28 96

Claims (3)

OBJECT OF THE INVENTION .A CLAIMS 1. A process for the selective polymerization of butadiene from fractions to homomers and copolymers, having a predetermined moocular tannonicity in the range of 1,000 to 200,000 and a microstructure selectable ranging from a high 1.4 structure content to a high 1.2 structure content. a homogeneous phase, optionally in the presence of three polar solvating agents and in the presence of dilitbo initiators, characterized in that compounds of general composition are used as initiators R 'R' » ^- (сн ₂ ) _а -» ^ c. I | CH £ /. 'CH CH ₂ -CH (LiJcCH-CR Li wherein R is isoalkyl, n-alkyl, cycloalkyl or aryl of 2 to 8 carbon atoms, R 'is isoalkyl, n-alkyl or cycloalkyl of 3 to 20 carbon atoms and n is 2 to 6. 2. Process according to claim 1, characterized in that the polymerization is carried out in the liquid phase. 3. The process of claim 1 wherein the polymerization is carried out at a temperature of from 263 to 373 H.