DD229138A1 - PROCESS FOR SELECTIVE BUTADIAL POLYMERIZATION FROM C LOW 4 FRACTIONS - Google Patents

Abstract

The invention relates to a process for the polymerization of 1,3-butadiene using the obtained in the Erdoelpyrolysis C4 fraction by means of stable Multilithiumtrialkylethylenediamine, wherein the polymerization in hydrocarbons selectively without prior separation of the other non-acidic constituents of the purified C4 fraction and without their incorporation into the polymer takes place. With the addition of suitable anionically polymerizable monomers, linear or star-shaped copolymers can be prepared. In all polymerizations, the molecular weights are specifically adjustable; By adding suitable agents, multifunctional polymers can be prepared.

Description

Title of the invention

Process for selective butadiene polymerization from G, fractions

Field of application of the invention

The invention "relates to an economical process for the selective polymerization of 1,3-butadiene from G. fractions, especially from obtained in the petroleum pyrolysis unseparated 01efingemischen, wherein a separation of the 1,3-butadiene before the polymerization is omitted and the 1.3 Furthermore, the invention relates to an economical possibility for the preparation of butadiene polymers of the type Β- £ A) and of copolymers with random monomer distribution.

Characteristic of the known technical solutions

It is known that 1,3-butadiene can be selectively polymerized by means of organolithium compounds from butadiene-containing G. fractions. The general relationships found in anionic polymerization can also be seen in butadiene polymerization from C. fractions, e.g. For example, the product obtained from a 1,3-butadiene or isoprene-containing G or C, fraction by treatment with butyl lithium has properties similar to those of a polymer prepared by using pure 1,3-butadiene or isoprene (Japanese Patent Provisional Publication No. Hei 342 717).

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According to DS-OS 2,431,258, polybutadienes can be prepared by solution polymerization by means of LitMumorganoverbindungen (R-Li (H = alkyl, aryl), for example n-butyllithium, from a butadiene-containing C.-stream, the cracking of petroleum and / or by dehydration of a However, the process has the disadvantage that up to 65 % of the lithium organo compound used is needed to trap the impurities and the butadiene conversion is only $ 60.

It is also disadvantageous that in principle only monofunctional products can be obtained. Furthermore, the preparation of block polymers of the type ABA, for which bifunctional initiators are necessary in the Hegel, is problematic (Faserforschung und Textiltechnik 25 (1974) 5, 3.191 | TTS-PS 3 135 716, BS-OS 2 425 924, STI-PS 296 775). Hydrocarbon streams of low butadiene concentration can be used to prepare polybutadienes and butadiene / styrene copolymers whose properties are similar to those of products obtained from hacksteadadiene, if the system has previously been purified of acetylenes and allenes (Am. Chem. Soc., Pol., Prep. 1, p. 346). In the case of polymerization with lithium alkylene E-Li, especially when E is a long hydrocarbon radical, polymer products having a high 1,4-structure content are obtained in non-polar solvents, but are functionalizable only at one end of the chain (J. Pol., Sci. 41 (1959 ), P. 381).

The particular interest in the synthesis of lithium organoinitiators for the preparation of nearly monodisperse elastomeric bifunctional polydienes has been reported in Macromol. 12 (1979), p. 344; U.S. Patent 3,135,716; DE-OS 2 425 924 | SU-PS 296 775 justified. Common initiators are dilithium adducts of dienes having 1-7 diene units (DE-PS 1 169 674, DE-AS 1 170 645) and 1,4-dilithium butane (JP-PS 7 229 196 * JP-PS 7 001 629; PS 7 001 628, JP-PS 7 001 627), which has also been described in an unsymmetrical high-boiling ether as a solvent as a selective polymerization onsinitiator (DD-PS 160 062).

Most bifunctional dialkali initiators are not or only slightly soluble in hydrocarbons, but especially in gasoline fractions, but this is necessary to prepare diene polymers having low molecular weights (10,000 - 5,000 g / mol), narrow molecular weight distribution and high 1,4-structure content. Attempts to solubilize initiators by adding initially small amounts of monomers, which are intended to cause the formation of living oligomers, often appear problematic and not always promising (DE-OS 2,634,391). The majority of bifunctional dilithium initiators can only be prepared in the presence of polar solvents (US Pat. No. 3,668,263, US Pat. No. 4,039,593). In such e.g. Ether-containing initiator solutions occur very easily lifting reactions, such as chain termination, chain transfer, ether cleavage u.a. on, which is associated with a decrease in the content of active Li-C bonds in the polymer solution, loss of functionality and an increase in the 1,2-structure content of the polymer product. In the removal of the ether vor.der polymerization, which was proposed in US-PS 3,377,404} US-PS 3,388,171 and DE-AS 1,768,188, in addition to increased operating costs additional deactivations of the initiator by the necessary manipulations are recorded ,

In DD-PS 154 981 and 154 982 and DE-OS 31 01 229 it has been proposed to polymerize 1,3-butadiene from technical C. mixtures by means of special Dilithiumditertiärdiamine or Dilithiumdiamide which are soluble in nonpolar solvents. With these initiators, however, only bifunctional polymers and linear homo- and copolymers can be represented. The synthesis of polymers with functionalities greater than 2 and of star-shaped polymers is not possible.

Object of the invention

The aim of the invention is to eliminate the brook parts of the known methods, i. 1,3-butadiene selectively from undissolved, freed from H-acid compounds O. fractions, which occur in particular in petroleum pyrolysis to polymerize j by admixture of other anionically polymerizable monomers to the C. fraction are also linear or star-shaped butadiene block copolymers of Type B- £ A) (x = 2 to 4) and / or Butadieneopolymere arise with statistical monomer distribution.

The molecular weight of the homopolymers and oopolymers should be adjustable in all desired ranges; it should be possible to prepare polydienes having an optional high 1,4- or 1,2-structural proportion. Likewise, the synthesis of end-capping butadiene homopolymers and copolymers by reaction with special functionalizing agents should be possible, the functionality being 2 to 4.

Explanation of the essence of the invention

The invention has for its object to develop an economical process for the selective butadiene homo- and copolymerization of fractions 0 by means of lithium initiators, wherein the disadvantages of the known methods are eliminated and the above requirements are ensured. The object is achieved in that 1,3-butadiene from a butadiene-containing G. fraction with the aid of special compounds containing 2 to 4 Idthiumatome in the molecule and the structure

₁ - or R ₁ R ₅ CH-C (Li) R ₁ -CHR ₁ - or

= CS _T -CHR-i R ₁ = H, n-alkyl, i-alkyl, oxyl.-alkyl, arylalkyl, aryl radical R, = n-alkyl, i-alkyl, cyclic alkyl , Arylalkyl, aryl; η = 2 to 6), is polymerized.

These initiators are reaction products of triallyl alkyl endi amine of the type

S 'R

(R - CHR ₁ = CR ₁ -OHR ₁ -JR ₁ = H, n-alkyl, i-alkyl, cyclic alkyl, arylalkyl, aryl radical $ η = 2 to 6)

with a Monolithiumorganyl R ^ -Li in an aliphatic, cycloaliphatic ^ olefinic or aromatic hydrocarbon or in a mixture thereof. The polymerization is carried out in a known manner with the addition of the C.-preach to the initiator solution at temperatures between 283 and 353 E, usually between 303 and 333 pounds and is completed after tO min to 6 h, usually after 0.5 to 3 h. As a result of the polymerization, living homopolymers formed by adding other anionically polymerizable monomers, especially vinylaromatic compounds, into living block copolymers of type B ~ £ A) (x = 2 to 4) and / or statistical copolymers can be converted

The polymerization is possible in the pure C 1 - fraction, the non-polymerisable components of this fraction acting as a diluent. Preferably, the polymerization takes place in the non-polar medium; With the addition of polar solvents, the proportion of units carrying vinyl groups in the polymer product increases considerably The selective process makes it unnecessary to remove the butadiene before the polymerization According to the invention, homo- and copolymers with low mimetics (eg 5.10 g / mol) and higher molecular weights (eg · 5.10 g / mol) are shown, wherein the desired ranges are adjustable.

The process is characterized by the fact that the conversion of the living polymers with functionalizing agents such as ethylene oxide, gamma-butyrolactone, carbonyl compounds and similar compounds leads to polymers which carry functional groups at the chain ends, which crosslink with corresponding polyfunctional reagents to give high polymers enable.

The examples given are intended to illustrate the process of the invention without limiting it in any way.

Example of Example Example 1

50 mmol of triallylethylenediamine (TRIAED) in 50 ml of benzene are formed with 205 mmol of i-butyllithium in 250 ml of benzene in a 1 l glass autoclave in 3 h at 343 K to a tetralithium initiator, lach cooling of the partially heterogeneous system to 313 E 183 C. C. fraction containing 926 mmol of 1,3-butadiene added; the polymerization is complete after two hours. It is then cooled to 268 TL and 410 mmol of ethylene oxide are added with stirring. The reaction mixture solidifies to a white solid gel, which can be stirred like a sand, after it was brought to room temperature with stirring and the butadiene-free C. fraction was removed, hydrolyzed the gel with 30 ml of water and separates the benzenic phase by centrifugation. After drying on a vacuum rotary evaporator, a low-viscosity polymer results with the following data «

^M over ^{1) = 100} ° ^M n ⁼ " ^{4 J = 3} ' ⁵

Yield: 97 ^

Microstructure: 25.6 $ 1.4-eis, 46.9 i ° 1.4-trans,

27.5 & 1,2-polybutadiene

1) In all examples, the molar mass of the initiator was not included in the calculation of the molar mass.

Example 2

From 5 mmol of TRIAED in 20 ml of benzene and 21 mmol of i-butyllithium in 20 ml of benzene is formed as in 1) the tetralithium and 313 E in a known VTeise with 183 ml C.Fraktion containing 926 mmol of 1,3-butadiene, reacted, laughing for 2 h, the polymerization is complete and the reaction is stopped by precipitation in methanol, after the butadiene-free G. fraction was distilled off. The result is a polymer of average molecular weights 11200 (M = 10000) and a microstructure analog 1). The yield was $ 93 d. Th.

Example 3

50 mmol of THIAED in 100 ml of benzene are formed with 155 mmol of i-butyl lithium in 150 ml of benzene as in 1) to give a trilithium initiator. The polymerization is carried out after addition of 183 ml.C. fraction containing 926 mmol of 1,3-butadiene, at 313 E. Uach 2 h is cooled to 268 K and functionalized with 300 mmol gamma-butyrolactone with stirring. The solution solidifies into a syrupy gel. After distilling off the butadiene-free C. Fraction, the work-up is carried out as described under 1); The result is a liquid polymer of average molecular weight M _n = 1550 (M ₁₃₆₂ , = 1000) with a functionality F = 2.5 and the following microstructure:

26.3 # 1,4-cis, 42.3 # 1,4-trans, 31,4 & 1,2-polybutadiene The yield was 96 fo d. Th

Example 4

50 mmol of TSIAED in 50 ml of benzene are formed with 205 mmol of i-butyllithium in 200 ml of benzene as in 1) to give the tetralithium initiator. At 313 K, 926 mmol of 1,3-butadiene, contained in 183 ml of C. fraction, are polymerized. awake

two-hour polymerization is cooled to 268 K and functionalized with acetaldehyde. From the resulting Idthiumalkoholatverbindung the OH groups are released by hydrolysis.

Example 5

From 50 mmol of TRIAED in 50 ml of benzene and 205 mmol of n-butyllithium in 150 ml of benzene, a tetralithium initiator is formed as described under 1). At 313 K, polymerization occurs after addition of 926 mmol of 1,3-butadiene contained in 183 ml of C.-Iraction. Hach 2 h is cooled to 268 Z and functionalized with 410 mmol of ethylene oxide, resulting in a white solid gel. Hach workup in a known manner to obtain a product having the same properties as that described under 1).

Example 6

50 mmol of TEIABD in 20 ml of benzene are reacted with 105 mmol of i-butyllithium in 70 ml of benzene analogously to 1) to form a bilithium initiator. It is then cooled to 283 ° and 200 ml of cold tetrahydrofuran, then 926 mmol of 1,3-butadiene, contained in 183 ml of C, to -raction, and polymerized for 2 h. The polymer is precipitated in methanol after distilling off the butadiene-free C-fraction. Bs results in a polymer with an average molecular weight of 1900 (K = 1000) and a microstructure characterized by 87 $ 1> 2 and 13 i ° 1,4-trans proportions. The yield is 94 i> d. OJH.

Example 7

From 5 mmol of TEIASD in 50 ml of benzene and 20.5 mmol of i-butyllithium in 20 ml of benzene, the initiator is formed as in 1). After cooling to 323 K under stirring 35 g of 1,3-butadiene, contained in 128 ml G ^ and 15 g of styrene

added. After 5 hours, the butadiene-free G. fraction is distilled off and the product is precipitated in methanol. The result is a random copolymer with 33 f ° polystyrene content. The Polybutadienanteil has a comparable 1) microstructure.

Example 8

To an initiator batch formed as described under 7), 35 g of 1,3-butadiene, contained in 128 ml of C, fraction are added and polymerized for 1.5 h at 313 -E. Thereafter, 15 g of styrene are added and polymerization is continued for 3 h. After working up as described in 7), to obtain a block copolymer having a Polystyrengehalt of 32 i <> and a polybutadiene microstructure of 27 i "1,2- and 1,4-73 f * Sinheiten.

Claims (3)

Inducement 1) Process for the selective polymerization of 1,3-butadiene from C. fractions to homo- and copolymers with and without functional groups and with predetermined molecular weights of e.g. 1000 to several 100,000, with microstructures that can be varied in the range of high 1.4 to 1.2 high structural contents, in homogeneous phase if necessary with the addition of polar solvation agents at temperatures between 283 K and 353 K and reaction times of 10 Min to 6 h in the presence of lithium initiators, characterized in that the polymerization and copolymerization of 1,3-butadiene is carried out with initiators, the reaction products of monolithium organyls, IW-Id, (R,. = I-alkyl, n-alkyl , cyclic alkyl, arylalkyl, aryl of up to 20 O atoms) and triallylalkylenediamines of the type (S = CBDEL = CIL CffiL-j R ₁ = H, n-alkyl, i-alkyl, cyel.-alkyl, arylalkyl, aryl; η = 2 to 6) in a phatic ali, cycloaliphatic, olefinic or aromatic hydrocarbon or in a mixture thereof and systems of the type. " (R ₀ = R ₁ CH 1 CR ₁ - or R ₁ R 1 OH-C (Li) R _n -CHR ₁ - or R 1 is CH = CR ₁ -CHR ₁ -JR ₅ = n-alkyl, i-alkyl, cyclic alkyl, arylalkyl, arylrestj η = 2 to 6), wherein 2 to 4 Li atoms in the initiator molecule are included. 2) Method according to item 1), characterized in that the polymerization in the C. fraction can be carried out without additional solvent. 3) Process according to item 1) and 2), characterized in that anionic polymerizable monomers, such as isoprene, styrene, alpha-methylstyrene, etc. are used as comonomers for the preparation of block polymers and of random copolymers.