CA1098913A

CA1098913A - Multifunctional lithium containing initiator

Info

Publication number: CA1098913A
Application number: CA257,737A
Authority: CA
Inventors: Lu H. Tung; Grace Y-S. Lo; Joseph W. Rakshys; Douglas E. Beyer
Original assignee: Dow Chemical Co
Current assignee: Dow Chemical Co
Priority date: 1975-08-01
Filing date: 1976-07-26
Publication date: 1981-04-07
Also published as: FR2321507B1; AU1643576A; GB1499467A; NL180666B; DE2634391A1; JPS627203B2; NL7608495A; DE2634391C2; AU501188B2; NL180666C; JPS5219192A; FR2321507A1

Abstract

ABSTRACT OF THE DISCLOSURE
Highly desirable multifunctional lithium con-taining initiators are prepared by reacting a compound such as an organo lithium with an organic compound con-taining at least two l,l-diphenylathylene groups. Such initiators can be prepared in the absence of polar solvents and are very desirable for the polymerization of dienes such as butadiene to a desirable 1,4 configuration.

Description

This invention provides an improved multi-functional lithium con~iningcompound suitable for initiation of polymerization in a hydrocarbon medium.
The initiator of this invention promotes polymerization of a 1,3-diene to give a high degree of 1,4 addition and is soluble or readily made soluble in polymerization initiation quantities in a hydrocarbon medium.
More particularly, the initiator of this invention comprises a multifunctional lithium contain-ing polymeriæation initiating compound having the Formula:

~ ~ ~-(R )-C ~

1~,~ =/ CH2 CH2 R3 R3 Rl Rl !
wherein Rl is hydrogen, a Cl-C16 alkyl hydrocarbon radical, a cycloalkyl hydrocarbon radical, an alkoxy radical or an i aromatic radical, R2 is a divalent organic radical having ;¦
at least 6 carbon atoms and at least one aromatic ring which is directly attached to a carbon which ls attached to a lithium atom and R3 is an alkyl radical containing j from 1 to 20 carbon atoms, a cycloalkyl hydrocarbon radical contalning from 4 to 16 carbon atoms or an aromatic ring structure containlng from 6 to 14 carbon atoms.
R1 is preferably hydrogen. When Rl is other than ~ ~ !
. -:, ' ' . . :

~98~3 hydrogen it may contain from 1 to 16 carbon atoms and ispreferably a hydrocarbon radical having a tertiary carbon atom directly attached to the aromatic ring or an aromatic ring struct~re R2 may be an aprotic organic solvent soluble oligomer or polymer of indefinite siæe~ but preferably R2 contains 6 to 12 carbon atoms and is most advantage-ously 1,4-phenylene, 4,4'-biphenylene or 4,4'-oxybis-phenylene. R2 contains carbon and hydrogen, and option-ally oxygen, iron, and/or sulfur. Oxygen and sulfur when present are present only in the configuration of a diphenyl oxide or a diphenyl sulfide. Iron is present in the ferrocene configuration.
~ 3 ad~antageousiy contains from ~ lo 2d carbon atoms and preferably contains from 3 to 10 carbon atoms.
The preferred R3 species is sec-butyl.
Also within the scope of the present invention is a solution particularly suited for the initiation of polymerizing a vinyl groupcontaining compounds which are polymerizable in the presence of a lithium containing catalyst, the solution comprising a major portion of a liquid aliphatic, cycloaliphatic or aromatic hydrocarbon solvent or mixture thereof and a minor proportion of a multifunctional lithium containing polymerization initi-ating compound of the Formula:

, .. . ~, , , . . .

.
.. . .. .

:~

9~3 7 Li Li 71 (R4)n (R5)m ~ 1 ~ ~ C- (R2) C

Rl \~ C~2 CH2 \R
Rl R3 3 wherein Rl, R2 and R3 are as above set out, and R4 and R5 axe individually chemically combined units of 1,3-butadiene or isoprene or mixtures thereof where n~m is at least 20~ Also within the scopa of the present invention is a method for the polymerization of vinyl compoundscontai~ng at least one vinyl cJroup and partic-ularly vinyl hydrocarbon compounds which are polymerizable in the presence of a lithium containing catalyst. The method is characterized by contacting the vinyl compound wi h the polymerization initiating compound of the Formula:

~ ~ L-~R )~

characterized in that R~ is hydrogen, or a Cl to C16 alkyl hyd~ocarbon radical, cycloalkyl hydrocarbon radical, alko~y radical, or aromatic radical; R2 is a divalent ... -- 3 -- .

.. : , - . ~: ~
. - , .
.. . ..

organic radical haviny at least 6 carbon atoms and at least one aromatic ring which is directly a-ttached to a carbon which is attached to a lithium atom, and R3 is an alkyl, cycloalkyl or aromatie radical containing from 1 to 20 carbon atoms.
Advantageously, the steps of the method comprise reacting a compound of the Formula:

Rl Rl ,, 2 ', 2 R--~ c-r -c~ Rl wherein Rl and R2 are as above set out with a lithium co~i.ni.ngcompound of the Formula:
. R3Li wherein R3 is as defined above, and reacting the result-ing product with isoprene or butadiene to provide a multifunctional lithium eompound having the Formula:

Rl Li Li Rl (R~)n (R~)m ~ ~ 1 R ~ ~ C-(R2)-C ~
\=~ / CH2 CH2 Rl 3 R3 wherein all of the substituents are as defined above and subsequently contacting the resultant dispersion with at - least one lithium polymerizable monomer to cause the poly-merization of the monomer to a corresponding polymer.
- 3a -Compounds employed herein include~
I. O O
~,C~/C\¢~ ~

4,4'-dibenzoyl-1,1'-biphenyl II. ,C,H2 ,CIH2 [~C ~ C ~ ~ ' 4,4'-bis(l-phenylethenyl)-1,1'-biphenyl III. Li Li ~C~ ~C~ '',.
,CH2 C,H2 CH -CH-CH2CH3 CH3-cH-cH2cH3 (1,1'-biphenyl)-4,4'diylbis(3-methyl-1-phenylpentylidene)~
bis(lithium) IV Li hi '~C~O~C~
,CH2 CH2 CH3-CH-CH2C~3 CH -CH-CH2CH3 oxydi-4,1-phenylenebis(3-methyl-1-phenylpentylidene) bis(lithium) ~7. 0 0 ~fC~L ~C ¢~

4,4"-oxydibenzophenone 17,753B-F _~

~ , .

~IL~B913 VI. C~2 CH2 ,.
~C~ C~

Bis[4~ phenyle~henyl)phenyl]ether VII. ,C,H2 ~ CH2 1,4~bis(1-phenylethenyl)benzene VIII. ~ L ~ i CH3_cH_cH2cH3 CH3-cH-cH2 CH3 1,4-phenylenebis(3-methyl-1-phenylpentylidene)bis(lithium) IX. O O
~ ~ C,H3 .
C 3 .

4,4"-isopropylidenedibenzophenone .

, .
X. CH2 " 2 .
~ C ~ CH3 ~ ~
- I~J ~ c ~ ~ ,.,

2 5 2-Bis[4~ phenylethenyl)phenyl]propane ~ 5 17,753B-F

" ~ .

~8~ 3 - C ~ CH~ = , \ 3 C~3-CH-CH C~ CH3-CH-CH2CH3 (l methylethylidene)bi5-[4,1-phenylene~3-methyl-l--phenylpentylidene)]bis(lithium) Compounds in accordance with the present in-vention may be readily prepared from compounds of the type hereinbefore disclosed and may be readily synthesized by condensing an aromatic acid chloride with an aromatic compound such as benzene, biphenyl, diphenyl ether and the ,' like in the presence of a Freidel-Crafts catalyst such as aluminum trichloride to form a diketone, the diketone `
having the katone groups separated by at least one aromatic ring. The diketone compound is then subjected to a Wittig reaction which transforms the ketone groups into 1,1--vinylidene groups. The divinylidene compound i5 then contacted wi~h an organic lithium compound such as, for example, secondary butyl lithium or tertiary butyl lithium. The organo lithi~n compound adds to the double bond to provide the desired compound. The resulting dilithium compound on contact with small amount of buta-diene or isoprene in an aliphatic, cycloaliphatic or aromatic hydrocarbon solvent such as hexane, cyclohexane or benzene becomes soluble. Generally the diene is employed in a proportion of from 20 to 200 mole per mole of the dilithium compound to xender the compounds soluble~

17,753B~F ~~

~ 1.

~g~

Example 1 A nitrogen purged reaction flask was charged with 23.4 grams of biphenyl dissolved in 50 milliliters of 1,2~dichloroethane. 85.5 grams of benzoylchloride and an additional 100 milliliters of 1,2-dichloroethane were added to the flask. The flask and conten-ts were then cooled to about 10C and 71.5 grams of aluminum trichloride was added slowly to the mix-ture with stirring. The solu-tion became dark red in color. Over a period of about four hours, the temperature of the reaction mixture wa5 raised to 85~C and maintained at that temperature for a period of 17 hours. At the end of 17 hours, the re-action mixture was poured into ice water with agitation.
The reaction mixture and ice water were then extracted with about one liter of methylene chloride. The water layer was discarded and the methylene chloride con-taining the remaining mixture was washed with a sodium bicarbonate solution, and then with water. The methylene chloride solution was agitated with anhydrous sodium sulfate for 30 minutes, the mixture filtered and the filtrate evaporated to dryness. The crude product obtained on drying of the organic layer was then washed with methanol and subsequently with a 1 to 1 mixture o benzene and ethanol. The product was recrystallized from benzene.
17.6 grams of 4,4l-dibenzoyl-1,1'-biphenyl (Compound I) were obtained having a melting range of 217-218C. Examination of the product with an infrared spectroscope indicated an absorbance of a C=O which agreed with that of the absorbance of benzophenone.

17,753B-F

Compound I was converted to 4/4 7 -bis(l--phenylethenyl)~l,1'-biphenyl (Compound II) in the following manner:
10.6 millimoles of n~butyllithium as a 0~53 Normal solution in benzene was admixed with 4.06 grams of methyl-triphenylphosphonium bromide dissolved in 50 milliliters of tetrahydrofuran in a nitrogen-purged glass reaction vessel and the vessel maintained at ambient temperature (about 22C) for a period o~ 2 hours. A suspension of 2.05 grams of Compound I in 30 milliliters of tetrahydrofuran was added to the reaction mixture~ The reaction vessel was maintained at room temperature for a period of about 16 hours. At the end of this period, the tetrahydrofuran was evaporated and the remaining solid dissolved in a 1:1 by volume diethyl ether-water mixture. The ether and water were separated and the ether layer washed with water and subsequently the ether was evaporated. The crude product Compound II was recrystallized twice from a 1 to 1 mixture of benzene and ethanol and the solid product obtained washed with n-hexane, the 4,4'-bis(l-phenylethenyl)-1,1' biphenyl (Compound II) had a melting point of 193-196C.
A benzene solution of Compound II was prepared in a nitrogen-filled serum bottle equipped with a magne~ic stirrer. The solution contained 0.5 grams (1l41 millimoles) of Compound II and 70 milliliters of dry benzene. 702 milliliters of 0.482 Normal secondary butyllithium n hexane solution was injected into the serum bottle with a hypo~
dermic syringe to provide 3.47 milliequivalents of sec---butyllithium~ The mixture was stirred at room temperature for 2 hours and 40 minutes, and resulted in a deep blue colored dispersion.

7~753B-F -8-The foregoing treatment of Compound II was repeated and a 15 milliliter portion of the resulting dispersion was withdrawn and injected into a serum bottle containing nitrogen and 0.05 milliliter of glacial acetic acid. The dispersed material dissolved and the solution color turned Erom deep blue to yellowO Lithium acetate formed in the solution and was removed therefrom. An infrared spectrum of the remaining liquid showed a complete disappearance of the absorption band at 900 cm 1 indicating that all vinyl groups had reacted with the sec~butyl-lithium. The deep ~lue dispersion obtained by the treatment of Compound II resulted in the formation oE Compound III, (l,l'-biphenyl) 4,4'-diylbis(3-methyl-1-phenylpentylidene)--bis(lithium). Butadiene was polymerized using Compound III
in the following manner: A nitrogen purged reaction flask was charged with 850 milliliters of degassed dry benzene and the reaction mixture containing Compound III. ~bout 10 grams of 1,3-butadiene monomer was added and the mixture agi~ated at room temperature for a period of about 1 hour and 35 minu~esO During this perio~d, the dispersion became a solutionO -An additional 40 grams of 1,3-butadie~e were added and polymerization proceeded for about 40 minutes and the temperature of the reaction mixture was maintained at about 45-55C~ The reaction mixture was subsequently cooled to room temperature a~d 4 milliliters of distilled tetrahydrofuran were added with agitation.
When the tetrahydrofuran was uniformly dispersed, a solution of 2044 milliequivalents of silicon tetrachloride in benzene was added. Visible gels formed immediately.
After agitation for abou~ 20 minutesJ 1.5 milliliters of glacial acetic acid was added and the mixture containing the gel allowed to stand at room temperature overnigh~.
The resultant polybutadiene contained 40 percent ungelled polymer and 60 percent gel, the foregoing being by weight thereby confirming that the initiator compound was di-unctional. The theoretical gel content was 86 percent.
For purpose of comparison, the foregoing polymerization procedure was repeated with the exception that sec-butyllithium was employed as catalyst instead of Compound III. The recovered polybutadiene was completely soluble in tetrahydrofuran, toluene and benzene. No gels were observed.
Example 2 Compound IV, oxydi-4,1-phenylenebis(3-methyl--l-phenylpentylidene)-bis(lithium), was prepared in the following manner:
A nitrogen-purged reaction vessel was charged with 106.4 grams of aluminum trichloride and a solution of 91.94 grams of benzoylchloride dissolved in 200 milli-liters of methylene chloride. The reaction vessel was cooled in an ice bath. A solution of 56 grams of diphenyl-oxide and 20 milliliters of methylene chloride was cooled to about 0C and added to the reaction vessel. A~ter a period of two and one-half hours, the ice bath was removed and the vessel warmed to room temperature and held at ambient temperature for about 20 hours. After 20 hours, some of the methylene chloride had evaporated and was replenished~ After an additional hour~ the reaction mixture was poured over iceO The resultant aqueous mixture was ex~racted twice with methylene chloride. The 17,753B-F

~S~9~ 3 water and organic layers were separated and the water layer was discarded. The organic layer was washed twice with a ten weight percent solution of potassium hydroxide in water~ The water layer was discardedO The remaining organic layer was evaporated to dryness. The remaining crude product was dissolved in benzene and decolorized with charcoal. An equal volume of methanol was added to the decolorized benzen~ solution and 56.03 ~rams of 4,4"~oxydiben~ophenone (Compound V), was obtained in the form of white, crystal platelets. The procedure of Example I
was used to convert Compound V into bis[4~ phenylethenyl)-phenyl]ether (Compound VI). A nitrogen purged serum bottle was charged with 1.62 millimoles of Compound VI dis-solved in 50 milliliters of dry benzene. Eight milli-liters of a 0.482 Normal secondary butyllithium solution in hexane was added to the serum bottle by means of a syrinye. A dark red dispersion of Compound IV in benzene ~;
resulted. In a separate experiment the dispersion was acidified in the manner of Example I and an infrared spectral analysis indicated the absence of the 900 cm 1 band indicating the absence of vinyl groups. A nitrogen purged reaction flask was charged with 780 milliliters of degassed dry benzene and the dispersion of Compound IV
containing 1.62 millimoles thereof and 10 grams of 1,3-butadiene. After about 90 minutes, the dispersion ~ecame a solution and an additional 60 grams of 1,3-butadiene was added. Th~ butadiene polymeriæed over a period of about 1 hour and 2 milliliters of tetrahydrofuran were added with agitation. When the tetrahydrofuran had been uni~

1 1 _ 17,753g-F

~8~3 formly dispersed, 2.09 milliequivalents of silicon tetra-chloride in benzene were added. After about one hour, 1.3 milliliters of glacial acetic acid were added. Visible gels were formed when the silicon tetrachloride was added.
The polybutadiene contained 56.6 percent gel. The theoretical amount of gel was calculated to be about 65 percent. The initiator was therefore difunctional~
~n additional quantity of Compound IV was prepared by charging to a nitrogen-purged flask 0.88 millimoles of Compound VI dissolved in 25 millilit~rs of dry benzene and adding thereto with agitating 1.85 milliequivalents of secondary butyllithium dissolved in 4.3 milliliters of hexane. Compound IV began to form as a red dispersion in benzene~ The dispersion was stirred for a period of 3 1/2 hours at room temperature and 2 milliliters of isoprene were added to the dispersion. The dispersion was then heated to a temperature of about 60C and after a period of about 10 minutes the red dispersion changed to a reddish-brown solution, The solution was added to a nitrogen purged flask containing 40 grams of butadiene dissolved in 450 milliliters of dry benzene. The reaction mixture was maintained within the temperature range of 45 to 55C. Polymerization of the butadiene was completed in about 50 minutes. The reaction mixture was then cooled to about 35C and 22 milliliters of styrene were added. The solution was stirred for about two minutes and 2 milliliters of distilled tetrahydrofuran were added. The temperature of the solution was maintained at about 35C for a period of about one hour, and 0.15 milli-- liters of glacial acetic acid added. The reaction mixture ~ ' 17,753B-F 12-~9~ 3 was diluted by the addition of methanol which caused pre-cipitation of the polymer formed~ The precipitate was separated from the liquid and vacuum dried at room temperature overnight. A portion of the polymer was compression molded in test bars at a temperature of about 180C. The polymer had a tensile strength at bxeak of 3245 lb. per square inch (227 kg/sq.cm) as measured at 23C and a jaw separation rate of 20 inches (50.3 cms) per minute. The elongation at break of the polymer sample was 1000 percent. The molecular weight of the polymer was determined by gel--permeation chromatography by the ~ethod described in the J. A~pl ed Polym. Sci. 13, 2359 (1969) Runyon et al. The molecular weight was 123,000 with a central block of butadiene of 83,000 and two styrene-end blocks of 20 t ;~
each.
Example 3 A reaction flask was purged with nitrogen and charged with 5~.5 grams of aluminum trichloride and 160 milliliters o benzene. A mixture of 40.6 grams of terephthaloyl chloride in 280 milliliters of benzene was added to the reaction flask from a dropping funnel over a period of 50 minutes. The temperature of the reaction mixture was maintained at about 44-47C for a period of about 40 minutes and raised to 68C for about one and one-half hours. The reaction vessel and contents were cooled with ice water bath and ice water mixed with the reaction mixture. Methylene chloride was added and the aqueous and organic layers separated. The organic layer was washed three times with aqueous sodium bicarbonate and washed twice with water. The organic layer was dried over 17,153B-F -13-~91~3 anhydrous sodium sulfate. The particulate sodium sulfate separated and the organic solvents removed by evaporation.
The resultant crude product remaining after the evaporation was recrystallized from absolute alcohol containing about 0.5 percent benzene. Thirty grams of 1,4-dibenzoylbenzene were obtained which had a melting range of 155-160C~
The 1,4-dibenzoylbenzene was then converted to 1,4--bis(l-phenylethenyl)benzene (Compound VII), employing the procedure set forth in Example 1 wherain Compound I was converted to Compound II. A nitrogen-purged flask was charged with 0.98 millimoles of Compound VII dissolved in 20 milliliters of dry benzene. Subsequently, 6 milli-liters of 0O483 Normal sec-butyllithium-hexane solution was added. The mixture was stirred for 2 hours at room tempera-ture. The mixture was a dark bluish red suspension and contains Compound VIII, 1,4-phenylenebis(3-methyl-1-phenyl-pentylidene)bis(lithium)l A portion of the solution containing Compound VIII was acidified with glacial acetic acid and the infrared spectrum showed no peak ln the 900 cm 1 region which indicated the absence of a vinyl group.
Butadiene was polymerized employiny the dispersion con-; taining Compound VIII. A nitrogen-purged reaction 1ask was charged with 450 milliliters of benzene and the dis-p~rsion containing Compound VIII~ Ten grams of 1,3 ; 25 -butadiene was added to the flask. The flask and contentswere maintained at a temperature of about 40~C for about one~half hour, the dispersion became a solution and `~ 28 grams of butadiene were added. The contents of the flask were warmed to about 45-55C for a period of about 50 minutes. The reaction mixture and flask were then cooled 17,753B-F 14 a3L3 to room temperature and 2 milliliters of distilled tetra-hydrofuran were added with stirring~ Subsequently, 1.12 milliequivalents of silicon tetrachloride in benzene were added. Gels were immediately obvious. After about 60 minutes, 0 1 milliliter of glacial acetic acid was added.
The reaction mixture was stirred for 3a minutes. The following day, the product was recovered by precipitation by addition of methanol. The product contained 55 percent gel. The theoretical gel content was 67 percent therefore the initiator was difunctional.
Example 4 Compound IX, 4,4"-isopropylidenedibenzophenone was prepared from 2,2-diphenylpropane and benzoylchloride using the same reaction conditions as set forth in Example I. The quantities of ingredients employed were: 2,2--diphenylpropane 20.8 grams t benzoylchloride 64.6 grams, aluminum trichloride 61 grams, and l,2-dichloroethane 160 milliliters. The resultant diketone ~Compound IX) was obtained as a viscous brown high boiling oil and showed one main peak on a gas chromatogram. The infrared spec-trum and the nuclear magnetic resona~ce spectru~ ~oth indicated that the product was the desired diketone (Compound IX). The above diketone ~Compound IX) was subjected to the Wittig reaction employing conditions set forth in Example 1 for the conversion of the diketone to the corresponding diolefin compound to obtain 2,2-bis[4-(1-phenylethenyl)phenyl~propane (Compound X). Compound X was obtained as a dark brown viscous oil. The infrared spectrum and the nuclear magnetic resonance spectrum both indicated that Compound X was 17,753B~F -15-obtained. Examination in a gas chromatograph indicated tha-t the material had a purity of over 90 percent. A
nitrogen-purged flask was charged with 2015 millimoles of Compound X dissolved in 20 milliliters of benzeneO
Twelve milliliters of O.482 Normal sec-butyllithium in n~hexane was added. The reactants all were at room temperature. On addition of the sec-butyllithium solution, the color of the mixture changed to a reddish brown and suspended solids were slowly formed. The solution then contained Compound XI, (l-methylethylidene)bis [4rl--phenylene(3~methyl-1-phenylpentylidene)]bis(lithium).
After the reaction mixture was agitated at room tempera-ture for a period of 3 hours, it was employed as a poly-merization initiator in the following manner: a nitrogen flushed reaction vessel was charged with 500 milliliters benzene, the dispersion containincJ Compound XI and 10 grams of 1,3-butadiene. After a period of about one and one-half hours at which time 45 grams of butadlene were added, the mixture was maintained at a temperature of about 45-50C and was cooled to room temperature after about 70 minutes. On cooling 6.5 milliliters of distilled tetrahydro~uran were added. On completion of the addition of tetrahydrofuran, and a short period of stirring 2.79 milliequivalents of silicon tetrachloride in benzene were added. On the addition of the silicon tetrachloride, gels became immediately obvious. The mixture was allowed to stand for about 20 minutes and 0.8 milliliters of glacial acetic acid was added and the mixture allowed to stand overnight. The following day, the polymer was recovered by precipitating with methanol and the resulting 17~753B F -16-~ ~19~3 product found contained greater than 90 percent gel~
Presence of gel indicated the diEunctionali~y of the initiator.
Examp e 5 Preparation of t-Butylstyrene-Styrene--t-Butylstyrene Triblock Copolymer To a nitrogen filled 1 liter flask 450 ml of degassed dry benzene and 55 ml of purified styrene were added. The residue impurities in the mixture were removed by titrating with a sec-butyllithium in cyclohexane solution (0.56 N) until a faint straw color appeared. A total of 0.31 milliequivalent of sec-butyllithium was used. To this mixture 2 ml of purified tetrahydrofuran and 0.394 millimole of compound IV as prepared in Example 2 were added. The reaction mixture turned immediately to a deep orange brown color ~r and heat began to evolve. After 60 minutes the flask was cool again. An additional 30 minutes was allowed to insure that all styrene monomers were reacted. Puri-fied t-butylstyreney 2.9 ml, was then added to the reaction flask containing the difunctional living poly-styrene anions. Polymerization of t-butylstyrene was allowed to continue for another 60 minutes before a 0.5 ml portion of glacial acetic acid was added to terminate the living dianions. The polymer recovered by the usual precipitation and drying technique was quantitative indicating that all monomers added were used.
Example 6 Preparation of ar ~-dihydroxypolybutadiene Ethylene oxide, approximatPly 2 ml~ was con-densed from a cylinder into a 50 ml vial equipped with a high vacuum stopcock and a rubber septum capped side arm. To this condensed ethylene oxide liquid 4 drops 17,753B-F -17-of a y-butyllithium (1. 5 N in hexane) solution was added to react with the impurities which might be pre-sent. The vial containing the condensed ethylene oxide was then attached to a side arm of a 1 liter reaction flask.
The reaction flask was -then filled with N2 degassed dry benzene and approximately 25 g of purified butadiene monomer. The residue inpurities in this reac-tion mixture were removed by the addition of 0.42 milli-equivalent of a sec-butyllithium in cyclohexane solution.
To this purified reaction mixture, 0.56 milli-mole of compound IV as prepared in Example 2 was added.
The reaction mixture was heated to 55C. Polymerization ~ was allowed to continue at this temperature for about -! 15 60 minutes. At the end of the reaction period, the 55C
water bath was removed, 2 ml of purified tetrahydrofuran was added. A reduction of viscosity was observed. After 5 more minutes of continuous agitation, the stopcock connecting the condensed ethylene oxide vial and the polymerization flask was opened. The dry ice-methylene chloride mixture which was used to keep the ethylene oxide in the vial condensed was also removed. A beaker of hot water was then used to hasten the vaporization of the ethylene oxide. The viscosity of the liquid in the polymerization flask increased now rapidly and the straw yellow color of the polybutadlenyl dianions started to fade. After about 4 minutes the color disappeared almost completely and the entire solution gelled up~ Agitation was now stopped. The gel was allowed to stand for 15 more minutes before a 1 ml portion of glacial acetic acid 17~753B-F -18-~:

was added. The gel structure disappeared into a normal viscosity liquid immediately upon the addition of the acetic acidO This appearance and disappearance of the gel structure indicated that the capping reaction to produce the +Li O ~ O Li+ dianions by ethylene oxide was essentially complete and the subsequent acidification produced the desired a,~-dihydroxypolybutadiene.
Initiators in accordance with the present invention are readily prepared in situ by maintaining a supply of the corresponding divinylidene compound. The divinylidene compound is readily and quickly converted to the corresponding lithium compound and solubilized by the addition of small quantities ;
of monomer such as butadiene. If desired, the entire system can avoid the addition of polar compounds such as ethers or amines and thus when employed the polymerization of diene polymers 1,2 addition is minimized; however, if it is - desired, appropriate polar compounds may be added to increase 1,2 addition, to increase the rate of polymerization and to reduce the viscosity of the reaction mixture~

17,753B-F -19-

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A multifunctional, lithium containing, poly-merization initiating compound of the Formula:

characterized in that Rl is hydrogen, or a Cl-C16 alkyl hydrocarbon radical, cycloalkyl hydrocarbon radical, alkoxy radical, or aromatic radical; R2 is a divalent organic radical having at least 6 carbon atoms and at least one aromatic ring which is directly attached to a carbon which is attached to a lithium atom, and R3 is an alkyl radical containing from 1 to 20 carbon atoms, a cycloalkyl hydro-carbon radical containing from 4 to 16 carbon atoms or an aromatic ring structure containing from 6 to 14 carbon atoms.

2. 1,4-phenylenebis(3-methyl-1-phenylpentyli-dene)bis(lithium).

3. (1,1'-biphenyl)-4,4'diylbis(3-methyl-1--phenylpentylidene)bis(lithium).

4. Oxydi-4,1-phenylenebis(3-methyl-1-phenyl-pentylidene)bis(lithium).

5. (1-methylethylidene)bis-[4,1-phenylene-(3-methyl-1-phenylpentylidene)]bis(lithium).

6. A solution particularly suited for the ini-tiation of polymerizing of vinyl group containing compounds which are polymerizable in the presence of a lithium con-taining catalyst, the solution comprising a major portion 17,753B-F

of a liquid aliphatic, cycloaliphatic or aromatic hydro-carbon solvent or mixture thereof and a minor proportion of a multifunctional lithium containing polymerization initiating compound of the Formula:

characterized in that R1 is hydrogen, or a C1-C16 allyl hydrocarbon radical, cycloalkyl hydrocarbon radical, alkoxy radical, or aromatic radical; R2 is a divalent organic radical having at least 6 carbon atoms and at least one aromatic ring which is directly attached to a carbon which is attached to a lithium atom, R3 is an alkyl radical con-taining from 1 to 20 carbon atoms, a cycloalkyl hydrocarbon radical containing from 4 to 16 carbon atoms or an aromatic ring structure containing from 6 to 14 carbon atoms, and R4 and R5 are individually chemically combined units of 1,3-butadiene or isoprene or mixtures thereof where n + m is at least 20.

7. A method for the polymerization of vinyl com-pounds which are polymerizable in the presence of a lithium containing catalyst characterized by contacting the vinyl compound with the polymerization initiating compound of the Formula:

characterized in that Rl is hydrogen, or a Cl to C16 alkyl hydrocarbon radical t cycloalkyl hydrocarbon radical, alkoxy radical~ or aromatic radical; R2 is a divalent organic radical having at least 6 carbon atoms and at lea~t one aromatic ring which is directly attached to a carbon which is attached to a lithium atom, and R3 is an alkyl, cycloalkyl or aromatic radical containing from 1 to 20 carton atoms.

8. A method for the polymerization of vinyl compounds which are polymerizable in ~he presence of a lithium containing catalyst characterized by contacting the vinyl compound with the solution of Claim 6.

~2 7,753B-F