DE2166023C3 - Process for making vinyl or oxirane polymers - Google Patents

Description

Many organometallic compounds are known to be suitable as polymerization initiators. The effectiveness such metal adducts depend on the particular metal, the production method of the adduct and its possible association in complexes with other materials. Such initiators are from of great economic importance, as they enable peculiar catalytic processes, for example stereospecific polymerizations of the Ziegler-Natta type.

According to "Chemistry and Industry" (March 30, 1968), page 423, styrene is in n-hexane in the presence of Bis- (triphenylmethyl) -calcium polymerized. After 18 hours at room temperature, a polymer yield is achieved achieved by only 60%.

In US 30 41 312 a process for the polymerization of vinylidene monomers is described, wherein a anionic initiator is used, which is composed of various adducts of alkali metals and aromatic Hydrocarbons or ketones or alkali metal salts of very weak acids can consist. Alkaline earth metal compounds are not mentioned in this patent specification.

The invention is based on the object of a method for producing vinyl or oxirane polymers by polymerization in bulk or in a solvent in the presence of an alkaline earth metal initiator to create which gives high polymer yields and the production of a wide variety of polymers including block copolymers with a regulated structure.

The invention is represented by claims 6S.

As the following exemplary embodiments show, according to the invention, up to

quantitative polymer yields can be achieved.

In the process according to the invention, certain vinyl or oxyran monomers are brought into contact with one of the initiator compounds to form a monomeric organometallic adduct between a portion of the monomer and the carbanion present in the initiator compound, the polymerization being initiated and further parts of the monomer on this Adduct can grow. The polymerization can be terminated as desired by adding an active hydrogen compound such as an alcohol, an amine or water. The added compound can combine with the growing carbanion, whereby further growth stops. Dixanthenylbarium or another organometallic compound suitable according to the invention thus delivers this active polymeric metal counterion by reacting with polymerizable monomer ί ϊΐι spreading center, from which the molecule continues to grow as long as there is no chain termination persists until the chain is terminated and enables dissimilar monomers to be added to form block copolymers. By suitable choice of the chain terminator, terminal functional groups can be incorporated into the homopolymers, copolymers or block copolymers obtained. For example, chain termination by means of epoxides or CO ₂ gives polymer chains with terminal hydroxyl or carboxyl groups. Thus, with the aid of the alkaline earth metal catalysts used according to the invention, because the polymer carbanions persist in solution, block copolymers with a regulated configuration and with selected terminal functionality can be produced.

The polymers produced according to the invention can then be subjected to further reactions be, for example with polyisocyanates to form polyurethanes or polyamides.

The vinyl monomers polymerizable according to the invention are those with an activated unsaturated double bond, for example monomers, which are adjacent for the double bond have an electrophilic component (atom or radical) that is stronger than Hydrogen is and cannot be easily removed by a strong base. Examples of such monomers are nitriles, for example acrylonitrile or methacrylonitrile, amides, for example acrylamide or methacrylamide, Acrylates and alkacrylates, for example methyl acrylate, ethyl acrylate, butylate ylate, ethylhexyl acrylate, Octyl acrylate, methyl methacrylate, ethyl methacrylate, Butyl methacrylate, methyl ethacrylate, ethyl ethacrylate, Butyl acrylate or octyl ethacrylate, the barium, Calcium and strontium salts of acrylic and alkacrylic acids, for example acrylic acid, methacrylic acid or ethacrylic acid, the dienes, for example butadiene, chloroprene, isoprene or dimethylbutadiene, and the vinylbenzenes, for example styrene, m-vinyltoluene or p-vinyltoluene, as well as mixtures thereof. the polymerizable oxirane monomers are those composed of carbon, hydrogen and oxygen that form a ring of two carbon atoms and one oxygen atom and easily form polyethers open and let polymerize. Examples of suitable oxirane monomers are alkylene oxides, such as ethylene oxide, Propylene oxide, butene oxide or isobutene oxide, allyl glycidyl ether, crotyl glycidyl ether, isoprene monoxide, ßutadiene monoxide and vinylcyclohexene monoxide as well

Mixtures thereof, these monomers have up to 14 carbon atoms and are free from groups which destroy the initiator.

The temperatures during the polymerization may vary from -90 to 100 ⁰ C. The amount of initiator used depends on the type of polymer desired. For example, when high average molecular weight polymers are made using a given amount of the monomer and catalyst, only a small amount of initiator is required, while larger amounts of initiator are used when making a low average molecular weight polymer. In addition, since the polymer is an active polymer, it continues to grow as long as monomer is added to the polymerization system. The molecular weight can thus be a million or even more.

The polymerization can be either bulk or solvent polymerization. at Solvent polymerizations are preferred, with no more than about 15 percent polymer solids concentration to work in the solvent to achieve rapid heat transfer and rapid To enable process flow. Solvents should be used that are not chain terminators works. The polymerization should of course be carried out in a reactor equipped with a Stirrers, heating and cooling devices, devices for pumping in inert gas, monomers and Catalyst and facilities for the recovery of the polymer is equipped

The organic alkaline earth metal compounds used according to the invention can be obtained by direct Metallization of the organic. Ligands with barium, strontium and / or calcium metal in the presence of a aprotic solvent. In this metallization reaction there is a metal-hydrogen exchange, and it creates compounds in which the metal passes through to the organic residue ionic carbon-metal bond is bonded The compounds obtained are according to the invention as highly effective initiators for the polymerization of vinyl or oxirane monomers used by anionic growth To explain the invention Polymerization should be indicated that if Dixanthenylbarium XBaX, A styrene, B butadiene and PO propylene oxide the following reactions occur:

(1) XBaX + 2nA— XA _n BaA _n X ₁

generally a homopolymer;

(2) XA _n BaA _n X + 2n B - XA _n B _n BaB _n A _n X,
generally a block polymer;

(3) XBaX + πΑ + πΒ

- X (... BABBAAA .. .JBa (AABBAB ...) X,

generally a copolymer or blended

Polymer and

(4) XDaX + 2 / jPO- X (PO) _n Ba (OP) _n X.

Treatment of the homopolymer from (1) [and (2), (3) and / or (4)] with ROH, where H is an acidic proton, can lead to a generally stoichiometric < > o Splitting of the polymer lead to:

(5) XA _n BaA _n X + 2 ROH - Ba (OR) ₂ + 2 XA _n H.

The treatment of the polymer from (t) [and (2), (3) and / or (4)] with coupling agents can reduce the chain length of the polymer obtained or bring about a long-chain branching, in which the Branches the same or different polymeric

50

55 may have re chain properties, are examples of coupling agents

1,2-pjcWaräthan,
Silicon tetrachloride,
2 £ ', 2 "-Trichlorotriäthylamm,
Maleic acid or

Phthalic anhydride,

P (C1 ₂ ) = NP (C1 ₂ ) = NP (C1 ₂ ) = N

and other coupling agents, e.g. B.

(6) XA _n BaA _n X + ClCH ₂ CH ₂ Cl

- * BaQ ₂ + XA _n CH ₂ CH ₂ A _n X.

Various polymers can be treated with the coupling agents, whereby one branches of different blocks

The reactions of a polymer produced according to the invention with ethylene oxide (AO), propylene oxide or CO ₂ and subsequent hydrolysis or ion exchange yield a polymer with OH or COOH functionality

(7) XA _n BaA _n X + 2ÄO- XA _n AOBaOAA _n X;
XA _n AOBaOAA _n X + ROH

- 2 XA _n (AO) H + Ba (OR) ₂ and

(8) XA _n BaA _n X + 2CO ₂ - XA _n COOBaOOCA _n X;
XA _n COOBaOOCA ₁ X

hydrolysis

HCI

- 2 XA _n COOH + BaCI ₂

The polymers produced by the process of the invention can be compounded and cured in the same manner as other plastic and rubber polymers. For example, they can be mixed with sulfur or sulfur-producing materials, peroxides, carbon black, SiO ₂ , TiO ₂ , Sb ₂ O ₃ , red iron oxide, phthalocyanine blue or green, tetramethyl or ethylthiuram disulfide, benzothiazyl disulfide. Stabilizers, antioxidants, UV light absorbers and other anti-degradation agents can be added to the polymers. They can also be mixed with other polymers such as natural rubber, butyl rubber or polyurethane elastomers.

The manufactured according to the invention. Polymers can be used for paints, protective coatings or fabrics, for the production of fibers and textiles, body and engine mountings for automobiles, seals, Tires, golf ball covers, foamed plastic insulation for buildings, support boxes, electrical wire and Cable insulation and as plasticizers and polymer fillers for other plastics and Types of rubber are used.

In the following examples and throughout the specification and claims, parts and Percentages are based on weight, unless stated otherwise. All reactions and polymerizations were carried out in closed vessels under nitrogen or argon (inert atmosphere)

example 1
Polymerization of styrene

Using a reaction mixture of dixanthenylbarium and the barium salt of o-hydroxydiphenylmethane as initiator, styrene was converted virtually quantitatively into polystyrene. 4.05 g (0.039 mol) of styrene were with dixanthenylbarium (7.38 χ ΙΟ- ^{4 of} an equivalent, calculated only on

Pixanthenylbarium) in 67 ml of a mixture Ähllkldihtöh (Vl% Äh

ygyy (y

Lenglykoldimethyläther) initiated at room temperature (about 25 ° C). After a few hours it was Conversion of the monomer into the polymer 95%. A part of the polystyrene obtained was through Precipitation obtained in methanol. About 50% of the polystyrene chains were terminated with a phenolic group occupied, which resulted from chain transfer with the Bariurra salt of o-hydroxydiphenylmeihans. This salt thus does not act as a catalyst or initiator, but acts as a chain transfer agent to lower the average molecular weight of the polymer obtained. The number of the The average molecular weight as measured by vapor pressure osmometry of 2,600 was lower than that theoretical number of average molecular weight of 5200, calculated from the ratio of g polymerized monomers to moles as the initiator present as dixanthenylbarium.

Initiator production

The initiator was prepared as follows: A solution of 91 parts of xanthene in 1200 parts was produced Ethylene glycol dimethyl ether produced 181 parts of barium metal filings were added to this solution. The reaction proceeded instantly, forming a solution of blue color which was slow changed to red. After a week, the soluble product solution became unreacted metal filtered off The carbon-barium content was determined by radiochemical titration and it was 0.13 meq / ml determined This shows that 30% of the starting reagents are in organometallic compound was transferred, in which barium was bound to xanthenyl residues by carbon-metal bonds. The rest Xanthene was converted into the barium salt of o-hydroxydiphenylmethane and a small amount of others did not identified by-products transferred

In another case, the direct metallization of xanthene with barium metal was attempted Xanthene in hydrocarbon solvents, e.g. B. benzene, was dissolved. It was found de B the xanthene could not be directly metallized with barium in this way. However, it turned out to be possible Solutions of dixanthenylbarium in mixtures of hydrocarbon and aprotic polar solvent to obtain by removing part of the aprotic polar solvent in which the metallization was carried out, exchanged with a hydrocarbon solvent by solvent exchange became. In another case, dixanthenylbarium was found in a mixture of benzene and ethylene glycol dimethyl ether with 99.5% benzene is soluble, prepared in this way to have a carbon-barium content of 0.016 meq / ml.

The structure of the colored product was determined as dixanthenylbarium by (a) agreement of the visible spectrum of the organnbarium product, A _m j, «· 464 ηιμ with the spectrum A _m “ = 470 ΐημ given for xanthenyl-lithium and (b) carbonization of the reaction mixture with preservation confirmed by xanthene-9-carboxylic acid (melting point 220 "C)

The carbanion content of the reaction product Barium metal and xanthene accounted for 20 to 30% of its total alkdinity as determined by titration of the hydrolyzed product with standard acid. An analysis of the ether rate of the hydrolyzed reaction product by NMR, infrared and GLC (gas-liquid chromatography) Process revealed the presence of a cleavage product of xantheir and a minor component believed to be hydrogenated xanthene. The cleavage product of the Xanthene has been identified as o-hydroxydiphenylmethane, which results from the C-O cleavage of the xanthene molecule revealed. Assuming that the catalyst or the reaction mixture consists only of dixanthenylbarium and the cleavage product, the total anion content closely matched that expected. The direct metallization of xanthen with barium in ethylene glycol dimethyl ether thus produced a mixture from about 20 to 30% dixanthenylbarium and the remainder of the barium salt of o-hydroxydiphenylmethane. By varying the reaction time and stirring intensity during the metallization, the overall conversion varied the reactants in carbanion + phenolate between 60 and 100% of the starting materials. The fission products or the salt do not seem to occur when the other acidic, organic ones Compounds or in other organic solvents and / or be metallized at low temperatures.

Example 2
Polymerization of butadiene

2432 g (0.45 mol) of butadiene were 1.05 χ Ί0- ³ equiv. Dixanthenylbarium polymerized in 86 ml of ethylene glycol dimethyl ether at room temperature, 12.73 g of polybutadiene being obtained after 5 days. The average molecular weight was 1,850 (VPO). By infrared examination it was shown that the microstructure of the diene consisted of 47% trans-1,4 units, 26% cis-1,4 units and 27% vinyl units.

In another case resulted in 10.75 g (0.20 mol) of butadiene, which in 64 ml of a mixture of ¹ · benzene / ethylene glycol dimethyl ether (80 vol .-% benzene) with 9.05 χ ΙΟ- ⁴ equiv. xanthenylbariiim was initiated in the 65 ml solution, 10.10 g polybutadiene after 4 days at room temperature. Vapor pressure osmometry gave an average molecular weight of 3000. The polymer contained 52% trans-1,4 units, 26% cis-1,4 units and 22% vinyl units.

Example 3
Polymerization of methyl methacrylate

9.71 g (0.097 mol) of methyl methacrylate were 934 x ΙΟ- ⁴ equiv. Dixanthenylbarium in 95 ml of a mixture of toluene and ethylene glycol dimethyl ether (87% by volume toluene) initiated at -75 ° C. The polymerization was completed within a few minutes at -75 ° C. The polymer was dissolved in chloroform and precipitated in petroleum ether to give 8.6 g of polymethyl methacrylate.

Example 4
Polymerization of propylene oxide

15.2 g (0.26 mol) of propylene oxide were 7.87 χ ΙΟ- ⁴ equiv. Dixanthenylbarium in 10 ml ethylene glycol dimethyl ether using a high Monomerenkon ^ cntration of 3-day 8,5molar initiated polymerization at 5O ⁰ C and then for one day at 80 ° C gave 6.0 g of polypropylene oxide.

Example 5
Block copolymerization

Using styrene as monomers! and the method of increasing monomer addition it was found that the polymerization of styrene proceeds in the absence of a chain termination reaction. 10.7 g (0.103 mol) of styrene were mixed with 5 ml of the active Dixanthenylpolystyfylbarium described in Example 1 initiated in 105 ml of a mixture of benzene and glyme (99 vol.% benzene) at room temperature. After one day the conversion of the monomer to the polymer was 89%. The middle one Molecular weight as measured by membrane osmometry was 135,000. The theoretical molecular weight ν was calculated to be 95,000.

Showed gel permeation chromatography on both polymers. that the molecular weight of the polystyrene initiator was increased. what by comparing the MWD values (molecular weight distributions) of the first Block polymer and the last polymer was detected. The MWD value of the finished Polymer showed no presence of the first block polymer, demonstrating that after Addition of the monomer growth takes place without chain termination. On the basis of these observations it can be concluded that polymerization with an organometallic compound that has an alkaline earth counterion has, as a terminal-free anionic polymerization

can be characterized.

Unreacted xanthene and the barium salt of o-hydroxydiphenylmethane can take part in a chain transfer reaction with the propagating polymer chain. The effect of the free xanthenes in chain transfer was shown when xanthene was added to a polystyrylbarium-initiated polymerization reaction of styrene (molar ratio of xanthene to initiator = 23). The molecular weight was reduced from M _n = 25,000 for a comparative polymerization without added xanthene to about 2000 for the finished polymer.

Chain transfer to the barium salt of o-hydroxydiphenylmethane leads to cleavage of the polymer chains with a hydroxyl function. In one case the phenolic group was incorporated to the extent that 50% of the chains of a polystyrene. M _n = 2600 and 33% of the chains of a polybutadiene. M _n = 2900. terminated by hydroxyl groups.

Example 6
Manufacture of polybiitadienes

A number of butadiene polymerizations have been carried out with organometallic barium compounds in several Kinds of solvents were carried out, and the obtained polybutadienes were subjected to microstructure analysis Subject to recognized procedures and resulted in those listed in the table below Results:

Attempt initiator

Solvent '' repetitive subtleties
cis-1.4 lrans-1.4 Vinvl

Λ
B.

DHxanthenyl) -Ba
Di- (xanthenyl) -Ba

Ί AlhylcnühkoldimethvUither.

""/Benzene

(80 vol. ", Benzene) 26
26th

47
52

27
22nd

The above results show that lower vinyl contents of the polybutadiene using i-, Organometallic initiators according to the invention are obtained in comparison to certain organometallic initiators Metal initiators leading to vinyl contents of 45% or more in the case of Na. K. Rb or Cs lead.

Vi

Example 7
Polymerization of acrylonitrile

A solution of dixanthenylstrontium was diluted with tetrahydrofuran and used to initiate the Polymerization of acrylonitrile used at 23 ° C. Quantitative conversion to polyacrylonitrile occurred a few minutes. The polymer was obtained by precipitation in methanol and filtered off a light yellow powder was obtained.

Initiator production

49 parts of strontium metal filings were mixed with 453 parts of xanthene dissolved in 526 parts of HMPA. After 3 days of stirring at 23 ^C C, a light-colored, yellow-green solution formed. After a further reaction at 80 "C, a red solution was produced which, on the basis of analysis, showed a carbon-strontium content of 0.021 meq / g. This value represents a 5% conversion of the xanthene into dixanthenylstrontium.

Example 8
Polymerization of acrylonitrile

1.1 g (0.02 mol) of acrylonitrile were with 5 χ ¹ O- ⁶ equiv. Diindenylcalcium initiated in hexamethylphosphoramide. A significant amount of heat was released upon addition of the initiator to the monomer at 23 ° C. Polymerization occurred instantly to give 1.0 g of a yellow-white powder.

Initiator production

20 parts of calcium metal filings were reacted with 32 parts of indene, dissolved in 519 parts of HMPA. No reaction was evident due to the lack of color formation after stirring at 23 ° C. for 3 days. The reaction mixture was for 3 days at 8O ⁰ C to produce a clear brown orange! Reacted solution The carbon Calriumgehalt the reaction product was 0.0005 meq / g.

Example 9
Polymerization of acrylonitrile

1.1 g (0.02 Mc!) Of acrylonitrile were with diindenylbarium polymerized in hexamethylphosphoramide at 23 ° C. The polymerization was immediately followed by the evolution of heat. The work-up of the reaction product by "precipitation in methanol, filtering off the polymer, Washing with methanol and drying gave 1.0 g of a yellow-orange powder. The indene molecule was identified as part of the polyacrylonite chain by infrared absorption at 670 cm '. this provides evidence of initiation by the indenyl anion.

Initiator manufacturing

70 parts Bariummetallfeilspäne were reacted with 29 parts of indene in 535 parts of HMPA at 23 ^1C. A yellow solution initially formed after stirring for 2 hours. The reaction proceeded to form an intense brown color after several days at 23 ° C. The carbon-barium content of the solution was around 0.285 meq / g, which represents a 65% conversion of indene to diindenylbarium.

Example 10
Polymerization of styrene

1.0 g (0.0096 mol) of styrene were 6 χ 10- 'Equiν. Bis (diphenylmethyl) barium initiated at room temperature. After a few minutes at room temperature (25 ° C.) the polystyrene obtained (1.0 g) was obtained by precipitation in methanol.

Initiator production

75 parts of barium metal filings were mixed with 42.0 g of diphenylmethane in 535 parts of mexamelhylphosphoramide implemented. After stirring for one day at 23 "C A light yellow green colored solution formed, indicating only a low level of hydrocarbon conversion to indicate carbanion. After the reaction was continued at 80 "C for 3 days an intense brown-orange solution formed. Based on the carbon-barium content of the Final product (0.06 meq / g), 14% of the diphenylinethane was converted into bis (diphenylmethyl) barium.

Claims (3)

Patent claims: 1. Method of making vinyl or Oxirane polymers by polymerization in bulk or in a solvent in the presence an Erdalkajimetallofganischen connection, thereby characterized in that at a temperature of -90 to 100 "C a Vüiylmonomeres with an activated double bond or an oxirane monomer consisting of carbon, hydrogen and oxygen, in the presence of dixanthenylbarium, Cicyclopentadienylbarium, Diindenylbarium, Di- [bis- (2-methoxyphenyl) -methyrj-bariuni, Bis- (l, l, 2-triphenyläthyi) -barium or bis-l, l- {diphenylalkyl) -barium, wherein the alkyl radical has 1 to 10 carbon atoms ^ or the corresponding Polymerized calcium or strontium derivatives or their mixtures as initiators 2. The method according to claim 1, characterized in that that the catalyst is in the form of a solution in an aprotic, polar solvent begins 3. The method according to claim 1 or 2, characterized in that the polymerization process is a solvent polymerization process using the monomer in such an amount that results in a polymer solids content of no more than 15% by weight in the solvent 30th