CS237360B1 - Processing of 1,3 diene homo-and copolymere - Google Patents

Description

The invention relates to a process for the preparation of homopolymers and copolymers of 1,3-dienes, in particular butadiene and isoprene, with 3 terminal functional groups having a low to moderate molecular weight of homogeneous anionic strength. polymerization of monomers. non-polar aliphatic, cycloaliphatic or aromatic solvents in the presence of trisantalkalkoxy initiators, in particular initiators, with the subsequent function of deactivating the living polymers with electro-active agents, in particular alkylene oxides, carbon dioxide or selfabsolectrolactone.

It is known that from the regulated dienes, anionic polymerization can be prepared with trivalent and more useful alkali metal initiators, mostly with trisanolithium compounds, with star-like or functionalized polymers having a functionality greater than 2 " (U.S. 3,644). ; 3,652,516; 3,725,368; 3,734,973; 3,862,251; NSR-DOS .2,003,384; 2,063,642; 2,231,958; 2,408,696; 2,427,955).

In this way, Oreagsí trsaosmotoOithitvé. compounds with polyvinylaromatic compounds such as divinylbenzoate or propoxybenzene to multiple, mostly bifunctional, compounds. Depending on the reaction conditions, the polyfunctional orsanoalkal compounds thus formed are more or less strongly branched or crosslinked to each other and, moreover, microgels. Partially or wholly intermocularly crosslinked products may also be formed. Such macrogels are insoluble and generally unusable as initiators for the polymerization of an polymer, or only conditionally applicable. In addition, the initiators have a relatively high molecular weight. thus, they are not suitable for the synthesis of low molecular weight telecheches.

polymers. Most iniciИ ^ о ^ О! ^ And multifunctional INP initiators can only be prepared in the case of stronger

- 2 237 380 polar. When initiator solutions such as ether, polymerization at room temperature or at higher temperatures are carried out with these solutions. very easily to side reactions such as disruption of their transfer chains or. ether fission. That's what it is. associated with a greater or lesser decrease in the content of active Li-C- bonds in the pslymerization system, so that polymers with a broad molecular weight distribution, lower functionalities, and higher molecular weights are obtained.

However, for the synthesis of dispersive living polymers with higher functionality, it is desirable that the aniline polymerization be carried out without side reactions using hydrocarbon-soluble α-functional lithium initiators. . These disadvantages are overcome by a process for the preparation of low-medium-molecular weight end-groups of polymers and esters of 1-3-dienes, especially butadiene and isoprene, by homogeneous polymerization of monomers in non-polar aliphatic, cycloaliphatic or aromatic solvents in the presence of triglyl alcocoa initiators. in particular liter initiators, with the subsequent function of isolating the living pslymers with electrophilic agents, in particular alkylene oxides, with carbon dioxide or with the alkali benzoyl peroxide according to the invention, which consists. characterized in that the polymerization is carried out at a temperature of 198 K to 423 K, preferably 2773 to 323 K, in the presence of polylithium initiators resulting from the reaction of the technical mixtures. with diáinylbenzenee, consisting of. from 10 to 70 nm. % divinvlbenzene 80 to 30. ethyl styrene and about 10 wt. the ratio of vinyl groups in the divinylbenzene mixture to alkyl lithium is 1.1: 1 to 2: 1, in a hydrocarbon solvent, preferably in benzene or toluene.

The initiators of the invention are fully soluble in hydrocarbons and form linear, unsaturated, low-molecular-weight, lithium-lithium compounds. Number of lithium atoms. The initiator molecules are determined by morphology. ratio of vinyl groups to vinyl chloride

237 360 and corresponds to a numerical value of 2 to 4.5. Therefore, these initiators are particularly suitable for the synthesis of low molecular weight telechelic polymers with a narrow molecular weight distribution and high functionality.

Particularly suitable monomers are conjugated dienes of butadiene-1,3 or isoprene or vinyl-substituted aromatic compounds, in particular styrene, alpha-methylstyrene or divinylbenzene. Other anionic polymerizable monomers may also be used for the synthesis of ABA-type block copolymers where V is a polydiene block. as comonomers. The polymerization takes place under known conditions for anionic solution polymerizations using organoalkalocene initiators. Suitable solvents are aliphatic, cycloaliphatic and aromatic hydrocarbons such as benzene, toluene, n-hexane, n-heptane, behzine fraction and cyclohexane.

The polymerization is carried out at atmospheric or elevated pressure and takes 1 to 3 hours. The amount of initiator used depends on the desired molecular weight of the polymer since it is a stoichiometric polymerization. No side reactions occur during the reaction, so that higher functionalities can be obtained after functionalization of the active polymers. The process of the invention overcomes the disadvantages of known processes such as low solubility of the initiator in non-polar solvents, unavailability, low molecular weight polyfunctional homogeneous lithium initiators, low efficiency of prior initiators, limited molecular weight adjustment and low functionality of polymer products. A particular advantage of the process according to the invention is that reactive polymers with a certain adjustable functionality above 2 can be prepared. The functionality of the polymers corresponds to the functionality of the initiator and lies between 2 and 4.5. These polymers can be easily crosslinked with bifunctional crosslinking agents.

237 380

The resulting polymers are star-shaped and have a lower viscosity than linear polymers, which facilitates their processing. The average molecular weight of the polymers is 1.2 to 1.3 on average.

Example 1

125 ml of the initiator solution prepared by reaction of 40 molar secondary with the technical divinyltoenzene mixture containing 78.9 mmol of vinyl groups in benzene and 300 ml of benzene were added to an argon atmosphere in a sulphonation flask. at 308 K. After completion of the reaction, the mixture was stirred for 0.5 h and then stirred. The polymerization disrupted 44 ethylene oxide, hydrolyzed with 50 ml of water, the aqueous phase separated and the solvent removed on a rotary evaporator. In 100% yield, liquid pollutants of butadiene with a mean molaroculum of 4900 and a 50 nanoelectructure were obtained. % 1,4-, 32 molar% 1,2- structure and divinylbenzene content 18 notary%. The hydroxyl group content determined by acidoneeric titration was 1.42 hr.%, Which corresponds to a function of 4.1.

Example 2

To a solution of the initiator obtained from 63 mol / l of hexane and technical divinyl-thiophene with 78.9 mol of vinyl groups in 140 ml of toluene was added under argon atmosphere. 400 ml of toluene and to the homogeneous solution were then gradually added over 1 hour for a total of 60. g iztprjou. The polyoeration temperature was 273 K. After completion of the polymerization, ethylene oxide was fococitalylated and hydrolyzed as in Example 1, including further processing. The insulated polyisoprene had a medium ooOekull rating of 2500 and a hydroxyl group content of 1.41 h · · which corresponds to a function of 2.15 ·

Theoooo ooOekull's rank was 2700.

- 5 Example 3 ^{237 380}

Using an initiator prepared from 80 mmol of n-butyllithium and technical divinyibenzene containing 157.8 mmol of vinyl groups dissolved in 750 ml of benzene, polymerization was carried out in succession over 2 hours at 323 K of 60 g of butadiene and 40 g of styrene. Thereafter, 88 mmol of ethylene oxide were functionalized and the usual further work-up was carried out. The block copolymer obtained consisted of 74.5 mol% butadiene and 25.5 mol% styrene. The molecular weight was 5400 and the functionality was 4 < 3 > which corresponded to a hydroxyl group content of 1.35 wt. % ·

Claims (2)

1. A process for the preparation of homopolymers and copolymers of 1,3-dienes, in particular butadiene and isoprene, with end-to-end moieties having a homogeneous anionic polymerization of monomers in non-polar, aliphatic, cycloaliphatic or aromatic solvents in the presence of lithium initiators. initiators, followed by. by functionalization of living polymers with electrophilic reagents, in particular alkylene oxides, carbon dioxide or carbon monoxide, characterized in that the polymerization is carried out at a temperature of 198 K to 423 K in the presence of polylithio initiators resulting from the reaction of technical mixtures with divinylbenzene consisting of 10 up to 70% by weight of divinylbenzene, 80% to 30% by weight. Ethyl styrene and 10% w / w of a diethylbenzene, with an alkylcythyl lithium compound, in particular a secondary, iso- or o-bryllithium, wherein the ratio of vinyl groups in the divinylbenzene mixture to the alkyl lithium is 1.1: 1 to 2: 1, in a hydrocarbon solvent, preferably benzene or toluene; 2. A process according to claim 1, wherein the polymerization is carried out at a temperature of 273 K to 323 K.