BE889002A - POLYMERS PRIMED BY DIENYL-LITHIUM - Google Patents

Description

       

  The present invention relates to polymers containing terminal groups comprising multiple unsaturation. The present invention also relates to branched polymers, prepared by the self-polymerization of living polymers having terminal conjugated dienyl groups. According to another

  
From its aspects, the present invention also relates to graft copolymers, using a sequential addition of a second monomer to a living polymer having terminal conjugated dienyl groups. According to another of its characteristics, the invention also relates to crosslinked high molecular weight polymers, using a priming of a preformed polymer comprising one or more terminal conjugated dienyl groups. According to yet another of its characteristics, the invention relates to coupled polymers.

  
Solution polymerization was carried out

  
conjugated dienes and other monomers with a variety of organolithium initiators and various types of "terminations" to place various active terminal groups on such polymers, such as hydroxyl groups and the like, at various stages of curing. However, a certain route was needed for the production of a polymer with more useful end groups leading to improved properties, to wider ranges of application, in particular for obtaining higher vulcanized products. .

  
The Applicant has now discovered that the employment

  
of what can in short be called dienyllithium initiators generated polymers and copolymers by carrying out solution polymerization processes which have unusually terminal reactive dienyl groups and which gives improved properties generating, for example products vulcanized upper.

  
The polymers in accordance with the present invention are prepared by initiating the polymerization of olefinically mono-unsaturated and di-unsaturated organic monomers, under solution polymerization conditions, with

  
a dienyllithium initiator. The living polymer thus obtained can be terminated with an agent containing an active hydrogen, can be coupled to various coupling agents

  
di- or poly-functional, terminated by styling with a compound which generates the polymer with a terminal group having a conjugated unsaturation, can be maintained under conditions suitable for ensuring the self-polymerization of the living polymer, treated with another reactive monomer to generate a grafted polymer, more reactive on another part of anionic initiator, or

  
well we can proceed to a combination of all these treatments.

  
Dienyllithium initiators are prepared by reacting hydrocarbon 1,4-diolefins with hydrocarbon lithium compounds.

  
Hydrocarbon 1,4-diolefins can be cyclic or acyclic and there currently appears to be no limitation on the number of atoms

  
carbon as far as it relates to the possibility of implementation. For reasons of convenient availability, 1,4-olefins having 5 to 12 carbon atoms per molecule are currently preferred. As examples of such 1,4-diolefins, mention may be made of 1,4-pentadiene, 2-methyl-1,4-pentadiene, 3-methyl1,4-pentadiene, 1,4-hexadiene, 1- 1,4-methyl-

  
  <EMI ID = 1.1>

  
y-terpinene and the like, alone or in mixtures.

  
The lithium hydrocarbon compounds used to react with the 1,4-diolefins can

  
  <EMI ID = 2.1>

  
R represents a hydrocarbon radical which can be a saturated aliphatic group, saturated cycloaliphatic group, aromatic group or a combination group and x represents an integer whose value varies from 1 to 4. The group R has a valence equal to x. There does not currently seem to be any limitation as regards the possibility of implementation, as regards the size of the group R, but, for reasons of convenience and availability, R contains, of. preferably

  
1 to 20 carbon atoms.

  
As examples of hydrocarbon organolithium compounds, mention may be made of the following substances:

  
  <EMI ID = 3.1>

  
sec-butyllithium, tert-butyllithium, n-decyllithium,! phenyllithium, naphthyllithium, 4-butylphenyllithium,

  
  <EMI ID = 4.1>

  
n-butyllithium, due to their availability. These dienyllithium initiators are prepared by implementing the general methods described by R.B. Bâtes, D.W. Gosselink and J.A. Kacynski in Tetrahedron Letters,

  
  <EMI ID = 5.1>

  
the reaction of one or more of the 1,4-diolefins with

  
  <EMI ID = 6.1>

  
saturated hydrocarbon and a polar solvent, such as a mixture of hexane and tetrahydrofuran.

  
The ratio of the organolithium compound to 1,4diolefin normally ranges from about 0.9: 1 to 1: 1 equivalent of lithium per mole of 1,4-diolefin. It is preferred to use a slight excess of diene to guarantee complete conversion of the entire organolithium.

  
  <EMI ID = 7.1>

  
The volume ratio of the saturated hydrocarbon to the polar solvent must predominate in favor of the hydrocarbon, and be such that about 20: 1 to 2: 1, preferably about 5: 1 to 2: 1, currently more preferably still about 3: 1. The amount of solvent used is that which is sufficient to keep the organolithium product substantially in solution.

  
The saturated hydrocarbon is chosen from one or more of the aliphatic hydrocarbons which are normally liquid, used alone or in mixtures. As examples of suitable hydrocarbons, there may be mentioned n-pentane, n-hexane, n-heptane, cyclopentane and cyclohexane, alone or in mixtures. N-heptane is currently preferred.

  
The polar solvent type component of the solvent mixture can be chosen from one or more of the normally liquid ethers, such as those of compounds having from 2 to 8 carbon atoms per molecule. As examples of suitable polar components, mention may be made of tetrahydrofuran, dimethyl ether, diethyl ether and di-n-butyl ether, alone or in mixtures. Tetrahydrofuran is currently preferred.

  
The reaction between 1,4-diolefin and the organolithium compound R (Li) x is considered to be a

  
  <EMI ID = 8.1>

  
when the reaction mixture is allowed to warm slowly. Therefore, the reagents and the solvent mixture should be mixed at a suitable convenient low temperature, since the reaction begins immediately, such as a temperature of about <EMI ID = 9.1>

  
The cooled mixture is then gradually reheated to a temperature which varies from temperature

  
  <EMI ID = 10.1>

  
The reaction mixture usually separates into two layers. When separation occurs,

  
  <EMI ID = 11.1>

  
days the case, the upper layer normally contains a minor amount of organolithium compound and

  
  <EMI ID = 12.1>

  
while the lower layer contains the initiator at

  
  <EMI ID = 13.1>

  
milk and a minor amount of hydrocarbon.

  
For use as a polymerization initiator, the dienyl layer is separated. Dienyllithium compounds require neither purification nor prior isolation and can be stored in the reaction solvent or in additional solvent at a low temperature, such as around -10 ° C, for an indefinite storage period . We typically use and consider

  
as necessary the use of a protective atmosphere, such as a nitrogen, argon or helium atmosphere.

  
The quantity of dienyl initiator which is used for the polymerization can vary between wide limits depending, of course, on the desired molecular weight of the polymer, on the reactivity of the monomer, etc.

  
  <EMI ID = 14.1>

  
milliequivalents-grams of lithium per 100 grams by weight of monomer, the preferred range varying from 0.5 to
20 milliequivalents, based on the titrated value in the dienyllithium initiator,

  
Although the Applicant does not wish to limit itself to any theory, we can consider the dienyllithium compounds as having a delocalization of charge on 5 carbon atoms and that they are consequently likely to adopt three conformations if the 1,4 - starting diolefin is not alicyclic in nature, as shown in Table 1. By this same theory, the alicyclic dienyllithium compounds would be limited to one conformation only, the specific conformation depending on the location of the double bonds in 1, Starting 4-diolefin, also as shown in Table 1:

Table 1

Dienyllithium compounds

  
From linear 1,4-diolefins, such as 1,4-
  <EMI ID = 15.1>
   <EMI ID = 16.1>

  

  <EMI ID = 17.1>


  
From cyclic 1,4-diolefins such as terpinolene

  

  <EMI ID = 18.1>


  
In each of these conformations, the primer site, that is to say the carbon atom which becomes linked to the first monomer unit, can be found on carbon atoms 1,3 or 5. If the attachment takes place at carbon atoms 1 or 5. the resulting terminal diolefin on the polymer chain will have the desired conjugated unsaturation, while if the attachment takes place on carbon atom 3 of the priming species , the resulting terminal diolefin will not be conjugated. These types of possible terminal unsaturation are assumed to be as shown in Table 2.

Table 2

  
Types of terminal unsaturation possible on the polymer From 1,3-butadiene (Bd) primed with dienyllithium
  <EMI ID = 19.1>
 
  <EMI ID = 20.1>
 The attachment point for any polymer

  
  <EMI ID = 21.1>

  
Statistical distribution of the types of terminal unsaturated functional group has hitherto not been determined with precision for the polymerizations in accordance with the invention. However, the formation of the polymer having the quantitative amount of the terminal conjugated dienyl groups based on the amount of dienyl initiator used, was not carried out in these polymerizations. All that we have analyzed is the conjugated diene. Either the rest of the terminal groups are not conjugated by attachment to carbon 3 (Table 2), or is a partially self-polymerized terminal group conjugate.

  
The monomers capable of being polymerized using the dienyllithium initiators for the production of polymers according to the present invention are the

  
  <EMI ID = 22.1>

  
di-unsaturated, polymerizable under solution polymerization conditions by the use of anionic initiators, such as organolithium initiators. Roughly speaking, these monomers include conjugated dienes, monovinylarenes, acrylates (esters of acrylic lucid and alkacrylic acids), vinylpyridines, vinylidene halides, vinylquinolines, nitriles, N, N-disubstituted acrylamides, vinylturan , N-vinylcarbazole. These mono-

  
  <EMI ID = 23.1>

  
technical specialists know this perfectly well.

  
Such monomers generally contain, for reasons of availability, from 2 to 12 carbon atoms per molecule. As typical examples of such monomers, mention may be made of 1,3-butadiene, isoprene, piperylene, styrene, 1-vinylnaphthalene, acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, acrylate d , methyl methacrylate, vinylidene chloride and others as well as specialists in

  
the technique know it perfectly well. Such monomers generally contain, for reasons

  
availability, from 2 to 12 carbon atoms per molecule. As typical examples of such monomers,

  
  <EMI ID = 24.1>

  
2-vinylpyridine, 4-vinylpyridine, ethyl acrylate, methyl methacrylate, vinylidene chloride

  
and others, as well as those skilled in the art, are well aware. Butadiene is currently preferred,

  
  <EMI ID = 25.1> <EMI ID = 26.1>

  
Polymers which can be prepared may include homopolymers, block copolymers, stochastic copolymers, graft copolymers, and mixtures and combinations of these products. Sequential polymerization processes, such as those described in the art, are perfectly suitable. Polymerization conditions.

  
The polymerization of the desired monomer (s) can be carried out by using methods and techniques well known to specialists in polymerization in anionic solution.

  
The desired monomer (s) can be brought into contact with the initiators based on dienyllithium in a hydrocarbon polymerization diluent. These hydrocarbon diluents include paraffins, cyclo

  
  <EMI ID = 27.1>

  
mixed, usually from 4 to 10 carbon atoms per molecule, including compounds such as pentane, hexane, cyclohexane, n-heptane, benzene, toluene and the like, alone or in mixtures.

  
The polymerization stage or stages can be carried out at the polymerization temperatures which are generally suitable for polymerization conditions in anionic solution. Typical suitable reaction conditions include temperatures which

  
  <EMI ID = 28.1>

  
about +30 to +75 [deg.] C, at any convenient pressure, usually sufficient to maintain substantially liquid phase conditions. The contact time can be as convenient or desirable, and usually varies from several minutes to several hours, so as to generate a solution of a living polymer, i.e. a polymer containing carbon- lithium at one end of the molecules <EMI ID = 29.1> further polymerization. The polymerization step is normally carried out until a substantially complete polymerization (complete conversion).

  
Those skilled in the art are already aware of methods of charging, protecting monomers, diluents, initiators, finishing polymer, and the like from moisture and other materials which could tend to destroy active lithium.

  
The treatment of living polymers thus obtained with a compound containing active hydrogen, such as isopropyl alcohol, generates a polymer which, as ultraviolet spectroscopy reveals, contains at least certain functional conjugated diene groups.

  
  <EMI ID = 30.1>

  
normally well below the maximum theoretical quantity as described above. The fact that a yield of a quantitative amount of a polymer with a terminal conjugated dienyl group is not obtained is believed to be due, at least in part, to the competition that occurs for the point of attach of

  
  <EMI ID = 31.1>

  
previously described.

  
A second competitive reaction occurs which is believed to also reduce the amount of functional conjugated dienyl groups in the final polymer. This reaction involves a branching or self-coupling reaction which occurs when the terminal living carbon-lithium bond of a polymer chain adds to the terminal functional conjugated dienyl group of a second polymer chain, as well as Table 3 l 'illustrates:

  
Table 3

  

  <EMI ID = 32.1>


  
This competitive reaction can lead to the formation of a branched polymer if additional monomer is present (residual or added), so as to react on

  
carbon-lithium groups after this self-coupling has occurred and can also lead to a crosslinked polymer ai the two carbon-lithium groups of the product

  
  <EMI ID = 33.1> <EMI ID = 34.1>

  
The proof that this autocoupling occurs is in the observed increase in molecular weight and in the widening of the molecular weight distribution of the polymer and in the reduction of the amount of unsaturation combined in the final polymer with more long polymerization times (delayed termination of living polymer).

  
Priming polymerization of monovinylarenes

  
with initiators based on dienyllithium results in a much faster speed and a much higher proportion of self-coupling & leading to a poly-
(monovinylarene) branched and crosslinked7 than those which

  
manifest themselves when conjugated dienes are primed with these same dienyllithium-based initiators.

  
The sequential addition of a second monomer to the living, self-coupled polymer leads to the formation of new graft copolymers. These polymers are believed to be complex branched copolymers having sections which are typically copolymeric in nature.

  
block and, moreover, the polymer has

  
homopolymer and block copolymer grafts at limited, specific sites on the polymer framework

  
as shown in Table 3.

  
  <EMI ID = 35.1>

  
  <EMI ID = 36.1> be terminated with any of the known active hydrogen-containing compounds.

  
Coupling

  
As an alternative to the treatment of the living polymer which

  
  <EMI ID = 37.1>

  
by a compound containing active hydrogen, the living polymer can be coupled with difunctional or even higher functionality coupling agents, or it can be reacted with a compound which provides a terminal group having conjugated unsaturation. The polymers thus obtained will be conjugated unsaturated telechelic polymers.

  
Coupling agents are preferably used because the products thus obtained exhibit an increase in Mooney viscosity as well as other desirable properties. The term "coupling" as used by the applicant in this memo is used in a broad generic sense and designates the association and the union of two or more of two of the polymer chains terminated with lithium alive by through a coupling group

  
or a central coupling atom.

  
A wide variety of compounds can be used for this purpose as the technique teaches. Among the suitable coupling agents, mention may be made of multivinyl aromatic compounds, multi-epoxides,

  
  <EMI ID = 38.1> multicetones, multihalides, multianhydrides, multi-esters which use esters of polyalcohola and monocarboxylic acids, as also diesters which are esters of monohydroxylated alcohol and dicarboxylic acids , agents with combination groups, carbon monoxide, carbon dioxide. sulfur halides, halogens and the like.

  
Examples of suitable multivinyl aromatic compounds include divinylbenzene, 1,2,4-

  
  <EMI ID = 39.1>

  
naphthalene, 1,3,5-divinylnaphthalene, 2,4-divinyldiphenyl and the like. We prefer hydrocarbons

  
  <EMI ID = 40.1>

  
whether it's the ortho, meta or para isomer. Commercial divinylbenzene which is a mixture of the 3 isomers

  
and other compounds are entirely satisfactory.

  
Although multi-oxides can generally be used, those which are liquid are more easily handled and form a relatively small nucleus for

  
the coupled polymer. Particularly suitable among multi-epoxides, epoxidized hydrocarbon polymers, such as epoxidized liquid polybutadiene and epoxidized vegetable oils, such as epoxidized soybean oil and epoxidized linseed oil. It is also possible to use other epoxidized compounds, such as 1,2; 5.6; 9,10-triepoxydecane and the like.

  
As examples of suitable multi-isocyanates,

  
  <EMI ID = 41.1>

  
arylpolyisocyanate having an average of 3 isocyanate groups per molecule and an average molecular weight of approximately 380. One can consider such a compound as consisting of a series of isocyanato-benzenic nuclei united via methylene bonds.

  
Multiimines, also known as multiaziridinyl compounds, are preferably those which contain 3 and more than 3 aziridine rings per molecule. As examples of such compounds, there may be mentioned sulfides or oxides of triaziridinyl phosphines, such as

  
  <EMI ID = 42.1>

  
aziridinyl) phosphine oxide, tri (2-ethyl-3-decyl-1aziridinyl) phosphine sulfide and the like.

  
Multi-aldehydes are represented by compounds

  
  <EMI ID = 43.1>

  
anthracènetricarboxaldehyde, 1,1,5-pentanetricarboxaldehyde and similar aliphatic and aromatic multi-aldehyde compounds.

  
Multi-ketones are represented by compounds

  
  <EMI ID = 44.1>

  
cyclohexanone and the like.

  
As examples of multi-anhydrides, mention may be made of pyromellitic dianhydride, copolymers of

  
styrene and maleic anhydride and the like.

  
As examples of multi-esters, there may be mentioned diethyladipate, triethyl citrate, 1,3,5-tricarbetoxy-

  
  <EMI ID = 45.1>

  
currently use silicon tetrahalides, such as silicon tetrachloride, silicon tetrabromide and silicon tetraiodide and trihalo-

  
  <EMI ID = 46.1>

  
trichlorethylsilane, tribromobenzylsilane and the like. Also preferred are multihalogenated hydrocarbons, such as 1,3,5-tri (bromo-

  
  <EMI ID = 47.1>

  
analogs, in which the halogen is attached to a carbon atom which is in relation to an activating group, such as an ether bond, a carbonyl group or a carbon to carbon double bond. Inert substituents with respect to lithium atoms in

  
the terminally reactive polymer may also be present in compounds containing active halogens. Alternatively, there may also be present other suitable reactive groups which differ from the halogens, as already described above.

  
Besides the silicon multi-halides as described above, it is also easy to employ <EMI ID = 48.1>

  
metals, such as silicon tetraethylate.

  
Examples of compounds containing more than one type of functional group include the following:

  
  <EMI ID = 49.1>

  
Difunctional coupling agents can be used when it is desired to obtain a linear polymer rather than a branched polymer.

  
Roughly and illustratively, we use

  
  <EMI ID = 50.1>

  
ment preferred varying from about 0.01 to 1.5 milliequivalents of coupling agent per 100 g of monomer, in order to obtain the desired Mooney viscosity. An equivalent of the lithium equivalent treatment agent is considered to be the optimum amount for one branch.

  
  <EMI ID = 51.1>

  
during the production of the desired product. We can

  
  <EMI ID = 52.1>

  
  <EMI ID = 53.1>

  
Termination of the living polymer by unsaturated compounds.

  
Other suitable compounds which can be reacted on living dienyllithium (terminal dienyl group) primed polymers to obtain an unsaturated, terminal conjugated group, include linear and cyclic conjugated unsaturated compounds which may also contain another group capable to react on the lithium present on the polymer. This is another method of forming the polymer having telechelic conjugated dienyl groups. These compounds

  
  <EMI ID = 54.1>

  
clicks that respond to the following structures:

  

  <EMI ID = 55.1>


  
at linear conjugated dlenes of the general structure

  
  <EMI ID = 56.1>

  

  <EMI ID = 57.1>


  
cIan8

  
  <EMI ID = 58.1> n is an integer with a varying value

  
from 1 to 6 and Y represents a functional group which reacts easily on the lithium present on the polymer, such as a halogen. As examples of compounds suitable for providing an unsaturated functional group which is terminal conjugate to the polymer, the following substances may be mentioned:

  
  <EMI ID = 59.1>

  
tion such that one obtains one mole of the unsaturated compound conjugated per equivalent of lithium initiator used for carrying out the polymerization. The conditions employed can be those previously described with regard to coupling agents. Termination.

  
  <EMI ID = 60.1>

  
unsaturated or coupling agents leads to the appearance of a polymer which still retains lithium, as is, for example, the case when resorting

  
  <EMI ID = 61.1>

  
with at least an equivalent amount of a compound containing active hydrogen per equivalent of lithium. This is obviously not necessary when the

  
  <EMI ID = 62.1>

  
  <EMI ID = 63.1>

  
  <EMI ID = 64.1> of the living polymer such as, for example, the lithium halide, when using tetrachloride

  
  <EMI ID = 65.1>

  
reacting.

  
Re-priming.

  
Semi-tele-terminated polymers can be primed

  
  <EMI ID = 66.1>

  
initiators of the organolithium type with the structure R (Li) x as previously described. The polymerization of the conjugated unsaturated end groups is reflected

  
  <EMI ID = 67.1>

  
distribution of molecular weights. Such polymers can become very strongly crosslinked and it can be tolerated that their formation progresses to the state of gelled product. Optionally, you can add a

  
  <EMI ID = 68.1>

  
  <EMI ID = 69.1>

  
species of polymer with a very wide molecular weight distribution.

  
Recovery.

  
In general, we add an antioxidant to the mixture

  
polymerization just before recovery. The various polymers which can be prepared by carrying out the process according to the present invention can be recovered or isolated by the use of any suitable means, such as coagulation in a

  
  <EMI ID = 70.1>

  
  <EMI ID = 71.1>

  
cbq8.

  
Utility.

  
The polymers have various fields of application depending on the particular polymer which is prepared, including use for example in stripes

  
  <EMI ID = 72.1>

  
sif, impact resistant resins, loose gels with controlled structure, mechanical rubber products and the like.

EXAMPLES

  
The examples which follow are intended to facilitate understanding of the invention to those skilled in the art. The particular materials used therein, relationships, species and the like, are only cited for purely illustrative purposes and do not limit the invention in any way.

  
EXAMPLE 1

  
The pentadienyllithium type polymerization initiator was prepared by implementing the general method described by R.B. Bâtes, D.W. Gosselink and J.A. Kaczynski,

  
  <EMI ID = 73.1>

  
We dried a Pyrex bottle with a capacity

  
  <EMI ID = 74.1>

  
  <EMI ID = 75.1>

  
dry, it was capped with a perforated crown capsule placed over a self-sealing rubber seal and it was put under a dry nitrogen pressure of 0.17 MPa.

  
After letting it cool to the temperature

  
  <EMI ID = 76.1>

  
in n-heptane and 80 ml of dry tetrahydrofuran in the bottle and the bottle and its contents were then cooled to -78 [deg.] C in a dry ice bath

  
  <EMI ID = 77.1>

  
At this temperature, 32 ml of 1,4-pentadiene was introduced into it and, after 15 minutes, the bottle was transferred to an ice-water bath and kept there for 30 minutes. During the transition period

  
  <EMI ID = 78.1>

  
lower layer, yellow-orange, consisting essentially of pentadienyllithium in tetrahydrofuran. A 70 ml fraction of the bottom layer was diluted with 700 ml of dry benzene and titrated

  
  <EMI ID = 79.1>

  
C.A. Uraneck, J.E. Burleigh and J.W. Cleary, Anal. Chem.
40 (2), 327 (1968). This solution was determined to be 0.2542 M in pentadienyllithium and was used as an initiator for carrying out the next polymerization.

  
Medium vinyl polybutadienes were prepared using the above-mentioned pentadienyllithium as initiator. Test polymer 2 was terminated with alcohol, Test polymer 3 was terminated with

  
  <EMI ID = 80.1>

  
test 4 by coupling the living polymer with <EMI ID = 81.1>

  
prepared in test 1, a medium vinyl polybutadiene using n-butyllithium as initiator and terminating with isopropyl alcohol. In this recipe, as in all of the following recipes, when it does not appear

  
  <EMI ID = 82.1>

  
it was terminated with alcohol.

  
The polymerizations were carried out using substantially anhydrous conditions and reagents, under an inert atmosphere (nitrogen) in beverage bottles with a capacity of 290 cc, fitted with crown capsules perforated over self-sealing rubber seals. . The bottles and their contents were shaken by tumbling in a constant temperature bath throughout the polymerization period. After a specified polymerization period,

  
  <EMI ID = 83.1>

  
phenol (2 parts by weight per 100 parts of monomer),

  
  <EMI ID = 84.1>

  
mixture of toluene and isopropyl alcohol (80/20 by volume) and the polymer was then coagulated by the addition of isopropyl alcohol to the polymerization mixture.

  
  <EMI ID = 85.1>

  
tion following step I in tests 1 and 2 and after step II in tests 3 and 4. After coagulation, the polymers were collected by filtration and

  
  <EMI ID = 86.1> <EMI ID = 87.1>

  
  <EMI ID = 88.1>

  
diene means according to recipe I:

RECIPE I

  

  <EMI ID = 89.1>


  

  <EMI ID = 90.1>


  
(a) w / w - parts by weight.
(b) Millimoles per 100 grams of total monomers used in the polymerization.
(c) Added as a 0.2486 M solution in benzene / THF approximately 10/1 by volume.
(d) Added as a 0.2133 M solution in benzene / THF approximately 10/1 by volume.
(e) Added as a 0.2542 M solution in benzene / THF approximately 10/1 by volume.
(f) Added as 0.1098 M solution in cyclohexane / n-heptane approximately 14/1 by volume.

  
(g) Added as a 0.09 M solution in cyclohexane.

  
(h) Added as 0.138 M solution in cyclohexane.

  
The physical properties of the medium vinylpolybutadiene polymers prepared by using recipe I are collated in table 1 which follows.

TABLE I

Physical properties of polymers containing terminal conjugated dényl groups

  

  <EMI ID = 91.1>


  
(a) Moonay viscosity. ASTM D1646-74.
(b) Percentage determined by infrared absorption spectroscopy. <EMI ID = 92.1> of the process described in the United States patent

  
  <EMI ID = 93.1>

  
  <EMI ID = 94.1>

  
as early as one. filtered a sample of the solution

  
  <EMI ID = 95.1>

  
porosity of degree C and pressurized directly in the viscometer.

  
  <EMI ID = 96.1> number average molecular. Determined using a gel chromatography method as described by Gerard Kraus and C.J. Stacy, J. Poly. Sci .:
Symposium N [deg.] 43, 329-343 (1973).
(e) I.H. m heterogeneity index. A measure of the distribution of molecular weights and this is the ratio <EMI ID = 97.1>

  
distribution of molecular weights.

  
(f) Percentage determined using the method described in United States patent N [deg.] 3,278,508, column 20, note b.

  
(g) Percentage determined by absorption spectroscopy

  
UV and calculated as percentage by weight of 1,3-pentadienyl groups present in the polymer.

  
The data in Table 1 demonstrate the effectiveness of pentadienyllithium as an initiator for the polymerization of 1,3-butadiene. UV spectroscopy confirmed the presence of conjugated dienyl groups in the poly-

  
  <EMI ID = 98.1>

  
incorporated into the polymer by the process described. The

  
  <EMI ID = 99.1>

  
about 20-35% of the theoretical quantity based on the

  
  <EMI ID = 100.1>

  
ration, had occurred, causing loss of conjugated unsaturation and / or (B) the point of attachment of the initiator to the first monomer was such that a terminal unconjugated unsaturated group formed.

  
EXAMPLE 2

  
The suitability of the medium vinyl polybutadiene polymers containing terminal conjugated unsaturation, as prepared in Example 1, was studied for use in a base vulcanizable blend.

  
Each of the polymers of tests 1-5 was mixed inclusive according to the formula indicated in recipe II.

RECIPE II

  

  <EMI ID = 101.1>


  
(a) Type N330; black industrial reference number 4. <EMI ID = 102.1>

  
Petroleum Co.

  
  <EMI ID = 103.1> All the ingredients, except sulfur and the accelerator, were mixed in a Banbury Midget blender for about 5 minutes at 110 rpm and

  
  <EMI ID = 104.1>

  
The sulfur and the accelerator were added during a second pass of the mixture in the mixer, this second mixing being carried out at 80 rpm for 1.5 minutes and

  
  <EMI ID = 105.1>

  
A further mixing was then carried out for

  
  <EMI ID = 106.1>

  
7.62 mm leaux. Each mixture of vulcanized

  
  <EMI ID = 107.1>

  
properties of each vulcanized rubber are collated in Table II.

TABLE II

  
&#65533; &#65533; &#65533; &#65533; &#65533; &#65533; &#65533;

  
  <EMI ID = 108.1>

  
mixed and vulcanized terminal conjugates
  <EMI ID = 109.1>
 (a) ASTM D412-75.
(b) ASTM D395-69. Process B was modified as follows: compression devices with 8.255 mm spacers were used, so as to obtain static compression for the 12.7 mm portion.

  
  <EMI ID = 110.1>

  
  <EMI ID = 111.1>

  
1 hour at 100 [deg.] C.

  
(c) ASTM D623-69.
(d) ASTM D945-72. The test was modified to mean that the sample was a straight circular cylinder with a diameter of 17.78 mm and a height of 25.4 mm.
(e) ASTM D2440-75.

  
These data demonstrate that the polymers of tests 2,3 and 4 having terminal conjugated dienyl groups, confer improved properties on the vulcanized base mixture, in comparison with what happens with test 1 control without terminal conjugated dienyl groups. This improvement is proven by the ac-

  
  <EMI ID = 112.1>

  
the tensile strength (tensile in the table) of the vulcanized mixed rubber of test 3; the reduced heat build-up and elasticity of the rubber in test 2 (the unusual poor tensile strength appears to be due to a poor test) and the relatively good values obtained on the vulcanized rubber in test 4 in due to its extremely low Mooney viscosity in the mixed state (the Mooney viscosity in the green state was significantly lower than that of the other polymers - see Table I). Applicants believe that if the polymer in test 4 had been prepared with a Mooney viscosity equivalent to that of the control in test 1, then all of the above-mentioned physical properties of the rubber in test 4 would have been significantly superior to that of rubber of control test 1.

  
EXAMPLE 3

  
Dienyl initiators were prepared from each of the following compounds:

  
  <EMI ID = 113.1>

  
terpinolence and 1,4-hexadiene.

  
In a Pyrex bottle with a capacity of
475 ml (dried and encapsulated in the manner described in Example 1), 150 ml of 1.61 M n-butyllithium were introduced into n-heptane, as well as 60 ml of dried tetrahydrofuran. After cooling this solution to -78 ° C., 20.8 g of 2-methyl-1,4pentadiene were added and the reaction mixture was kept at this temperature for 15 minutes. Then we have

  
  <EMI ID = 114.1>

  
this temperature for 45 minutes. During this period, a lower red layer separated. This layer was removed (approximately 60 ml) and diluted with 607 ml of toluene. The disulfide titration indicated that this solution was 0.246 M in 2-methylpentadienyllithium.

  
An organolithium compound was prepared from

  
  <EMI ID = 115.1>

  
similar way. Dilution of the lower layer of the reaction mixture with a 1/1 volume of a mixture of tetrahydrofuran and cyclohexane resulted in a

  
  <EMI ID = 116.1>

  
revealed that it was 0.849 M in 3-methylpentadienyllithium.

  
Terpinyllithium was prepared using 19 ml of 1.61 M n-butyllithium, 8 ml of tetrahydrofuran and 3.72 g of tercinolene, in a similar manner to that described above. However, there was no separation of the reaction mixture into 2 layers during the preparation of the terpinyllithium, as it had occurred during the preparation of all the other initiators based on dienyllithium previously described. 25 ml of the reaction mixture was diluted with
172 ml of toluene, so as to obtain a 0.1121 M terpinyllithium solution.

  
1,3-hexadienyllithium was prepared in a similar manner using 100 ml of 1.61 M n-butyllithium,
40 ml of dry tetrahydrofuran and 14 g of 1,4-hexadiene. The separation of the reaction mixture into 2 layers did not occur during its preparation, but occurred at a slower rate than that observed during the preparation of the pentadienyllithium described in Example 1. In addition, there was formation of a certain yellow precipitate. The lower deep red layer was diluted with toluene to give a 0.1284 M hexadienyllithium solution.

  
Medium vinyl polybutadienes were prepared using the 4 preferred initiators as described above and using the general method described in Example 1, in accordance with Recipe III.

RECIPE III

  

  <EMI ID = 117.1>


  
Stage II
  <EMI ID = 118.1>
 RECIPE III (continued)
  <EMI ID = 119.1>
(a) Added as a 0.1490 M solution in <EMI ID = 120.1> hexane approximately 2/1 by volume.
(c) Added as 0.246 M solution in toluene / <EMI ID = 121.1>
(e) Added as a 0.1264 M solution in toluene /

  
  <EMI ID = 122.1>

  
(f) Added as a 0.0876 M solution in cyclohexane.

  
The physical properties of these polymers are

  
gathered in Table III-A:

TABLE III-A

  
Physical properties of medium vinyl polybutadienes

  
primed using initiators based on dienyl-

  
'1 i + hium
  <EMI ID = 123.1>
  <EMI ID = 124.1>
 These polymers were mixed according to recipe II and the process described in Example 2 and their properties were evaluated as a vulcanized base mixture. The properties of mixed and vulcanized rubber (45 minutes at 150 [deg.] C) appear in Table III-B:

TABLE III-B

  
  <EMI ID = 125.1>

  
using an initiator based on dienyllithium, mixed

  
and vulcanized

  

  <EMI ID = 126.1>


  
  <EMI ID = 127.1>
  <EMI ID = 128.1>
 (a) n-Butyllithium.
(b) 3-Methylpentadienyllithium. <EMI ID = 129.1>
(d) Terpinyllithium.
(e) Hexadienyllithium. <EMI ID = 130.1> coupling.

  
These data demonstrate the reduced heat accumulation (AT) and the improved elasticity as a whole of the polymers initiated in the dienyllithium of tests 6-11,

  
  <EMI ID = 131.1>

  
control test 5. These superior properties of the polymers of tests 6-11 in accordance with the invention are

  
  <EMI ID = 132.1>

  
be incorporated into the structure due to the vulcanized product and which results in a more efficient contribution of the polymer molecules to the resistance of the network.

KXKMPU

  
  <EMI ID = 133.1> coupling is not included in the recipe, the tormination was carried out using alcohol:

RECIPE IV

  

  <EMI ID = 134.1>


  
(a) Added as a 1.030 M solution in

  
THF / cyclohexane, approximately 2/1 by volume.

  
  <EMI ID = 135.1>

THF / cyclohexane, approximately 2/1 by volume,

  
The analysis of the conjugate unsaturation of these polymers is given in Table IV.

TABLE IV

  
Conjugated unsaturation of polymers primed with 2-methyl and 3-methylpentadienyllithium, as a function of duration

  
polymerization
  <EMI ID = 136.1>
(a) 2-Methylpentadienyllithium.
(b) 3-Methylpentadienyllithium.

  
These data demonstrate that living polymers

  
  <EMI ID = 137.1>

  
terminal terminals are less prone to self-curing

  
  <EMI ID = 138.1>

  
  <EMI ID = 139.1>

  
EXAMPLE 5

  
Tests 16 and 17 demonstrate the self-polymerization of living vinyl polybutadiene. Medium vinyl polybutadiene was prepared by implementing the general methods described in Example 1 and in accordance with recipe V.

RECIPE V

  

  <EMI ID = 140.1>


  
(a) Added as a 0.2644 M solution in benzene / THF approximately 10/1 by volume.

  
When no coupling agent is indicated, the termination is carried out by alcohol.

TABLE V

  
Physical properties of polymers as a function of time

  
polymerization

  

  <EMI ID = 141.1>


  
These data illustrate that self-polymerization of living polybutadiene with pentadienyl groups

  
terminals operate after the quantitative conversion of the monomer to polymer. The self-polymerization results in a combined loss of unsaturation and a concomitant increase in the inherent viscosity and in the molecular weight and in an enlarged distribution of the molecular weights (higher H.I.) as a function of time after the quantitative conversion of the monomer into polymer.

  
EXAMPLE 6

  
Tests 18 and 19 demonstrate the preparation of a multi-branched polybutadiene by initiating the polymerization with the aid of pentadienyllithium, terminating the living polymer, after substantially quantitative conversion of the monomer into the polymer, with a stoichiometric amount of isopropyl alcohol and then re-priming the semi-telechelic pentadienyl polybutadiene

  
using n-butyllithium.

  
Each polymer was prepared using general processes as described in Example 1, in accordance with

  
  <EMI ID = 142.1>

RECIPE VI

  

  <EMI ID = 143.1>


  
(a) Added as a 0.1341 M solution in benzene / THF, approximately 20/1 by volume.
(b) Added as a 1.50 M solution in cyclohexane.
(c) added as a 0.0611 M solution in cyclohexane / n-heptane, approximately 25/1 by volume.

  
Samples of each polymer were recovered by coagulation with excess isopropyl alcohol and isolation by typical methods after steps 2, 3 and 4. The physical properties of these polymers

  
  <EMI ID = 144.1>

TABLE VI

  
Physical properties of branched polybutadiene

  
multiple
  <EMI ID = 145.1>
(a) Primed with pentadienyllithium and terminated with isopropyl alcohol after substantially quantitative conversion of the monomer to polymer.
(b) Polymer terminated in isopropyl alcohol re-primed with n-butyllithium.

  
These data demonstrate that the rearrangement of the polybutadiene terminated with isopropyl alcohol which comprises

  
  <EMI ID = 146.1>

  
the formation of a rssified polymer having a much higher molecular weight) and a much wider distribution of molecular weights (heterogeneity index)

  
  <EMI ID = 147.1>

  
function of time,

  
HUBWJJ 7

  
  <EMI ID = 148.1> <EMI ID = 149.1>

  
telechelic polybutadiene using n-butyllithium.

  
Polymers were prepared using the general methods as described in Example 1, in accordance with recipe VII:

RECIPE VII

  

  <EMI ID = 150.1>


  
  <EMI ID = 151.1>

  
val &#65533; &#65533;

  
Samples of each of the polymers were recovered after steps I, II, III and IV, by coagulation with an excess of isopropyl alcohol and isolation by using typical methods. the physical properties of these recovered polymers appear in Table VI:

TABLE VI

  
Physical properties of highly cross-linked polybutadiene

  
branched
  <EMI ID = 152.1>
(a) Before coupling.
(b) Coupled.

  
  <EMI ID = 153.1>

  
"411 thread.

  
EXAMPLE 8

  
Tests 25 to 28 inclusive demonstrate the polymerization of styrene by pentadienyllithium as initiator.

  
The polystyrene was prepared using the general method as described in Example 1, in accordance with recipe VIII:

RECIPE VIII

  

  <EMI ID = 154.1>


  
(a) Added us form of a 0.1405 M solution in <EMI ID = 155.1>

  
volume.

  
(b) Added torme wheel of a 0.443 M solution in toluèno / <EMI ID = 156.1>

  
  <EMI ID = 157.1>

  
  <EMI ID = 158.1>

  
  <EMI ID = 159.1>

  
The physical properties of these polystyrene polymers are collated in Table VIII:

TABLE VIII

  
Physical properties of polystyrene initiated by penta-

  
  <EMI ID = 160.1>
  <EMI ID = 161.1>
(a) n-Butyllithium.
(b) Pentadienyllithium.

  
The data from tests 25-28 inclusive demonstrate that for the same initiator concentration: <EMI ID = 162.1> polystyrene prepared using pentadienyllithium as initiator is 4 to 5 times greater than that obtained using n-butyllithium and is also approximately 5 times the theoretical kinetic molecular weight.

   The kinetic molecular weight is defined as the weight of the polymerized monomer / moles of the initiator;
(B) the molecular weight distribution (heterogeneity index) of the polystyrene prepared using pentadienyllithium is notably greater than that of the polystyrene prepared using n-butyllithium; (C) maintaining the living polymer cement at the reaction temperature, after complete conversion of the monomeric styrene to polystyrene, results in a significant increase in molecular weight and a widening of the distribution of molecular weights when

  
  <EMI ID = 163.1>

  
meritization, in comparison with a very slight increase only when n-butyllithium is the initiator.

  
These results are compatible with a self-polymerization process, the reaction of the polymer-lithium on the terminal conjugated dienyl group of a second living polymer-lithium and the subsequent propagation reactions, after the complete conversion of the monomer to polymer has occurred. . The applicant assumes that the self-polymerization process takes place not only after complete conversion of the monomer, but is probably a competitive reaction during the polymerization of the monomer to polymer.

EXAMPLE IX

  
Tests 29 and 30 demonstrate the preparation of butadiene-styrene copolymers by the sequential polymerization first of butadiene and then of styrene, using pentadienyllithium as initiator.

  
The polymers were prepared in accordance with the general procedures described in Example 1 and according to recipe IX:

RECIPE IX

  

  <EMI ID = 164.1>


  
(a) Added in the form of a 0.139 M solution in 10/1 by volume cyclohexane / n-heptane.
(b) Added as a 2.1 M solution in benzene /

  
THF, approximately 2/5 by volume.

  
Again, as in Example 1, the termination was carried out using alcohol when no coupling agent is indicated in the recipe.

  
The results are collated in Table IX:

TABLE IX

  

  <EMI ID = 165.1>


  
The graft polymer of test 30 prepared using pentadienyllithium as initiator had

  
  <EMI ID = 166.1>

  
which can be compared to the value of 0.5 MPa only for the control block copolymer of test 29 prepared using sec-butyllithium.

  
EXAMPLE 10

  
Tests 31 and 32 inclusive demonstrate the

  
  <EMI ID = 167.1>

  
prepared by the sequential polymerization of butadiene and styrene using pentadienyllithium as initiator and their evaluation in an adhesive composition.

  
The polymers were prepared according to the general procedures described in Example 1 and in accordance with recipe X:

RECIPE X

  

  <EMI ID = 168.1>
 

  
(a) Added as a 2.1 M solution in benzene /

  
THF, approximately 2/5 by volume.

  
  <EMI ID = 169.1>

  
THF, approximately 21/1 by volume.

  
The termination is carried out with alcohol when no coupling agent is indicated.

  
The physical properties of the two polymers of tests 31 and 32 compared with those of a commercial butadiene / styrene 70/30 copolymer with radial teleblocks,

  
  <EMI ID = 170.1>

  
in table X-A:

TABLE X-A

  
  <EMI ID = 171.1>

  
and styrene

  

  <EMI ID = 172.1>


  
  <EMI ID = 173.1> Adhesive composition
  <EMI ID = 174.1>
(a) A highly stabilized rosin ester conferring viscosity from the company Hercules, Inc. <EMI ID = 175.1>

  
  <EMI ID = 176.1>

  
the invention of tests 31 and 32 are presented in table X-B:

TABLE X-B

  
  <EMI ID = 177.1>

  
grafts
  <EMI ID = 178.1>
 (a) Measured from time to hours for a slip of 1.6 mm when 6.5 cm <2> adhesive on a Mylar backing film are bonded to stainless steel and loaded with shears; a high number represents better slip resistance.
(b) Measured using a Polyken test-tube bonding tester manufactured by the company Testing Machine Inc. The test conditions were as follows: speed of the test-tube: 1 cm / s,

  
  <EMI ID = 179.1>

  
a high number represents a higher degree of bonding.

  
(c) Measured in centimeters as described in the publication <EMI ID = 180.1>

  
(10/64); a high number represents a lower degree of sticking.

  
These data illustrate the suitability of butadiene / styrene copolymers with grafted blocks for entering into the manufacture of adhesives.

  
EXAMPLE 11

  
Tests 33-39 inclusive demonstrate the

  
  <EMI ID = 181.1>

  
  <EMI ID = 182.1> Polymers were prepared according to the general methods given in the previous examples and in accordance with recipe XI:

RECIPE XI

  

  <EMI ID = 183.1>


  
(a) Added as a 0.2613 M solution in <EMI ID = 184.1>

  
various polymerization periods are shown in Table XI.

TABLE XI

  

  <EMI ID = 185.1>


  
TABLE XI (continued)
  <EMI ID = 186.1>
 These data illustrate self-polymerization
(self-coupling) of the polybutadiene block in function

  
time and also the manifestly higher self-polymerization (self-coupling) power of the ter-

  
  <EMI ID = 187.1>

  
In comparison, the sequential polymerization of a

  
  <EMI ID = 188.1>

  
approximately 3.5 mhm of a saturated organo-monolithium, such as n-butyllithium, normally translates

  
  <EMI ID = 189.1>

  
milk by adding styrene to the bright polybutadiene polymer. The self-polymerization or self-coupling which occurs in accordance with one of the characteristics of the present invention appears to lead to a notable increase in the tensile strength in the green state.

  
EXAMPLE 12

  
Tests 40 to 43 inclusive demonstrate the preparation of butadiene-styrene copolymers containing a high proportion of styrene and reveal their advantage as impact-resistant resins.

  
Polymers were prepared according to the general procedures, as previously described and in accordance with recipe XII:

RECIPE XII

  

  <EMI ID = 190.1>


  
(a) Added as 0.135 M solution in benzene / n-heptane approximately 10/1 by volume.
(b) Added as 0.124 M solution in <EMI ID = 191.1>

  
The physical properties of these resins containing a high proportion of styrene from tests 40 to 43 inclusive are presented in Table XII:

TABLE XII

  
Physical properties of butadiene-styrene copolymers

  
containing high proportions of styrene
  <EMI ID = 192.1>
 (a) n-Butyllithium.
(b) Pentadienyllithium.
(c) Based on the technique described by I.M. Kolthoff, T. S.

  
Lee and C.W. Carr, J. Poly. Sci. 1, 429 (1946)
(d) ASTM D1238-73, condition G <EMI ID = 193.1>
(f) ASTM D2240-75.

  
(g) An arrow of 0.509 kg is dropped on

  
Injection molded test pieces mounted horizontally, measuring approximately 8.38 cm x 3.56 cm x 0.254 cm, from various heights measured at 5.08 cm intervals above the test piece. By a trial and error process, the maximum height at which a set of 4 test pieces is not broken is determined. The arrow is then made to dute on 4 additional test pieces 5.08 cm higher in height and the percentage of test pieces that are broken is noted. This procedure is repeated at consecutive intervals of 5.08 cm more in height until reaching a height for which the 4 test pieces of a given clearance break. The "arrow shock" is determined by first calculating a designated value

  
  <EMI ID = 194.1>

  

  <EMI ID = 195.1>


  
where F50 - height in meters for 50% failure

  
test tubes

  
  <EMI ID = 196.1>

  
which the 4 test pieces of a given game break

  
I - increasing fraction of height in meters <EMI ID = 197.1>

  
set of 4 test pieces tested at various heights, including the height where 11 does not break and inclusive of all heights

  
  <EMI ID = 198.1>

  
The shock of the arrow is then calculated from:

  
  <EMI ID = 199.1>

  
  <EMI ID = 200.1>

  
wider distribution of the molecular weights of the polymers initiated at the pentadienyllithium of tests 41 and 43 indicate the course of a self-polymerization or self-coupling during the polymerization, giving

  
  <EMI ID = 201.1>

  
with improved elongation and better impact resistance of the boom, compared to control polymers

  
  <EMI ID = 202.1>

  
ialma li

  
  <EMI ID = 203.1>

  
  <EMI ID = 204.1> and in accordance with recipe XIII:
  <EMI ID = 205.1>
(a) Added as a 0.153 M solution in <EMI ID = 206.1>

  
Woluw.

  
(b) Added under melting of a 0.194 M solution including <EMI ID = 207.1>

TABLE XIII

  
  <EMI ID = 208.1>
  <EMI ID = 209.1>
(a) Vulcanized for 45 minutes at 150 ° C.

  
These data demonstrate superior properties

  
  <EMI ID = 210.1> it should be noted that the polymers may have a somewhat different microstructure in the polyisoprene blocks due to the presence of tetrahydrofuran during the polymerization of isoprene in control test 44, while in l Test 45 according to the invention, there was no tetrahydrofuran present during the polymerization of isoprene. This difference in fine structure can intervene at least in part in the difference in the properties of the mixed rubbers.

  
Data for teleblock polymers

  
  <EMI ID = 211.1>

  
no improvement in properties has been shown as a function of the presence of the terminal hexadienyl groups (compare tests 46 and 47). This could have been due to the lower Mooney viscosity of the terminated polymer

  
  <EMI ID = 212.1>

  
46 and 47 had the same Mooney viscosity, the request

  
  <EMI ID = 213.1>

  
witness 46.

  
name 1

  
These @sotie illustrating the preparation of a polymer

  
  <EMI ID = 214.1>

  
The hexadienyllithium was prepared as described in Example 3: The polymer was prepared according to the general procedure described in Example 1 and in accordance with recipe XIV-A:

RECIPE XIV-A

  

  <EMI ID = 215.1>


  
(a) Added as a 0.128 M solution in <EMI ID = 216.1>

  
in volume.

  
(b) Added as a 0.088 M solution in cyclohexane.

  
This polymer was mixed according to the general procedure indicated in Example 3 and recipe XIV-B:

RECIPE XIV-B

  

  <EMI ID = 217.1>


  
(a) PhilblackR N-339; Phillips Petroleum Co ..
(b) Circosol 4240; Sun Oil Company; described by ASTM

  
D 2226, Type 103; contains 47.5% aromatics.

  
(c) An antioxidant; namely, 1,2-dihydro-2,2,4trimethylquinoline polymerized; R.T. Vanderbilt.
(d) An antioxidant, namely symmetrical di-p-naphthyl-t-phenylene diamine; R.T. Vanderbilt.
(e) Crystex treated with oil, 20% polymerized sulfur;

  
Stauffer Chemical.

  
(f) An accelerator; namely N-t-butyl-2-benzothiazole sulfenanide; Monsanto.

  
The properties of vulcanized mixed rubber are presented in Table XIV.


    

Claims (1)

TABLE XIV Properties of an isoprene-styrene pentabloc copolymer, <EMI ID = 218.1> mixed and vulcanized ^ 8 '  <EMI ID = 219.1> (a) Vulcanized for 30 minutes at 150 [deg.] C. These data illustrate that a pentabloc copolymer having terminal hexadienyl groups have good properties in the vulcanized state. The description above, including the specific data, illustrate the value and effectiveness of the invention. But he it is however obvious that the invention is not limited in no way to the examples above and that we can bring to the invention of many modifications and variations without going beyond its framework and its spirit. 1. Process characterized in that it comprises the stages or stages consisting of: (A) polymerizing until substantially complete conversion of at least one first olefinically unsaturated monomer which can be polymerized under anionic solution polymerization conditions, using a dienyllithium initiator, so as to obtain a polymerization mixture containing at least one finished polymer partly by a functional group of the conjugated dienyl type, wherein said initiator of the dienyllithium group is a product prepared by bringing at least one lithium R (Li) hydrocarbon compound into contact with at least one hydrocarbon 1.4 diolefin in a mixed solvent consisting of a polar compound and a saturated hydrocarbon, in initiator formative temperature conditions  <EMI ID = 220.1> carbyl of valence x and x representing an integer whose value varies from 1 to 4; (B) treating said polymerization mixture containing a polymer terminated at least in part by a group <EMI ID = 221.1> treatment capable of producing a polymer chosen from the group formed by: a) a polymer produced by treating with an effective amount of at least one polyfunctional coupling agent of at least double functionality, so as to  <EMI ID = 222.1> coupled conjugated dienyl of increased molecular weight, characterized by conjugated dienyl groups on the terminal ends of the coupled polymer; b) a polymer produced by treatment with at least one unsaturated compound chosen from the group consisting of <EMI ID = 223.1> linear conjugated dienes, so as to obtain a polymer containing at least partly a terminal conjugated unsaturation at the two ends of the polymer chain, c) a polymer produced by treatment with a compound containing active hydrogen sufficient to terminate the active lithium and then re-initiation of the polymerization with an initiator based on lithium hydrocarbon-  <EMI ID = 224.1>  <EMI ID = 225.1> of the above-mentioned first polymerizable monomer, so as to form a branched polymer with an enlarged molecular weight, d) a polymer produced by maintaining said dienyl terminated polymer conjugate at substantially polymerization temperatures for a period  <EMI ID = 226.1> partial and then adding a second polymerizable monomer and polymerizing thereon, so as to obtain at least partly a branched polymer, e) a polymer produced by treatment as defined in paragraph a) above, followed by re-initiation of the polymerization with an additional amount  <EMI ID = 227.1> or without additional addition of a second "number  <EMI ID = 228.1> aforementioned polymerizable monomer, so as to obtain at least in part a branched polymer; (C) when any polymer originating from any of the treatments a) to e) inclusive retains active lithium, subsequent treatment with a compound containing active hydrogen effective in terminating said active lithium. 2. Method according to claim 1, characterized in that said R (Li) x in said step (A) and in said paragraphs c) and e) when used, said  <EMI ID = 229.1> per molecule and in that in said step (A) said 1,4-diolefin hydrocarbon contains from 5 to 12 carbon atoms per molecule. 3. Method according to any one of claims 1 and 2, characterized in that said 1,4-diolefine hydrocarbon is selected from the group formed by the following compounds: 1,4-pentadiene, 2-methyl-1 , 4-  <EMI ID = 230.1> and a-terpinene. 4. Method according to any one of the claims  <EMI ID = 231.1> is chosen from the group formed by the compounds which  <EMI ID = 232.1> <EMI ID = 233.1> 5. Method according to any one of the preceding claims, characterized in that in said step (A) said at least one polymerizable monomer is chosen from the group formed by conjugated dienes, monovinylarenes, esters of acrylic acid and alkacrylic acids, vinyl pyridines, vinylidene halides, vinylquinolines, nitriles, N, N-disubstituted acrylamides, vinylfuran, N-vinylcarbazole and mixtures thereof .  <EMI ID = 234.1> contact of step (A) uses a ratio of R (Li) x 1,4-hydrocarbon diolefin of about 0.9: 1 to 1.1: 1, a volume ratio of the mixed solvent of the saturated hydrocarbon to polar component from 20: 1 to 1: 1 and at a  <EMI ID = 235.1>  <EMI ID = 236.1> tions above, characterized in that said treatment mode (B) is carried out with step c) where said compound containing active hydrogen is chosen from the group formed by lower alcohols. 8. Method according to any one of claims 1 to 6, characterized in that said treatment mode (B) is carried out with said mode a) where said functional treatment agent is chosen from the group  <EMI ID = 237.1> multialdehydes, multicetonones, multihalides, multianhydrides, multiesters, agents of the combination type of these products, carbon oxides, sulfur halides and halogens. 9. Method according to any one of claims 1 to 6, characterized in that said modes of treatment are carried out with said mode b), with said tetraene or said alicyclic conjugated diene or said linear conjugated diene. 10. Method according to claim 9, characterized in that in said mode b) said tetraene or alicyclic conjugated diene or said linear conjugated diene corresponds to the structure chosen from the group of the following structures:  <EMI ID = 238.1> where each substituent R 'represents a "hydrogen tome  <EMI ID = 239.1> of carbon atoms in the molecule does not exceed 20,  <EMI ID = 240.1>  <EMI ID = 241.1>  <EMI ID = 242.1> integer whose value varies from 1 to 6 and Y represents a functional group easily reactible with lithium on the polymer. 11. Method according to claim 10, characterized alicyclic and in that this compound is chosen from the group formed by the following substances: 1,3,5-cycloheptatriene, cyclooctatetraene, 5-chloro-1,3pentadiene, 7-chloro-1,3,5-cycloheptatriene, 7-bromo- 1,3,5-cyclooctatriene and 7-chloro-1-methyl-1,3,5-cycloheptatriene. 12. Method according to claim 8, characterized in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is pentadienyllithium and in that in said treatment mode (B) a), said agent  <EMI ID = 243.1> 13. Method according to any one of claims 9 to 11, characterized in that in said step (A) said first polymerizable monomer is 1,3-b butadiene and said initiator based on dienyllithium is pentadienyllithium and in that in said treatment mode (B) b), said unsaturated compound is 5-chloro1,3 -pentadiene. 14. Method according to claim 8, characterized in that in said step (A), said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is 2-methylpentadienyllithium and in that in said treatment mode (B) a), said polyfunctional treatment agent is a, a'-dichlorop-xylene. 15. The method of claim 8, characterized in that in said step (A), said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is 3-methylpentadienyllithium and in that in the treatment mode (B) a), said polyfunctional treatment agent is a multihalide and  <EMI ID = 244.1> 16. The method of claim 8, characterized in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is terpinyllithium and in that in said treatment mode (B) a), said polyfunctional treatment agent is a multihalide and is a, a'-dichloro-p-xylene. 17. The method of claim 8, characterized in that in said step (A), said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is hexadienyllithium and in that in said treatment mode ( B) a), said polyfunctional treatment agent is a multihalide and is a, a'-dichloro-p-xylene. 18. Method according to any one of claims 1 to 6, characterized in that in said step (A), said first polymerizable monomer is 1,3butadiene and said initiator of the dienyllithium type is pentadienyllithium and in that said treatment mode (B) is carried out with said step e). 19. The method of claim 7, characterized in that in said step (A), said first polymerizable monomer is 1,3-butadiene and said initiator  <EMI ID = 245.1> that said treatment mode (B) c) is carried out without a second polymerizable monomer mentioned above. 20. Method according to any one of claims 1 to 6, characterized in that in said step (A), said first polymerizable monomer is 1,3butadiene and said initiator of the diphenyllithium type <EMI ID = 246.1> treatment (B) uses step 3 e) where said polyfunctional treatment agent is a multihalo  <EMI ID = 247.1> in said step e), is n-butyllithium. 21. Method according to any one of claims 1 to 6, characterized in that in said step (A) said first polymerizable monomer is styrene and said initiator of dienyllithium type is pentadienyllithium and in that said treatment mode (B) is carried out with said step e). 22. Method according to any one of claims 1 to 6, characterized in that in said step (A) said first polymerizable monomer is 1,3-butadiene followed by styrene and in that said initiator of the dienyllithium type is pentadienyllithium and in that said processing mode (B) is carried out with step e). 23. The method of claim 8, characterized in that in said step (A), said first polymerizable monomer is isoprene followed by butadiene and said initiator of dienyllithium type is pentadienyllithium and in that said mode of treatment (B) is carried out with said step a). 24. The method of claim 8, characterized in that in said step (A) said first polymerizable monomer is isoprene followed by styrene followed by butadiene and said initiator of the dienyllithium type is pentadienyllithium and in that said mode of treatment (B) is carried out with said step (A). 25. Process for the preparation of an isoprene-styrene-butadiene-styrene-isoprene pentabloc copolymer with hexadienyl termination prepared by use the method according to any of the claims 1 to 6, characterized in that in step (A), said polymerization of at least one first polymerizable monomer uses the sequential addition and polymerization in the first place of isoprene, followed by that of styrene, followed by that 1,3-butadiene, using hexadienyllithium as initiator of the aforementioned dienyllithium type and in that said step (B) uses said step a) where said polyfunctional treatment agent is  <EMI ID = 248.1> 26. Method according to any one of the claims -  <EMI ID = 249.1> steps consisting in (A) polymerizing until substantially complete conversion of at least one first oleaginally unsaturated, polymerizable olea [pound] monomer, under conditions of polymerization in anionic solution, using an initiator of the dienyllithium type, so as to obtain a polymerization mixture containing a polymer terminated at least in part by a functional group of the conjugated dienyl type,  <EMI ID = 250.1> product prepared by bringing at least one  <EMI ID = 251.1> a hydrocarbon 1,4-diolefin, in a mixed solvent consisting of a saturated hydrocarbon and a polar compound, under initiator temperature conditions of the dienyllithium type, where R represents a  <EMI ID = 252.1> integer whose value varies from 1 to 4 and (D) treating said polymerization mixture containing the polymer terminated at least in part with a functional group of the dienyl type conjugated with an effective amount of at least one polyfunctional coupling agent <EMI ID = 253.1> thus at least partially adorning a terminated polymer  <EMI ID = 254.1> terminal mites of the coupled polymer. 27. Method according to any one of claims 1 to 6, characterized in that it comprises the steps consisting in: (A) polymerizing until substantially complete conversion of at least one first olefinically unsaturated monomer polymerizable under conditions of polymerization in anionic solution, using an initiator of the dienyllithium type, so as to obtain a polymerization mixture containing a polymer terminated at least in part by a functional group of the conjugated dienyl type, in which said initiator of the dienyllithium type is a product prepared by bringing at least one lithium R (Li) hydrocarbon compound into contact with at least one hydrocarbon 1,4diolefin, in a solvent mixed consisting of a saturated hydrocarbon and a polar compound, under conditions of initiator forming temperature of the dienyllithium type, where R represents a hydro- radical <EMI ID = 255.1> whose value fluctuates from 1 to 4 and (B) treating said polymerization mixture containing the polymer terminated in the monk in part with a functional group of the dienyl type conjugated with at least one unsaturated composa chosen from the group formed by <EMI ID = 256.1>  <EMI ID = 257.1>  <EMI ID = 258.1>  <EMI ID = 259.1> p01y _ ,. *. 28. Method according to any one of claims 1 to 6, characterized in that it comprises the steps consisting in: (A) polymerizing until substantially complete conversion of at least one first uniquely unsaturated key monomer which can be polymerized under anionic solution polymerization conditions, using an initiator of the dienyllithium type, so as to obtain a polymerization mixture containing at least one finished polymer partly by a functional group of the conjugated dienyl type, wherein said dienyllithium type initiator is a product prepared by contacting at least one lithium R (Li) hydrocarbon compound with at least a hydrocarbon 1,4-diolefin, in a mixed solvent consisting of a saturated hydrocarbon and a polar compound, under conditions of formative temperature  <EMI ID = 260.1> integer whose value varies from 1 to 4 and (B) treating said polymerization mixture containing a polymer terminated at least in part with an <EMI ID = 261.1> containing enough active hydrogen to terminate the active lithium and then to prime the poly-  <EMI ID = 262.1> R (Li) x, with or without additional addition of a second polymerizable monomer, identical or different from said first polymerizable monomer, so as to generate a branched polymer with an enlarged molecular weight. 29. Method according to any one of claims 1 to 6, characterized in that it comprises the steps consisting in: (A) polymerize until substantially complete conversion, at least one first oleinically unsaturated monomer polymerizable under conditions of polymerization in anionic solution, using an initiator of the dienyllithium type so as to thus obtain a polymerization mixture containing a polymer terminated at least in part by a conjugated dienyl functional group, wherein said initiator of the dienyllithium type is a product prepared by bringing into contact at least one compound <EMI ID = 263.1> hydrocarbon diolefin, in a mixed solvent consisting of a saturated hydrocarbon and a polar compound, under the conditions of initiator-forming temperature of the dienyllithium type, where R represents a hydrocarbyl radical of the valence x and x represents an integer whose value fluctuates from 1 to 4 and (B) maintaining said polymerization mixture containing the polymer terminated at least in part by a functional group of the dienyl type conjugated at substantially polymerization temperatures for a period which <EMI ID = 264.1> then add a second polymerizable monomer and to polymerize on the latter, so as to obtain an at least partially branched polymer. 30. Method according to any one of claims 1 to 6, characterized in that it consists in: (A) polymerize until substantially <EMI ID = 265.1> conversion unsaturated, polymerizable under anionic solution polymerization conditions, using an initiator of the dienyllithium type, so as to thus obtain a polymerization mixture containing a polymer terminated at least in part by a functional group of the conjugated dienyl type, wherein said initiator of the dienyllithium type is a product prepared by bringing at least one lithium hydrocarbon compound R (Li) with at least one hydrocarbon 1,4diolefin, in a mixed solvent of a saturated hydrocarbon and a polar compound, under conditions of initiator forming temperature of the dienyllithium type, where R represents a hydrocarbyl radical of the valence x and x represents an integer of which the value fluctuates from 1 to 4 and (B) treating said polymerization mixture containing a polymer terminated at least in part by a functional group of the dienyl type conjugated with an effective amount of at least one polyfunctional coupling agent of at least double functionality, so as to thus prepare at least in part a polymer with conjugated dienyl termination coupled with an increased molecular weight, then re-initiating the polymerization with a complementary addition of a hydrocarbon lithium initiator R (Li), with or without additional addition of a second olefinically monomer polymerizable unsaturated, identical to or different from the above-mentioned first polymerizable monomer, so as to generate at least partially a branched polymer. 31. Polymer produced by the stages which consist of: (A) polymerizing at least one olefinically unsaturated monomer chosen from the group formed by conjugated dienes, monovinylarenes, acrylates, vinylpyridines, vinylidene halides and vinylquinolines, under polymerization conditions in anionic solution using an initiator of the dienyllithium type, so as to generate a polymer terminated at least in part by a functional group of the dienyl conjugate type, wherein said dienyllithium type initiator is a reaction product of at least one lithium hydrocarbon compound R (Li) x on at at least one hydrocarbon 1,4-diolefin, in a mixed solvent consisting of a saturated hydrocarbon and a polar compound, under conditions of initiator forming temperature of the dienyllithium type,  where R has the valence of x and represents a hydrocarbyl radical containing from 1 to 20 carbon atoms and x represents an integer whose value varies from 1 to 4 and (B) then treating said polymer containing at least in part a termination with a functional group of the dienyl type conjugated by a treatment method such that a polymer chosen from the group <EMI ID = 266.1> is produced a) a polymer produced by treatment with an effective coupling amount of a polyfunctional coupling agent of at least double functionality, so as at least in part to couple said polymer with conjugated dienyl termination and to generate a weight-coupled polymer increased molecular and characterized by dienyl groups <EMI ID = 267.1> b) a polymer produced by treatment with an unsaturated compound selected from the group consisting of alicyclic conjugated tetraenes and trienes and linear conjugated dienes, in an amount effective to generate about one mole of said unsaturated compound per equivalent of initiator based on lithium used in (A) above-mentioned, so as to obtain a polymer containing at least in part a terminal conjugated unsaturation at each end of the polymer chain, c)  a polymer produced by treatment with a compound containing active hydrogen sufficient to terminate the active lithium and subsequent re-initiation of the polymerization with an organolithium initiator R (Li), with or without additional addition of a second, identical, polymerizable monomer  <EMI ID = 268.1> so as to generate a branched polymer with an enlarged molecular weight, d) a polymer produced by maintaining said dienyl-terminated polymer conjugated at polymerization temperatures for a period which is sufficient to effect at least partial self-coupling and by the subsequent addition of a second polymerizable monomer and the polymerization on that -ci, so as to generate a branched polymer and e) a polymer produced by a treatment carried out as in a) above, followed by a re-initiation of the polymerization with an organolithium initiator R (Li) x, with or without additional addition of a second polymerizable monomer, identical or different from said first polymerizable monomer and then (C) termination of any residual active lithium. 32. Polymer according to claim 31, characterized in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is pentadienyllithium and in that said treatment step (B) s 'performs with said mode b) where said unsaturated compound is 5-chloro-1,3pentadiene. 33. Polymer according to claim 31, characterized in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is 2-methylpentadienyllithium and in that said treatment step (B ) is said  <EMI ID = 269.1> dichloro-p-xylene.  <EMI ID = 270.1> in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator  <EMI ID = 271.1> and in that said processing step (B) is said  <EMI ID = 272.1> dichloro-p-xylene.  <EMI ID = 273.1>   <EMI ID = 274.1> risé in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator of the dienyllithium type is pentadienyllithium and in that said treatment step (B) is said mode e).  <EMI ID = 275.1> laughed in that in said step (A) said first mono-  <EMI ID = 276.1> of the dienyllithium type is pentadienyllithium and in this  <EMI ID = 277.1> without a second polymerizable monomer mentioned above. 39. Polymer according to claim 31, characterized in that in said step (A) said first polymerizable monomer is 1,3-butadiene and said initiator  <EMI ID = 278.1> styrene and said initiator of the dienyllithium type is pentadienyllithium and in that said treatment step (B) is said mode e). 42. Polymer according to claim 31, characterized in that in said step (A) said first polymerizable monomer is isoprene followed by butadiene and said initiator of the aforementioned dienyllithium type is pentadienyllithium and in that said treatment step (B) is said mode a). 43. Polymer according to claim 31, character-  <EMI ID = 279.1> uses a sequential polymerization of isoprene, then styrene, then butadiene, as aforementioned first polymerizable monomer and said initiator of the type  <EMI ID = 280.1>  <EMI ID = 281.1>  <EMI ID = 282.1> 48. Polymer according to claim 31, characterized in that said processing step (B) uses said mode d). 49. Polymer according to claim 31, characterized in that said treatment step (D) uses said mode e) without additional addition of monomer. 50. Polymer according to claim 31, characterized in that said treatment step (D) uses said mode e) with said additional addition of monomer. 51. Coupled polymer according to claim 31, characterized in that it is prepared by the steps consisting in: (A) polymerizing at least one monomer chosen from the group formed by conjugated dienes, monovinyl- <EMI ID = 283.1> of initiator of the dienyllithium type, where R has the valence of x and is a hydrocarbyl radical containing from 1 to 20 carbon atoms and x represents an integer whose value fluctuates from 1 to 4 and <EMI ID = 284.1> parts a functional group terminus of the dienyl type conjugated with an effective coupling amount of a polyfunctional coupling agent of at least double functionality, so as at least in part to couple said polymer with conjugated dienyl termination and to generate a coupled polymer of increased molecular weight and characterized by the existence of conjugated dienyl groups on the ends of the coupled polymer. 52. The polymer according to claim 31, containing at least in part a terminal conjugated unsaturation at each end of the polymer chain, prepared by the steps consisting in: (A) polymerizing at least one monomer chosen from the group formed by conjugated dienes, monovinylarenes, acrylates, vinylpyridines, vinylidene halides and vinylquinolines, under polymerization conditions in anionic solution, using an initiator of the dienyllithium type, so as to generate a polymer terminated at least in part by a functional group of the dienyl conjugate type, or said initiator of the dienyllithium type is the product of the reaction of at least one lithium hydrocarbon compound R (Li) x on at least one hydrocarbon 1,4-diolefin, in a mixed solvent consisting of a saturated hydrocarbon and a polar compound, under conditions of initiator forming temperature of the dienyllithium type, where R has the valence of x and represented  <EMI ID = 285.1> carbon and x represents an integer whose valence fluctuates from 1 to 4 and (B) treating said polymer containing at least part of a dienyl conjugated functional group termination with a compound selected from the group consisting of alicyclic conjugated tetra and trienes and linear conjugated dienes, in an amount effective for generate approximately 1 mole of said unsaturated compound per equivalent of lithium initiator used in (A) above, so as to generate a polymer containing at least in part a terminal conjugate unsaturation at each end of the polymer chain. 53. Branched polymer according to claim 31, prepared by carrying out the steps consisting in: (A) polymerizing at least one monomer chosen from the group formed by conjugated dienes, monovinylarenes, acrylates, vinylpyridines, vinylidene halides and vinylquinolines, under polymerization conditions in anionic solution, using an initiator of the type dienyllithium, so as to generate a polymer terminated at least in part by a functional group of the conjugated dienyl type, wherein said initiator of the dienyllithium type is a reaction product of at least one lithium and hydrocarbon compound R (Li) x on at least one hydrocarbon 1,4-diolefin, in a mixed solvent consisting of a saturated hydrocarbon and a polar compound,  under conditions of initiator forming temperature of the dienyllithium type where R has the valence of x and represents a hydrocarbyl group having from 1 to 20 carbon atoms and x represents an integer whose value fluctuates by 1 to 4 and (B) treating said polymer containing at least in part a termination with a dienyl type functional group conjugated with a compound containing active hydrogen sufficiently to terminate the active lithium and then re-initiating the polymerization with an initiator of the hydrocarbon lithium type R (Li ), with or without additional addition of a second polymerizable monomer mentioned above, identical to or different from said first polymerizable monomer, so as to generate a branched polymer with an enlarged molecular weight. 54. Branched polymer according to claim 31, prepared by carrying out the steps consisting in (A) polymerize at least one monomer chosen from the group formed by conjugated dienes, monovinylarenes, acrylates, vinylpyridines, vinylidene halides and vinylquinolines, under polymerization conditions in anionic solution using an initiator of the dienyllithium type , so as to obtain a polymer terminated at least in part by a functional group of the conjugated dienyl type, wherein said initiator of the dienyllithium type is the product of the reaction of at least one hydrocarbon compound of lithium R (Li) x with at least one 1,4-diolefin hydro-  <EMI ID = 286.1> saturated carbide and of a polar compound, under conditions of initiator forming temperature of the dienyllithium type, where R has the valence of x and represents a hydrocarbyl radical which contains from 1 to 20 carbon atoms and x represents an integer of which the value fluctuates from 1 to 4 and (B) maintaining said polymer containing at least partially a functional group terminus of the dienyl type conjugated at polymerization temperatures for a period which is sufficient to carry out at least partial self-coupling and then to add a second polymerizable monomer mentioned above and to polymerize thereon to produce a branched polymer. 55. Branched polymer according to claim 31, prepared by carrying out the steps consisting in: (A) polymerizing at least one monomer chosen from the group formed by conjugated dienes, monovinylarenes, acrylates, vinylpyridines, vinylidene halides and vinylquinolines, under polymerization conditions in anionic solution, using an initiator of the type diennylithium, so <EMI ID = 287.1>  <EMI ID = 288.1> wherein said initiator of the dyllyllithium type is the product of the reaction of at least one lithium hydrocarbon compound R (Li) x with at least one hydrocarbon 1,4-diolefin, in a mixed solvent consisting of a hydrocarbon saturated with a polar compound, under conditions of initiator forming temperature of the dienyllithium type, where R has the valence of x and represents a  <EMI ID = 289.1> carbon and x represents an integer whose value fluctuates from 1 to 4 and (B) treating said polymer containing at least partially a functional group termination of the type <EMI ID = 290.1>  <EMI ID = 291.1> at least double nality, so as to at least partially couple said polymer 0 dienyl termination  <EMI ID = 292.1> steps which include: (A) the polymerization of isoprene, sequentially followed by the polymerization of styrene, sequentially followed by the polymerization of 1,3-butadiene, under conditions of polymerization in anionic solution, using the initiator of the dienyllithium type, so thus obtaining a polymer terminated at least in part by a functional group of the conjugated dienyl type, wherein said initiator of the dienyllithium type is the product of the reaction of at least one lithium hydrocarbon compound R (Li) on at least one 1, Hydrocarbon 4-diolefin, in a mixed solvent consisting of a hydrocarbon saturated with a polar compound, under conditions of  <EMI ID = 293.1> where R has the valence of x and represents a hydrocarbyl radical which contains from 1 to 20 carbon atoms and x represents an integer whose value varies from 1 to 4 and  <EMI ID = 294.1> at least one part is terminated with a functional group of the dienyl type conjugated by a decoupling quantity  <EMI ID = 295.1> 57. Pentabloc polymer according to claim 56, characterized in that said step (A) uses hexadienyllithium as initiator of the aforementioned dienyllithium type and said step b) uses a treatment agent  <EMI ID = 296.1>