FR3087441A1 - Polyhydroxytelechelic derivatives of epichlorohydrin and their preparation - Google Patents

Abstract

The present invention relates to polyhydroxytelechelic derivatives of epichlorohydrin corresponding to formula (I) or to formula (I '): formula (I) in which A is the residue of a polyol of formula A- (OH) m, in which m is an integer at least equal to 3 (m ≥ 3), said polyol having a molecular mass of between 92 and approximately 500 g / mol, and n is an integer, not necessarily the same for all the m groups, between 1 and 50 (1 ≤ n ≤ 50); formula (I ') in which A 'is the residue of a polyol of formula (I) above, the number average molecular weight of which is less than about 5000 g / mol, o = m and p is an integer, not necessarily the same for all o groups, between 1 and <50 ((1 ≤ p ≤ 50); as well as mixtures of at least two such derivatives of formula (I) with different A's, mixtures of at least two such derivatives of formula (I ') with different A' and mixtures of at least one derivative of formula (I) and at least one derivative of formula (I '). These plurifunctional derivatives are particularly advantageous as precursors of hydroxytelechelic glycidyl polyazides.

Description

The present invention relates to: polyhydroxytelechelic compounds, more precisely polyhydroxytelechelic derivatives of epichlorohydrin, a process for preparing said compounds, as well as energetic materials capable of being obtained by azidation of said compounds.

The present invention falls within the field of propulsion.

It falls within the context of solid propellants, more precisely in that of binders for composite propellants.

Hydroxytelechelic polybutadienes (PBHT), the synthesis of which is based on the polymerization of 1,3-butadiene, have been and still are widely used in the formulation of composite propellants loaded, in particular with ammonium perchlorate.

They constitute (crosslinked via their terminal hydroxyl functions by polyisocyanates) of the binders of choice, by virtue of their physical and mechanical properties, but fail due to their lack of energetic power.

Hence a great deal of research carried out to find high-performance energy binders, research carried out in particular on glycidyl polyazides (PAG) (hydroxytelechelic, capable of being crosslinked via their terminal hydroxyl functions by polyisocyanates or via some of their azide functions by crosslinking agents with alkyne functions) and on other nitrogenous polymers (in particular containing tetrazene units).

Hydroxytelechelic glycidyl azides (PAGs) are obtained by azidation of polyepichlorohydrins (PECHs) (hydroxytelechelic precursor polymer), themselves obtained from epichlorohydrin (ECH).

To obtain a polyepichlorohydrin (PECH) (hydroxytelechelic), epichlorohydrin (ECH) is therefore polymerized.

The polymerization in question, for obtaining molecular masses 2 of approximately 2000 to approximately 5000 g / mol (better controlled for obtaining molecular masses of approximately 2000 girnol), is today a cationic polymerization carried out in a chlorinated solvent, such as dichloroethane (DCE), in the presence of at least one catalyst, such as S tin IV chloride or boron trifluoride etherate (BF30Et2), or even also in the presence of at least one acid co-catalyst.

The epichlorohydrin is added slowly (the reaction is very exothermic) to a solution containing at least one initiator and the at least one catalyst (or even, in addition, the at least one co-catalyst) in the solvent.

Application FR 2 638 751, published in May 1990, describes this cationic polymerization reaction.

It mentions the use, as initiators, of numerous chemical compounds whose formula contains at least one alcohol function, in particular the use of such compounds whose formula contains from 1 to 4 alcohol functions.

It illustrates, in fact, only the use, within dichloroethane (DCE), of di-functional alcohols, and very particularly that of 1,4-bis (hydroxymethyl) cyclohexane.

For many years, conventionally has been carried out in dichloroethane (DCE) with 1,4-butanediol or chloropropanediol (3-chloro, 1,2-propanediol) as initiator, in the presence of tin tetrachloride or of Boron trifluoride etherate (catalyst) and trichloroacetic acid (cocatalyst).

The inventors were interested in the cationic polymerization of epichlorohydrin from two aspects: the polyepichlorohydrins (PECHs) prepared conventionally are essentially linear.

Their growth kinetics, during their elongation, are weaker and weaker.

The hydroxytelechelic glycidyl polyazides (PAGs) prepared (from said polyepichlorohydrins (PECHs), precursor polymer), which are also essentially linear, once crosslinked, do not exhibit very satisfactory mechanical properties.

The inventors sought to obtain more interesting polyepichlorohydrin structures (PECH = PAG precursor polymer), polyfunctional structures (having a functionality greater than 2); 5 the use of dichioroethane (DCE) as a solvent is currently subject to authorization (with reference to the REACH regulation).

It will undoubtedly pose more and more problems.

The inventors therefore also sought alternative solvents (less toxic).

It is to the merit of said inventors, in such a context, to propose original conditions for carrying out the cationic “polymerization”, as regards the nature of the initiator (at least trifunctional polyol) and also advantageously as regards the nature. of the solvent (less toxic than dichioroethane (DCE)), conditions which allow control of the polyfunctionality of the hydroxytelechelic compounds prepared, compounds of the polyhydroxychelic derivative type of epichlorohydrin, particularly useful as precursors of polyhydroxytelechelic glycidyl azides (PAG).

We can already insist on the fact that the good results obtained were by no means acquired in advance (the reactivity of epichlorohydrin being in particular sensitive to the nature of the solvent in which it is in solution).

We have spoken of “polymerization”, but we see further on in the present text that the initiator + epichlorohydrin reaction does not necessarily initiate a polymerization reaction (this obviously depends on the amount of epichlorohydrin reacted with the initiator exhibiting a given number of reactive hydroxyl functions) and that therefore some of the compounds of the invention (polyhydroxychelic derivatives of epichlorohydrin) are not polymers (very particularly the compounds of formula (I) (see below) in which n = 1).

These compounds are, however, poly (n 3) epichlorohydrins.

4 As regards the polymers (resulting from a polymerization reaction), they correspond to formula (I) below in which n 2 and exist, this will not surprise those skilled in the art, as a mixture (all molecules of formula (I), obtained from an initiator (with m 5 reactive alcohol functions) and of epichlorohydrin, do not all correspond to the same formula (I), not necessarily being the same for all m branches of a molecule of formula (I) and said m branches of different lengths not necessarily distributed in the same way for all molecules of formula (I)).

The complexity of the compounds and mixtures involved and the "conventional" approach are understood by a (single) formula, in fact formula (T) or formula (F).

According to its first object, the present invention therefore relates to polyhydroxytelechelic compounds of polyhydroxytelechelic derivatives of epichlorohydrin - of the type mentioned above, ie obtained from a polyol initiator (having a functionality of at least 3) and of epichlorohydrin.

Details are given below on the process for obtaining said compounds, which constitutes the second subject of the invention.

Said compounds, which constitute the first object of the present invention, correspond to formula (I) or to formula (I ') below: (I) 25 5 (F) - formula (I) in which 5 - A is the residue of a polyol of formula A- (0F1) r, 'in which m is an integer at least equal to 3 (m 3), said polyol having a molecular mass of between 92 and approximately 500 g / mol, and - n is an integer, not necessarily the same for all the m 10 oY groups, between 1 and 50 (1 n 50); - formula (1) in which - A 'is the residue of a polyol of formula (I) above, the number average molecular mass of which is less than about 5000 g / mol, o = m, and 15 - p is an integer, not necessarily the same for all o groups, between 1 and 50 ((1 n S 50).

According to its first subject, the present invention also relates to mixtures of such derivatives of formula (I) with A of different nature (mixtures of at least two such derivatives) and mixtures of such derivatives of formula (I ') with A 'of different nature (mixtures of at least two such derivatives).

It will be understood that such mixtures can be obtained "directly" with the joint use of at least two different initiators (respectively two different initiators A or two different initiators A ') and / or with the use of a single initiator A or A'. capable of decomposing, in situ, at least partially, into at least one other initiator A1 or A1 (this is referred to as sucrose which can, at least in part, be hydrolyzed to fructose and glucose); or “indirectly” by mixing at least two compounds of formula (I) (with A's of different nature) obtained previously or of at least two compounds of formula (I ') (with A' of different nature) obtained previously.

Mixtures of at least one compound of formula (I) and at least one compound of formula (I ') cannot be excluded from the scope of the invention.

With regard to formula (I) - it is understood that A is the residue of an initiator polyol, at least trifunctional, of formula A- (OH) m, m therefore being an integer at least equal to 3 (m 3 ).

It is thus understood that said compound of formula (I) is not a linear compound; its structure having m groups (m branches) (each of a length fixed by the value of n relating to it) and each of said m groups (branches) ending in a hydroxyl group; hence the polyfunctionality.

Said integer is advantageously at least equal to 5 (m 5), for a greater polyfunctionality.

It is generally less than or equal to 10 (i.e. generally between 3 and 10 (3 s m 10), advantageously between 5 and 10 (5 m 5_ 10)).

The polyol of formula A- (OH) has a molecular weight of between 92 and about 500 g / mol (including extreme values).

The minimum value of 92 corresponds to the poly (m = 3) ol, stable, of smaller molecular mass: propane triol.

The molecular mass of the initiator polyol is limited (to approximately 5500 g / mol), with particular reference to the ratio: mass of initiator / mass of the final product, so more generally that the remainder A does not have too much influence on the characteristics of the final product of formula (I).

Below is a list, without limitation, of suitable A values (which correspond to suitable initiators of formula A- (OH) m).

Thus, A can in particular correspond to the remainder of a polyol chosen from trimethylolethane (TME; m = 3; Mn = 120.15 g / mol), tris (hydroxymethyl) proparie (TMP; m = 3; Mn = 134.17 g / mol), tris (hydroxymethyl) nitromethane (TNM; m = 3; Mn = 151.118 g / mol), butanetriol (m = 3; Mn = 106.12 g / mol), pentaerythritol ( PLI I; m = 4; Mn = 136.15 g / mol), di (trimethylolethane) (DTME; m = 4; Mn = 222.3 g / mol), di (trimethylolpropane) (DTMP; m = 4 ; Mn = 250.33 g / mol), sucrose (m = 8; Mn = 342.29 g / mol), glucose (m = 5; Mn = 180.156 g / mol), fructose (m = 5; Mn = 180.16 g / mol), dipentaerythritol (DPEn; m = 6; Mn = 254.28 g / mol)), tripentaerythritol (TPt II; m = 8; Mn = 372.41 g / mol) ) and cellulose (Mn of at most about 500 g / mol).

Advantageously, A is the residue of a polyol chosen from tris (hydroxymethyl) nitromethane (TNM), glucose, fructose, dipentaerythritol (DPE I I), sucrose, tripentaerythritol (TPL I I) and cellulose; very advantageously, A is the residue of a polyol chosen from glucose, fructose, dipentaerythritol (Dl% I I), sucrose, tripentaerythritol (TPL I I) and cellulose; - It is understood that n represents the number of units (of units) of epichlorohydrin on each branch m (within each group m).

8 When n = 1, the compounds of formula (I) are not, as indicated above, polymers; their formula (I) however contains m units of epichlorohydrin (at least 3 units of epichlorohydrin); these are poly (n 3) epichlorohydrins.

When the value of n increases, it is then possible to speak of the presence of recurring units of epichlorohydrin on at least some and then each of the m branches (of the m groups) of formula (I) of a polymer.

It has been expressly indicated that the number of recurring units, n, is, in the m branches (m groups), identical or different.

In fact, each of said branches does not necessarily grow at the same speed (see the description of the method below).

It is for obvious reasons of simplification that a unique n is shown in formula (I); - it has been indicated that n (the identical n of each of the m branches of the same length (on the assumption that said m branches have the same number n of epichlorohydrin unit (s)) or each of the n of which at least two have different values (at least two of the m branches not having the same number n of epichlorohydrin units)) is less than or equal to 50.

An upper limit is imposed with reference to the viscosity of the synthesis medium in which the compound is obtained, to the processability of said medium, to the growth kinetics of the m groups which is decreasing ... and also with reference to the target average molecular mass for the compound of formula (I).

There is advantageously n, integer, between 7 and 40 (75_ n 5_ 40).

The structural formulas of some compounds of formula (I) according to the invention are proposed hereinafter, purely by way of illustration (it will be recalled incidentally that the n indicated in a formula may vary from chain to chain. other): - formula (I) in which A is the remainder of TME: 5 - formula (I) in which A is the remainder of TMP: 10 - formula (I) in which A is the remainder of PETT: 15 10 - formula (I) in which A is the remainder of TPE i I: li GI - formula (I) in which A is the remainder of DPE II: CI 11 - formula (I) in which A is the remainder of sucrose: - formula (I) in which A is the remainder of glucose: 5 1.0 12 - formula (1) in which A is the remainder of fructose: te 0- / efo tu Çc + C: H 5 The compounds of formula (I ') are second generation compounds insofar as the A 'of said formula (I') is the residue of a polyol of formula (I) (of which the at least three branches are more or less long).

Said polyol of formula (1) (which performed the function of precursor (see below)) has a number-average molecular weight of less than about 5000 g / moL Its molecular weight is limited with reference to the kinetics of the reaction.

With an initiator "too big", the kinetics of the reaction become too slow ...

Said polyol of formula (I) advantageously exhibits a number average molecular mass of less than approximately 4000 g / mol, very advantageously a number average molecular mass of less than approximately 3000 g / mol.

It will be understood that the number of branches o of formula (I ') is necessarily equal to the number of branches m of the polyol (initiator, "precursor") of formula (I): o = ni.

The functionality of the compounds of formula (Ir) remains that of the precursor polyols, here of formula (I).

The integer o is therefore also at least equal to 3, advantageously at least equal to 5 (o 5), for also a greater polyfunctionality.

It is also generally 13 less than or equal to 10 (i.e. generally between 3 and 10 (3 o S 10), advantageously between 5 and 10 (5 5 o 10)).

As regards the length of the chains containing an epichlorohydrin unit grafted onto the chains containing an epichlorohydrin unit of the residue of polyol A ', one ap, independently of n, which can also be between 1 and 50 (1 5_ p 50), which is also advantageously between 7 and 40 (7 p 40).

It can be seen that if n is (already) large, it may take a long time to obtain also an important p (s) (problem of the kinetics of the polymerization reaction).

The p's of formula (I ') are, like the n's of formula (I), all equal or at least two of them are different.

Here, too, we can see that all the branches (lengthening of the branches attached to A) do not grow at the same speed.

The compounds of formula (I ') can therefore exist according to numerous variants in view of the respective values of n (of A': residue of a polyol of formula (I)) and of p (number of repeating units added ” on the polyol of formula (I)).

The compounds of formula (I ') exhibit, of course, due to the lengthening of their chains, due to the incorporation of additional epichlorohydrin units in their structure, a molecular mass which is higher than that of their initiator (precursor) of formula (I).

The structure of the compounds of formula (I) and of those of formula (I ') is easily understood having in mind the process for obtaining, by cationic polymerization, conventional PECHs and is all the more easily understood on consideration. of the following description of the process for obtaining said compounds.

The invention described above in terms of product is also fully understood in terms of product per process.

14 The molecular mass of the compounds of the invention (molecular mass (for non-polymeric compounds) or number-average molecular mass (for polymeric compounds)) obviously follows from their formula (therefore from the nature of A, values of m and those of n (for the compounds of formula (I)), and in addition to those of p (for the compounds of formula (I ')).

It obviously depends on the number of recurring units (“ECH”) present in said formula.

It is at least about 370 g / mol (the theoretical calculation gives 366.6 g / mol for {propane triol + 3 ECH} ((92 + (3 x 92.524) - 3 = 10 366.572)).

It is generally, in view of the applications sought for the PAG prepared from the PECH of formula (I) or (I ′), at most of about 15000 g / mol, advantageously at most of about 12000 g / mol.

According to one variant, said molecular mass is between a molecular mass of approximately 370 g / mol and a number-average molecular mass of approximately 3000 g / mol.

According to this variant, there is advantageously a number-average molecular weight between approximately 1000 and approximately 3000 g / mol.

The compounds of the invention having such molecular masses generally correspond to formula (I) and are suitably obtained by carrying out the first variant of the process described below (for obtaining compounds of formula (I)). (ie they are suitably obtained according to Protocol No. 1 of the Examples (under so-called “standard” conditions of the initiator / epichlorohydrin molar ratio reacted (see below))).

According to another variant (independent of the first), said number-average molecular mass is between approximately 1000 and approximately 6000 g / mol.

The compounds of the invention having such molecular weights generally correspond to formula (I) but also possibly to formula (n.

They can suitably be obtained by carrying out a) the second variant of the process described below (to obtain compounds of formula (I)) (They are suitably obtained according to Protocol No. 2 of the examples (in so-called “optimized” conditions of the initiator / epichlorohydrin molar ratio reacted (see below))) or b) possibly the first or the second variant of the process described below (ie therefore according to protocol n ° 1 or Protocol No. 2 of the Examples (under so-called “standard” conditions or under so-called “optimized” conditions) for the preparation of a compound of formula (I) 21. the first or the second variant of the above process after (ie therefore according to Protocol No. 1 or Protocol No. 2 of the Examples (under so-called “standard” conditions or under so-called “optimized” conditions (see below))) for the preparation of a compound of formula (I ') (see protocol n ° 3 of the examples).

According to another variant (independent of the previous two), said number-average molecular mass is between approximately 4000 and approximately 15000 g / mol.

The compounds of the invention having such molecular masses possibly correspond to formula (I) but more generally to formula (I ′).

They can suitably be obtained by carrying out a) possibly the second variant of the process described below (for obtaining compounds of formula (I)) (They are suitably obtained according to Protocol No. 2 of the Examples (under so-called “optimized” conditions of the initiator / epichlorohydrin molar ratio reacted (see below))) but b) more generally the first or the second variant of the process described below (ie therefore according to protocol no. ° 1 or protocol n ° 2 of the examples (under conditions called “standard” or under conditions called “optimized” (see below))) for the preparation of a compound of formula (I) then the first or the second variant of the process below 16 (under so-called “standard” conditions or under so-called “optimized” conditions (see below)) for the preparation of a compound of formula (I ′) (see protocol no. ° 3 of the examples).

The compounds of the invention can exhibit number average molecular weights quite similar to those of the polyepichlorohydrins (PECH) obtained according to the process of the prior art, using dichloroethane (DCE) as solvent and a difunctional initiator.

However, at similar number average molecular weights, they exhibit a more dense, non-linear structure.

The compounds of the invention, most particularly those of formula (I ') (but not exclusively these) can also have number-average molecular weights greater than those of the polyepichlorohydrins (PECH) obtained according to the process of the art. earlier, using dichloroethane (DCE) as a solvent and a difunctional initiator.

Alternative methods are recommended below, the implementation of which allows management of the molecular mass of the compound prepared.

According to its second subject, the present invention therefore relates to the preparation of the compounds of formula (I) and of the compounds of formula (I ') described above (said compounds being analyzed as compounds capable of being obtained by said process ).

It relates more exactly to a process for preparing at least one polyhydroxytelechelic derivative of epichlorohydrin of formula (I) or (I ′).

Said process comprises: - for the preparation of at least one polyhydroxytelechelic derivative of epichlorohydrin of formula (I), the addition, with temperature control, of epichlorohydrin (ECH), in a medium consisting essentially of a organic solvent (S) and containing, besides said organic solvent (S), at least one initiator of polyol type, at least one catalyst of Lewis acid type (C) and optionally also at least one acid co-catalyst (C ' ); said organic solvent (S) being chosen from chlorinated aliphatic solvents and aromatic solvents, miscible with epichlorohydrin and said at least one initiator, of polyol type, corresponding to the formula A- (OH) m in which m is a integer at least equal to 3, advantageously at least equal to 5 and having a molecular mass of between 92 and approximately 500 g / mol; and - for the preparation of at least one polyhydroxytelechelic epichlorohydrin derivative of formula (I '), that prior to at least one polyhydroxytelechelic epichlorohydrin derivative of formula (1), the number average molecular mass of which is less than approximately 5000 g / mol under the conditions indicated above and the use of said at least one polyhydroxytelechelic derivative of epichlorohydrin of formula (I) thus prepared as an initiator in a reaction of the same type.

It is understood that the processes in question are processes for the cationic polymerization of epichlorohydrin according to the prior art which use original initiators (at least trifunctional).

It is recalled, for all practical purposes, the abuse of language, with regard to the term “polymerization” if the amount of epichlorohydrin added is small, or even strictly limited, with reference to the number of reactive hydroxyl functions of the initiator. A (n = 1).

With reference to the molecular weight of the polyol initiator of formula A- (OH), (minimum molecular weight (92 g / mol) and maximum molecular weight (about 500 g / mol)) and to the number average molecular weight of the polyol initiator of formula (I) (Mn less than about 5000 g / mol), reference may be made to what has been written above.

With reference to the exact nature of the initiator of formula A- (OH) ,, it is recalled that the at least one polyol can in particular be chosen from trimethylolethane (TME), tris (hydroxymethyl) propane (TMP), 18 le trishydroxymethylnitromethane (TNM), a butanetriol, pentaerythritol (Pt II), di (trimethylolethane) (DTME), di (trimethylolpropane) (DTMP), sucrose, glucose, fructose, dipentaerythritol (DI% II), tripentaerythritol (TPETT), cellulose and mixtures thereof; 5 that said at least one polyol is advantageously chosen from tris (hydroxymethyl) nitromethane (TNM), glucose, fructose, dipentaerythritol (DI% II), sucrose, tripentaerythritol (TPE I 0 and cellulose; that said at least one polyol is very advantageously chosen from glucose, fructose, dipentaerythritol (DPETT), sucrose, tripentaerythritol (TPE II) and cellulose.

It is also recalled that the use of several initiators or of a single initiator transforming at least in part into at least one other initiator leads to mixtures.

For better management of the reactions in question, it is preferred to use a single initiator of formula A- (OH) n, (we then have, as specified above, all the molecules prepared corresponding to formula (I) but not necessarily all have the same formula (I): n not necessarily being the same on the m branches of a molecule and said m branches of different lengths not necessarily being distributed in the same way for all the molecules of formula ( I)) then, optionally, that of an initiator, rest of the polyol of formula (I), obtained from said initiator of formula A- (OH), '(also at this second level, all the branches of the molecules are not not necessarily extended by the same number of patterns, with the same distribution over all molecules).

With reference to the organic solvent, chosen from chlorinated aliphatic solvents (such as dichloromethane, dichloroethane (DCE), chloroform, etc.) and aromatic solvents (such as toluene, xylene, etc.), it is obviously understood that it is miscible with epichlorohydrin (ECH).

As indicated above, it is strongly recommended to no longer use dichloroethane (DCE).

The use of a solvent chosen from chloroform and toluene is strongly recommended.

It is to the inventors' credit for having shown that the cationic polymerization within these solvents is quite manageable.

As regards the catalysts and co-catalysts, the teaching of the prior art can be transposed into the context of the invention.

The inventors noticed that compounds of different type were obtained as a function of the ratio (molar): number of mole (s) of initiator (put (s) to react) / number of mole (s) of epichlorohydrin (total , set (s) to react).

Said molar ratio: number of mole (s) of initiator (set (s) to react) / number of mole (s) of epichlorohydrin (total, set (s) to react) is generally between 0.003% and 5% .

It is understood that this molar ratio "appreciates" at the end of the addition of the epichlorohydrin.

According to a first variant (protocol no. 1 of the examples), said ratio is between 0.03% and 5%, advantageously between 0.03% and 4%.

We can speak of “standard” conditions (see above).

According to a second variant (protocol no. 2 of the examples), said ratio is between 0.003% and less than 0.03%.

One can speak of “optimized” conditions (see above), with a priori view of obtaining polymers of higher molecular masses.

With reference to the increase in molecular weight, it has indeed proved to be appropriate to minimize the amount of initiator used (to use the minimum amount for the reaction to start) and then to maximize the amount of epichlorohydrin. reacted (to react a maximum amount of epichlorohydrin, even adding it very slowly for a long time).

It should be noted incidentally that compounds of formula (I) can be obtained according to one or the other of these two variants and used as initiators for the preparation of compounds of formula (I '), independently, according to one or the other. other of said two variants.

5 It has obviously been understood that the invention very generally relates to the compounds and polymers (mixtures of polymers) capable of being obtained by the process as described above (the formulas (I) and (I ') representing “schematically »Said compounds and polymers (polymer mixtures)).

According to another of its objects, the present invention relates to an energetic material capable of being obtained by azidation of at least one polyhydroxytelechelic derivative of epichlorohydrin as described above (of formula (I) or of formula (11). , and / or as obtained by the process as described above.

The azidation reaction in question is that, conventional, implemented to obtain the PAGs from the PECHs reaction of said PECHS with sodium azide (NaN3), in a solvent (generally dimethylsulfoxide (DMSO). , at a temperature of about 80 ° C.

Owing to the plurality and the distribution in space of the hydroxytelechelic functions of the precursor polyepichlorohydrins, the corresponding hydroxytelechelic glycidyl polyazides are likely to exist in many variants and to exhibit more or less advantageous mechanical properties.

It is in fact particularly advisable to have a range of polyhydroxytelechelic derivatives of epichlorohydrin (precursors), from which it is possible to prepare mixtures, with a view to optimizing the mechanical properties of the corresponding PAGs.

In any case, it can be understood that the density of the final network depends, in the first place, on the value of m.

It is now proposed to illustrate the invention, in a non-limiting manner, in its product and process aspects.

21 EXAMPLES I.

Protocol No. 1 for obtaining polyhydroxy-telechelic derivatives of epichlorohydrin (initiator = polyol of formula A- (OH) ,,, and “standard” conditions) In a 500 ml reactor equipped with a condenser, with stirring mechanical, a double jacket connected to a cryothermostat, an isobaric pouring funnel and a temperature measurement, were introduced 60 mL of chloroform with 0.05 mol of initiator (polyol), 0.021 mol d 'trichloroacetic acid (co-catalyst) and 0.006 mol of tin tetrachloride (catalyst).

The medium was stirred at 30 ° C. then epichlorohydrin (1.47 mol) was added, dropwise, via the dropping funnel.

Addition of the "monomer" at a very low rate allowed temperature control (maintained at 30 ° C).

After the addition of the epichlorohydrin, 100 ml of water were added to the reacted medium.

The aqueous phase generated was then removed.

A carbonate solution was then added, until a pH of 7 was obtained in the new aqueous phase. The organic phase, containing the product synthesized, was then extracted.

A final washing with distilled water was carried out to obtain a solution of synthesized product + chloroform.

The chloroform was evaporated on a rotary evaporator.

The isolated product was finally dried over magnesium sulfate.

This protocol no. 1 has been carried out many times with different initiators, in different solvents, and in particular: with a difunctional initiator (m = 2): chloropropane diol (CLPD), in chloroform and in toluene.

The results obtained (reaction yields, characteristics of the product prepared (number-average molecular mass (Mn, determined by size exclusion chromatography) and dispersity (Ip))) are specified below and listed in the first part of the table of results below: Example A: Solvent = chloroform and Initiator = CLPD S Yield: 83%, Mn = 1322 g / mol and Ip = 1.22 Example B: Solvent = Toluene and Initiator = CLPD Yield: 71%, Mn = 1519 g / mol and Ip = 1.15 with, according to the invention, plurifunctional initiators (m> 3): dipentaerythritol (DPE II; m = 6), tris (hydroxymethyl) nitromethane (TNM; m) = 3), tripentaerythritol (TPE II; m = 8), sucrose (rn = 8), in chloroform and toluene.

The results obtained (reaction yields, characteristics of the product prepared (number average molecular mass (Mn, determined by size exclusion chromatography) and dispersity (Ip)) are given in the first part of the table of results below. .

Example la: Solvent = chloroform and Initiator = DPETT Yield: 73%, Mn = 1565 g / mol and Ip = 1.8 Dl% II is very slightly soluble in the medium but the reaction is very exothermic which compensates for the kinetics of reaction and allows a good yield.

Example lb: Solvent = chloroform and Initiator = TNM Yield: 69%, Mn = 1945 g / mol and Ip = 1.6 TNM is also partially soluble in chloroform.

Example le: Solvent = chloroform and Initiator = TPETT 25 Yield: 76%, Mn = 1224 g / mol and Ip = 3.22 Example ld: Solvent = chloroform and Initiator = Sucrose Yield: 68%, Mn = 2000 g / mol and Ip = 1.48 23 Example 2a: Solvent = toluene and Initiator = DPETT Yield: 38%, Mn = 1200 g / mol and Ip = 1.68 DPETT is soluble in the medium.

Example 2b: Solvent = toluene and Initiator = TNM 5 Yield: 68%, Mn = 2176 g / mol and Ip = 1.35 TNM is soluble in toluene.

Example 2c Solvent = toluene and Initiator = TPETT Yield: 39%, Mn = 1623 g / mol and Ip = 1.4 10 Significant yields (from 38 to 76%) were obtained, confirming the possibility of obtaining according to the invention (by implementing a “basic” process of cationic polymerization with a plurifunctional initiator (m 3) in a solvent other than DCE) of PECHs, with a number-average molecular mass of 1200 to 2000 g / mol.

It is understood that the process of the invention thus makes it possible to prepare PECHs having average molecular masses similar to those of PECHs obtained with difunctional initiators (m = 2) in DCE).

The PECHs obtained always exhibit at least 3 20 functionalities.

It will be the same for the corresponding PAGs; hence the opportunity to generate denser networks by crosslinking said PAGs.

We have also understood the advantage of being able to have a range of “different” PECHs for obtaining appropriate mixtures.

25 24 He.

Protocol No. 2 for obtaining polvhvdroxytelechelic derivatives of ecrichlorohydrin (initiator = polyol of formula A- (OH), ', and “optimized” conditions) 5 In a 500 ml reactor equipped with a condenser, with stirring mechanical, a double jacket connected to a cryothermostat, an isobaric pouring funnel and a temperature measurement, were introduced 60 mL of chloroform with 0.005 mol of initiator (polyol), 0.021 mol of trichloroacetic acid (cocatalyst) and 0.006 mol of tin chloride tetrachloride (catalyst).

The medium was stirred at 30 ° C. then epichlorohydrin (5.82 mol) was added, dropwise, via the dropping funnel.

The addition of the monomer, at a very low flow rate, will allow temperature control (maintained at 30 ° C).

After the addition of the epichlorohydrin, 100 ml of water were added to the reacted medium.

The aqueous phase generated was then removed.

A carbonate solution was then added until a pH of 7 was obtained in the new aqueous phase.

The organic phase, containing the synthesized product, was then extracted.

A final wash with distilled water was carried out to obtain a solution of the synthesized product + chloroform.

The chloroform was evaporated on a rotary evaporator.

The isolated product was finally dried over magnesium sulfate.

This protocol no. 2 has been carried out many times with different initiators, in different solvents, and in particular: with a difunctional initiator (m = 2): chloropropane diol (an)) in chloroform and in toluene.

The results obtained (reaction yields, characteristics of the product prepared (number-average molecular mass (Mn, determined by size exclusion chromatography) and dispersity (Ip))) are specified below and listed in the first part of the document. table of results below: Example A ': Solvent = chloroform and Initiator = CLPD Yield: 78%, Mn = 2866 g / mol and Ip = 1.27 5 Example B': Solvent = Toluene and Initiator = CLPD Yield: 76 %, Mn = 2932 g / mol and Ip = 1.29 with, according to the invention, plurifunctional initiators (mk 3): dipentaerythritol (DE% II; m a-- 6), tris (hydroxymethyl) nitromethane ( TNM; m = 3), thpentaerythritol 10 (TPt II; m = 8), sucrose = 7) in chloroform and toluene.

The results obtained (reaction yields, characteristics of the product prepared (number-average molecular mass (Mn, determined by size exclusion chromatography) and dispersity (Ip)) are given in the first part of the table of results below.

Example 3a: Solvent = chloroform and Initiator = DPETT Yield: 52%, Mn = 3190 g / mol and Ip = 2.35 DPETT is very slightly soluble in the medium but the reaction is very exothermic, which compensates for the reaction kinetics. and allows to have a good yield.

Example 3b: Solvent = chloroform and Initiator = TNM Yield: 42%, Mn = 3368 g / mol and Ip = 1.83 TNM is also partially soluble in chloroform.

Example 3c: Solvent = chloroform and Initiator = TPETT Yield: 51%, Mn = 5192 g / mol and Ip = 1.74 25 Example 3d: Solvent = chloroform and Initiator = Sucrose Yield: 42%, Mn = 2502 g / mol and Ip = 2.97 Example 4a: Solvent = toluene and Initiator = DPETT Yield: 61 0/0, Mn = 2258 g / mol and Ip = 3.46 The Dl% II is soluble in the medium.

Example 4b: Solvent = toluene and Initiator = TNM Yield: 30%, Mn = 1999 g / mol and Ip = 2.47 TNM is soluble in toluene.

Example 4c: Solvent = toluene and Initiator = TPETT Yield: 52%, Mn = 4703 g / mol and Ip = 2.58 Example 4d: Solvent = toluene and Initiator = Sucrose Yield: 52%, Mn = 2527 g / mol and Ip = 3.05 Significant yields (from 30 to 61%) were obtained, confirming the possibility of obtaining according to the invention (by implementing an "optimized" process (with a small amount of initiator) of cationic polymerization. with a plurifunctional initiator (mk 3) in a solvent other than DCE) of PECHs, of number average molecular mass of 1999 to 5192 gjmol.

It is understood that the process of the invention allows a priori to thus prepare PECHs having higher average molecular weights.

The PECHs obtained always have at least 3 functionalities.

It will be the same for the corresponding PAGs; hence the opportunity to generate denser networks by crosslinking said PAGs.

We have also understood the advantage of being able to have a range of “different” PECHs for obtaining appropriate mixtures.

27 III.

Protocol n ° 3 (= protocol n ° 1 (initiator = Polvol of formula A- (01-1) m and “standard” conditions) + protocol n ° 2 (initiator = polyol of formula (D and “optimized” conditions) d 'obtaining polyhydr xytelechelic derivatives of epichlorohydrin 5.

In a first step, a polyhydroxytelechelic derivative of epichlorohydrin corresponding to formula (I) was prepared, using sucrose as initiator.

The operation was carried out in chloroform, according to Protocol No. 1, as specified in Example 1d above.

The derivative prepared, isolated and then dried therefore exhibited a number molecular mass (Mn) of 2000 g / mol (Ip = 1.48). .

Secondly, this derivative of formula (I) was used as an initiator to obtain a derivative of formula (I '), exhibiting a higher molecular weight in number.

The operation was carried out in chloroform, according to Protocol No. 2, more precisely with 0.005 mol of initiator (of said polyhydroxytelechelic derivative of epichlorohydrin corresponding to formula (I)) and 5.83 mol of epichlorohydrin.

Example 5a: Solvent = chloroform and Initiator = polymer obtained in example 1d Yield: 59%, Mn = 8949 g / mol and Ip = 3.04 It is confirmed here that this variant of the implementation of the process of 25 The invention makes it possible to obtain polyhydroxytelechelic derivatives of epichlorohydrin of high average molecular mass.

The results obtained in each of the above examples are collated in the table below.

28 RESULTS TABLE Result,,: p (%) Mn (cymol) Ip p (%): Mn (g / mol): Ip, -......, Chloroform Toluene Solvent Initiator CLPD method - protocol n ° 1 83 1322 1.22 71 1519 1.15 - protocol n ° 2 78 2866 1.27 76 2932 1.29 ---------- 1 DPb II - protocol n ° 1 73 1565 1.8 38 1200 1.68 - protocol n ° 2 52 3190 2.35 61 2258 TNM - protocol n ° 1 69 1945 1.6 68 2176 1.35 - protocol n ° 2 42 3368 1.83 30 1999 2.47 TPETT - protocol n ° 1 76 1224 3.22 39 1623 1.4 - protocol n ° 2 51 5192 1.74 57 4703 1.79 Sucrose - protocol n ° 1 68 2000 * 1.48 - protocol n ° 2 42 2502 2.97 52 2527: 3.05 PECH't - protocol n ° 1 - protocol n ° 2 59 8949 3.04

Claims (12)

CLAIMS 1. Polyhydroxytelechelic derivatives of epichlorohydrin: corresponding to formula (I) cl in which - A is the residue of a polyol of formula A- (OH) ,,,, in which m is an integer at least equal to 3 (m 3 ), said polyol having a molecular mass of between 92 and approximately 500 g / mol, and - n is an integer, not necessarily the same for all the m groups between 1 and 50 (1 <n. 5_ 50), as well as mixtures of at least two such derivatives of formula (I) with different A's; or corresponding to formula (r) in which 30 - A 'is the residue of a polyol of formula (I) above, the number average molecular mass of which is less than approximately 5000 g / mol, o = m, and - p is an integer, not necessarily the same for all the o groups or): 5, between 1 and <50 ((1 p 5 50); as well as mixtures of at least two such derivatives of formula (I ') with different A'; as well as mixtures of at least one derivative of formula (I) and at least one derivative of formula (I '). 2. Polyhydroxy-telechelic epichlorohydrin derivatives according to claim 1, of formula (I) or of formula (I '), in which m is at least equal to 5. 15 3. Polyhydroxytelechelic epichlorohydrin derivatives according to claim 1 or 2, of formula (I) or of formula (I '), in which m is less than or equal to 10. 4. Polyhydroxy-telechelic epichlorohydrin derivatives according to claim 1, characterized in that A is the residue of a polyol chosen from among thrnethylolethane (TME), tris (hydroxymethyl) propane (TMP), tris (hydroxymethyl) nitromethane (TNM) ), a butanetriol, pentaerythritol (Ph II), di (trimethylolethane) (DTME), di (trimethylolpropane) (DTMP), sucrose, glucose, fructose, dipentaerythritol (DPETT), tripentaerythritol (TPE II ) and cellulose; 31 characterized in that A is advantageously the remainder of a polyol chosen from tris (hydroxymethyl) nitromethane (TNM), glucose, fructose, dipentaerythritol (DPE), sucrose, tripentaerythritol (TPE I) and cellulose ; characterized in that A is very advantageously chosen from glucose, fructose, dipentaerythritol (DPETT), sucrose, tripentaerythritol (TPL I I) and cellulose. 5. Polyhydroxytelechelic epichlorohydrin derivatives according to any one of claims 1 to 4, of formula (I) in which n is an integer between 7 and 40 (7 5 n 5 40) or of formula (I ') in which n and p are, independently, integers between 7 and 40 (7 5 p S 40). 15 6. Polyhydroxytelechelic epichlorohydrin derivatives according to any one of claims 1 to 5, the molecular mass of which is between a molecular mass of approximately 370 g / mol and a number-average molecular mass of approximately 15,000 g / mol, preferably between a molecular weight of about 370 g / mol and a number average molecular weight of about 12000 g / mol. 7. Process for preparing at least one polyhydroxytelechelic epichlorohydrin derivative according to any one of claims 1 to 6, characterized in that it comprises: - for the preparation of at least one polyhydroxytelechelic epichlorohydrin derivative of formula (I), the addition, with temperature control, of epichlorohydrin (ECH), in a medium consisting essentially of an organic solvent (S) and containing, in addition to said organic solvent (S), at least one initiator of polyol type, at least one catalyst of Lewis acid type (C) and optionally also at least one acid co-catalyst (C '), said organic solvent (S) being chosen from chlorinated aliphatic solvents and aromatic solvents, miscible with epichlorohydrin and said at least one initiator, of polyol type, corresponding to the formula A- (OH) ,,, in which m is an integer at least equal to 3, advantageously at least equal to 5 and exhibiting a molecular mass between 92 and approximately 500 g / mol ; and - for the preparation of at least one polyhydroxytelechelic epichlorohydrin derivative of formula (I '), the prior preparation of at least one polyhydroxytelechelic epichlorohydrin derivative of formula (I), the number average molecular mass of which is less than approximately 5000 g / mol under the conditions indicated above and the use of said at least one polyhydroxytelechelic derivative of epichlorohydrin of formula (I) thus prepared as an initiator in a reaction of the same type. 15 8. Method according to claim 7, characterized in that said solvent (S) is chosen from chloroform and toluene. 9. Process according to one of claims 7 or 8, characterized in that, at the end of the addition of the epichlorohydrin, the initiator / epichlorohydrin molar ratio is between 0.003% and 5%. 10. Process according to claim 9, characterized in that said molar ratio is between 0.003% and less than 0.03% or between 0.03% and 5%, advantageously between 0.03 and 4%. 11. Method according to any one of claims 7 to 10, characterized in that it comprises the preparation of a polyhydroxytelechelic derivative 33 of epichlorohydrin of formula (I) with a single initiator of formula A- (OH) '' , then optionally the preparation of a polyhydroxy-telechelic epichlorohydrin derivative of formula (I ') with said polyhydroxy-telechelic epichlorohydrin derivative of formula (I) as initiator. 12. Energetic material obtainable by azidation of at least one polyhydroxytelechelic derivative of epichlorohydrin, according to any one of claims 1 to 6, and / or obtained by the process according to any one of claims 7 to. 11.