Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/60—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which all the silicon atoms are connected by linkages other than oxygen atoms
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/48—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms
  • C08G77/50—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms by carbon linkages
  • C08G77/52—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms by carbon linkages containing aromatic rings

Definitions

• the present invention relates to polymers of poly (ethynylene phenylene ethynylene polysiloxene (silylene)).
• the present invention relates, in particular, to poly (ethynylene phenylene ethynylene polysiloxene (silylene)) of low viscosity, preferably of determined molecular mass.
• the invention further relates to processes for the preparation of said polymers and to the cured products capable of being obtained by heat treatment of said polymers.
• the polymers according to the invention can in particular be used in matrices for composites.
• the technical field of the present invention can be defined as that of thermostable plastics, that is to say polymers which can withstand high temperatures which can reach for example up to 600 ° C.
• the industrial needs for such thermostable plastics have increased enormously in recent decades, particularly in the electronic and aerospace fields.
• Such polymers have been developed to remedy the shortcomings of materials previously used in similar applications. Indeed, it is known that metals such as iron, titanium and steel are thermally very resistant, but they are heavy. Aluminum is light but not very resistant to heat, ie up to around 300 ° C. Ceramics such as SiC, Si 3 N 4 and silica are lighter than metals and very heat resistant but they are not moldable. This is the reason why many plastics have been synthesized which are light, moldable and have good mechanical properties; these are mainly carbon-based polymers.
• Polyimides have the highest heat resistance of all plastics with a thermal deformation temperature of 460 ° C, however these compounds which are listed as being the most stable known at present are very difficult to use.
• Other polymers such as polybenzimidazoles, polybenzothiazoles and polybenzooxazoles have a heat resistance still higher than that of polyimides but they are not moldable and they are flammable.
• Polymers based on silicon such as silicones or carbosilanes have also been widely studied.
• the latter such as poly (sylylene ethynylene) compounds are generally used as ceramic precursors of the silicon carbide SiC type, resist compounds and conductive materials.
• process (C) makes it possible to obtain polymers without structural defects with good yields and a low mass distribution.
• thermosetting polymers The compounds obtained by this process are perfectly pure and have perfectly characterized thermal properties. These are thermosetting polymers.
• This document also discloses the preparation of the above-mentioned polymers reinforced with glass, carbon or SiC fibers.
• polymers are prepared essentially by the method of scheme (C) and optionally by the process of scheme (B), and they have a weight average molecular weight of 500 to 1,000,000.
• This document also describes cured products based on these polymers and their preparation by heat treatment. It is indicated that the polymers of this document can be used as thermostable polymer, fire-resistant polymer, conductive polymer, material for electroluminescent elements. In fact, it appears that such polymers are essentially used as organic precursors of ceramics.
• the various methods call upon injection techniques (in particular RTM), or prepreg compaction techniques.
• Prepregs are semi-finished products of small thickness made of fibers impregnated with resin.
• Prepregs which are intended for the production of high performance composite structures contain at least 50% fiber by volume.
• the matrix must have a low viscosity to penetrate the reinforcing ply and properly impregnate the fiber in order to avoid its distortion and to preserve its integrity.
• the reinforcing fibers are impregnated either with a resin solution in an appropriate solvent, or with pure resin in the molten state, this is the so-called "hot melt” technique.
• the technology for manufacturing prepregs with a thermoplastic matrix is largely governed by the morphology of the polymers.
• Injection molding is a process which consists in injecting the liquid resin into the textile reinforcement, positioned beforehand in the impression formed by the mold and the counter-mold.
• the most important parameter is the viscosity which must be between 100 and 1000 mPa.s at the injection temperature which is generally 50 to 250 ° C.
• amorphous polymers correspond to macromolecules whose skeletal structure is completely disordered. They are characterized by their glass transition temperature (Tg) corresponding to the transition from the glassy state to the rubbery state. Beyond Tg, thermoplastics are however characterized by a high creep resistance.
• the polymers prepared in document EP-B1-0 617 073 are compounds which are in powder form. The inventors were able to show, by reproducing the syntheses described in this document, that the polymers prepared would produce glass transition temperatures close to 50 ° C.
• the object of the invention is to provide polymers which meet inter alia these needs which do not have the defects, drawbacks, limitations and disadvantages of the polymers of the prior art as shown in particular by document EP-B1-0 617,073, and which solve the problems of the prior art.
• the object of the invention is also to provide a process which makes it possible to prepare said polymers.
• R represents a halogen atom (such as F, Cl, Br and I), an alkyl group (linear, or branched) having from 1 to 20 carbon atoms, a cycloalkyl group having from 3 to 20 carbon atoms (such as methyl, ethyl, propyl, butyl, cyclohexyl), an alkoxy group having from 1 to 20 carbon atoms (such as methoxy, ethoxy, propo y), an aryl group having from 6 to 20 carbon atoms (such as a phenyl group), an aryloxy group having 6 to 20 carbon atoms (such as a phenoxy group), an alkenyl group (linear, or branched) having 2 to 20 carbon atoms, a cycloalkenyl group having 3 to 20 carbon atoms (such as vinyl, allyl, cyclohexen
• R x and R 2 which may be the same or different represent a hydrogen atom, a halogen atom, an alkyl group having from 1 to 20 carbon atoms, a group cycloalkyl having 3 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an alkenyl group having from 2 to 20 carbon atoms, a cycloalkenyl group having from 3 to 20 carbon atoms, an alkynyl group having from 2 to 20 carbon atoms, one or more of the hydrogen atoms bonded to the atoms carbon atoms of R x and R 2 may be replaced by halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, amino groups, disubstituted amino groups or silanyl groups, examples of these groups have already been mentioned above
• the polymers according to the invention have a structure substantially similar to that of the polymers of document EP-B-0 617 073 with the fundamental exception, however, of the fact that the silicon atom of the silylene groups carries, on the one hand, a hydrogen atom and, on the other hand, a particular substituent, which is specifically a polysiloxene group
• Ri and R 2 are identical.
• they represent an alkyl group of 1 to 20 C, more preferably a methyl group.
• the polymer according to the invention intrinsically has a low viscosity, namely a viscosity generally less than 100 Pa.s at 140 ° C. This low viscosity is obtained, fundamentally, by virtue of the polysiloxene group, whatever the nature of the group Y, in particular it is not compulsory for Y to be a group derived from a chain-limiting agent.
• the polymers according to the invention can, moreover, also differ from the polymers of document EP-B1-0 610 073, due to the presence at the chain end of groups Y derived from a chain-limiting agent.
• the presence of the specific polysiloxene groups has the effect that the polymer (I) or (la) according to the invention has perfectly defined and modular rheological properties.
• the group Y is a group resulting from a chain limiter, the presence at the chain end of this group will have precisely the effect that the polymer of formula (I) or (la) will have a length and therefore a mass molecular molecules, perfectly defined like its rheological properties.
• Y can be H or a halogen atom, such as Cl, I, Br or I, preferably Cl, or another of hydrogen.
• Y can also be a group resulting from a chain-limiting agent.
• Y depends on the nature of the chain-limiting agent from which it is derived, Y may, in the case of the polymers of formula (I), represent a group of formula (II):
• R "' has the same meaning as R and can be the same or different from the latter
• n' has the same meaning as n and can be the same or different from the latter.
• R 3 , R 4 and R 5 which may be identical or different have the same meaning as R, already given above.
• a particularly preferred polymer of formula (I) according to the invention corresponds to the following formula:
• q is an integer from 1 to 40, for example 10, and where p is an integer from 1 to 40.
• the invention also relates to polymers, preferably polymers of determined molecular mass, capable of being obtained by hydrolysis of the polymers of formula (la), in which Y is a group derived from a chain-limiting agent, and corresponding to the following formula (Ib):
• the molecular mass of the polymers (I) and (la) according to the invention is, in the case where the group Y is a group derived from a chain-limiting agent, perfectly defined and the length of the polymer and therefore its molecular mass can be easily controlled by metered additions of chain limiter in the reaction mixture reflected by varying proportions of group Y in the polymer.
• the molar ratio of the Y groups (chain limiters) at the end of the chain to repeating units ethynylene phenylene ethynylene polysiloxene (silylene) is it generally from 0.01 to 1.5. Preferably, this ratio is 0.25 to 1.
• the molar proportion of the Y groups (chain limiters) at the end of the chain is generally from 1 to 60 and preferably from 20 to 50% of the polymer of formula (I) or (la).
• the number-average molecular mass of the polymers (I), (la) and (Ib), according to the invention, in the general case, is generally from 400 to 1,000,000 and their weight-average molecular mass is generally from 400 to 1,000,000.
• the number-average molecular mass of the polymers (I), (la) and (Ib), according to the invention, in the case where Y is a group derived from a chain-limiting agent, and which is then perfectly defined, is generally 400 to 50,000 and the weight average molecular weight is 600 to 100,000.
• the viscosity of the polymer according to the invention is low, that is to say that it is, for example, in the range of 0.1 to 500 mPa. s for temperatures of 50 to 150 ° C., regardless of the molecular weight of the polymer, that is to say without the need to use a group Y derived from a chain-limiting agent .
• the low viscosity is due to the specific polysiloxene groups carried by the silicon. If we want to define the viscosity of the polymer even better, we can do this by controlling its molecular mass. Indeed, advantageously, due to the presence of Y groups derived from a chain-limiting agent, the molecular mass is generally within the aforementioned advantageous range, which makes it possible, moreover, to perfectly control the viscosity of the polymers, which is in any case already sufficiently low, due to the presence of the polysiloxene groups, for the desired applications.
• the viscosity also depends on the nature of the groups carried by the aromatic rings.
• the viscosity is also linked to the glass transition temperature (Tg).
• Tg glass transition temperature
• the glass transition temperature of the polymers according to the invention will therefore generally be from -250 to + 10 ° C.
• the invention further relates to a first process for the preparation of a poly (ethynylene phenylene ethynylene polysiloxene (silylene)) polymer, preferably of determined molecular mass, optionally bearing at the end of the chain groups derived from a chain limiting agent , said polymer corresponding to formula (I) below:
• the phenylene group of the central repeating unit can be in the form o, m or p, and R, R ', Y, n, p (of R'), and q have the meaning already given above.
• phenylene group may be in the form o, m or p, and R, and n have the meaning indicated above for the formula (I), and X represents a halogen atom such as Cl Br or I, optionally mixed with a chain limiting agent of formula:
• Y - MgX (V) X having the meaning already given above, and Y is a group chosen from the groups of formula:
• a variant of the first process according to the invention makes it possible to prepare a poly (ethynylene phenylene ethynylene polysiloxene (silylene)) polymer of formula (la):
• phenylene group of the central repeating unit can be in the form o, m, or p, and R, R ', Y, p (of R') q and n have the meaning already given above; said process comprising the reaction of a GRIGNARD reagent of general formula (IV) above, and of a dihalide of general formula (VII), already indicated above, optionally in admixture with a chain-limiting agent of formula:
• the first process of the invention in this variant and in the case where Y is a group derived from a chain limiter, can, moreover, also, comprise a final hydrolysis step to give the polymer of formula (Ib ) already mentioned above.
• the invention also relates to a second process for the preparation of a polymer of poly (ethynylene phenylene ethynylene polysiloxene (silylene)), preferably of determined molecular mass, optionally bearing at the chain end groups derived from a chain limiting agent, said polymer corresponding to the following formula - (I):
• the phenylene group of the central repeating unit can be in the form o, m or p, and R, and R ', Y, n, q and p (of R') have the meaning already given above.
• phenylene group may be in the form o, m, or p and R and n have the meaning already indicated above for formula (I), optionally in admixture with a chain-limiting agent of formula (XI):
• R '' ' has the same meaning as R and can be the same or different from the latter, and has the same meaning as n and can be the same or different from the latter with a compound of formula (XII):
• A. variant of the second process according to the invention makes it possible to prepare a polymer of poly (ethynylene phenylene ethynylene polysiloxene (silylene)), preferably, of determined molecular mass, optionally carrying at the chain end groups derived from a chain limiting agent, of formula (la):
• phenylene group of the central repeating unit can be in the form, o, m or p, and R, R ', Y, q, n, and p have the meaning already given above; said process comprising reacting a compound of formula (X) already mentioned above, with a compound of formula (XII), already mentioned above, optionally in admixture with a chain-limiting agent (monohydrosilane) of formula ( XIII):
• the second method of the invention in this variant can, moreover, comprise a final hydrolysis step to give the polymer of formula (Ib) already mentioned above.
• the presence, as a substituent, on the silicon atom of the silylene groups, of a polysiloxene group surprisingly gives the polymers according to the invention a low viscosity and, moreover, , perfectly controlled, if Y is a group derived from a chain-limiting agent, in other words, the polymers according to the invention have in all cases excellent rheological properties.
• control of the masses of the polymers of formula (I), (la) and (Ib) can be obtained by adding to the reaction medium a reactive species also called chain limiting agent which blocks the polymerization reaction without affecting the overall yield of the reaction.
• This reactive species is generally an analogue of one of the main reactants, but which has only one function allowing coupling. When this species is introduced into the polymer chain, growth is stopped.
• the length of the polymer and therefore its molecular weight and consequently its viscosity are in direct correlation with the molar percentage of chain-limiting agent.
• This molar percentage is defined by the mole ratio of the chain-limiting agent to the total of the moles of chain-limiting agent and of diacetylene compounds of formula (IV) or (X) x 100. This percentage can range from 1 to 60%, preferably from 20 to 50%.
• molecular weight is related to the degree of activation of the catalyst [4]. As this is highly hygroscopic, it is very difficult to predict the molecular masses a priori. The less the catalyst is activated and the lower the masses, but this drop is accompanied by a significant drop in the yield of the polymerization reaction. In addition, the distribution can be so wide that several fractions of different mass can be isolated by selective fractionation.
• the first preparation process of the invention makes it possible to dispense with - when a chain limiter is used - a step in the process of EP-B1-0 617 073 which involves a silylated monohalogenated compound , which results in shorter reaction times as well as substantial savings in reagents.
• the first preparation process is the same as that described in document EP-B1-0 617 073, that is to say that beforehand on final hydrolysis, the reaction product of the GRIGNARD reagent (IV) and the dihalide (VII) is treated with a monohalide.
• the invention also relates to the hardened product capable of being obtained by heat treatment at a temperature of 50 to 700 ° C of the polymer described above.
• the hardened product has an infinite mass. It advantageously comes from a polymer with a mass of 500 to 20,000 and by weight of 600 to 100,000.
• the invention also relates to a composite matrix comprising the polymer described above.
• the first process for preparing a poly (ethynylene phenylene ethynylene polysiloxene (silylene)) polymer according to the invention is substantially similar to that described in document EP-B1-0 617 073 with the exception, however, of the presence of the polysiloxene substituent and of the possible incorporation into this mixture in accordance with the invention of a chain-limiting agent, of the final treatment of the polymers and optionally of the molar ratio of the organomagnesium and dichlorosilane reagents.
• the Grignard reagents of formula (IV) used in the first preparation process according to the invention are in particular those described in document EP-B1-0 617 073 on pages 5 to 7 (Formulas (3) and (8) to (20).
• the optional chain-limiting agent of formula (V) can be a monoacetylene organomagnesium compound of formula:
• Examples of the monoacetylene compounds from which the monoacetylene organomagnesium compounds (V) are derived are the following: phenylacetylene, 4-ethynyltoluene 4-ethynylbiphenyl, 1-ethynyl 4-methoxybenzene.
• dihalosilanes examples are the dichlorosilanes described on pages 7 to 9 of patent EP-B1-0 -617 093 and correspond in particular to formulas (21) to (26) given in this document.
• one of the substituents of these dihalosilanes is necessarily H and the other substituent is a specific polysiloxene group, which is not the case in the aforementioned patent.
• the conditions of the polymerization reaction such as the solvent, the reaction time, the temperature, etc. (excluding "post-treatment") are substantially the same as those described in document EP-B1-0 617 073 to which reference is made in particular on page 14.
• the only differences in this step proper polymerization relate, in addition to the specific group polysiloxene, the optional addition of an additional reagent chain limiter.
• reaction conditions are moreover substantially the same.
• the ratio of the number of acetylenic function by the number of halogen functions carried by the silane must be as close as possible to 1, and preferably from 0.9 to 1.1.
• the molar ratio of “phenylacetylene” to “diethynylbenzene” is preferably between 0.01 and 1.5 and ideally between 0.25 and 1 (percentage from 1 to 60%).
• a final hydrolysis step is carried out directly, so in this case it is freed a step compared to the analogous process of the prior art, in particular in the case where the chain limiter is an organomagnesium.
• reaction mixture is then decanted and the solvent of the organic phase is substituted with a volume for example of 0.1 to 100 ml per gram of polymer and ideally of 1 to 10 ml per gram of polymer for any type of solvent immiscible with water, such as xylene, toluene, benzene, chloroform, dichloromethane or alkane with more than 5 carbons.
• this step can be omitted.
• the organic phase is then washed for example from 1 to 5 times and preferably 2 to 3 times with a volume of water. for example from 0.1 to 100 ml per gram of polymer and ideally from 1 to 10 ml per gram of polymer, so as to neutralize the organic phase and extract all the impurities such as magnesium and halogen salts therefrom .
• the pH of the organic phase should preferably be between 5 and 8 and ideally between 6.5 and 7.5.
• the polymer is dried under a vacuum of between 0.1 and 500 mbar at a temperature between 20 and 150 ° C for a time between 15 minutes and 24 hours.
• the second process for preparing the polymers of formula (I) is a process using dehydrogenation in the presence of a basic metal oxide. Such a process differs from the analogous process described in documents [1] and [4] as well as in document EP-B-0 617 073 only in that a chain-limiting agent is optionally added to the reaction mixture and basically by the presence of polysiloxene groups in one of the reagents.
• the reaction mixture comprises a compound of formula (X) for example: 1, 3-diethylnylbenzene and optionally a chain-limiting agent which in this second process is a monoacetylene (XI) analogous to that already described above for the first process.
• X formula (X) for example: 1, 3-diethylnylbenzene and optionally a chain-limiting agent which in this second process is a monoacetylene (XI) analogous to that already described above for the first process.
• the basic metal oxide used is preferably chosen from oxides of alkali metals, alkaline earth metals, oxides of lanthanides, oxides of scandium, yttrium, thorium, titanium, zirconium, hafnium, copper, zinc, cadmium and their mixtures.
• the cured products prepared by heat treatment of the polymers according to the invention are for example produced by melting this polymer or by dissolving it in a suitable solvent, then optionally putting it in the desired form and heating it in a gaseous atmosphere. air, nitrogen or inert gas such as argon or helium.
• the temperature of the treatment generally ranges from 50 to 700 ° C, preferably from 100 to 400 ° C and more preferably from 150 to 350 ° C, and the heating is generally carried out for a period of one minute to 100 hours.
• the curing reaction can optionally be carried out in the presence of a curing agent and the polymer according to the invention can also be mixed with other resins or polymers.
• EP-B1-0 617 073 their hardening process is substantially identical and reference may be made to this document page 17 for more details.
• the organic solution is then dehydrated by passage over a bed of magnesium sulfate.
• the polymer is then obtained by evaporation of the solvent.
• the polymer is finally purified by drying under 0.4 mbar at 20 ° C. 34 g (80% yield) of polymer are thus obtained, which is in the form of a yellow oil.
• the number average molecular mass of this compound is 11,500 for a mass average mass of 5,500 (polydispersity of 2.1). These masses were determined by GPC from a polystyrene calibration.
• the organic solution is then dehydrated by passage over a bed of magnesium sulfate.
• the polymer is then obtained by evaporation of the solvent.
• the polymer is finally purified by drying under 0.4 mbar at 20 ° C. 33 g (78% yield) of polymer are thus obtained, which is in the form of a yellow oil.
• the number average molecular mass of this compound is 5,000 for a mass average mass of 2,150 (polydispersity of 2.3). These masses were determined by GPC from a polystyrene calibration.

Landscapes

• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Silicon Polymers (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=8856294

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (7)

Family Cites Families (4)

• 2000
  • 2000-11-10 FR FR0014460A patent/FR2816623B1/fr not_active Expired - Lifetime
• 2001
  • 2001-11-09 WO PCT/FR2001/003493 patent/WO2002038653A1/fr not_active Application Discontinuation
  • 2001-11-09 US US10/415,340 patent/US6872795B2/en not_active Expired - Fee Related
  • 2001-11-09 JP JP2002541980A patent/JP2004514005A/ja active Pending
  • 2001-11-09 EP EP01993643A patent/EP1355974A1/de not_active Withdrawn
  • 2001-11-09 CA CA002428104A patent/CA2428104A1/fr not_active Abandoned

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events