FR2510128A1 - Fireproof polymer, pref. polystyrene, compsn. - contg. poly:phosphazene homopolymer or grafted by the polymer - Google Patents

Abstract

Fireproof compsns. comprise 1-99 wt.% polymer and 99-1 wt.% polyphosphazene, homopolymer of formula (I) (where A is halogen, alkyl, aralkyl, aryl, alkoxy, phenyl or amine, all these being opt. substd., or OCH2CX3 (X being halogen), n is 3-15000) and/or polyphosphazene grafted by the polymer, i.e. phosphazene homopolymer having substituents similar to those of the polymer to be made fireproof and which have formulae (II), (III) (IV) and/or (V). Where A is as above, B is a grafted unit or sequences of the homopolymer to be made fireproof and C is an opt. gp. which is bivalent gp. linking B to the polyphosphazene back bone. Prepn. of the fireproof polymers is also claimed and comprises grafting the polyphosphazene with the desired gps. Compsn. is used in the building industry, in storage stable and does not alter the properties of the polymer which is being made fireproof.

Description

 The present invention relates to new flame retardant polymer compositions as well as to their methods of preparation.

 Fires (homes, factories, shops and places of leisure) are currently very frequent especially since the introduction of new synthetic building materials, inexpensive materials light, resistant, but unfortunately very flammable. Among these new materials, one of the most used is for example polystyrene and in particular in its expanded form and this thanks to its excellent thermal and sound insulation properties. Conventional fireproofing techniques consisting of impregnating or coating combustible materials with products (in the form of coatings, varnishes, paints, etc.) having the property of making them non-flammable or hardly flammable are often inapplicable, for example in the case of polystyrene foams. In addition, these techniques are very expensive. We also recommended the addition into the mass of the flame retardant polymer of numerous additives so as to reduce the flammability of the polymer. However, the quantities of micromolecular additives which it was necessary to incorporate in order to make the polymer non-flammable or capable of extinguishing spontaneously were important, so that the mechanical properties or the resistance to temperature were seriously impaired.

 The present invention is therefore given to provide a new composition perfectly stable during more or less prolonged storage and making polymers and especially polystyrene flame retardant, without in any way altering the excellent mechanical and thermal characteristics of this material.

dans laquelle
A représente un atome d'halogène ou un radical monovalent
pris dans le groupe qui comprend le groupe alkyle subs
titué ou non, le groupe aralkyle substitué ou non, le
groupe aryle substitué ou non, le groupe alcoxy- subs
titué ou non, le groupe OCH2CX3 (X représentant un
atome d'halogène), le groupe phényle substitué ou non,
une amine substituée ou non, et n est le degré de polymérisation compris entre 3 et 15 000 et/ou du polyphosphazène greffé par du polymère, c'est-àdire homopolymère de phosphazène portant des substituants similaires à ceux du polymère à ignifuger et qui correspond aux structures II et/ou III et/ou IV et/ou V, suivantes:

dans lesquelles
A a la même signification que ci-dessus
B représente des greffons ou des séquences de l'homo
polymère à ignifuger, et
C dont la présence est facultative, représente un radical
bivalent q u i sert à rattacher le greffon de l'homo
polystyrène au squelette polyphosphazène.The subject of the present invention is new compositions of flame retardant polymers, characterized in that they contain: - from 1 to 99% by weight of polymer, and - from 99 to 1% by weight of polyphosphazene, homopolymer
of general formula I below

in which
A represents a halogen atom or a monovalent radical
taken from the group which includes the alkyl group subs
whether or not substituted, the substituted or unsubstituted aralkyl group, the
substituted or unsubstituted aryl group, the alkoxy-subs group
whether titled or not, the OCH2CX3 group (X representing a
halogen atom), the substituted or unsubstituted phenyl group,
a substituted or unsubstituted amine, and n is the degree of polymerization between 3 and 15,000 and / or of the polyphosphazene grafted with the polymer, that is to say homopolymer of phosphazene carrying substituents similar to those of the polymer to be flame retarded and which corresponds to structures II and / or III and / or IV and / or V, as follows:

in which
A has the same meaning as above
B represents grafts or sequences of homo
flame retardant polymer, and
C, the presence of which is optional, represents a radical
bivalent which is used to attach the homo graft
polystyrene with polyphosphazene skeleton.

 According to an advantageous embodiment of the object of the invention, the homopolymer consists of poly styrene.

 By polystyrene according to the present invention is meant a homopolymer of styrene and styrene derivatives as well as copolymers with other monomers containing at least about 30% of styrene or styrene derivatives. As a styrene derivative, mention may be made of substituted styrene such as methylstyrene, vinyltoluene or chlorostyrene. As a comonomer, there may be mentioned, without this list being exhaustive, vinyl compounds such as acrylonitrile, acrylic, methacrylic acids and their esters, heterocyclic vinyl compounds such as vinylpyridine, vinylcarbazol, conjugated dienes such as butadiene and isoprene.

 The polystyrene used can be used in any desired form. Owing to their flammability, the expanded or pre-expanded materials are remarkably improved by the use of the compositions in accordance with the invention.

 According to an advantageous embodiment of the object of the present invention, the structures II, III, IV and V are statistically distributed.

According to another advantageous embodiment of the object of the present invention, the structures II, III,
IV and V are distributed in sequence.

 The polyphosphazene block is the special case of a grafted polyphosphazene comprising only one or two grafts per chain at one or both ends thereof.

 The present invention also relates to a process for the preparation of flame retardant polymers, characterized in that the desired grafts are hooked onto the polyphosphazene.

 According to the invention, the operation is carried out by direct attachment of a living monofunctional polymer to the poly dihalogenophosphazene, the deactivation reaction of the living polymer being carried out by nucleophilic substitution of the halogen atoms of the polyphosphazene chair.

The grafting reaction is carried out between the .organometallic end of the living polymer and the halogen of the polyphosphazene, according to a reaction VI.

 The synthesis of O carbanionic polymers is now extensively described (cf. in particular 1, Journ.

of Polymer Sciences "; vol. 58 L19727 p. 1363-1375).

 According to another embodiment of the process according to the present invention, the attachment is effected by a chemical reaction in an appropriate solvent between the halogens located on the polyphosphazene chain and a chemical function (-OH, -NH, -SH or analog) located at the end of the chain of the polymer to be flame retarded.

According to a particular modality of this embodiment, the polymer capable of being attached to the polyphosphazene is prepared anionically in a first step, then this attachment is carried out according to diagram VII below.

 The functionalization of carbanions is also described in the literature and makes it possible to attach a large number of reactive functions to one end of the polymer.

 The carbanionic oligomer, polymer or copolymer (B) can themselves be obtained by a known anionic polymerization or copolymerization of vinyl or diene monomers, the anionic initiators used can be for example n-butyllithium, sec-butyl- lithium, butyl lithium-TMEDA, phenyllithium, alkali metals, organometallic initiators.

 The monomers used for the preparation of the macromolecular substances (B) are vinyl and / or diene compounds known to those skilled in the art, in particular vinyl monomers such as styrene and substituted styrenes, such as chlorostyrene or bromostyrene , methoxystyrene, methylstyrene, butylstyrene and dimethylaminostyrene, a-methylstyrene, acrylonitrile, vinyl chloride, vinylpyridine, vinylnaphthalene, alkyl methacrylates and acrylates of which the alkyl group comprises from 1 to 4 carbon atoms, diene monomers such as isoprene (or 2-methyl butadiene-1, 3), butadiene and substituted butadienes, and preferably isoprene and butadiene, nitriles and in particular acrylonitrile, cyclic ethers and in particular propylene oxide, ethylene oxide or ethylene sulfide, lactams and in particular caprolactam, lactones and mono- and diisocyanates.

 The mixture of the polymer and of the macpholecular polyphosphazene and / or polyphosphazene grafted substances for obtaining the composition according to the invention can be carried out by any process known per se. One can for example operate dry using a mixer of the BANBURY type or a single or twin screw extruder; the polymers can also be dissolved in a solvent, preferably a volatile solvent, in the desired proportions and the solvent is evaporated to collect the product. it is also possible to incorporate the macromolecular substances at the end of polymerization of the polymer A. It should be understood that the manner of operating the mixing cannot in any way limit the scope of the invention.

 If it is desired to obtain foam-forming structures, liquid or gaseous blowing agents can be incorporated into the composition, for example aliphatic or cycloaliphatic hydrocarbons such as propane, butane, pentane, hexane, cyclohexane or halogenated hydrocarbons such as chloride methyl, dichlorodifluoro-methane or trichlorotrifluoro-ethane.

They can be incorporated before, during or after the polymerization of the polymer (for example styrene) and independently with the macromolecular substance with phosphonated ends.

 The compositions can also contain usual additives and fillers such as antioxidants, stabilizers, antistatics, pigments and dyes, dispersing agents, foam structure regulators, inert fillers, etc.

 The compositions can be used according to the usual polymer transformation methods: molding, injection, extrusion, calendering, thermoforming, etc.

 In addition to the foregoing arrangements, the invention also comprises other arrangements which will emerge from the description which follows.

 The invention relates more particularly to new flame retardant polymer compositions containing in any proportion the polymer, the polyphosphazene and / or the polyphosphazene grafted with the polymer, the processes for preparing these compositions, as well as the means used for the preparation of these compositions and the overall methods in which these methods are included as well as the products and compositions according to the present invention.

 The invention will be better understood with the aid of the additional description which follows, which refers to examples of implementation of the process which is the subject of the present invention and to the appended drawing (single figure) representing an example of the necessary equipment for the synthesis of products in accordance with the present invention.

 It should be understood, however, that these examples of implementation and the example of apparatus are given solely by way of illustration of the subject of the invention, of which they do not in any way constitute a limitation.

In the examples, the oxygen index is also indicated as a measure of the flame retardant properties. The method used to carry out the measurement of the oxygen index consists in igniting a powder sample placed in a chimney into which a homogeneous oxygen / nitrogen mixture of known composition is sent, at a flow rate corresponding to a speed of passage of about 4 cm / second. The flame is kept in contact with the sample until the latter melts. The index taken corresponds to the oxygen content of the gas mixture necessary for the sample to burn for at least 30 seconds. The oxygen index is given by the relation
I = O2 / CO2 + N2 x 100
EXAMPLE 1
SYNTHESIS OF POLYSTYRENE GRAFT ON POLY PHOSPHAZENE
A perfectly dry apparatus (represented in FIG. 1) was used (drying in an oven at 2500 ° C. for 12 hours) comprising a three-necked reactor 1, thermostatically controlled and in which a mechanical stirrer 2 and three bromine bulbs 3 are placed. , 4 and 5, two of which are interconnected. This reactor is connected to a second thermostatically controlled three-necked reactor 6, into which a mechanical agitator 7 plunges and which is surmounted by a dropping funnel 8, the reaction product being discharged through the bottom 9 of the reactor 6 and a device for the disposal of deletions is planned in 10.

 The assembly is placed under vacuum and then filled with nitrogen (or argon). This vacuum-nitrogen (or argon) alternation is repeated 4 times, thus checking the tightness of the assembly. 1100 cm3 of pure benzene are introduced into the reactor via the bromine bulb 5. 230 ml of purified styrene on a living anion are added via the bromine bulb 4, and 69 cm3 of a normal solution of sbutyllithium in benzene are introduced through bulb 3. The mixture is stirred at room temperature for 2 hours.

 In reactor 6, 180 g of a 10% by weight polymer polychlorophosphazene benzene solution are placed. A circulation of water thermostatically controlled at 100 ° C. is established in the envelope of the reactor 6. The solution from the reactor 1 is introduced dropwise to the reactor 6 with stirring. At the end of the addition, the grafting reaction is left stirring for one hour.

 The content of reactor 6 is then poured dropwise into a solution of sodium trifluoroethanolate CF3CH2ONa (380 g) in tetrahydrofuran (400 cm). The mixture is left overnight under reflux, then is neutralized with hydrochloric acid in solution. The whole is poured into water to remove the salts. The precipitating polymer is taken up in tetrahydrofuran, then reprecipitated in water. The polymer is then dried under vacuum.

LAW Index: 57
EXAMPLE 2
SYNTHESIS OF A HYDROXYLATED POLYSTYRENE U
The preparation is similar to that of Example No. 1. The only difference consists, at the end of the polymerization, in adding ethylene oxide (60 g) via the inlet 11 of the reactor 1 provided with a thermowell cooled to -600C.

 At the end of the addition of ethylene oxide, the content of reactor 1 is poured as previously into reactor 6 and the experimental process is then the same.

LAW Index: 50
EXAMPLE 3
SYNTHESIS OF A POLYPHOSPHAZENE GRAFT WITH POLYISOPRENE
The assembly and procedure are similar to those given for polystyrene.

 The initiation of isoprene (143 cm3) with s.butyllithium (43 cm3 of a normal solution in benzene) is done at room temperature, then when the addition of the initiator is complete, reactor 1 is thermostatically controlled at 400C to carry out the propagation reaction. The deactivation in reactor 6 and the rest of the operations are similar to what is described in example 1.

EXAMPLE 4
SYNTHESIS OF A POLYPHOSPHAZENE GRAFT BY A POLY
ISOPRENE U OL
The polymerization reaction is carried out as in Example 3. Functionalization with ethylene oxide as in Example 2 and the grafting reaction on polyphosphazene as in Example 1.

 As is apparent from the above, the invention is in no way limited to those of its modes of implementation, embodiment and application which have just been described more explicitly; on the contrary, it embraces all the variants which may come to the mind of the technician in the matter, without departing from the framework, or the scope, of the present invention.

Claims (1)

 10- New compositions of flame retardant polymers, characterized in that they contain - from 1 to 99% by weight of polymer, and - from 99 to 1% by weight of polyphosphazene, homopolymer  of general formula I below

 in which A represents a halogen atom or a monovalent radical  taken from the group which includes the alkyl group subs  whether or not substituted, the substituted or unsubstituted aralkyl group, the  substituted or unsubstituted aryl group, the alkoxy-subs group  whether or not incorporated, the OCH2CX3 group (X representing a  halogen atom), the substituted or unsubstituted phenyl group,  a substituted or unsubstituted amine and n is the degree of polymerization of between 3 and 15,000 and / or of the polyphosphazene grafted by the polymer, that is to say homopolymer of phosphazene carrying substituents similar to those of the polymer to be flame retarded and which corresponds to structures II and / or III and / or IV and / or V, following

 in which A has the same meaning as above B represents grafts or sequences of the homo-  flame retardant polymer, and C, the presence of which is optional, represents a radical  bivalent that is used to attach the homo graft  polystyrene with polyphosphazene skeleton.  20- Composition according to Claim 1, characterized in that the homopolymer consists of polystyrene.  30- Composition according to any one of Claims 1 and 2, characterized in that the structures II, III, IV and V are statistically distributed.  40- Composition according to any one of Claims 1 and 2, characterized in that the structures II, III, IV and V are distributed by sequence.  50- Process for the preparation of flame retardant polymers according to Claim 1, characterized in that the desired grafts are hung on the polyphosphazene.  60- Method according to Claim 5, characterized in that one operates by direct attachment of a living monofunctional polymer to the polydihalogenophosphazene, the deactivation reaction of the living polymer being carried out by nucleophilic substitution of the halogen atoms of the polyphosphazene chain .  70- Method according to Claim 5, characterized in that 11 attachment is effected by a chemical reaction in an appropriate solvent between the halogens located on the polyphosphazene chain and a chemical function (-OH, -NH, -SH or the like) located at the chain end of the polymer to be flame retarded.  80- Process according to Claims 5 and 7, characterized in that an polymer is prepared in an anionic way in a first step, the polymer capable of being attached to the polyphosphazene, then this attachment is carried out according to scheme VII below.

 9 - Flame retardant products prepared using a composition according to any one of Claims 1 to 5, characterized in that said compositions also contain a blowing agent and / or conventional fillers and additives (antioxidants and / or stabilizers and / or antistatic agents and / or pigments and dyes and / or dispersing agents and / or structure regulators and / or inert fillers).