NL8900661A - INHIBITS COPOLYMER ON THE BASIS OF ALFA-OLEQUE, METHOD FOR THE PREPARATION THEREOF AND USE FOR THE PREPARATION OF THERMOPLASTIC ALLOYS, AND THE THERMOPLASTIC ALLOYS OBTAINED. - Google Patents

Description

VO 2051

Grafted α-olefin based copolymer, process for its preparation and use for the preparation of thermoplastic alloys, as well as the resulting thermoplastic alloys.

The present invention relates to a grafted α-olefin-based copolymer, a method of preparation and its use, in particular, as a means of rendering at least two incompatible thermoplastic polymers compatible.

It is known in certain specific blends to make two polymers incompatible by adding a third polymer, which is partially compatible with both polymers.

Thus, for example, for the polypropylene-polyamide mixture, several third polymers have been proposed:

Mitsubishi Rayon Japanese Patent Publication No. 70-030943 discloses a blend comprising polypropylene, polyamide and maleic anhydride grafted polypropylene.

Mitsui's Japanese patent, published under No. 59-149940, has claimed a mixture containing polypropylene, polyamide and an ethylene-propylene copolymer grafted with maleic anhydride.

20 In the French patent of Mitsubishi Rayon, published under no. FR. 2,107,538, discloses a blend of polypropylene and polyamide reinforced by glass fibers, which is compatibilized by adding a poly. amide chains grafted propylene-a-olefin copolymer. This grafted copolymer has been obtained by polycondensation of an amino acid in the presence of a propylene copolymer previously grafted with maleic anhydride.

The Japanese patent to Toa Gosei and Mitsui Toatsu, published under No. 60-233131, discloses the preparation of a grafted copolymer for compabilizing a mixture of polypropylene and polyvinyl chloride. This grafted copolymer was obtained by reaction

8900661S

4 Ί -2- of a polypropylene modified with 2-20 wt% maleic anhydride, with a polymethyl methacrylate containing a terminal hydroxyl group.

The invention primarily relates to novel grafted copolymers consisting of at least one monoamine polyamide oligomer and a polymer (or copolymer) of an α-olefin grafted with a monomer capable of reacting with an amine function of the monoamine polyamide oligomer.

The invention also relates to the process for the preparation of this grafted copolymer. It is prepared by free radical grafting on a polymer chain containing motifs derived from α-olefin of a monomer capable of reacting with an amine function, followed by addition of the monoamine polyamide oligomer to the grafted copolymer.

The invention also relates to the use of this grafted copolymer for addition to at least two thermoplastic polymers, which are incompatible with each other, but of which at least one is compatible with the polyamide oligomer and at least one compatible with the α-olefin polymer or copolymer.

The copolymer according to the invention consists of a grafted copolymer represented by the expression (see formula 1 of the formula sheet) in which: • corresponds to the (co) polymer strain, • XcP ^ corresponds to the (co) polymer strain grafted polymers, • A is a motif derived from an α-olefin containing 30. 2-8 carbon atoms and preferably a motif derived from propylene, • M is selected from the group consisting of: - the motifs derived from an α-olefin with 2-8 carbon atoms and preferably ethylene, Q9 0 0 6 6 1 £ -3- - the motifs derived from multiple α-olefins, as previously described, which may simply be mixed together or copolymerized into random or block copolymers and preferably one of the α-olefins being 5 echene, - the motifs, derived of a monomer, which may be polymerized with one of the α-olefins as previously described, for example an alkyl acrylate, - the motifs A and M, which form said (co) polymer strain 10 are copolymerized or simply mixed in a statistical or block-forming manner, • X is a monomer-derived motif which is grafted to an ot-olefin homo or copolymer by free radicals and which has a function which can react with an amine motif, • P is derived from a polyamide oligomer with the formula 2 of the formula sheet, in which: • f is a number between 3 and 11, • g is a number between 5 and 80 and preferably between 15 and 55, • Rj. is hydrogen or a linear or branched alkyl group of up to 20 carbon atoms, • Rg is a group of up to 20 carbon atoms, linear or branched alkyl or alkenyl, a saturated or unsaturated cycloaliphatic radical, an aromatic radical or a combination of the mentioned, • a, b, c and d are numbers, corresponding to the following definitions: • a is between 0 and 5,000 and preferably between 350 and 2,000, • the sum a + b is between 350 and 45,000 and preferably between 500 and 10,000 ° C is selected such that the weight ratio of the monomer X grafted onto the (co) polymer strain to the X grafted copolymer is between 500 ppm and 10%, preferably less than 2%, and most preferably between 5,000 ppm and 1.5%, 8900661.

-4- • d is zero and less than or equal to c and preferably at least equal to 0.3 c.

By (co) polymeric strain of the formula: AM, & Jj in which a, b, A and M are defined as above, each copolymer consisting of motifs A and B, derived from monomers, which are statistically or block-formed lead polymers are polymerized, or optionally any mixture of polymers, obtained by separate polymerizations of monomers, from which motifs A and M10 are derived.

This copolymerization or mixing can take place in the known ways.

As an example can be mentioned the copolymerization of propylene with an α-olefin in the presence of a Ziegler catalyst or coordination catalyst. The grafted copolymer of the invention can be obtained by grafting using free radicals on the (co) polymer strain of a monomer capable of reacting with an amine function, followed by addition of the oligomer to the previously grafted (co) polymer.

The monomer X, which is grafted with free radicals on the (co) polymer strain and which contains a function that can react with an amine function, can in particular correspond to one of formulas 3, 4 and 5 of the formula sheet, in which: 25 · R ^ and R2 are either hydrogen, or a linear or branched alkyl chain of up to 8 carbon atoms, at least one of these symbols representing hydrogen, • is hydrogen or a straight or branched alkyl group of up to 10 carbon atoms, 30 · R ^ is a linear or branched alkenyl group with up to 12 carbon atoms.

The preferred monomers X are citraconic anhydride, fumaric acid, mesaconic acid, triallyl succinyl anhydride and most particularly maleic anhydride.

The grafting of the monomer X onto the (co) polymer strain, carried out according to a radical mechanism, takes place 3900661.

% -5- in the presence of a radical initiator, which may be dicumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (tert-butyl peroxy) hexane.

Usually, the initiator is used at a rate of 2.5-10 to 4 * 10 based on the weight of the (co) polymer.

The free radical inoculation of the monomer X on the (co) polymer strain can be done in the molten state or in solution in a solvent of the (co) polymer strain.

As an example of such solvents, mention can be made of toluene, xylene and chlorobenzene.

The solution grafting technique is especially recommended if one wishes to achieve a grafting degree greater than 1.5% (weight ratio of the monomer X grafted onto the X grafted (co) polymer strain).

The (co) polymer strain, the monomer X and the radical polymerization initiator are placed in a solvent of the (co) polymer. The whole is brought to such a temperature that thermal decomposition of the radical initiator takes place in order for the grafting reaction to proceed. Overall, the duration of this reaction is between 0.5 and 10 times and preferably between 1 and 4 times the duration of the half-life of the radical initiator at the reaction temperature.

Usually the temperature of the thermal decomposition of the radical initiator is between 90 and 200 ° C and preferably between about 110 and 140 ° C.

The molten free radical grafting technique of the monomer X on the (co) polymer strain is particularly well suited if one wishes to obtain a grafting degree between 500 ppm and 1.5%.

The radical inoculation in the molten state consists of mixing the (co) polymer strain with the selected amounts of monomer X and radical initiator, for example in an extruder. The mixture is brought to a temperature, usually between 170 and 250 ° C and preferably between 180 and 200 ° C.

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The average residence time of the molten material in the extruder is usually chosen between 15 sec and 3 min, and preferably between 40 and 80 sec.

The grafting rate of the monomer X on the (co) polymer strain can be measured by determining the content of the anhydride functions by infrared spectrometry.

Then, the monoamine polyamide oligomer P of the formula 6 of the formula sheet is added to the grafted (co) polymer, wherein f, g, R ,. and Rg are described as earlier-10.

This monoamine polyamide oligomer can be obtained by polycondensation of an amino acid of the formula 7, or by polyaddition of a lactam of the formula 8, wherein f has the previously indicated meaning, in the presence of a monofunctional polymerization-limiting agent of the formula 9 , in which and Rg have the meanings given previously.

The monomeric amino acids or lactams that are preferred for the synthesis of the monoamine oligomer of the invention are selected from caprolactam, 11-amino-undecanoic acid or dodecalactam. The preferred monofunctional polymerization limiting agents are laurylamine and oleylamine.

The above-described polycondensation is performed according to known conventional methods, for example at a temperature, usually between 200 and 300 ° C, in vacuo or under an inert atmosphere, with stirring of the reaction mixture.

The average chain length of the oligomer 30 is determined by the original molar ratio between the polycondensable monomer or lactam and the mono-functional polymerization-limiting agent.

To calculate the average chain length, one molecule of chain-limiting agent is usually counted on one oligomer chain.

8900661-% -7-

The addition of the monoamine polyamide oligomer to the monomer X-grafted (co) polymer strain is effected by reaction of an amine function of the oligomer with at least one anhydride or acid function of the grafted (co) -5 polymer. Amide or imide bonds are thus created.

The addition of the oligomer P to the grafted (co) polymer strain preferably takes place in the molten state. Thus, in an extruder, the oligomer and (co) polymer can be kneaded at a temperature usually between 10 230 and 250 ° C. The average residence time of the molten material in the extruder can be between 15 sec and 5 min and preferably between 1 and 3 min.

The addition of the oligomer to the grafted (co) polymer strain is evaluated by selective extraction of the free polyamide oligomers, ie, those that have not reacted to form the finished grafted copolymer.

The grafted α-olefin copolymers according to the invention offer the following advantages over third polymers from the literature: The grafting degree of the polyamide oligomer on the grafted (co) polymer can be controlled and thus better control of the structure of the grafted copolymer.

The average molecular weight of the mono-25 amine polyamide oligomer can be adjusted and controlled. Namely, the average molecular weight of the polyamide oligomer is a determining factor for the activity and effectiveness of the grafted copolymer of the invention as a compatibilizer for alloys of incompatible polymers.

Since the grafted copolymers according to the invention do not exhibit any reactive chain ends in the sense of the polydondensation, when kneading the constituents of the alloy with the grafted copolymer according to the invention, the said chain ends will not react in an uncontrolled manner.

8900661.

-8- «

In particular, the grafted copolymer of the present invention homogeneously enables at least two mutually incompatible thermoplastic polymers, but at least one of which is compatible with said copoly-5-forming polyamido oligomer and the other with the (co ) polymer strain.

The grafted copolymer can be incorporated in the mixture of thermoplastic resins in the molten state in a kneader in a conventional manner. The amount of copolymer introduced can be between 0.1 and 30% and preferably between 5 and 15% by weight, based on the weight of the mixture of thermoplastic resins.

As examples of polymers or thermoplastic resins, which are compatible with the polyamide oligomers, which are part of the graft copolymer composition, may be mentioned in particular: - aliphatic polyamides, such as the polyamides-6, -11 or - 12, - the semi-aromatic polyamides, in particular those described in French patents 1,588,130, 2,324,672 and 2,575,756, in European patent 53,876 and in Japanese patents 60,217,237 and 59,015,447, - polyetherester block amides or polyether block amides, and in particular the products described in US patents 4,332,920 and 4,331,786, - hydrolysed ethylene-vinyl acetyl copolymers, - resins containing phenolic motifs, such as the poly-p-vinylphenol. copolymers, to the extent that the content of motifs compatible with the copolymer is sufficient to maintain compatibility.

The term polymers should also be understood to mean the mixture of polymers (or copolymers) with various additives, (shock modifiers, mineral charges, glass fibers, pigments 89 00 6 61 o -9-

As examples of thermoplastic polymers compatible with the (co) polymeric strain, particular mention may be made of polypropylene, polyethylene and the ethylene-propylene copolymers.

Thanks to the compatibilizing agent according to the invention it is possible to prepare improved alloys such as polyamide-6 - polypropylene polyamide-6 - polyethylene 10 polyamide-6 - copolymer ethylene / propylene polyamide-11 or -12 - polypropylene or polyethylene or copolymer ethylene / propylene copolymer ethylene - hydrolysed vinyl acetate - polypropylene or polyethylene 15 or copolymer ethylene / propylene poly-p-vinylphenol - polypropylene or polyethylene or copolymer ethylene / propylene polyether-block amide - polypropylene or polyethylene or copolymer ethylene / propylene 20 semi-aromatic - polypropylene or polyethylene Or copolymer ethylene / propylene

The compatibility obtained by the grafted copolymer according to the invention is evident from an electron microscopic examination and from the mechanical properties of the product obtained by mixing the incompatible thermoplastic polymers.

Morphologically, a mixture of thermoplastic polymers without the grafted copolymer of the invention in electron microscopic examination presents as thick nodules of one polymer contained in the matrix formed by the other polymer, with virtually no adhesion between the nodules and the matrix . Addition of the grafted copolymer causes a significant decrease in the size of the nodules. Strong adhesion is also observed between the visible phases by covering the nodules through the matrix. Under those conditions 8900 661. * -10-, what may be called an alloy, is formed, analogous to structures existing in the metal industry, which differ from simple mixtures.

The mechanical properties of such thermoplastic alloys are at least equal to those of the components, taking into account the volume reaction of each component, and in some cases better than that of the two components, for example, impact strength.

Different from these alloys according to the invention, simple blends of the same incompatible polymers, without the intervention of the grafted copolymer of the invention, have mechanical properties usually close to those of the component having the least properties.

The examples below illustrate the invention without, however, limiting it.

EXAMPLE I

A. Synthesis of the X-grafted copolymer strain.

Into a Werner extruder, a mixture is continuously charged, that 100 parts by weight of propylene-ethylene block copolymer (with 12% by weight of ethylene, melt index = 5, melting point = 163 ° C), 1.6 parts of maleic anhydride and 1.7 parts of 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane dissolved in 1 part of chlorobenzene.

The whole is brought to 200 ° C and the rotational speed of the worm is 100 rpm.

The mixture is devolatilized before it enters the spinneret to remove the chlorobenzene and the unreacted maleic anhydride.

A sample of the grafted polymer is taken from the spinneret, which is dissolved in xylene and then precipitated with acetone to purify it.

Determination of the content of the anhydride functions by infrared spectrophotometry yields 1.16% by weight of grafted anhydride.

8900661 -11-

Gel permeation chromatography determines that the average number molecular mass is 32,000.

B. Synthesis of the polyamide oligomer (P).

Into a 100 liter stainless steel reactor, 5 kg of caprolactam, 0.91 kg of laurylamine and 3.5 liters of water are added.

The reactor is heated in a closed state for 2 hours at 250 ° C, after purging it with nitrogen and stirring at 35 rpm. Then the atmosphere of the reactor is relaxed in 1 hour.

After purging the reactor with nitrogen for 15 minutes, the oligomer is poured into water, filtered off, washed with water at 80 ° C and then dried in a vacuum drying oven at 80 ° C for 16 hours.

There is thus obtained a polyamide oligomer, the average number molecular mass of which is 5,700, determined by potentiometric determination of the terminal amine functions.

C. Preparation of the grafted copolymer.

In a Werner ZSK30 extruder, a mixture is kneaded in the molten state, containing 59.8 parts of the grafted copolymer strain described under A and 40.2 parts of the oligomer described under B.

The whole is brought to 240 ° C.

The average residence time of the mixture in the extruder is about 3 minutes.

At the exit of the extruder, a sample is taken from the material which is fed into an extractor of the Kumagawa type.

Thus, the polyamide oligomers which have not reacted with the anhydride functions of the maleized copolymer are selectively extracted with formic acid. This method determines a degree of condensation of the polyamide oligomer on the grafted (co) polymer of 65%.

The graft copolymer thus obtained can be represented by the expression according to formula 10 of the formula sheet, wherein: 890066 1.

* -12- A is a propylene-derived motif, M is an ethylene-derived motif, X is a motif derived from maleic anhydride, P is an oligomer of caprolactam Mn = 5,700.

EXAMPLE II

A mixture containing 33 parts of polypropylene, 57 parts of polyamide-6 and 10 parts of the maleized copolymer strain described in Example 1a is continuously introduced into a Werner extruder (sample 1).

10 The material temperature along the cylinder is between 255 and 270 ° C. The rotational speed of the worm is 150 rpm and the material flow rate is 20 kg / hour.

Under the same conditions, a mixture is extruded containing 33 parts of polypropylene, 57 parts of polyamide-6 and 10 parts of grafted copolymer described in Example 1C (sample 2).

Also, under the same conditions, a control mixture containing 36.7 parts by weight of polypropylene and 63.3 parts by weight of polyamide-6 is prepared (sample 3).

For samples 1, 2 and 3, the polypropylene used is a propylene homopolymer with a melt index = 3 and a melting point = 166 ° C and the polyamide-6 used is a homopolymer of caprolactam -melting point = 218 ° C.

Samples 1, 2 and 3 are sprayed in the form of plates 25 with dimensions of 100 x 100 x 3 mm, from which test samples is cut iso 1/2 according to the standard NFT 51034.

Test samples are cut out in the direction of the spray flow (test samples A); others are cut perpendicular to the direction of the spray flow (test samples B). 30 Test samples are also formed with samples according to the standard defined by the Institut Francais du Caoutchouc (test samples C).

Test samples A, B and C are evaluated in tensile tests in accordance with standard NFT 51034.

35 The test samples of sample 3 (control) are very fragile? they already break at 5-6% elongation; this indicates 8900 661 · -13- «a coarse and inhomogeneous morphology, as well as an absence of adhesion between the two components of the control sample 3.

Test samples A, B and C of sample 1 behave differently: test samples A and B have a more fragile behavior than test sample C; this corresponds to an inhomogeneity of the sample, as well as to a directionality.

A homogeneous ductular behavior is observed in the three types of test samples of sample 2: this indicates good homogeneity of sample 2, as well as a high sensitivity to deformation and direction.

Samples 1 and 2 are also tested for impact strength (Charpy) at ambient temperature after spraying them into bars.

For the sample 1, a fracture content of 60% is observed.

Not a single bar tested was broken for sample 2.

EXAMPLE III

A. Into a Werner ZSK30 extruder, a mixture containing 100 parts by weight of ethylene-propylene block copolymer (containing 12% by weight of ethylene, melting index = 5, and melting point = 163 ° C), 1.5 parts by weight maleic anhydride is continuously introduced. and 1.7 parts of 2,5-dimethyl-2,5 * -di (tert-butylperoxy) hexane dissolved in one part of chlorobenzene.

The extrusion and purification conditions are identical to those described in Example 1A.

Determination of the anhydride functions by infrared spectrophotometry of a sample grafted copolymer indicates that 1.02% by weight of anhydride has been grafted.

The mean number molecular mass Mn determined by gel permeation chromatography is 19,700.

B. A monoamine polyamide oligomer 35 is prepared under the same conditions as described in Example IB

with a weight ratio of the caprolactam to the 89 00661-14-laurylamine of 15.7. The average number molecular mass Mn of the oligomer is 2,800.

C. In a Werner ZSK30 extruder, a mixture is kneaded in the molten state under the same conditions as described in Example 1, containing 77 parts by weight of the above-described grafted copolymer and 23 parts by weight of the previously described polyamide oligomer.

After the extrusion, the degree of condensation of the oligomer on the grafted copolymer strain is determined under the same conditions as described in Example 1C, which is 65.8%.

The graft copolymer thus obtained can be represented by the expression (according to formula 11 of the formula sheet), wherein: 15 A represents a motif derived from propylene, M represents a motif derived from ethylene, X represents a motif derived from maleic anhydride, and P a motif derived from the caprolactam oligomer 20 M = 2,800. n

EXAMPLE IV

A mixture consisting of 50 parts by weight of polypropylene and 50 parts by weight of hydrolysed ethylene-vinyl acetate copolymer (EVOH) is brought to 220 ° C and kneaded in the vessel of a Brabender plastograph for 30 minutes at a stirring speed of 50 rpm. min (sample 4).

A mixture containing 49 parts of polypropylene, 49 parts of EVOH and 2 parts of the maleized ethylene-propylene copolymer strain described in Example UIA is kneaded under the same conditions as above (Sample 5).

A mixture is also prepared under the same conditions, containing 49 parts by weight of polypropylene, 49 parts by weight of EVOH and 2 parts by weight of the grafted (co) polymer described in Example IIIC (sample 6).

For samples 4, 5 and 6, the polypropylene used has a melt index of 5 and a melting point of 166 ° C and the EVOH used is such that its ethylene content is 89 00 66 1 7 -15-

38 mole%. Samples 4, 5 and 6 are then examined electron microscopically with scanning (magnification X 2,500). Examination 4 shows that the two polymers are very little compatible: very widely dispersed tubers of EVOH are distinguished, the diameter of which varies from 11 to 27 yam in the polypropylene matrix. moreover, it is observed that the adhesion between the tubers EVOH and the polypropylene matrix is very poor. Examination of the sample 5 indicates a fairly gross morphology: 10 tubers of EVOH with a diameter between 5.7 and 7 yam are distinguished, whose adhesion to the polypropylene matrix is poor. Examination of the sample 6 indicates a fine morphology characterized by nodules with a diameter between 1.7 and 2.8 yam and of which the adhesion to the polypropylene matrix is very good. EXAMPLE V

A mixture containing 50 parts by weight of polypropylene and 50 parts by weight of poly-p-vinylphenol (PPVP) is brought to 200 ° C and kneaded in the vessel of a Brabender plastographer for 15 minutes at a stirring speed of 50 rpm. min (sample 7).

A mixture containing 49 parts of propylene, 49 parts of poly-vinyl vinyl phenol and 2 parts of the maleized ethylene-propylene copolymer described in Example UIA is kneaded under the same conditions as above (Sample 8).

One also prepares under the same conditions.

A mixture containing 49 parts of polypropylene, 49 parts of polypara-vinyl phenol and 2 parts of the grafted copolymer described in Example IIIC (sample 9).

For samples 7, 8 and 9, the polypropylene used has a melt index of 5 and a melting point of 166 ° C and 30, the poly-p-vinylphenol is an oligomer, the weight average molecular weight of which is 4,000 and the melting point is between 160 and 200 ° C is smeared.

Samples 7, 8 and 9 are then examined electron microscopically by scanning (magnification X 2,500).

Examination of the sample 7 indicates a gross morphology, involving co-continuous phases or ovoid tubers 8900661.

-16- of PPVP with an average diameter of 30 µm dispersed in a PP matrix are located. The complete incompatibility of the two polymers can be seen by observing the fracture surfaces.

Examination of the sample 8 shows a better dispersion of the poly-p-vinylphenol (PPVP) in the polypropylene. The average size of the tubers of PPVP dispersed in the PP matrix is about 10 yam. The adhesion between the phases has not improved compared to sample 7.

Examination of the sample 9 indicates a fine morphology characterized by nodules of PPVP with an average diameter of 2 µm dispersed in the PP matrix and in which the adhesion to this matrix has been greatly improved compared to that of the samples 7 and 8.

EXAMPLE VI

A mixture containing 50 parts by weight of polypropylene and 50 parts by weight of polyether ester amide is brought to 200 ° C and kneaded in the vessel of a Brabender plastographer for 15 minutes at a stirring speed of 50 rpm (sample 10). . A mixture containing 49 parts of propylene, 49 parts of polyetheresteramide and 2 parts of the maleized ethylene-propylene copolymer described in Example IIIA is kneaded under the same conditions as above (Sample 11).

A mixture containing 49 parts by weight of polypropylene, 49 parts by weight of polyether ester amide and 2 parts by weight of the grafted copolymer described in Example IIIC is also prepared under the same conditions (sample 12).

For samples 10, 11 and 12 it has been used

polypropylene, a melt index of 5 and a melting point of 166 ° C

30 and the polyetherester amide is obtained by (co) poly condensation of α, ω-dicarboxyl polyamide-12 blocks of M = 600 with α, ω-dihydroxyl-polytetramethylene glycol blocks of M = 2,000. n

Samples 10, 11 and 12 are then examined electron-microscopically by scanning (magnification X 2,500).

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Examination of the sample 10 indicates a particularly gross morphology, characterized by a three-dimensional network.

Examination of the sample 11 shows no improvement in adhesion 5 or reduction in the size of the three-dimensional network compared to sample 10.

Examination of sample 12 shows a less coarse morphology than that of samples 10 and 11.

The morphology of the sample 12 is no longer characterized by a three-dimensional network, but by dispersion of nodules of polyetheresteramide in a polypropylene matrix. EXAMPLE VII

A mixture containing 50 parts by weight of polypropylene and 50 parts by weight of semi-aromatic amorphous polyamide is brought to 220 ° C and kneaded in the vessel of a Brabender plastograph for 30 minutes at a stirring speed of 50 rpm. min (sample 13).

A mixture containing 49 parts of polypropylene, 49 parts of amorphous semi-aromatic polyamide and 2 parts of the maleized ethylene-propylene copolymer described in Example UIA is kneaded under the same conditions as above (Sample 14 ).

A mixture is also prepared under the same conditions, containing 49 parts of polypropylene, 49 parts of amorphous semi-aromatic aromatic polyamide and 2 parts of the grafted copolymer described in Example IIIC (Sample 15).

For samples 13, 14 and 15, the polypropylene used has a melt index of 5 and a melting point of 166 ° C and the semi-aromatic polyamide used is based on terephthalic acid and 2,2,4- and 2,4,4- trimethyl-1,6-diamino-hexane.

Samples 13, 14 and 15 are then examined electron microscopically with scanning (magnification X 2,500).

Examination of the sample 13 indicates an incompatibility between the two polymers: Tubers of semi-aromatic amorphous polyamide, the average of which is 89 006 61, are observed.

The partial diameter is 30 ym dispersed in the polypropylene matrix. In addition, there is no adhesion between the tubers of semi-aromatic amorphous polyamide and the polypropylene matrix.

The sample 14 shows a fairly coarse morphology; tubers of semi-aromatic amorphous polyamide with a diameter of 5 µm are dispersed in the polypropylene matrix; adhesion of the tubers to the matrix is moderate.

Examination of the sample 15 indicates a fairly fine morphology, characterized by nodules of semi-aromatic amorphous polyamide with an average diameter of 3.3 µm and good adhesion to the polypropylene matrix. EXAMPLE VIII

A mixture containing 50 parts by weight of polypropylene and 50 parts by weight of polypropylene and 50 parts by weight of semi-aromatic amorphous polyamide is brought to 280 ° C and kneaded in a Haake plastograph vessel for 20 minutes with a stirring speed of 50 rpm (sample 16).

A mixture containing 49 parts of polypropylene, 49 parts of semi-aromatic amorphous polyamide and 2 parts of maleized ethylene-propylene copolymer described in Example UIA is kneaded under the same conditions as above (sample 17).

A mixture is also prepared under the same conditions which contains 49 parts of polypropylene, 49 parts of semi-aromatic amorphous polyamide and 2 parts of the grafted copolymer described in Example IIIC (Sample 18).

For samples 16, 17 and 18, the polypropylene used has a melt index of 5 and a melting point of 166 ° C; The semi-aromatic amorphous polyamide is based on isophthalic acid, 4,4'-diamino-3,3'-dimethyldicyclohexylmethane and lauryllactam.

Samples 16, 17 and 18 are then examined electron microscopically with scanning (magnification X 2,500).

Examination of sample 16 indicates an incompatibility between the two polymers: Tubers 69 0066 1 are taken.

Semi-aromatic amorphous polyamide, the average diameter of which is 20 µm, dispersed in the polypropylene matrix. In addition, there is no adhesion between the tubers of semi-aromatic amorphous polyamide and the polypropylene-5 matrix.

Examination of the sample 17 shows a rather gross morphology: Tubers of semi-aromatic amorphous polyamide with an average diameter of 10 µm are dispersed in the polypropylene matrix; adhesion of the tubers to the matrix is moderate.

Examination of the sample 18 indicates a fairly fine morphology, characterized by nodules of semi-aromatic amorphous polyamide with an average diameter of 3.5 yam and good adhesion to the polypropylene matrix.

EXAMPLE IX

A mixture containing 26 parts of polypropylene, 67 parts of polyamide-6 and 7 parts of the maleized ethylene-propylene copolymer described in Example UIA (sample 19) is continuously introduced into a Werner extruder.

The material temperature along the cylinder is between 260 ° C and 290 ° C. The rotational speed of the worm is 150 rpm and the material flow rate is 20 kg / hour.

Under the same conditions, a mixture is extruded containing 26 parts of polypropylene, 67 parts of polyamide-6 and 7 parts of the grafted copolymer described in Example 1C (sample 20).

A control mixture containing 32.7% by weight of polypropylene and 67.3% by weight of polyamide-6 is also prepared under the same conditions.

For samples 19, 20 and 21, the polypropylene and polypropylene homopolymer used, with a melt index 12 and a melting point of 166 ° C, and the polyamide-6, is a caprolactam homopolymer with a melting point of 318 ° C.

The samples 19, 20 and 21 are injected into bars with dimensions of dimensions 127 x 12.7 x 6.4 mm and their impact strength is determined according to the ISO standard at 23 ° C and 40 ° C. The results of 89 0 066 1 · '

a

-20- these assays are listed in the table below.

IZOD IMPACT STRENGTH

SAMPLE 23 ° C 40 ° C

19 6 9 20 10.5 13 21 2 3 4 8900661

Claims (11)

1. Grafted copolymer, characterized in that it corresponds to the expression (see formula 1 of the formula sheet), in which: • Α & Μ ^ corresponds to the (co) polymer strain, 5. corresponds to the on the (co) polymer strain grafted polymers, • A is a motif derived from an α-olefin of 2-8 carbon atoms and preferably a motif derived from propylene, Grafted copolymer according to claim 1, characterized in that the monomer from which X is derived is selected from the products having the formulas: 3, 4, 5 of the formula, wherein: • and are either hydrogen or a straight or branched alkyl chain with up to 8 carbon atoms, at least one of these symbols representing hydrogen, • R ^ is hydrogen or a linear or branched alkyl-25 group having up to 10 carbon atoms, • R ^ is a linear or branched alkenyl group having up to 12 carbon atoms. 3. Process for preparing the grafted copolymer according to any one of claims 1-2, characterized in that it comprises: - a grafting by free radicals on the (co) polymer strain of a monomer capable of having an amine function reacting, followed by addition of a polyamide oligomer 35 to the previously grafted copolymer. 8900661. -23- Preparation process according to claim 3, characterized in that the monomer which can react with an amine function is selected from: citraconic anhydride, fumaric acid, mesaconic acid, 3-allyl succinyl anhydride and preferably maleic anhydride. Preparation process according to claims 3-4, characterized in that the polyamide oligomer has the formula 6 of the formula sheet, wherein: f, g, Rj. and R 1 are as previously defined, and it is obtained by polycondensation of an amino acid of the formula 7. or by polyaddition of a lactam of the formula 8, wherein: f is as defined above, in the presence of a monofunctional, the polymerization-limiting agent of formula 9, wherein: R, _ and Rg are as defined above. 6. Process according to claim 5, characterized in that the monomer for the synthesis of the polyamide oligomer 20 is selected from caprolactam, 11-amino-decanoic acid or dead-calactam. Process according to claims 5-6, characterized in that the monofunctional polymerization-limiting agent is laurylamine or oleylamine. Alloy of at least two incompatible thermoplastic polymers rendered compatible by adding the compound of claims 1 or 2. Alloy according to claim 8, characterized in that it comprises the grafted copolymer according to any one of claims 1 or 30 and one of the following couples of thermoplastic polymers: aliphatic (co) polyamide (co) polymer propylene and / or ethylene, half -aromatic (co) polyamide (co) polymer propylene and / or ethylene, polyether block amide (co) polymer propylene and / or ethylene, polymer vinyl phenol (co) polymer propylene and / or ethylene, hydrolysed copolymer ethylene vinyl acetate - (co) polymer propylene and / or ethylene. 8900661. -24- Alloy according to claim 9, selected from the couple: polyamide-6 - polypropylene polyamide-6 - polyethylene 5 polyamide-6 - copolymer ethylene / propylene polyamide-11 or -12 - polypropylene or polyethylene or copolymer ethylene / propylene copolymer ethylene - hydrolyzed vinyl acetate - polypropylene or polyethylene 10 or copolymer ethylene / propylene poly-p-vinylphenol - polypropylene or polyethylene or copolymer ethylene / propylene polyether-block amide - polypropylene or polyethylene or copolymer ethylene / propylene 15 semi-aromatic - polypropylene or polyethylene polyamide / COpolymer ethylene propene 10. M is selected from the group consisting of: - the motifs derived from different α-olefins, as previously described, which may be simply intermixed or copolymerized in a statistical or block polymer manner and of which one of the 15 a- olefins is preferably ethylene, - the motifs derived from a monomer which may be copolymerized with one of the α-olefins, as described above, for example an alkyl acrylate, - the motifs A and M which form said (co) polymer strain 20 are copolymerized Statistically or block-polymer or simply blended, • X is a motif derived from a monomer which may be grafted to an α-olefin homo- or copolymer by free radicals and which contains a function which can react with an amine motif, • P is derived from a polyamide oligomer of the formula 2 of the formula sheet, wherein: • f is a number between 3 and 11, • g is a number between 5 and 80 and preferably 30 between 15 and 55, hydrogen or a linear or branched alkyl group of up to 20 carbon atoms, 8900661. -22- Rg is a linear or branched alkyl or alkenyl group of up to 20 carbon atoms, a saturated or unsaturated cycloaliphatic radical, are an aromatic radical or a combination of the foregoing, 5. a, b, c and d numbers, corresponding to the following definitions: • a is between 0 and 5,000 and preferably between 350 and 2,000, • the sum a + b is between 350 and 45,000 and preferably between 500 and 10,000 ° C is chosen such that the weight ratio of the monomer X grafted onto the (co) polymer strain to the X-grafted copolymer is between 500 ppm and 10% and preferably between 5,000ppm and 2%, 15.d is zero and less than or equal to c and preferably at least equal to 0.3c. Alloy according to any one of claims 8-10, characterized in that it contains 0.1-30% by weight of the grafted copolymer as defined in claims 1 or 2, and preferably 5-15% based on the weight of the mixture of thermoplastic resins. 8900 6 6 1.