Thermoplastic polymer composition, method for preparing same and vibration-damping device incorporating same

Abstract

The invention relates to a thermoplastic polymer composition comprising polyamides, its preparation method and a device for a motor vehicle capable of damping vibrations. The composition (I1, I2, I3, I4) comprises an aliphatic polyamide a polyphthalamide coming from a C6-C12 aliphatic diamine and from an aromatic diacid comprising terephthalic acid, the aliphatic polyamide/polyphthalamide weight ratio being >1 and a reinforcing filler comprising glass fibers. The composition has, after “RH50” conditioning, maximum tan delta values according to ISO 6721-5 between 60-90° C. and 1-3000 Hz, with (i) tan delta >4.20% at 60° C. and/or (ii) tan delta >4.00% at 80° C. and/or (iii) tan delta >3.80% at 90° C.

Claims

1. Thermoplastic polymer composition having properties of damping vibrations in a range of frequencies ranging from 1 Hz to 3000 Hz and at a temperature of 60° C. to 90° C., the composition comprising: at least one aliphatic polyamide, at least one polyphthalamide coming at least partly from an aliphatic diamine having from 6 to 12 atoms of carbon and from an aromatic dicarboxylic acid comprising terephthalic acid, said at least one polyphthalamide is chosen from the group consisting of the PA 6T polyamides, the PA 6T/66/6 copolyamides and the PA 10T/X copolyamides, wherein X is at least one other polyamide unit coming from an aliphatic diamine having from 6 to 12 atoms of carbon and from an aromatic dicarboxylic acid comprising terephthalic or isophthalic acid, the weight ratio of said at least one aliphatic polyamide to said at least one polyphthalamide being greater than 1, and a reinforcing filler comprising glass fibers, wherein the composition has, after conditioning in air at 50% relative humidity, tan delta values measured by dynamic mechanical analysis according to the standard ISO 6721-5 on rectangular test pieces 34.81 mm long, 4 mm wide and 2 mm thick, by implementing frequency sweeps at a sweeping frequency varying from 0.1 Hz to 20 Hz and with an amplitude of deformation of 2.5 μm, said tan delta values, obtained by the principle of time-temperature superposition, being maximum at a temperature between 60° C. and 90° C. in said range of frequencies of from 1 Hz to 3000 Hz for damping vibrations, and satisfying at least one of the following conditions (i), (ii), (iii), for at least one frequency of said range of frequencies: (i) tan delta >4.20% at 60° C., (ii) tan delta >4.00% at 80° C., (iii) tan delta >3.80% at 90° C.

2. Composition according to claim 1, wherein said values of tan delta further satisfy at least one of the following conditions (ia), (iia), (iiia), both for frequencies of 1 Hz and 3000 Hz: (ia) tan delta >4.30% at 60° C., (iia) tan delta >4.20% at 80° C., (iiia) tan delta >3.90% at 90° C.

3. Composition according to claim 2, wherein said values of tan delta further satisfy at least one of the following conditions (ib), (iib), (iiib), both for frequencies of 1 Hz and 100 Hz: (ib) tan delta >4.80% at 60° C., (iib) tan delta >5.00% at 80° C., (iiib) tan delta >5.50% at 90° C.,.

4. Composition according to claim 1, wherein the composition has: at 23° C. after dry as molded (DAM) conditioning, at least one of the following properties measured according to the standard ISO 527: a Young's modulus>14.7 GPa, a breaking strength>200 MPa, an elongation at break>2.1%; and/or at 120° C. after said dry as molded conditioning (DAM), at least one of the following properties measured according to the standard ISO 527: a Young's modulus>4.6 GPa, a breaking strength>80 MPa, an elongation at break≥2.0%.

5. Composition according to claim 1, wherein the composition has: at 23° C. after said wet conditioning in air at 50% relative humidity (RH50), at least one of the following properties measured according to the standard ISO 527: a Young's modulus≥12.0 GPa, a breaking strength>165 MPa, an elongation at break>3.0%; and/or at 120° C. after said wet conditioning in air at 50% relative humidity (RH50), at least one of the following properties measured according to the standard ISO 527: a Young's modulus≥4.8 GPa, a breaking strength≥73 MPa, an elongation at break>3.5%.

6. Composition according to claim 1, wherein the weight ratio of said at least one aliphatic polyamide to said at least one polyphthalamide is inclusively between 1.1 and 5.0.

7. Composition according to claim 1, wherein the composition comprises according to the following mass fractions with reference to the whole composition: said at least one aliphatic polyamide according to 20% to 55%, said at least one polyphthalamide according to 5% to 30%, said glass fibers according to 20% to 55%.

8. Composition according to claim 1, wherein said reinforcing filler consists of said glass fibers.

9. Composition according to claim 1, wherein the composition is free of any compatibilizing agent.

10. Composition according to claim 1, wherein said at least one aliphatic polyamide is chosen from the group consisting of PA 66, PA 6, PA 11, PA 12, PA 6/66, PA 4.6, PA 5.6, PA 6.9, PA 6.10, PA 6.12, PA 10.10, PA 10.12.

11. Composition according to claim 10, wherein said at least one aliphatic polyamide is a PA 66 and/or a PA 6.

12. Composition according to claim 1, wherein said at least one polyphthalamide is chosen from the PA 10T/X, coming from 1,10-decamethylene diamine and from terephthalic acid and from a unit X coming from an aliphatic diamine having from 6 to 9 atoms of carbon and from terephthalic acid.

13. Composition according to claim 12, wherein said at least one polyphthalamide consists of a PA 10T/X with X chosen from PA 6T and PA 6-3-T, where PA 6-3-T is defined by the formula below: ##STR00003##

14. Composition according to claim 13, wherein said at least one polyphthalamide consists of a PA 10T/PA 6-3-T, with a PA 10T:PA 6-3-T molar ratio inclusively between 1.1 and 10.

15. Composition according to claim 14, wherein said at least one polyphthalamide consists of a PA 10T/PA 6-3-T having a number-average molecular weight measured by GPC between 10000 and 12000 g/mol, with said PA 10T:PA 6-3-T molar ratio inclusively between 1.2 and 2.

16. Composition according to claim 14, wherein said at least one polyphthalamide consists of a PA 10T/PA 6-3-T having a number-average molecular weight measured by GPC between 12000 and 14000 g/mol, with said PA 10T:PA 6-3-T molar ratio inclusively between 8 and 10.

17. Composition according to claim 13, wherein said at least one polyphthalamide consists of a PA 10T/PA 6T, with a PA 10T:PA 6T molar ratio inclusively between 8 and 10.

18. Composition according to claim 1, comprising the product of a melt mixing of said at least one aliphatic polyamide, said at least one polyphthalamide and said reinforcing filler, by extrusion.

19. Method for preparing a composition according to claim 1, wherein melt mixing, in an extruder of said at least one aliphatic polyamide, said at least one polyphthalamide and said reinforcing filler is implemented, without using a compatibilizing agent.

20. Method according to claim 19, wherein a step of premixing said at least one aliphatic polyamide and said at least one polyphthalamide is implemented before introducing into the extruder said reinforcing filler.

21. Device with dynamic operation for a motor vehicle, the device being capable of damping vibrations in a range of frequencies ranging from 1 to 3000 Hz and at a temperature of 60 to 90° C., wherein the device comprises a composition according to claim 1.

22. Device according to claim 21 for a motor vehicle with a heat, hybrid or electric engine, wherein the device is chosen from the structural parts transmitting vibrations from the wheels of the vehicle, and the anti-vibration supports combining first and second rigid elements while damping vibrations between them and while supporting a load.

23. Composition according to claim 6, wherein the weight ratio of said at least one aliphatic polyamide to said at least one polyphthalamide is inclusively between 1.5 and 4.5.

24. Composition according to claim 7, wherein the composition comprises according to the following mass fractions with reference to the whole composition: said at least one aliphatic polyamide according to 25% to 50%, said at least one polyphthalamide according to 10% to 27%, said glass fibers according to 25% to 50%.

25. Composition according to claim 9, wherein the composition is free of any polyolefin and of any polyether.

26. Composition according to claim 25, wherein the composition consists of said at least one aliphatic polyamide, said at least one polyphthalamide and said reinforcing filler.

27. Composition according to claim 13, wherein said at least one polyphthalamide consists of a PA 10T/X with X chosen from PA 6T and PA 6-3-T, with a PA 10T:X molar ratio greater than 1.

28. Composition according to claim 15, wherein said at least one polyphthalamide consists of a PA 10T/PA 6-3-T having a number-average molecular weight measured by GPC between 10700 and 11700 g/mol, with said PA 10T:PA 6-3-T molar ratio inclusively between 1.3 and 1.7.

29. Composition according to claim 16, wherein said at least one polyphthalamide consists of a PA 10T/PA 6-3-T having a number-average molecular weight measured by GPC between 12500 and 13500 g/mol, with said PA 10T:PA 6-3-T molar ratio inclusively between 8.5 and 9.5.

30. Composition according to claim 17, wherein said at least one polyphthalamide consists of a PA 10T/PA 6T, with a PA 10T:PA 6T molar ratio inclusively between 8.5 and 9.5.

31. Device with dynamic operation according to claim 21, wherein the device is free of any metal part, the device consisting of said composition injection molded.

32. Device with dynamic operation according to claim 21, wherein the device consists of said composition injection molded that is rigidly connected to a metal insert.

33. Device according to claim 22 for a motor vehicle with a heat, hybrid or electric engine, wherein the device is an anti-vibration support which is a linking support connecting the engine to an element of the structure of the vehicle.

34. Device according to claim 33, wherein the motor vehicle has a body and said element of the structure of the vehicle is the body of the vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features, advantages and details of the present invention will appear upon reading the following description of several embodiments of the invention, given for illustrative and non-limiting purposes with the appended drawings, among which:

(2) FIG. 1 shows two photographs, the photograph on the left showing a “DMA Q800” apparatus from TA Instruments used for dynamic mechanical analysis (DMA) according to the invention in order to obtain the damping values (tan delta) according to the frequency, and the photograph on the right showing a mounting of the “dual cantilever” type used for this dynamic mechanical analysis (DMA) with this apparatus.

(3) FIG. 2 is a graph showing the damping properties (tan delta) obtained at 80° C. according to the frequency (Hz) with the apparatus and the mounting of FIG. 1, for a control composition C1 of the PA66 GF50 type and four compositions according to the invention I1, I2, I3, I4 comprising a PA 10T/X copolymer in addition to the PA 66, all conditioned under a wet atmosphere according to said RH50 conditioning as defined above.

(4) FIG. 3 is a graph showing the damping properties (tan delta) obtained at 80° C. according to the frequency (Hz) with the apparatus and the mounting of FIG. 1, for the PA 66 and two PA 10T/X of the compositions I1-I2 and I3-I4, all conditioned under a wet atmosphere according to said RH50 conditioning as defined above.

(5) FIG. 4 is a graph showing the damping properties (tan delta) obtained at 80° C. according to the frequency (Hz) with the apparatus and the mounting of FIG. 1, for the control composition C1, a composition C2 not according to the invention comprising a PA 66+PA 4T alloy and four other compositions according to the invention I5, I6, I7, I8, comprising in addition to the PA 66 respectively a PA 6T/X, a PA 9T, another PA 10T/X and a PA 10T, all conditioned under a wet atmosphere according to said RH50 conditioning as defined above.

(6) FIG. 5 is a graph showing the damping properties (average tan delta between 1 and 3000 Hz) obtained according to the temperature (° C.) with the apparatus and the mounting of FIG. 1, for the control compositions C1, C3 of the PA6 GF50 type and the compositions according to the invention I9, I10 comprising a PA 6+PA 10T/X alloy, all conditioned under a wet atmosphere according to said RH50 conditioning as defined above.

EMBODIMENTS OF THE INVENTION

(7) In all the following examples, the compositions C1-C2 and I1-I8 were melt prepared without any compatibilizing agent or processing aid, as follows (mass fractions of the ingredients in each composition in %).

Formulations of the Compositions Tested C1-C4 not According to the Invention and I1-I16 According to the Invention, and Ingredients Used

(8) With PA 66 and 50% glass fibers: C1: PA66 GF50, with 50% of an “Akulon S223D” PA 66 (DSM) and 50% “DS 1128-10N” glass fibers (3B). I1: 40% of the “Akulon S223D” PA 66 (DSM), 10% of the “Vestamid HT plus M3000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. I2: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “Vestamid HT plus M3000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. I3: 40% of the “Akulon S223D” PA 66 (DSM), 10% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. I4: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. C2: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “ForTii Ace XTR31” PA 4T (DSM) and 50% of the “DS 1128-10N” glass fibers. I5: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “Vestamid HT plus M1000” PA 6T/X (PA 6T/66/6I from Evonik) and 50% of the “DS 1128-10N” glass fibers. I6: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “Genestar N1000 A” PA 9T (Kuraray) and 50% of the “DS 1128-10N” glass fibers. I7: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “Grivory HT3Z (EMS Grivory)” PA 10T/X and 50% of the “DS 1128-10N” glass fibers. I8: 30% of the “Akulon S223D” PA 66 (DSM), 20% of the “Badamid 10T” PA 10T (Bada) and 50% of the “DS 1128-10N” glass fibers.
With PA 6 and 50% Glass Fibers: C3: PA6 GF50, with 50% of an “Akulon F136DH” PA 6 (DSM) and 50% “DS 1128-10N” glass fibers (3B). I9: 40% of the “Akulon F136DH” PA 6 (DSM), 10% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. I10: 30% of the “Akulon F136DH” PA 6 (DSM), 20% of the “Vestamid HT plus C2000” PA 1 OT/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. I11: 40% of the “Akulon F136DH” PA 6 (DSM), 10% of the “Vestamid HT plus M3000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers. I12: 30% of the “Akulon F136DH” PA 6 (DSM), 20% of the “Vestamid HT plus M3000” PA 10T/X (Evonik) and 50% of the “DS 1128-10N” glass fibers.
With PA 6 and 35% Glass Fibers: C4: PA6 GF35, with 65% of an “Akulon F136DH” PA 6 (DSM) and 35% “DS 1128-10N” glass fibers (3B). I13: 52% of the “Akulon F136DH” PA 6 (DSM), 13% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 35% of the “DS 1128-10N” glass fibers. I14: 50% of the “Akulon F136DH” PA 6 (DSM), 15% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 35% of the “DS 1128-10N” glass fibers. I15: 45% of the “Akulon F136DH” PA 6 (DSM), 20% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 35% of the “DS 1128-10N” glass fibers. I16: 39% of the “Akulon F136DH” PA 6 (DSM), 26% of the “Vestamid HT plus C2000” PA 10T/X (Evonik) and 35% of the “DS 1128-10N” glass fibers.

(9) Chem. 1 shows the semi-developed chemical formula common to the PA 10T/X copolymer “Vestamid HT plus M3000” (grade usually recommended for extrusion) present in each of the compositions I1-I2, and to the PA 10T/X copolymer “Vestamid HT plus C2000” (grade usually recommended for injection) present in each of the compositions I3-I4, a formula obtained by analysis via the 1H NMR technique with X=PA 6-3-T. These two copolymers thus each satisfy the formula PA 10T/PA 6-3-T.

(10) ##STR00001##

(11) For the “Vestamid HT plus M3000” PA 10T/PA 6-3-T of the compositions I1-I2, the .sup.1H NMR analysis gave a PA 10 T block:PA 6-3-T block molar ratio of 90:10 (incertitude of ±5%). The number-average molecular weight Mn of this PA 10T/PA 6-3-T was evaluated at 13000 g/mol by GPC, which gives a number-average degree of polymerization (DPn) of 38.7 for the PA 10T blocks and of 4.5 for the PA 6-3-T blocks.

(12) For the “Vestamid HT plus C2000” PA 10T/PA 6-3-T of the compositions I3-I4, the .sup.1H NMR analysis gave a PA 10 T block:PA 6-3-T block molar ratio of 60:40 (incertitude of ±5%). The number-average molecular weight Mn of this PA 10T/PA 6-3-T was evaluated at 11200 g/mol by GPC, which gives a number-average degree of polymerization (DPn) of 22.3 for the PA 10T blocks and of 15.6 for the PA 6-3-T blocks.

(13) Chem. 2 shows the semi-developed chemical formula of the PA 10T/X copolymer “Grivory HT3Z” (grade usually recommended for extrusion) of the composition 17, a formula obtained by analysis via the .sup.1H NMR technique with X=PA 6T. This copolymer thus satisfies the formula PA 10T/PA 6T.

(14) ##STR00002##

(15) For this “Grivory HT3Z” PA 10T/PA 6T of the composition I7, the .sup.1H NMR analysis gave a PA 10 T block:PA 6T block molar ratio of 90:10 (incertitude of ±5%).

Method for Preparing the Compositions Tested C1-C4 and I1-I16

(16) The physical mixtures of the compositions C1-C4 and I1-I16 were implemented by extrusion in a “Leistritz” twin screw extruder of the ZSE40MAXX (L/D 40) type. Table 1 below indicates the formulations (mass fractions) and extrusion parameters of the compositions C1 and I1-I4.

(17) TABLE-US-00001 TABLE 1 C1 I1-I2 I3-I4 Ingredients PA 66 Akulon S223D 50% 40-30% 40-30% PA 10T/X Vestamid HT 0  10-20% 0  plus M3000 PA 10T/X Vestamid HT 0  0  10-20% plus C2000 Glass fibers DS 1128-10N 50% 50% 50% Extrusion parameters Material temperature at output (° C.) 302 305 305 Power (%) 51 55 48 Speed of the screw (rpm) 250 250 250 Total flow rate (kg/h) 60 60 60 Feeding speed (rpm) 80 80 80 Number of holes in the die 2 2 2 Number of blades 7 7 7 Speed of the blades (rpm) 4200 4200 440 Output pressure (10.sup.5 Pa) 84 83 79

(18) Table 2 below indicates the formulations (mass fractions) and extrusion parameters of the compositions C1-C2 and I5-I8.

(19) TABLE-US-00002 TABLE 2 C1 C2 I5 I6 I7 I8 Ingredients PA 66 Akulon S223D 50% 30% 30% 30% 30% 30% PA 4T ForTii Ace XTR31 0 20% 0 0 0 0 PA6T/X Vestamid HT plus 0 0 20% 0 0 0 M1000 PA9T Genestar N1000A 0 0 0 20% 0 0 PA10T/X Grivory HT3Z 0 0 0 0 20% 0 PA10T Badamid 10T 0 0 0 0 0 20% Glass fibers DS 1128-10N 50% 50% 50% 50% 50% 50% Implementation parameters Material temperature at output in (° C.) 302 304 303 307 303 306 Power (%) 51 44 56 51 51 46 Speed of the screw (rpm) 250 250 250 250 250 250 Total flow rate (kg/h) 60 60 60 60 60 60 Feeding speed (rpm) 80 80 80 80 80 80 Number of holes in the die 2 2 2 2 2 2 Number of blades 7 7 7 7 7 7 Speed of the blades (rpm) 4200 5000 4200 4500 5000 4500 Output pressure (10.sup.5 Pa) 84 51 81 57 45 46

(20) Table 3 below indicates the formulations (mass fractions) and extrusion parameters of the compositions C3 and I9-I12.

(21) TABLE-US-00003 TABLE 3 C3 I9 I10 I11 I12 Ingredients PA 6 Akulon F136 DH 50% 40% 30% 40% 30% PA10T/X Vestamid HT plus 0 10 20% 0 0 C2000 PA10T/X Vestamid HT plus 0  0 0 10% 20% M3000 Glass fibers DS 1128-10N 50% 50% 50% 50% 50% Implementation parameters Matenal temperature at output 252 257 259 256 259 in (° C.) Power (%) 73 77 70 75 68 Speed of the screw (rpm) 280 1250 250 250 250 Total flow rate (kg/h) 60 60 60 60 60 Feeding speed (rpm) 80 80 80 80 80 Number of holes in the die 2 2 2 2 2 Number of blades 7 7 7 7 7 Speed of the blades (rpm) 3600 4000 4000 4000 3600 Output pressure (10.sup.5 Pa) 92 110 115 106 97

(22) Table 4 below indicates the formulations (mass fractions) and extrusion parameters of the compositions C4 and I13-I16.

(23) TABLE-US-00004 TABLE 4 C4 I13 I14 I15 I16 Ingredients PA 6 Akulon F136 DH 65% 52% 50% 145% 39% PA10T/X Vestamid HT plus 0  13% 15% 20% 26% C2000 Glass fibers DS 1128-10N 35% 35% 35% 35% 35% Implementation parameters Material temperature at exit (° C.) 253 256 257 257 253 Power (%) 74 68 61 52 60 Speed of the screw (rpm) 280 280 280 280 280 Total flow rate (kg/h) 60 160 50 50 60 Feeding speed (rpm) 80 80 80 80 80 Number of holes in the die 2 12 12 12 12 Number of blades 7 7 7 7 7 Speed of the blades (rpm) 3600 3600 4000 4000 3600 Output pressure (10.sup.5 Pa) 90 89 86 62 71

(24) Pellets of PA66 or of PA6 according to the compositions and of the PPA (i.e. of the PA10T/X for I1-I4, I7, I9-I16, of the PA 4T for C2, of the PA 6T/X for I5, of the PA 9T for I6 and of the PA 10T for I8) were premixed, then they were introduced into the extruder using a dosing unit, and the glass fibers were then introduced into the extruder at the zone Z6 of the latter using a side feeder. As visible in tables 1 to 4, it can be noted that the incorporation of the PPA into the compositions I1-I16 did not lead to a major modification of the parameters of implementation of the compositions I1-I16.

(25) The glass transition temperatures Tg of the compositions obtained by the aforementioned “dual cantilever” “DMA” technique were measured via said rectangular test pieces having the dimensions 34.81*4*2 mm by temperature sweeps at 2.5 μm of deformation, at a frequency f of 1 Hz and with a ramp of 3° C./minute. Table 5 below shows as examples the values thus obtained for the compositions C1, C2 and I1-I8.

(26) TABLE-US-00005 TABLE 5 Compositions C1 C2 I1 I2 I3 I4 I5 I6 I7 I8 Tg (° C.) 32 61 73 86 67 80 83 60 77 75

Static Mechanical Properties of the Compositions C1-C4 and I1-I16

(27) Tables 6 and 7 below each describe in detail the static properties obtained for injection molded test pieces of the H2 type consisting of the compositions C1-C2 and I1-I8, measured at two temperatures of 23 and 120° C. either in the aforementioned initial “DAM” state (i.e. after drying of the H2 test pieces for 4 hours at 80° C.) or after said later RH50 wet conditioning as defined above. The standard ISO 527 was followed to measure these properties.

(28) TABLE-US-00006 TABLE 6 Test conditions Properties C1 I1 I2 I3 I4 23° C. Young's modulus (GPa) 14.7 14.9 15.6 16.5 14.9 DAM standard deviation 0.7 0.6 0.6 0.1 0.3 Breaking strength (MPa) 194 209 221 206 209 standard deviation 4 5 4 6 4 Elongation at break (%) 2.4 2.3 2.7 2.2 2.4 standard deviation 0.1 0.1 0.2 0.2 0.1 120° C. Young's modulus (GPa) 6.0 6.2 5.3 6.7 4.7 DAM standard deviation 0.4 0.3 0.2 0.6 0.2 Breaking strength (MPa) 100 100 90 103 85 standard deviation 3 3 3 3 1 Elongation at break (%) 4.4 6.2 7.9 5.7 2.0 standard deviation 0.6 0.4 0.9 0.6 0.2 23° C. Moisture content (%) 1.20 1.17 0.91 1.10 0.94 RH50 Young's modulus (GPa) 11.2 12.2 14.3 12.0 14.2 standard deviation 0.6 0.7 0.6 0.5 0.7 Breaking strength (MPa) 148 167 187 175 189 standard deviation 6 6 9 3 5 Elongation at break (%) 2.8 3.4 3.5 3.4 3.2 standard deviation 0.4 0.2 0.3 0.1 0.3 120° C. Moisture content (%) 1.20 1.17 0.91 1.10 0.94 RH50 Young's modulus (GPa) 5.6 6.3 5.6 6.1 5.3 standard deviation 0.4 0.3 0.4 0.1 0.5 Breaking strength (MPa) 87 90 81 89 81 standard deviation 4 3 2 3 1 Elongation at break (%) 4.5 6.3 8.4 6.3 8.4 standard deviation 0.8 5.2 0.1 0.7 1.2

(29) At 23° C., table 6 globally shows an improvement of the mechanical properties of the compositions I1-I4 of the invention with respect to the composition C1 via the addition of a PA10T/X to the PA 66, this improvement being particularly clear after said RH50 conditioning where it was observed that the compositions I1-I4 were much less sensitive to the humidity absorption than the composition C1.

(30) At 120° C., table 6 shows that this improvement of the mechanical properties related more particularly to the compositions I1 and I3 with a mass fraction of PA10T/X of 10%, in comparison to the compositions I2 and I4 characterized by a mass fraction of PA10T/X of 20%.

(31) TABLE-US-00007 TABLE 7 Test conditions Properties C1 C2 I5 I6 I7 I8 23° C. (Young's modulus (GPa) 14.7 16.9 17.4 16.0 15.2 14.8 DAM standard deviation 0.7 0.8 0.4 1.6 1.0 0.4 Breaking strength (MPa) 194 163 230 228 201 223 standard deviation 4 4 1 5 7 4 Elongation at break (%) 2.4 1.6 2.5 2.9 2.9 2.8 standard deviation 0.1 0.1 0.1 0.1 0.2 0.1 120° C. Young's modulus (GPa) 6.0 6.5 5.7 6.2 5.4 5.6 DAM standard deviation 0.4 0.7 0.1 0.8 0.4 0.2 Breaking strength (MPa) 100 81 100 103 91 100 standard deviation 3 1 1 5 3 1 Elongation at break (%) 4.4 4.2 7.0 8.7 9.2 8.3 standard deviation 0.6 0.3 0.4 0.9 0.7 0.2 23° C. Moisture content (%) 1.20 0.83 0.91 0.68 0.66 0.63 RH50 Young's modulus (GPa) 11.2 13.8 14.2 15.0 14.0 14.3 standard deviation 0.6 0.3 0.4 0.5 0.8 0.9 Breaking strength (MPa) 148 138 201 207 184 198 standard deviation 6 1 4 3 5 6 Elongation at break (%) 2.8 1.9 3.2 3.3 3.1 3.3 standard deviation 0.4 0.1 0.3 0.1 0.1 0.1 120° C. Moisture content (%) 1.20 0.83 0.91 0.68 0.66 0.63 RH50 Young's modulus (GPa) 5.6 6.4 5.6 6.3 5.3 4.8 standard deviation 0.4 0.3 0.2 0.6 0.2 0.1 Breaking strength (MPa) 87 73 90 97 81 84 standard deviation 4 4 2 2 2 1 Elongation at break (%) 4.5 3.6 8.5 5.7 7.8 8.5 standard deviation 0.8 0.2 0.5 0.9 1.0 0.3

(32) At both 23° C. and 120° C., table 7 globally shows an improvement of the mechanical properties of the compositions I5-I8 of the invention with respect to the compositions C1 and C2 via the addition to the PA 66 of a PPA according to the invention, this improvement being particularly clear after said RH50 conditioning where it was observed that the compositions I5-I8 were much less sensitive to the humidity absorption than the compositions C1 and C2.

(33) Table 8 below describes in detail the static properties obtained for injection molded test pieces of the H2 type consisting of the compositions C3 and I9-I12, measured at two temperatures of 23 and 120° C. either in the aforementioned initial “DAM” state (i.e. after drying of the H2 test pieces for 4 hours at 80° C.) or after said later RH50 wet conditioning as defined above. The standard ISO 527 was followed to measure these properties.

(34) TABLE-US-00008 TABLE 8 Test conditions Properties C3 I9 I10 I11 I12 23° C. Young's modulus (GPa) 13.6 14.7 13.9 15.5 15.9 DAM standard deviation 0.3 0.2 0.4 0.5 1.0 Breaking strength (MPa) 172 195 208 202 203 standard deviation 4 5 2 2 3 Elongation at break (%) 3.4 2.4 2.6 2.3 2.7 standard deviation 0.4 0.1 0.2 0.1 0.2 120° C. Young's modulus (GPa) 4.6 4.3 3.4 4.7 4.6 DAM standard deviation 0.3 0.2 0.1 0.7 0.6 Breaking strength (MPa) 82 70 64 84 84 standard deviation 2 3 4 4 3 Elongation at break (%) 10.0 10.4 14.8 8.4 8.2 standard deviation 0.5 0.4 2.8 0.2 0.8 23° C. Moisture content (%) 1.43 1.28 1.09 1.31 1.04 RH50 Young's modulus (GPa) 7.8 10.3 13.4 10.1 11.8 standard deviation 0.2 0.5 0.2 0.4 0.6 Breaking strength (MPa) 124 143 170 147 166 standard deviation 3 2 7 2 2 Elongation at break (%) 7.0 5.3 3.5 4.1 3.1 standard deviation 0.4 0.2 0.3 0.4 0.1 120° C. Moisture content (%) 1.43 1.28 1.09 1.31 1.04 RH50 Young's modulus (GPa) 4.1 3.6 3.0 4.6 3.6 standard deviation 0.5 0.1 0.4 0.4 0.5 Breaking strength (MPa) 77 62 62 71 68 standard deviation 2 1 1 2 1 Elongation at break (%) 8.4 10.6 12.4 8.6 9.7 standard deviation 0.5 0.9 0.3 0.6 1.3

(35) Table 8 globally shows an improvement or at least a conservation of the mechanical properties of the compositions I9-I12 of the invention with respect to the composition C3 via the addition of a PA10T/X to the PA 6.

(36) Table 9 below describes in detail the static properties obtained for injection molded test pieces of the H2 type consisting of the compositions C4 and I13-I16, measured at two temperatures of 23 and 120° C. either in the aforementioned initial “DAM” state (i.e. after drying of the H2 test pieces for 4 hours at 80° C.) or after said later RH50 wet conditioning as defined above. The standard ISO 527 was followed to measure these properties.

(37) TABLE-US-00009 TABLE 9 Test conditions Properties C4 I13 I14 I15 I16 23° C. Young's modulus (GPa) 10.5 10.8 10.5 12.0 10.2 DAM standard deviation 0.1 1.0 1.5 3.0 1.3 Breaking strength (MPa) 164 177 185 168 182 standard deviation 2 3 3 6 6 Elongation at break (%) 4.1 3.9 4.2 2.9 3.5 standard deviation 0.1 0.3 0.2 0.1 0.2 120° C. Young's modulus (GPa) 2.8 3.1 3.6 2.0 2.7 DAM standard deviation 0.2 0.4 0.4 0.7 0.4 Breaking strength (MPa) 74 72 76 62 59 standard deviation 3 3 1 4 3 Elongation at break (%) 15.8 19.1 19.9 16.1 20.4 standard deviation 1.1 0.7 0.9 0.2 3.4 23° C. Moisture content (%) 2.06 1.71 1.90 1.14 1.13 RH50 Young's modulus (GPa) 5.1 6.2 6.3 6.3 11.1 standard deviation 0.2 0.3 0.2 0.4 1.2 Breaking strength (MPa) 100 122 121 114 163 standard deviation 2 2 4 2 3 Elongation at break (%) 12.3 8.0 9.3 7.2 3.9 standard deviation 0.7 1.0 1.0 0.5 0.2 120° C. Moisture content (%) 2.06 1.71 1.90 1.14 1.13 RH50 Young's modulus (GPa) 2.7 2.8 2.6 2.3 2.3 standard deviation 0.3 0.3 0.3 0.2 0.6 Breaking strength (MPa) 70 68 65 53 55 standard deviation 4 3 2 1 2 Elongation at break (%) 13.9 17.4 18.0 16.9 20.6 standard deviation 1.4 0.4 1.4 1.7 1.1

(38) Table 9 globally shows an improvement or at least a conservation of the mechanical properties of the compositions I13-I16 of the invention with respect to the composition C4 via the addition of a PA10T/X to the PA 6.

Dynamic Mechanical Properties of the Compositions C1-C4 and I1-I16

(39) Tables 10-13 below each describe in detail the dynamic properties obtained for rectangular test pieces having a length L of 34.81 mm, a width I of 4 mm and a thickness e of 2 mm, the damping performance of the compositions C1-C4 and I1-I16 being measured as follows.

(40) The values of tan delta were measured on the “DMA Q800” apparatus via the dual cantilever mounting (see FIG. 1) according to the standard ISO 6721-5, by carrying out frequency sweeps ranging from 0.1 to 20 Hz at various temperatures (from −60° C. to +60° C. by plateaus of 5° C. with respect to the glass transition temperature Tg of each composition C1-C4, I1-I16), and by applying to the test pieces a movement of 2.5 μm (amplitude of deformation imposed).

(41) The “TTS” principle of time-temperature superposition was then used to construct index contours of tan delta covering a broad range of frequencies including the range of frequencies of interest from 1 to 3000 Hz at the desired temperatures, wherein these index contours can be “translated” along the horizontal axis of the frequencies by using the Williams-Landel-Ferry empirical relationship (“WLF” translation law, see FIGS. 2 to 4) to represent the damping thus obtained for each composition C1-C4, I1-I16 at the desired temperature. The “TTS” principle allows to analyze the values of tan delta of the compositions at various temperatures, the preferred range for which these compositions were developed extending from 60 to 90° C., and the frequency range from 1 to 3000 Hz.

(42) FIG. 2 shows the damping compared according to the frequency of the compositions C1 and I1-I4 at 80° C. after said conditioning in RH50 humidity, in relation to the values of tan delta listed in table 10 at the four temperatures of 60° C., 70° C., 80° C. and 90° C.

(43) TABLE-US-00010 TABLE 10 Temperature tan delta (%) (° C.) Compositions 1 Hz 100 Hz 500 Hz 1000 Hz 3000 Hz 60 C1 3.71 3.81 3.83 3.83 3.82 I1 4.50 4.43 4.36 4.30 4.22 I2 5.47 4.17 3.68 3.41 3.16 I3 4.82 4.63 4.52 4.45 4.37 I4 6.53 4.91 4.40 4.15 3.79 70 C1 3.61 3.73 3.76 3.79 3.80 I1 4.41 4.51 4.49 4.45 4.44 I2 6.08 5.28 4.80 4.65 4.28 I3 4.77 4.80 4.74 4.69 4.64 I4 7.70 6.07 5.54 5.30 4.91 80 C1 3.42 3.64 3.68 3.70 3.72 I1 4.23 4.45 4.50 4.50 4.51 I2 6.38 5.90 5.60 5.47 5.23 I3 4.55 4.82 4.83 4.82 4.79 I4 8.31 7.13 6.53 6.32 5.93 90 C1 3.13 3.51 3.59 3.61 3.65 I1 3.93 4.33 4.40 4.43 4.45 I2 6.67 6.21 6.03 5.96 5.77 I3 4.21 4.68 4.78 4.80 4.83 I4 8.27 7.96 7.44 7.19 6.82

(44) Table 10, illustrated by FIG. 2, shows that the compositions I1-I4 had a damping clearly greater than that of the composition C1 in the aforementioned ranges of temperatures and of frequencies of interest. It is noted that this damping was even more clearly improved for the compositions I3 and I4 comprising a PA 10T/X with a molar ratio of the PA 10T blocks:X of 60:40 (±5%) and an Mn between 10000 and 12000 g/mol.

(45) This table 10 also shows that the damping increases with the quantity of PA 10T/X present in the composition, as shown by the values of tan delta for the compositions I2 and I4 (with 20% by weight of PA 10T/X) in comparison to I1 and I3 (with 10% by weight of PA 10T/X). It is noted that the composition I4 thus represents a particularly advantageous embodiment of the invention given its very high values of tan delta: at 60° C., in particular greater than 6.50% at 1 Hz, than 4.90% at 100 Hz and of 4.40% at 500 Hz, at 70° C., in particular greater than 7.50% at 1 Hz, than 6.00% at 100 Hz and than 5.50% at 500 Hz, at 80° C., in particular greater than 8.30% at 1 Hz, than 7.10% at 100 Hz and than 6.50% at 500 Hz, and at 90° C., in particular greater than 8.20% at 1 Hz, than 7.90% at 100 Hz, than 7.40% at 500 Hz and surprisingly greater than 7.10% at 1000 Hz and than 6.80% at 3000 Hz (values often more than double in comparison to those of the composition C1).

(46) FIG. 2 further shows an offset of the maximum of tan delta towards the low frequencies (less than or equal to 1 Hz, for example between 10.sup.−2 Hz and 1 Hz) with an increase in the quantity of PA 10T/X present in the composition, as shown by the peaks of tan delta for the compositions I2, I4.

(47) FIG. 3 compares the damping properties at 80° C. after said RH50 conditioning of the two respective PPAs of the compositions I1-I2 and I3-I4 to those of the “Akulon S223D” non-fibered PA66 also used. FIG. 3 shows that the maximum damping (peak of tan delta), if it is greater for each of these two PPAs than for this PA 66, is located at very low frequencies (approximately 10.sup.−10 Hz for the PPAs of the compositions I1-I2, and 10.sup.−9 Hz for the PPAs of the compositions I3-I4). As a result, a mass fraction in the composition of PPA greater than or equal to that of the PA 66 would be capable of causing: an undesirable offset of the peak of tan delta of the compositions towards frequencies that are too low, and would thus reduce the damping of the compositions in the frequency range of interest from 1 to 3000 Hz targeted in the invention, and a significant change in the parameters of implementation of the compositions, whereas a goal of the invention is for them to be capable of being implemented in the closest manner possible to the “PA66 GF50” composition C1.

(48) Consequently, the use in the compositions of the invention of a PA 66 to PPA weight ratio greater than 1 allows to overcome these disadvantages.

(49) Table 11 below shows the damping compared according to the frequency of the compositions C1-C2 and I5-I8 at the aforementioned four temperatures of 60° C., 70° C., 80° C. and 90° C., after said conditioning in RH50 humidity as defined above.

(50) TABLE-US-00011 TABLE 11 Temperature tan delta (%) (° C.) Compositions 1 Hz 100 Hz 500 Hz 1000 Hz 3000 Hz 60 C1 3.71 3.81 3.83 3.83 3.82 C2 4.37 4.19 4.10 4.04 3.96 I5 5.17 4.46 4.19 4.06 3.82 I6 5.37 4.77 4.41 4.26 3.95 I7 5.00 4.19 3.90 3.74 3.53 I8 5.10 4.11 3.74 3.55 3.32 70 C1 3.61 3.73 3.76 3.79 3.80 C2 4.42 4.36 4.31 4.28 4.23 I5 5.67 5.00 4.76 4.65 4.49 I6 5.49 5.34 5.18 5.08 4.90 I7 5.46 4.92 4.69 4.54 4.34 I8 5.63 5.00 4.71 4.54 4.27 80 C1 3.42 3.64 3.68 3.70 3.72 C2 4.38 4.41 4.40 4.38 4.36 I5 5.89 5.49 5.25 5.14 4.97 I6 5.39 5.49 5.45 5.42 5.35 I7 5.65 5.39 5.22 5.11 4.97 I8 5.88 5.54 5.34 5.22 5.05 90 C1 3.13 3.51 3.59 3.61 3.65 C2 4.20 4.41 4.42 4.42 4.41 I5 5.82 5.79 5.63 5.55 5.38 I6 5.11 5.45 5.48 5.49 5.48 I7 5.72 5.60 5.51 5.46 5.36 I8 5.97 5.81 5.69 5.63 5.52

(51) Table 11 combined with FIG. 4, which illustrates it at the temperature of 80° C., shows that the compositions I5-I8 had a damping clearly greater than that of the compositions C1-C2 in the ranges of temperatures and of frequencies of interest, i.e. between 1 and 3000 Hz, even if this damping was sometimes less than that measured for the compositions I1-I4 comprising a PA 10T/X as the PPA. It can be noted that the presence in the composition C2 of a PA 4T as the PPA mixed with the PA 66 does not allow sufficient damping at 60-90° C. at the frequencies of interest of 1-3000 Hz to be obtained, as shown by the values of tan delta of the composition C2 often lower than those obtained for the compositions I1-I4 (despite a mass fraction of PA 4T in the composition C2 of 20%).

(52) In particular, the composition I7 which comprises, as the PPA, 10% by weight of a PA 10T/X other than those of the compositions I1-I4 (i.e. a PA 10T/PA 6T characterized by a PA 10T:PA 6T molar ratio between 8 and 10), has a damping improved with respect to that obtained for the compositions I1 and I3 (also comprising 10% by weight of a PA 10T/X of the PA 10T/6-3-T type).

(53) Moreover, the compositions I5, I6 and I8 according to the invention, comprising 20% by weight of a PA 6T/X, of a PA 9T and of a PA 10T, respectively, each have a damping substantially greater than or equal to those obtained for the compositions I1 and I3 both comprising 10% by weight of PA 10T/X.

(54) Table 12 below shows the damping compared according to the frequency of the compositions C3 and I9-I12 at the aforementioned four temperatures of 60° C., 70° C., 80° C. and 90° C., after said conditioning in RH50 humidity as defined above.

(55) TABLE-US-00012 TABLE 12 Temperature tan delta (%) (° C.) Compositions 1 Hz 100 Hz 500 Hz 1000 Hz 3000 Hz 60 C3 4.15 4.49 4.64 4.69 4.81 I9 7.23 7.34 7.15 7.00 6.80 I10 10.49 8.81 7.19 6.31 5.25 I11 4.97 4.87 4.83 4.81 4.75 I12 6.10 5.59 5.31 5.17 4.91 70 C3 3.96 4.24 4.35 4.41 4.49 I9 6.79 7.36 7.41 7.39 7.32 I10 10.27 10.27 9.53 9.12 8.01 I11 5.02 4.95 4.91 4.90 4.88 I12 6.32 6.04 5.89 5.80 5.68 80 C3 3.67 4.06 4.15 4.19 4.27 I9 6.38 7.06 7.26 7.33 7.39 I10 9.91 10.51 10.42 10.27 9.81 I11 4.95 5.00 4.98 4.96 4.94 I12 6.42 6.26 6.17 6.13 6.04 90 C3 3.56 3.85 3.98 4.04 4.11 I9 5.92 6.71 6.96 7.06 7.21 I10 9.64 10.27 10.47 10.50 10.44 I11 4.74 5.00 5.02 5.01 5.00 I12 6.29 6.39 6.33 6.30 6.24

(56) Table 12 shows that the compositions I9-I12 had a damping clearly greater than that of the composition C3 in the ranges of temperatures and of frequencies of interest, i.e. between 60 and 90° C. and between 1 and 3000 Hz, in particular for the compositions I9, I10 and I12.

(57) As illustrated in FIG. 5, it is noted that the composition 19 represents a preferred embodiment of the invention for the use in an electric motor vehicle, because of its temperature at which tan delta is maximum which is approximately 60° C. while having at this temperature a high average value of tan delta between 1 and 3000 Hz. For comparison, the composition 110, although having even higher values of tan delta, had a temperature at which tan delta is maximum of approximately 90° C., a temperature exceeding the usual limit of 85° C. for electric vehicles.

(58) Table 13 below shows the damping compared according to the frequency of the compositions C4 and I13-I16 at the aforementioned four temperatures of 60° C., 70° C., 80° C. and 90° C., after said conditioning in RH50 humidity as defined above.

(59) TABLE-US-00013 TABLE 13 Temperature tan delta (%) (° C.) Compositions 1 Hz 100 Hz 500 Hz 1000 Hz 3000 Hz 60 C4 4.75 5.06 5.22 5.31 5.43 I13 6.71 7.27 7.31 7.28 7.22 I14 7.20 8.20 8.30 8.30 8.20 I15 8.21 8.13 7.86 7.62 7.35 I16 10.24 7.26 6.31 5.94 5.51 70 C4 4.44 4.85 4.95 4.99 5.08 I13 6.23 6.96 7.15 7.22 7.28 I14 6.54 7.70 8.03 8.14 8.28 I15 7.93 8.31 8.29 8.24 8.10 I16 11.32 9.12 8.04 7.65 6.92 80 C4 4.07 4.62 4.76 4.81 4.88 I13 5.71 6.51 6.77 6.87 7.03 I14 5.92 7.09 7.21 7.70 7.91 I15 7.65 8.13 8.26 8.30 8.32 I16 11.25 10.56 9.60 9.12 8.42 90 C4 3.79 4.34 4.51 4.59 4.69 I13 5.07 6.17 6.41 6.51 6.68 I14 5.26 6.60 7.00 7.18 7.44 I15 7.19 7.91 8.07 8.13 8.23 I16 10.78 11.28 10.76 10.37 9.77

(60) Table 13 shows that the compositions I13-I16 had a damping clearly greater than that of the composition C4 in the ranges of temperatures and of frequencies of interest, i.e. between 60 and 90° C. and between 1 and 3000 Hz, these compositions I13-I16 appearing to be advantageous in particular for their use in the aforementioned linking support in an electric motor vehicle.