Stabilized polyamide compositions

1. A composition, comprising:

a thermoplastic polyamide resin, wherein the thermoplastic polyamide resin is selected from the group consisting of polyamide 6, polyamide 610, and polyamide 66;

a compound of formula (I) or a salt thereof:

(R 1 )NH—R—(OH) n   (I)

 wherein:

R is a substituted or unsubstituted aliphatic, cycloaliphatic or arylalkyl hydrocarbon-based radical, optionally comprising N, S, O and/or P heteroatoms, wherein the —(OH) substituents of the compound of formula (I) are borne by aliphatic carbons of the R group,

R 1 is a hydrogen atom or a substituted or unsubstituted aliphatic hydrocarbon-based radical, optionally comprising N, S, O and/or P heteroatoms, and

n is greater than or equal to 2, provided that, if R 1 is substituted with —OH, then n is greater than or equal to 1, and/or

a reaction product comprising polyamide resin covalently bonded with residues of the compound of formula (I); wherein the composition further comprises a reinforcing filler selected from glass fibers.

2. The composition of claim 1 , wherein the composition comprises:

polyamide resin covalently bonded with residues of compound of formula (I),

polyamide resin not bonded with a residue of compound of formula (I), and

compounds of formula (I) not bonded with polyamide resin.

3. The composition of claim 1 , wherein the mole proportion of compound of formula (I) covalently bonded to polyamide resin is between 10% and 100%.

4. The composition of claim 1 , wherein n is between 2 and 20.

5. The composition of claim 1 , wherein the compound of formula (I) comprises tris(hydroxymethyl)aminomethane, 3-amino-1,2-propanediol, 2-amino-1,3-propanediol, 2-amino-2-methyl-1,3-propanediol, 3-methylamino-1,2-propanediol, diethanolamine, bis(2-hydroxypropyl)amine, N,N′-bis(2-hydroxyethyl)ethylenediamine, aminopropyldiethanolamine, and/or salts thereof.

6. The composition of claim 1 , wherein the composition is obtained by adding from 0.05% to 20% by weight of compound of formula (I), relative to the total weight of the composition.

7. The composition of claim 1 , wherein the polyamide is a semicrystalline polyamide with an apparent melt viscosity of between 0.5 and 1200 Pa·s, measured according to standard ISO 11443 at a shear rate of 1000 s −1 at a temperature equal to 20° C. above the melting point of the polyamide.

8. The composition of claim 1 , wherein the composition comprises between 20% and 90% by weight of polyamide, relative to the total weight of the composition.

9. The composition of claim 1 , wherein said composition comprises at least one impact modifier.

10. An article made by forming the composition of claim 1 .

11. The article of claim 10 , wherein the article is an article of the water/glycol cooling circuit, an article of the air circuit, or an article of the oil circuit.

12. The article of claim 10 , wherein the article is a radiator tank, a transfer pipe, a thermostatic tank, a degassing tank, a radiator, a turbo pipe, an air/air exchanger, an air inlet or outlet box of a turbo cooler, an air intake collector and the associated pipework, an article of the exhaust gas recycling circuit, a catalytic converter, a part of the engine-fan group, an intermediate cooler, a cylinder head cover, an oil sump, an oil filtration unit, a distribution sump or oil-transporting assembly pipework.

13. A process for making a polyamide composition according to claim 1 , comprising mixing at least one polyamide, and/or precursors thereof, with a compound of formula (I).

14. The composition of claim 1 , wherein the compound of formula (I) comprises tris(hydroxymethyl)aminomethane or a salt thereof.

15. A polyamide composition made by the process of claim 13 .

16. A method for stabilizing and/or improving the fluidity of a polyamide resin, comprising adding a compound according to formula (I), and/or a salt thereof:

(R 1 )NH—R—(OH) n   (I)

wherein:

R is a substituted or unsubstituted aliphatic, cycloaliphatic or arylalkyl hydrocarbon-based radical, optionally comprising N, S, O and/or P heteroatoms, wherein the —(OH) substituents of the compound of formula (I) are borne by aliphatic carbons of the R group,

R 1 is a hydrogen atom or a substituted or unsubstituted aliphatic hydrocarbon-based radical, optionally comprising N, S, O and/or P heteroatoms, and

n is greater than or equal to 2 or, if R 1 is substituted with —OH, is greater than or equal to 1,

and a reinforcing filler selected from glass fibers, to the polyamide resin and/or a precursor thereof.

17. A process for making a polyamide composition, comprising mixing at least one polyamide resin selected from polyamide 6.6, polyamide 6.10, polyamide 6, their blends, and their (co)polyamides, and a reinforcing filler selected from glass fibers, with a compound according to formula (I):

(R 1 )NH—R—(OH) n   (I)

wherein:

R is an aliphatic radical,

R 1 is a hydrogen atom or an aliphatic radical, which may optionally be substituted with —OH, and

n is greater than or equal to 2 or, if R 1 is substituted with —OH, is greater than or equal to 1,

and/or a salt thereof.