Polyamide, composition comprising such a polyamide, and uses thereof

Abstract

The invention relates to a polyamide comprising at least one repeat unit corresponding to the general formulation: X.Math.Y in which: X represents a cycloaliphatic diamine and Y represents an aliphatic dicarboxylic acid chosen from dodecanedioic (C.sub.12) acid, tetradecanedioic (C.sub.14) acid and hexadecanedioic (C.sub.16) acid, characterized in that said dicarboxylic acid comprises organic carbon of renewable origin, determined according to Standard ASTM D6866. The invention also relates to a composition comprising this polyamide and also to the use of this polyamide and of such a composition.

Claims

1. A process for the preparation of a polyamide having at least one repeat unit corresponding to the formula:
X.Math.Y in which: X represents a cycloaliphatic diamine and Y represents an aliphatic dicarboxylic acid that is dodecanedioic (C.sub.12) acid, said dicarboxylic acid comprising organic carbon of renewable origin, determined according to Standard ASTM D6866, said process comprising at least one polycondensation of at least one fatty diacid, said diacid comprising carbon of renewable origin determined according to Standard ASTM D6866, with a cycloaliphatic diamine, said process comprising: a) obtaining a fatty monoacid from vegetable oil, the fatty monoacid being lauric acid extracted from rich oil made up of palm kernel or coconut oil, as renewable starting material, containing mainly impurities with an even number of carbon atoms, and optionally purifying, b) preparing a diacid Y from the fatty monoacid resulting from a), c) polycondensing the said diacid Y with the cycloaliphatic diamine X.

2. The process according to claim 1, wherein the polyamide produced has a content, expressed as percentage, of organic carbon of renewable origin, denoted % C.sub.renew.org, of greater than or equal to 20%.

3. The process according to claim 1, wherein the polyamide produced is a homopolyamide.

4. The process according to claim 1, wherein monomer X is 3,3-dimethyl-4,4-diaminodicyclohexylmethane (BMACM or MACM) or p-bis(aminocyclohexyl)methane (PACM).

5. The process according to claim 1, wherein the polyamide produced has formula MACM.12, or PACM.12, with 12 meaning dodecanedioic (C.sub.12) acid.

6. The process according to claim 1, wherein the polyamide produced is a copolyamide comprising at least two distinct units of the formula:
X.Math.Y/Z in which: Z is a unit obtained from an amino acid, a unit obtained from a lactam or a unit of the formula (Ca diamine).Math.(Cb diacid), with a representing the number of carbon atoms of the diamine and b representing the number of carbon atoms of the diacid, a and b each being between 4 and 36.

7. The process according to claim 6, wherein the copolyamide has the formula: B.12/11, B.12/12, P.12/11, P.12/12, B.12/10.12, P.12/10.12, B.12/10.10, or P.12/10.10, B denoting 3,3-dimethyl-4,4-diaminodicyclohexylmethane and P denoting p-bis(aminocyclohexyl) methane, 10 meaning decanoic acid (C.sub.10), 11 meaning undecanoic acid (C.sub.11), and 12 meaning dodecanedioic (C.sub.12) acid.

8. The process according to claim 2, wherein the polyamide produced has a content, expressed as a percentage, of organic carbon of renewable origin, denoted % C.sub.renew.org, of greater than or equal to 40%.

9. The process according to claim 8, wherein the polyamide produced comprises a content, expressed as a percentage, of organic carbon of renewable origin, denoted % C.sub.renew.org, of greater than or equal to 50%.

10. The process according to claim 9, wherein the polyamide produced has a content, expressed as a percentage, of organic carbon of renewable origin, denoted % C.sub.renew.org, of greater than or equal to 52%.

Description

EXAMPLES

1/ Preparation of Various Polyamides (Trials A to H)

(1) The monomers used in trials A to Hare as follows: 11-aminoundecanoic acid (denoted A11 in Table 1), supplied by Arkema, CAS 2432-99-7, bis(3-methyl-4-aminocyclohexyl)methane (denoted MACM in Table 1), sold under the name Laromin C260 by BASF, CAS 6864-37-5, p-bis(aminocyclohexyl)methane (denoted PACM20 in Table comprising 21% by weight of trans/trans isomer, sold under the name Amicure by Air Products, CAS 1761-71-3, dodecanedioic acid (denoted DC12 in Table 1), obtained from lauric acid, tetradecanedioic acid (denoted DC14 in Table 1), obtained from myristic acid, lactam 12 (denoted L12 in Table 1), sold by Arkema, CAS 947-04-6.

(2) Various homopolyamides and copolyamides were prepared from 2 or 3 monomers, as a mixture with several additives, according to the specific compositions (Examples A to H) given in Table 1.

(3) The preparation process, which can be adapted for all of Examples A to H, will now be described in detail for Example A.

(4) It is specified that the amounts contents by weight of additives indicated below are applicable for all of Examples A to H.

(5) The composition of Example A comprises the following monomers and additives (benzoic acid, hypophosphorous acid, Irganox 1098, which is an antioxidant sold by CIBA, demineralized water), in the following contents by weight: 13.98 kg of dodecanedioic acid (60.82 mol) 14.58 kg of MACM (61.16 mol) 72.17 g of benzoic acid (0.59 mol) 35 g of Irganox 1098 8.75 g of hypophosphorous acid (H.sub.3PO.sub.2) 525 g of distilled water

(6) This composition is introduced into a 92 l autoclave reactor which, once closed, is heated with stirring to 260 C. After a phase of maintaining under autogenous pressure for 2 hours, the pressure is then reduced to atmospheric pressure over 1.5 h. The reactor is then degassed for approximately 1 h at 280 C. by flushing with nitrogen.

(7) The homopolyamide obtained is then extruded in the form of laces, cooled in a water bath at ambient temperature and then granulated.

(8) The granules obtained are subsequently dried at 80 C. for 12 h under vacuum, in order to achieve a moisture content of less than 0.1%.

(9) The homopolyamides and copolyamides of Examples A to H are in accordance with the invention, in the sense that the content % C.sub.renew.org is indeed strictly greater than 0.

(10) In addition, the copolyamides of Examples A to H are additionally transparent.

(11) Furthermore, copolyamides comprising 2 or three distinct units have been explicitly described. However, nothing forbids the envisaging of copolyamides comprising more than three distinct units, for example four or five distinct units, each of these multiple units being obtained either from an amino acid or from a lactam or corresponding to the formula (diamine).Math.(diacid), with the proviso that the polyamide comprises organic carbon of renewable origin determined according to Standard ASTM D6866, in other words the content % C.sub.renew.org, determined by the equation (I) set out above, is strictly greater than 0.

(12) TABLE-US-00001 TABLE 1 MACM PACM DC 12 DC 14 A 11 L 12 %(w) Renewable Examples mol % mol % mol % mol % mol % mol % C (ASTM D6866) A 50 0 50 0 0 0 44.4 B 0 50 50 0 0 0 48.0 C 50 0 0 50 0 0 48.3 D 0 50 0 50 0 0 51.9 E 30 0 30 0 0 40 27.9 F 0 30 30 0 0 40 29.3 G 30 0 30 0 40 0 64.0 H 0 30 30 0 40 0 67.2

2/ Comparison of the Proportions of Impurities Present in Samples of Diacids of Fossil and Vegetable Origin

(13) Samples of the following diacids were analysed: a dodecanedioic acid prepared according to the following process:

(14) Laurie acid can be extracted from coconut oil or else from palm kernel oil. A dodecanedioic acid can subsequently be obtained by biofermentation, using the appropriate microorganism, starting from lauric acid. The diacid can subsequently be subjected to an amination in the presence of ammonia and of at least one strong base, without solvent. a dodecanedioic acid of fossil origin, a tetradecanedioic acid prepared according to the following process:

(15) Myristic acid can be extracted from coconut oil or else from palm kernel oil. A tetradecanedioic acid can subsequently be obtained by biofermentation, using the appropriate microorganism, starting from myristic acid. The diacid can subsequently be subjected to an amination in the presence of ammonia and of at least one strong base, without solvent. a tetradecanedioic acid of fossil origin.

(16) All these products were derived beforehand by silylation in a mixture of acetonitrile, trimethylamine and bis(trimethylsilyl)trifluoroacetamide.

(17) Samples of each of the products obtained are analysed semiquantitatively by coupled gas chromatography/mass spectrometry. The internal standard used is Tinuvin 770, and the column is of the CP-SIL 5CB type (Varian) with a length of 50 m.

(18) This analysis makes it possible to identify a certain number of impurities of aliphatic diacid type, some comprising an even number of carbon atoms and others an odd number of carbon atoms, and to semiquantitatively compare their mutual contents.

(19) Thus, for each of the samples analysed, the following ratio R was calculated:

(20) $R=\frac{\begin{array}{c}\mathrm{amount}\mathrm{of}\mathrm{impurity}\mathrm{comprising}\\ \mathrm{an}\mathrm{odd}\mathrm{number}\mathrm{of}\mathrm{carbon}\mathrm{atoms}\end{array}}{\begin{array}{c}\mathrm{amount}\mathrm{of}\mathrm{impurity}\mathrm{comprising}\\ \mathrm{an}\mathrm{even}\mathrm{number}\mathrm{of}\mathrm{carbon}\mathrm{atoms}\end{array}}$
The results appear in the table below:

(21) TABLE-US-00002 TABLE 2 Origin R Dodecanedioic fossil 0.650 acid vegetable 0.115 Tetradecanedioic fossil 0.175 acid vegetable 0.098

(22) These analyses show that the proportion of impurities comprising an odd number of carbon atoms is much lower in the case of products of vegetable origin, which contributes to inflicting less disturbance on the macromolecular structure of the polyamides prepared from these products.

3/ Evaluation of the Atmospheric CO2 Exited from the Carbon Cycle

(23) The amounts of atmospheric CO.sub.2 exited from the carbon cycle when one tonne of the polyamides of the invention is produced are given in the table below.

(24) TABLE-US-00003 TABLE 3 B.12 B.14 B.16 Atmospheric 1.22 tonnes 1.34 tonnes 1.44 tonnes CO.sub.2 equivalent stored/tonne of PA

4/ Evaluation of the Weight of CO2 Potentially Released at the End of Life

(25) The measurement is carried out on. B.12 having a molecular formula for the repeat unit of C.sub.27H.sub.48N.sub.2O.sub.2, the molar mass of the repeat unit being 432 g/mol with a weight of carbon C of 324 g/mol, i.e. a total % C=75%.

(26) TABLE-US-00004 TABLE 4 B.12 B.12 100% resulting from Partially fossil resources bioresourced % Renewable C/all of the 0 44 C constituting the PA Weight of non-neutral CO.sub.2 2.75 1.53 (t) originating from the backbone per tonne of PA potentially released at the end of life (incineration) % of reduction in fossil CO.sub.2 0 44 released during incineration