Polyamides modified with (per)fluoropolyether segments

Abstract

The present invention relates to thermoplastic polyamides (PA) comprising recurring units derived from a PFPE dicarboxylic acid (PFPA-DA) or a PFPE diamine (PFPE-NN) in a defined weight amount with respect to other units derived from the other monomers used in the course of polymerization. Polyamides (PA) are endowed with improved surface properties, chemical resistance and reduced brittleness and do not require the addiction of impact modifiers.

Claims

1. A polyamide (PA) consisting of recurring units derived from monomers (A) and (B), wherein monomer (A) is selected from at least one of: (i) a mixture of: one or more hydrogenated aliphatic, cycloaliphatic or aromatic diamine(s) [amine (NN)] or derivative(s) thereof; and one or more hydrogenated aliphatic, cycloaliphatic or aromatic dicarboxylic acid(s) [acid (DA)] or derivative(s) thereof; and (ii) one or more aminoacid(s) [aminoacid (AN)] or lactam(s) [lactam (L)], and wherein monomer (B) is at least one (per)fluoropolyether monomer (PFPE-M) selected from a PFPE-diamine (PFPE-NN) and PFPE-dicarboxylic acid (PFPE-DA), wherein the amount of monomer (B) ranges from 0.1 to 10% wt with respect to the overall weight of monomers (A) and (B).

2. The polyamide (PA) according to claim 1, wherein amine (NN) is an alkylene diamine having 2 to 36 carbon atoms.

3. The polyamide (PA) according to claim 1, wherein amine (NN) is an aromatic diamine selected from meta-xylylene diamine (MXDA), and para-xylylene diamine.

4. The polyamide (PA) according to claim 1, wherein acid (DA) is aromatic dicarboxylic acid comprising two reactive carboxylic acid groups [acid (AR)] or an aliphatic dicarboxylic acid comprising two reactive carboxylic acid groups [acid (AL)].

5. The polyamide (PA) according to claim 4, wherein acid (DA) is an acid (AL) selected from adipic acid and sebacic acid.

6. The polyamide (PA) according to claim 1, wherein (PFPE-DA) is a fluoropolymer comprising a fully or partially fluorinated polyalkyleneoxy chain [(per)fluoropolyoxylakylene chain (R.sub.f)] having two chain ends, wherein each chain end comprises a COOH group or a derivative thereof selected from salts, anhydrides, esters and acid halides and wherein (PFPE-NN) is a fluoropolymer comprising a fully or partially fluorinated polyalkyleneoxy chain [(per)fluoropolyoxylakylene chain (R.sub.f)] having two chain ends, wherein each chain end comprises an amino group or a salt thereof.

7. The polyamide (PA) according to claim 6, wherein (R.sub.f) comprises recurring units R having at least one catenary ether bond and at least one fluorocarbon moiety, and wherein said repeating units are randomly distributed along the chain and are selected from the group consisting of: (i) CFXO, wherein X is F or CF.sub.3; (ii) CF.sub.2CFXO, wherein X is F or CF.sub.3; (iii) CF.sub.2CF.sub.2CF.sub.2O; and (iv)CF.sub.2CF.sub.2CF.sub.2CF.sub.2O.

8. The polyamide (PA) according to claim 7, wherein chain (R.sub.f) comprises the following recurring units R: (i) CF.sub.2O and (ii)CF.sub.2CF.sub.2O wherein the molar ratio between recurring units (ii) and (i) ranges from 0.1 to 10.

9. The polyamide (PA) according to claim 6, wherein (PFPE-DA) and (PFPE-NN) comply with general formula (I):
A-O-R.sub.f-A(I) wherein: R.sub.f is a fully or partially fluorinated polyalkyleneoxy chain; A and A represent groups of formula:
CF.sub.2-L.sub.x-T in which: L represents a bivalent radical selected from: (a) a C.sub.1-C.sub.20 straight or branched C.sub.3-C.sub.20 alkylene chain (C.sub.alk), optionally containing one or more heteroatoms selected from O, N, S and P and/or one or more groups of formula C(O), -C(O)O, OC(O)O,C(O)NH,NHC(O)NHand C(O)S, said chain optionally containing a (heterocyclo)aliphatic ring (R.sub.ali) or (heterocycloaromatic) ring (R.sub.ar) as defined herein below; (b) a C.sub.3 -C.sub.10 cycloaliphatic ring (R.sub.ali), optionally substituted with one or more straight or branched alkyl groups, optionally containing one or more heteroatoms selected from N, O, S or groups of formula C(O), C(O)Oand C(O)NH, and optionally further linked to or condensed with a further ring (R.sub.ali) or with a C.sub.5-C.sub.12 aromatic or heteroaromatic ring (R.sub.ar) as defined herein below, which can optionally be substituted with one or more straight or branched alkyl groups; or (c) a C.sub.5 -C.sub.12 aromatic ring (R.sub.ar), optionally containing one or more heteroatoms selected from N, O, S, optionally being substituted with one or more straight or branched alkyl groups and optionally further linked to or condensed with another equal or different ring (R.sub.ar); x is 0 or 1; T is COOH, NH.sub.2, or a derivative thereof.

10. The polyamide (PA) according to claim 9, wherein x is 1 and linking group L comprises one of the following groups directly bound to the CF.sub.2group between chain (R.sub.f) and linking group L: CH.sub.2O, CH.sub.2OC(O)NH, CH.sub.2NR.sup.1wherein R.sup.1 is hydrogen or straight or branched C.sub.1-C.sub.3 alkyl, and C(O)NH.

11. A polyamide composition comprising at least one polyamide (PA) according to claim 1 in admixture with further ingredients and/or additives.

12. The polyamide composition of claim 11, wherein the at least one polyamide (PA) is in admixture with glass fibers.

13. A method for manufacturing the polyamide composition of claim 11, said method comprising mixing together the at least one polyamide (PA) with further ingredients and additives.

14. A formed article comprising at least one polyamide (PA) according to claim 1.

15. A formed article according to claim 14, said article being selected from a fuel line hose, a miniature circuit breaker, an electrical switch and a smart device.

16. A method for manufacturing a formed article comprising a polyamide (PA) according to claim 1, said method comprising: melting the at least one polyamide (PA) according to claim 1 to obtain a molten polyamide (PA); casting the molten polyamide (PA) into a mold; and cooling.

17. A formed article comprising at least one polyamide composition of claim 11.

18. A formed article according to claim 17, said article being selected from a fuel line hose, a miniature circuit breaker, an electrical switch and a smart device.

19. A method for manufacturing a formed article comprising at least one polyamide composition of claim 11, said method comprising: melting a polyamide composition according to claim 12 to obtain a molten polyamide composition; casting the molten polyamide composition into a mold; and cooling.

20. The polyamide (PA) according to claim 1, wherein the amount of monomer (B) ranges from 1 to 5% wt, with respect to the overall weight of monomers (A) and (B).

Description

EXPERIMENTAL SECTION

(1) 1. Materials and Methods

(2) Fluorolink D10H PFPE, characterized by the following structure:
HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nCF.sub.2CH.sub.2OH
(m/n=2.5; MW 1,500), available from Solvay Specialty Polymers was used as received.

(3) m-xylylene diamine was purchased from Mitsubishi Gas Chemical Company, Inc. Japan and was used as received.

(4) Adipic acid was purchased from Loba Chemie PVT LTD and used as received.

(5) Sebacic acid was purchased from Biotor Industries Ltd. and used as received.

(6) 1H-NMR, .sup.19F-NMR and .sup.13C-NMR spectra were recorded on a Varian Mercury 300 MHz instrument.

(7) IR spectra were recorded on a Nicolet Avatar 360 FTIR-ESP instrument interfaced with OMNIC software.

(8) Contact angle measurements were carried out with a Dataphysics Contact Angle System OCA 20 instrument. Contact angle measurements were used to confirm the present of fluorine in the polyamide samples.

(9) 2. Synthesis Examples

(10) 3. Synthesis of (PFPE-DA) and (PFPE-NN)

EXAMPLE 1

Synthesis of an ethyl ester of a (PFPE-DA) of formula:

(11)
EtO(O)CCH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nCF.sub.2CH.sub.2OCH.sub.2C(O)OEt
(m/n=2.5; MW: 1,793; EW: 896)

(12) 40 g t-But-OH and 19 g (170 meq) t-BuOK were charged in a l reactor, then 100 g (130 meq) Fluorolink D10H was added under stirring at room temperature.

(13) The reaction mass was maintained under these conditions for 30; then 19.7 g (170 meq) ClCH.sub.2C(O)OEt was added and internal temperature was raised to 80 C. for 12 hours. Thereafter, the reaction mass was cooled down to room temperature and 200 ml water containing 10% by weight 37% HCl was added, to obtain two phases. The two phases were separated and the bottom one was dried, to provide 104 g title product. .sup.1H-NMR and IR analysis confirmed the structure reported in the title. .sup.1H-NMR: 4.2 (CH.sub.2 to the CF.sub.2); 3.95 (CH.sub.2 to the carbonyl group).

EXAMPLE 2

Synthesis of a (PFPE-NN) of formula:

(14)
NH.sub.2CH.sub.2CH.sub.2NH(O)CCH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nCF.sub.2CH.sub.2OCH.sub.2C(O)NHCH.sub.2CH.sub.2NH.sub.2
(m/n=2.5; MW: 1,829; EW: 910)

(15) The ethyl ester of Example 1 (20 g, 22 meq) was charged in a reactor under inert atmosphere. 5.3 g (88 meq) ethylene diamine was added and the reaction mass was heated at 80 for 2 hours. IR analysis confirmed, by the disappearance of the ester carbonyl stretching, the completion of the amidation reaction. The excess of ethylene diamine was removed by vacuum distillation at 80 C. .sup.1H-NMR confirmed structure reported in the title:

(16) .sup.1H-NMR: 4.2 (CH.sub.2 to the CF.sub.2); 3.95 (CH.sub.2 to the carbonyl group); 3.4 (CH.sub.2 to the NH); 2.5 (CH.sub.2 to the NH.sub.2).

EXAMPLE 3

Synthesis of a (PFPE-NN) of formula:

(17)
H.sub.2NCH.sub.2CH.sub.2NHCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nOCF.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2
(m/n=1.2; EW=1,651 g/eq)

(18) A 4-necked glass reactor equipped with a water-cooled condenser, a magnetic stirring bar and a dropping funnel was kept under inert atmosphere (N.sub.2) by flowing N.sub.2 for 20 min. The reactor was maintained under a static inert atmosphere by means of a nitrogen-filled balloon kept atop the condenser. The reactor was then loaded with 65.7 g (73 ml; 2.19 eq) ethylene diamine. Keeping the temperature at 20 C., 50 g PFPE nonaflate (43.8 meq; 22.18 mmoles; average MW=2,254 g/mol; average EW=1141 g/eq), prepared from a commercial Fomblin Z DOL PFPE having MW=1,588; EW=827; functionality 1.82, were dropped in 145 min. with vigorous stirring (1100 rpm). The crude mixture was kept at 20 C. and at 1100 rpm for further 4 hrs. The progress of the reaction was followed by monitoring the amount of C.sub.4F.sub.9SO.sub.3.sup.()(+)H.sub.3NC.sub.2H.sub.4NH.sub.3.sup.(+)()O.sub.3SC.sub.4F.sub.9 in the upper ethylene diamine layer. Once complete, the crude reaction mixture was placed in a separating funnel and the lower PFPE layer was collected. The lower layer was then distilled under high vacuum at 70 C. and 5.310.sup.1 residual atm in order to eliminate residual ethylene diamine which partitioned in the lower PFPE layer, obtaining 35 g of pale-yellow, clear oil. .sup.1H-NMR and IR analyses confirmed the structure reported in the title, in admixture with 9% mol of dimeric by-products. Isolated yield=83 mol %. MW (GPC and NMR)=3,119 g/mol; EW=1,580 g/eq PFPE dimer/monomer selectivity=91/9 in moles ethylene diamine and PFPE diol (Fomblin Z-DOL PFPE resulting from hydrolysis of the nonaflate) absent or under the detectable limit. TGA: 0% wt loss up to 150 C.; 16.6 wt % loss between 150-300 C.

(19) .sup.1H-NMR (neat): 4.3 (CF.sub.2CH.sub.2NH); 3.9 (NHCH.sub.2CH.sub.2NH of dimer); 3.8 (NHCH.sub.2CH.sub.2NH.sub.2); 2.8 (NH+NH.sub.2).

(20) .sup.19F-NMR (neat): 78+80 (PFPE-OCF.sub.2CH.sub.2NR.sub.h)

(21) .sup.13C-NMR (neat): 134-106 (PFPE); 52 (OCF.sub.2CH.sub.2); 50 (NHCH.sub.2CH.sub.2); 46 (NHCH.sub.2CH.sub.2NH dimer); 38 (CH.sub.2NH.sub.2).

EXAMPLE 4

Synthesis of a mixture of (PFPE-NN) of formula:

(22)
Rf[OCF.sub.2CH.sub.2N(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2NH.sub.2].sub.2/Rf(OCF.sub.2CH.sub.2NHCH.sub.2CH.sub.2CH.sub.2NHCH.sub.3).sub.2
wherein Rf represents (CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.n with m/n=1.09 and EW=1,380 g/eq

(23) N-methyl-propyldiamine (97.59 grams, 1.109 moles; 116 ml) was placed in the same equipment under the same reaction conditions as described in Example 3. The same PFPE nonaflate as used in example 3 (50 g; 43.8 meq; 22.18 mmoles) was dropped in 155 min. with vigorous stirring (1200 rpm). The crude mixture was let to stir for further 5 hrs after the addition of the PFPE nonaflate. Once the reaction was complete (quantification of the nonaflate salt by NMR as described in Example 3), the crude mixture was separated in a separating funnel and the lower PFPE layer was distilled at 80 C. and 0.2 residual atm. The distillate was treated with 1% by wt active charcoal at 20 C. and filtered on a pressure filter with a 0.2 m PFPE membrane, to afford 34.7 grams of pale-yellow, clear oil. NMR and IR analyses confirmed the structure reported in the title in admixture with dimeric by-products. Isolated yield=85.5 mol %. MW (GPC and NMR)=2,649 g/mol; EW=1,380 g/eq PFPE Dimer/Monomer selectivity=47/53 in moles. Regioselectivity OCF.sub.2CH.sub.2N[CH.sub.3](CH.sub.2).sub.3NH.sub.2/OCF.sub.2CH.sub.2NH(CH.sub.2).sub.3NHCH.sub.3=36/64 N-methyl propyldiamine and Fomblin Z-DOL PFPE (resulting from hydrolysis of the nonaflate) absent or under detectable limits. TGA: 0% wt loss up to 150 C.; 10 wt % loss between 150-236 C.; 20% wt. Loss up to 280 C.

(24) .sup.1H-NMR (neat): 3.5, 3.6 (CF.sub.2CH.sub.2N); 3.2 [N(H)CH.sub.2CH.sub.2CH.sub.2N(H) of dimer]; 3.3 (N(CH.sub.3)CH.sub.2); 3.1 (CH.sub.2NH); 2.9, 2.87 (N(CH.sub.3)); 2.1 (CH.sub.2+NH.sub.2+NH).

(25) .sup.19F-NMR (neat): 72+73.7; 74.4+75.5 (PFPE-OCF.sub.2CH.sub.2N)

(26) .sup.13C-NMR (neat): 134-106 (PFPE); 61 (OCF.sub.2CH.sub.2N(CH.sub.3)); 53.5 (OCF.sub.2CH.sub.2NH); 48+31 [N(CH.sub.3)(CH.sub.2).sub.3NH].

EXAMPLE 5

Synthesis of a (PFPE-NN) of formula:

(27)
Rf[OCF.sub.2CH.sub.2NH(CH.sub.2).sub.6NH.sub.2].sub.2
wherein Rf represents (CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.n with m/n=1.09 and EW=2430 g/eq)

(28) Hexamethylene diamine (121 g, 1.042 moles, 136 ml) was placed in the same equipment as described in Example 3 and the mixture was heated to 60 C. PFPE nonaflate of commercial Fomblin Z DOL PFPE (47 g; 41.89 meq; 20.85 mmoles; average MW=2,254 g/mol; average EW=1,141 g/eq) were dropped in 400 min. with vigorous stirring (1200 rpm), maintaining the reaction temperature at 60 C. The crude mixture was let to stir for further 8 hrs after the addition of the PFPE nonaflate. Once the reaction was complete (quantification of the nonaflate salt by NMR as described in Example 3) the crude mixture was first diluted in 60 ml CH.sub.2Cl.sub.2, in order to prevent unreacted hexamethyldiamine to solidify (f.p.=45 C.) and then poured in a separating funnel. The lower phase was collected and then distilled at 80 C. and 0.52 residual atm. obtaining 31 grams of a pale-yellow oil. NMR and IR analyses confirmed the structure reported in the title, in admixture with dimeric and trimeric by-products.

(29) Isolated yield=78.8 mol %. MW (GPC and NMR)=4,803 g/mol; EW=2,430 g/eq PFPE Dimer/Trimer selectivity=53/47 in moles. Hexamethyldiamine and Fomblin Z-DOL PFPE (resulting from hydrolysis of the nonaflate) absent or under detectable limits.

(30) TGA: 0% wt loss up to 200 C.; 10 wt % loss between 200-312 C.

(31) .sup.1H-NMR (neat): 4.5, (CF.sub.2CH.sub.2N; dimer+trimer); 4.1 (CH.sub.2NHX; X=H, CH.sub.2); 2.9-2.6 ([CH.sub.2].sub.4; NH; NH.sub.2).

(32) .sup.19F-NMR (neat): 75+78; (PFPE-OCF.sub.2CH.sub.2N)

(33) .sup.13C-NMR (neat): 134-106 (PFPE); 53.5 (OCF.sub.2CH.sub.2NH); NH.sup.fCH.sub.2.sup.eCH.sub.2.sup.d CH.sub.2.sup.cCH.sub.2.sup.bCH.sub.2.sup.aCH.sub.2NH.sub.2; NH.sup.1CH.sub.2.sup.2CH.sub.2.sup.3CH.sub.2.sup.3CH.sub.2.sup.2CH.sub.2.sup.1CH.sub.2NH: 50.5 (f+1); 43.5 (a); 35 (b); 31.5 (e+2); 28 (c+d+3).

EXAMPLE 6

Synthesis of a (PFPE-DA) of Formula

(34) ##STR00003##
wherein Rf represents (CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.n with m/n=1.79 and Ew=EW=790 g/eq

(35) In the same apparatus as described in Example 3, 1,2,4-tricarboxylic anhydride (37.3 g; 0.1944 moles) was dissolved in 140 ml anhydrous DMF to obtain a homogeneous reaction mixture, which was heated to 100 C. and stirred at 900 rpm. Thereafter, a (PFPE NN) of formula A-OR.sub.f-A (60 g; 35.2 mmoles; 64.8 meq; wherein R.sub.f represents (CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.n, A and A represent CF.sub.2CH.sub.2NH.sub.2 and in which m and n are selected in such a way as the average MW is 1,704 g/mole and the average EW is 926 g/eq) was added in approximately 25 min, to obtain a slightly opaque mixture. The mixture was then heated to 136 C. for 6 hrs and then to 155-160 C. for further 10 hrs. The resulting crude mixture was cooled to 25 C. and extracted with 200 ml of Galden HT-110 PFPE. Two clear-cut layers separated. The desired product, along with DMF and traces of Galden HT-110 PFPE was in the top layer. The top layer was then extracted with 200 ml of distilled H.sub.2O and a white solid precipitated. Upon addition of CH.sub.2Cl.sub.2, a fraction of the solid remained undissolved and it was identified (NMR) as unreacted 1,2,4-tricarboxilic anhydride. The CH.sub.2Cl.sub.2 solution was extracted with H.sub.3O.sup.(+)Cl.sup.() (2:1 vol); a waxy, white solid precipitated which was scarcely soluble in Freon/acetone. This product was identified (NMR) as a polyamide resulting from the reaction between PFPE diamine and the 4-carboxylic group of the anhydride or of the target product. The purified CH.sub.2Cl.sub.2 phase is evaporated obtaining 62 grams of a dense oil which crystallized overnight at 20 C. IR and NMR analyses confirmed the structure reported in the title: Isolated yield=63.4 mol % MW=1,510 g/mol; EW=790 g/eq. TGA: 20% wt loss at 200 C.; 50% wt loss at 300 C. due to the COOH moiety.

EXAMPLE 7

Synthesis of a (PFPE-NN) of formula:

(36)
NH.sub.2(CH.sub.2).sub.10NH(O)CCH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.m(CF.sub.2O).sub.nCF.sub.2CH.sub.2OCH.sub.2C(O)NH(CH.sub.2).sub.10NH.sub.2
(m/n=2.5; MW: =1,990; EW=1,010)

(37) The PFPE-diester derivative of example 1 was reacted with a 5 molar excess of 1,10-diaminodecane (C.sub.10-diamine) by heating the two reagents neat in a round bottom flask fitted under nitrogen at a temperature of 110 C. The progress of the reaction was monitored for complete disappearance of the diester by FT-IR, which typically took 16-24 h. The excess of 1,10-diaminodecane was allowed to sublime by heating the reaction mixture to about 100 C. over a period of several hours and the sublimed amine was separated manually from the cold reactor spots. FT-IR and .sup.1HNMR analyses confirmed the structure reported in the title.

(38) 4. Synthesis of Polyamides (PA)

EXAMPLE 8 (COMPARATIVE EXAMPLE)

Synthesis of MXD10

(39) Sebacic acid (1 mol, 202 g) was charged in a 500 mL glass kettle attached with kettle head fitted with four ground joints having a T-joint adapter, thermometer pocket, thermometer, anchor type overhead stirrer, water condenser and a receiver round bottom flask. The kettle was flushed with nitrogen and submerged in an oil bath and the temperature was raised gradually so as to melt the acid (m.p.=134.5 C.). When the acid was completely in molten form, it looked transparent. Stirring was further continued at 50 rpm using an overhead stirrer. MXDA (m-xylenediamine, 1 mol, 136 g) was added drop wise through an addition funnel in such a way that addition lasted for 45-60 min. During this time, the temperature was raised to 210 C. The salt formation initiated and water started to distil out. When water generation ceased, the temperature of the oil bath was raised to 250 C. When the desired torque was built up, stirring was stopped, setup unassembled and the molten polymer was poured and quenched in an ice-cold water bath.

EXAMPLE 9

Polyamide MXD10 Containing 5% w/w of the (PFPE-NN) of Example 7

(40) A procedure similar to that described in Example 8 was followed, except that once the sebacic acid was completely in the molten form, the (PFPE-NN) of Example 7 was added to the kettle in order to reach a final PFPE concentration in the polymer of 5% (w/w). The mixture was then allowed to mix thoroughly. After 30 min of mixing, MXDA (m-xylylenediamine) was added dropwise and the reaction was continued as indicated in Example 8. .sup.1H-NMR, .sup.13C-NMR and .sup.19F-NMR analyses confirmed that the desired polyamide was obtained. The disappearance of signals at 41.1 and 39.8 due to PFPE-CF.sub.2CH.sub.2OCH.sub.2CONHCH.sub.2 (CH.sub.2).sub.8CH.sub.2NH.sub.2 and the appearance of a single signal at 40.1 due to PFPE-CF.sub.2CH.sub.2OCH.sub.2CONHCH.sub.2(CH.sub.2).sub.8CH.sub.2NHCO(CH.sub.2).sub.8CO due to amidation of PFPE-NN with sebacic acid in .sup.13C-NMR confirmed that the (PFPE-NN) was covalenty bound in the polyamide. Fluorine estimation by combustion ion chromatoraphy indicated that the fluorine content was 1.6% w/w (vs a theoretical value 2.5%).

EXAMPLE 10

Synthesis of Polyamide MXD10 Containing 2% w/w of the (PFPE-NN) of Example 7

(41) Similarly to what described in Example 8, a polyamide (PA) comprising blocks of sebacic acid, MXDA and 2% w/w of (PFPE-NN) of Example 7 was obtained. .sup.1H-NMR, .sup.13C-NMR and .sup.19F-NMR analyses confirmed that the desired polyamide was obtained, and that the PFPE diamine was covalently bound in the polyamide. Fluorine estimation by combustion ion chromatography indicated that the fluorine content was 0.8% w/w (vs a theoretical value of 1.2%).

EXAMPLE 11

Synthesis of Polyamide MXD10 Containing 1% w/w of (PFPE-NN) of Example 7

(42) Similarly to what described in Example 8, a polyamide (PA) comprising blocks of sebacic acid, MXDA and 1% w/w of (PFPE-NN) of Example 7 was obtained. .sup.1H-NMR, .sup.13C-NMR and .sup.19F-NMR analyses confirmed that the desired polyamide was obtained, and that the PFPE diamine was covalently bound in the polyamide. Fluorine estimation by combustion ion chromatography indicated that the fluorine content was 0.4% w/w (vs a theoretical value 0.5%).

EXAMPLE 12 (COMPARATIVE EXAMPLE)

Synthesis of Polyamide MXD6

(43) Polyamide of MXD6 was synthesised from adipic acid and MXDA, following a procedure similar to that of Example 8, with the difference that adipic acid and MXDA were added one pot and the temperature was raised to about 275 C.

EXAMPLE 13

Synthesis of Polyamide MXD6 Containing 2% w/w of PFPE NN of Example 7

(44) The procedure of Example 12 was followed, with the difference that a solution of the (PFPE-NN) of Example 7 in hexafluoroxylene (HFX) and methanol (MeOH) was also added. The amount of (PFPE-NN) in the solution was calculated in order to reach a final amount of (PFPE-NN) block in the polyamide of 2% w/w. The solvents and water were distilled out during the course of the reaction and the polyamide was isolated as described above. .sup.1H-NMR, .sup.13C-NMR and .sup.19F-NMR confirmed the desired polyamide (PA) was obtained, and that the (PFPE-NN) was covalently bound in the polyamide. Fluorine estimation by combustion ion chromatography indicated that the fluorine content was 0.8% w/w (vs a theoretical value of 1.2%).

EXAMPLE 14

Synthesis of Polyamide MXD6 Containing 1% w/w of (PFPE-NN) of Example 7

(45) The procedure of Example 13 was followed, with the difference that the amount of (PFPE-NN) of Example 7 in the solution was calculated in order to reach a final amount of (PFPE-NN) block in the polyamide of 1% w/w. .sup.1H-NMR, .sup.13C-NMR and .sup.19F-NMR analyses confirmed that the desired polyamide was obtained, and that the (PFPE-NN) was covalenty bound in the polyamide. Fluorine estimation by combustion ion chromatography indicated that the fluorine content was 0.4% w/w (vs a theoretical value of 0.5%).

EXAMPLES 15

Synthesis of Polyamide MXD6 Containing 2% w/w of PFPE DA of Example 1

(46) The procedure of Example 12 was followed, with the difference that the PFPE-diester derivative of Example 1 was added without solvents in an amount of 2% w/w with respect to adipic acid and MXDA

EXAMPLES 16

Synthesis of Polyamide MXD6 Containing 2% w/w of (PFPE-NN) of Example 2

(47) The procedure of Example 13 was followed, with the difference that the amount of (PFPE-NN) of Example 2 was calculated in order to reach a final amount of (PFPE-NN) block in the polyamide of 2% w/w. .sup.1H-NMR, .sup.13C-NMR and .sup.19F-NMR analyses confirmed that the desired polyamide was obtained. Similarly as described in Example 9, signals at 41.9 and 44.7 in .sup.13C-NMR confirmed that the (PFPE-NN) was covalently bound in the polyamide. Contact angle measurement showed the increase in hydrophobocity and oleo-phobicity (Table 1).

EXAMPLES 17a-17c

Synthesis of Polyamides MXD6 Containing 1, 3 and 5% of PFPE DA of Example 1

(48) A stirred batch stained steel vessel (5 L capacity) was charged with adipic acid (4.44 mol, 648.9 g), m-xylenediamine (4.45 mol, 605.8 g) and PFPE-diester derivative of Example 1 (1 wt %, 0.0068 mol, 12.56 g) and closed. The mixture was blanketed with nitrogen and then heated up to 200 C. At this point of time, the internal pressure rose close to 4.5 kg and was kept constant for about an hour. During this step, the temperature was raised to 250 C. Afterwards, the vessel was depressurized gradually over a period of 30 min. The polymerization was continued for another 30 min under nitrogen atmosphere wherein the torque increased to the desired value. The final polymer melt was drawn from the bottom valve and quenched in ice cold water and pelletized.

EXAMPLE 18

Preparation of Compositions of PA Reinforced with Glass Fibers

(49) MXD6 or the PA of Examples 17a-17c and glass fibre [OCV EC10 983 (4.5 mm)] were co-extruded in a ratio of 70:30 on a ZSK-26 twin screw extruder. The PA were fed to the first barrel of zone-1 of the extruder comprising of 12 zones via a loss in weight feeder. The barrel settings were in the range of 220-250 C. The glass fibre was fed from zone 7 through a side stuffier via a loss in weight feeder. The screw rate was 100 rpm. The extrudates were cooled and pelletized using a conventional equipment.

EXAMPLE 19

Preparation of Formed Articles by Injection Molding

(50) The compositions prepared according to Example 18 were molded on a Sumitomo 75 TON injection molding machine. The temperature range was 265 C.-280 C. The mold temperature controller was set to 140 C.-165 C. The cooling cycle time was fixed to 35-50 sec. Under these setup conditions, ISO tensile test pieces, impact bars and colour plaques were molded.

(51) Tests

(52) Contact Angle Measurements

(53) Table 1 summarizes the results of static contact angle measurements of the polyamides PA of Examples 8-16 vs water and n-hexadecane.

(54) TABLE-US-00001 TABLE 1 Static contact angle measurements of the PA of Ex 8-16 Polymer water n-hexadecane Ex 8 91.7 37.4 Ex 9 109.4 69.5 Ex 10 108.1 69.5 Ex 11 109.3 69.2 Ex 12 92.3 38.4 Ex 13 115.8 69.3 Ex 14 98.7 69.4 Ex 15 102.4 68.8 Ex 16 100.7 71.4

(55) It is evident from the results reported in Table 1 that the polyamides according to the present invention show significantly higher contact angle values towards water and n-hexadecane than the polyamides of reference Examples 8 and 12. Therefore, the polyamides according to the invention are endowed with higher hydro- and oleo-phobicity.

(56) In order to confirm that the PFPE DA or PFPE NN was covalently bound in the polyamides, the polyamides PAs according to the invention were heated in a mixture of hot hexafluoroxylene and methanol at reflux temperature for several hours. The residual polymers were then filtered, washed with solvent and dried under vacuum. Contact angles towards water and n-hexadecane of these residual polymers were measured; the results showed no significant changes with respect to the measurements carried out before the treatment.

(57) Gel Permeation Chromatography (GPC) Analysis of MXD6 and of the PA of Examples 17a-17c

(58) MXD6 and the PA of Examples 17a-17c were completely dissolved in hexafluoroisopropanol (HFIPA) containing 0.05M potassium trifluoro acetate (KTFAT). Any fillers and insoluble additive were removed by filtration through 0.2 micron PTFE disposable syringe filters. The filtered PA solutions were separated on a size exclusion chromatography (SEC) system consisting of a Waters HPLC pump (model no. 515), Shodex refractive index (RI) detector (model no. 109), Waters column oven (capable for room temperature to 150 C.) maintained at 40 C. during the analysis, set of two mini mixed B SEC columns and mini mix B guard column (from Agilent), Clarity SEC integration software (Version 5.0.00.323). Mobile phaseHFIPA/0.05M potassium trifluoro acetate (KTFAT) at a flow rate of 0.4 mL/minute. The system was calibrated using the set of narrow polydisperse PMMA standard samples. Molecular weights were calculated using a calibration file generated using PMMA standards with the help of a Clarity SEC integration software. The results are reported in Table 2.

(59) TABLE-US-00002 TABLE 2 GPC data of MXD6 and PA of Ex 17a-17c Polyamide Mn Mw Mz Mz1 PDI* MXD6 22903 54874 97186 151203 2.39 PA of Ex 17a 22959 55022 101024 164851 2.40 (containing1% wt PFPE-DA) PA of Ex 17b 22994 56522 111346 196648 2.46 (containing 3% wt PFPE-DA) Pa of Ex 17c 21381 58658 122914 222514 2.74 (containing 5% PFPE-DA) *PDI = polydispersity index

(60) Differential Scanning Calorimetry (DSC) of the PA of Examples 17a-17c

(61) The glass transition temperatures of the MXD6 and of the PA of Examples 17a-17c were measured according to ASTM E1356 using a TA Instruments Model Q20/Q1000 Differential Scanning calorimeter fitted with refrigerating cooling system (RCS) operated with TA Thermal Advantage and Universal Analysis software. The instrument was calibrated using a heating and cooling rate of 10 C./min under nitrogen atmosphere at 50 ml/min. The measurements were also carried out using a heating and cooling rate of 10 C./min under nitrogen atmosphere.

(62) With respect to MXD6, glass transition [83 C. (T.sub.g) and melting temperature of 237 C. (T.sub.m)] remained more or less unchanged, whereas a delay in crystallization of about 10-15 C. during the cooling cycle was observed, with an insignificant change in H.sub.c.

(63) Determination of the Glass Fiber Content

(64) About 1 g of each composition prepared according to Example 18 was placed in a pre-weighed quartz fibre crucible. The quartz fibre crucible was then placed in a microwave furnace (Phoenix Airwave Microwave furnace from CEM). The temperature program was as follows: heating from room temperature to 500 C. in 2 hrs; maintenance at 500 C. for 2 minutes; 500 C. to 600 C. in 30 minutes; maintenance at 600 C. for 90 minutes; cooling from 600 C. to room temperature in 2 hrs. Once the furnace was cooled to room temperature, the crucible was removed and re-weighed using an analytical balance. The glass fiber content was calculated using the following formula:
Glass fiber (% wt)=[(wt of residue+wt of empty crucible)wt of empty crucible]*100/[(wt of sample+wt of empty crucible)wt of empty crucible]

(65) The total glass fiber (GF) content is reported in Table 3.

(66) TABLE-US-00003 TABLE 3 GF content in the compositions prepared according to Example 18 GF content Composition Remarks (% wt) Reference MXD6 + 28.87 composition glass fiber C-1* C-1 PA of Ex 17a + 28.18 glass fiber C-2 PA of Ex 17b + 29.11 glass fiber C-3 PA of Ex 17c + 29.09 glass fiber

(67) Measurements of Contact Angles of Formed Articles

(68) Static contact angles were measured against 2 l each of water and n-hexadecane (HD) on 2 mm fibre-reinforced injection molded bars prepared as described in Example 19 using a Dataphysics Contact Angle System OCA 20 instrument according to the Sessile drop method. Images were captured after a fixed time of 10 seconds after dispensing the liquids (except in case of reference composition C-1* with HD, where it was immediate, as the drop used to spread too fast to be captured). Multiple data points (16-20) were collected and the average and standard deviation was calculated. The results are reported in Table 4 below.

(69) TABLE-US-00004 TABLE 4 Static contact angles of molded bars prepared according to Example 19 Bar from ref. Bar from ref. Bar from ref. Bar from ref. Contact Angle composition composition composition composition Against C-1* C-1 C-2 C-3 Water (dry as 71.2 0.5 79.5 1.1 88.2 2.2 92.4 0.5 molded) Water 79.5 0.2 81.7 1.1 92.2 0.6 96.4 1.6 (*annealed) HD (dry as 12.1 0.5 48.2 1.9 73.7 0.4 73.0 0.3 molded) HD 30.7 1.8 50.5 1.1 73.0 0.2 74.7 0.3 (*annealed) *annealed at 120 C. for 3 hours

(70) Mechanical Tests on Formed Articles

(71) Molded bars prepared according to Example 19 were tested as dry as molded. For this purpose, after injection molding, the molded bars test bodies were stored for at least 48 h at room temperature in a desiccator in sealed aluminium bags. The tensile properties of the bars were measured according to the ISO 527 test procedure, while the notched and unnotched Izod impact strengths were measured according to the ISO 180 test procedure. Table 5 reports tensile strength, strain at break and modulus. Table 6 reports the impact strength data for unnotched and notched bars.

(72) TABLE-US-00005 TABLE 5 Tensile strength of the molded bars prepared according to Example 19 Tensile Strain Modulus Strength at Break Molded bar (GPa) (MPa) (%) Molded bar 11.6 0.4 168 5 1.17 0.07 from ref composition C-1* Molded bar 11.3 0.1 194 4 1.47 0.04 from composition C-1 Molded bar 11.7 0.1 203 5 1.45 0.05 from composition C-2 Molded bar 11.5 0.6 204 6 1.45 0.10 from composition C-3

(73) TABLE-US-00006 TABLE 6 Impact strength of the molded bars prepared according to Example 19 Unnotched IZOD Notched IZOD impact strength impact strength Molded bar (Kg/m2) (Kg/m2) Molded bar 24.31 0.70 7.38 0.19 from ref composition C-1* Molded bar 31.04 0.81 8.33 0.18 from composition C-1 Molded bar 35.06 1.37 9.04 0.19 from composition C-2 Molded bar 35.44 3.11 9.29 0.26 from composition C-3