MULTI-LAYER STRUCTURE FOR STORING HYDROGEN

Abstract

Multi-layer structure intended for storing hydrogen, including, from the inside out, a sealing layer and a composite reinforcing layer, the innermost composite reinforcing layer being wound around the outermost adjacent sealing layer, at least the innermost sealing layer being made of a composition including: a. 20.5 to 99.845% by weight of a polyamide; b. 0.005 to 0.5% by weight of a catalyst; c. 0.05 to 1% by weight of a heat stabilizer; d. 0.1 to 3% by weight of a oligo- or poly-carbodiimide; e. 0 to 1.5% by weight of a plasticiser; f. 0 to less than 15% by weight of a polyolefin; g. 0 to 30% of an additive, and at least one of the composite reinforcing layers of a fibrous material in the form of continuous fibres impregnated with a composition including at least one polymer P2j, j=1 to m, m being the number of reinforcing layers.

Claims

1. A multilayer structure intended for storing hydrogen, comprising, from the inside to the outside, at least one sealing layer and at least one composite reinforcing layer, said innermost composite reinforcing layer being wound around said outermost adjacent sealing layer, at least said innermost sealing layer consisting of a composition comprising, relative to the total weight of the composition: a. 20.5 to 99.845% by weight of at least one polyamide; b. 0.005 to 0.5% by weight of at least one catalyst; c. 0.05 to 1% by weight of at least one thermal stabilizer; d. 0.1 to 3% by weight of at least one oligo- or poly-carbodiimide; e. 0 to 1.5% by weight of at least one plasticizer; f. 0 to less than 15% by weight of at least one polyolefin; g. 0 to 30% of at least one additive, and at least one of said composite reinforcing layers consisting of a fibrous material in the form of continuous fibers, which is impregnated with a composition predominantly comprising at least one polymer P2j, j= 1 to m, m being the number of reinforcing layers, in particular an epoxy resin or epoxy-based resin.

2. The multilayer structure according to claim 1, wherein each sealing layer comprises the same type of polyamide.

3. The multilayer structure according to claim 1, wherein each reinforcement layer comprises the same type of polymer, in particular an epoxy resin or epoxy-based resin.

4. The multilayer structure according to claim 2,wherein each sealing layer comprises the same type of polyamide and each reinforcing layer comprises the same type of polymer, in particular an epoxy resin or epoxy-based resin.

5. The multilayer structure according to claim 1, wherein it has a single sealing layer and a single reinforcing layer.

6. The multilayer structure according to claim 1, wherein said polyamide of the innermost sealing layer is a long-chain aliphatic polyamide or semi-aromatic.

7. The multilayer structure according to claim 1, wherein said polymer P2j is an epoxy resin or epoxy-based resin.

8. The multilayer structure according to claim 6, wherein said multilayer structure consists of a single reinforcing layer and a single sealing layer in which said long-chain aliphatic polyamide or semi-aromatic, and said polymer P2j is an epoxy resin or epoxy-based resin.

9. The multilayer structure according to claim 1,wherein said melt viscosity of said composition of said innermost sealing layer is substantially constant up to 20 minutes.

10. The multilayer structure according to claim 1, wherein said composition of said innermost sealing layer additionally has resistance to thermo-oxidation.

11. The multilayer structure according to claim 1, wherein said composition of said innermost sealing layer has a melt viscosity of 13,000 to 23,000 Pa.s, as determined by oscillatory rheology at 270° C., 10 rad/sec under nitrogen flushing with 5% deformation and 10 sec-1 shear between two parallel plates 25 mm in diameter.

12. The multilayer structure according to claim 1, wherein the fibrous material of the composite reinforcing layer is selected from glass fibers, carbon fibers, basalt fibers or basalt-based fibers, or a mixture thereof.

13. The multilayer structure according to claim 1, wherein said structure further comprises at least one outer layer consisting of a fibrous material made of continuous glass fibers, which is impregnated with a transparent amorphous polymer, said layer being the outermost layer of said multilayer structure.

14. A method for producing a multilayer structure as defined in claim 1, wherein it comprises a step of preparing the sealing layer by extrusion blow molding.

15. The method for producing a multilayer structure as defined in claim 14, wherein it comprises a step of filament winding of the reinforcing layer around the sealing layer.

Description

EXAMPLES

[0258] In all the examples, the tanks are obtained by rotational molding of the sealing layer (liner) at a temperature adapted to the nature of the thermoplastic resin used.

Examples

Products Used

[0259] The polyamide used is Rilsan®PA11 (BESNO, sold by Arkema),

[0260] The thermal stabilizer is ANOX® NDB TL89: phenol phosphite organic stabilizer sold by Chemtura.

[0261] The carbodiimide used is Stabiliser® 9000 (poly-(1,3,5-triisopropylphenylene-2,4-carbodiimide) sold by Raschig.

[0262] The catalyst used is H3PO3 or H3PO4.

[0263] BBSA: n-butylbenzene sulfonamide sold by PROVIRON

[0264] EXXELOR VA 1801: polyolefin (maleic anhydride-functionalized ethylenepropylene copolymer) sold by Exxon.

Example 1: Evaluation of the Compositions of the Invention: Melt Viscosity and Thermal Resistance at 140° C.

[0265] The proportions indicated are percentages by weight relative to the total weight of the composition.

[0266] Test on twin-screw extruder (Coperion ZSK40 having two screws with a diameter of 40 mm and a length corresponding to 40 times the diameter thereof) at 280° C. -300 rpm under vacuum - 600 mmHg at 60 kg/h.

[0267] The PA base is dried (< 0.1% humidity)

[0268] The compositions of the invention and comparative compositions are presented in table 1

TABLE-US-00001 Comp. 1 Comp. 2 Inv. 1 Inv. 2 BBSA 6 12 0 1.5 PA 11 + 600 ppm H.sub.3PO.sub.4 (Inherent viscosity: 1.45) 82.8 76.8 88.8 87.3 EPR 1801 10 10 10 10 ANOX NDB TL89 0.2 0.2 0.2 0.2 STABILISER 9000 1 1 1 1

Example 2: Comparison of the Properties of the Compositions According to the Invention With Comparative Composition 1

[0269] Liners made of PA11 with the comparative composition 1 and comparative composition 2 and the compositions of the invention 1 and 2 were prepared by rotational molding.

[0270] The hydrogen permeability is determined according to the following protocol: this consists in flushing the upper face of the film with the test gas (hydrogen) and in measuring the flow that diffuses through the film in the lower part by gas chromatography, flushed by the carrier gas: nitrogen

[0271] The experimental conditions are presented in table 2 and the results are presented in table 3:

TABLE-US-00002 Device LYSSY GPM500 / GC coupling Detection Chromatographic (TCD) Column Poraplot Q (L=27.5 m, Dint=0.530 mm, Ep.film=20 .Math.) Vector gas NITROGEN Diffusing gas HYDROGEN U (H2) Test surface area 50 cm.sup.2 Calibration Absolute by direct injection through a septum Pressure at column head 18 psi Oven temperature Isothermal 30° C. Detector temperature 200° C. detector: TCD [-] Injector temperature Temperature of the lyssy injection loop Temperature /relative humidity 23° C. /0% RH

TABLE-US-00003 Liner based on composition Permeability H2 Comp 1 371 cc.mm/m.sup.2.24h.atm Comp 2 480 cc.mm/m.sup.2.24h.atm Inv 1 265 cc.mm/m.sup.2.24h.atm Inv 2 290 cc.mm/m.sup.2.24h.atm

[0272] The results of table 3 show a lower hydrogen permeability of the liners prepared from the compositions of the invention (Inv 1 and Inv 2).

Example 3: Notched Charpy Impact Strength at -30° C. According to ISO 179-1:2010

[0273] The same liners as for example 2 were prepared by rotational molding.

[0274] These liners were tested for notched Charpy impact strength at -30° C.

[0275] The notched Charpy impact strength results are shown in table 4.

TABLE-US-00004 Liner based on composition Notched Charpy impact strength at -30° C. Inv 1 10 kJ/m2 Inv 2 10 kJ/m2 Comp. 1 7 kJ/m2 Comp. 2 6 kJ/m2

[0276] The cold resistance of the PA11 liners without plasticizer or with 1.5% of plasticizer is greater than those of the PA11 liner with 6% plasticizer or 12% plasticizer.