THERMOPLASTIC COMPOSITES MATERIALS

Abstract

Multilayer composites laminates comprising continuous fibers and a polymer matrix including a thermoplastic polymer and an impact modifier are disclosed. The invention further relates to articles incorporating the thermoplastic composites laminate.

Claims

1. A composite material comprising at least two layers (L), each layer (L) comprising continuous reinforcing fibers and a polymer matrix, wherein the polymer matrix comprises: at least one thermoplastic polymer selected from the group consisting of aliphatic polyamides, semi-aromatic polyamides, polyaryleneetherketones, polyphenylenesulfides, liquid crystalline polymers, and mixtures thereof, and at least one impact modifier.

2. The composite of claim 1, wherein the at least one thermoplastic polymer is selected from the group consisting of aliphatic polyamides, semi-aromatic polyamides, polyaryleneetherketones, liquid crystal polymers, and mixtures thereof.

3. The composite of claim 1, wherein the at least one thermoplastic polymer is selected from the group consisting of semi-aromatic polyamides and polyaryleneetherketones, and mixtures thereof.

4. The composite of claim 1, wherein the at least one thermoplastic polymer is selected from the group consisting of semi-aromatic polyamide polymers.

5. The composite of claim 1, wherein the continuous reinforcing fibers are selected from the group consisting of glass fibers, carbon fibers, aramid fibers, ceramic fibers, and mixtures thereof.

6. The composite of claim 1, wherein the volume of the continuous reinforcing fibers is from 20% to 80% with respect to the total volume of layer (L).

7. The composite of claim 3, wherein the impact modifier is selected from the group consisting of ethylene-butene copolymers; ethylene-octene copolymers; polypropylenes and copolymers thereof, polybutenes; polyisoprenes; ethylene-propylene-rubbers (EPR), ethylene-propylene-diene monomer rubbers (EPDM), ethylene-acrylate rubbers; butadiene-acrylonitrile rubbers, ethylene-acrylic acid (EAA), ethylene-vinylacetate (EVA), acrylonitrile-butadiene-styrene rubbers (ABS), block copolymers styrene ethylene butadiene styrene (SEBS); block copolymers styrene butadiene styrene (SBS), core shell elastomers of methacrylate-butadiene-styrene (MBS) type, terpolymers of ethylene, acrylic ester and glycidyl methacrylate, copolymers of ethylene and butyl ester acrylate; copolymers of ethylene, butyl ester acrylate and glycidyl methacrylate; ethylene-maleic anhydride copolymers; EPR grafted with maleic anhydride; styrene copolymers grafted with maleic anhydride; SEBS copolymers grafted with maleic anhydride; styrene-acrylonitrile copolymers grafted with maleic anhydride, ABS copolymers grafted with maleic anhydride, and mixtures thereof.

8. The composite of claim 1, wherein the at least one impact modifier is selected from the group consisting of ethylene-higher alpha-olefin polymers and ethylene-higher alpha-olefin-diene polymers grafted or copolymerized with reactive carboxylic acids or their derivatives.

9. The composite of claim 1, wherein the polymer matrix comprises from 0.5 wt. % to 25.0 wt. % of the at least one impact modifier, with respect to the total weight of the polymer matrix.

10. The composite of claim 1, wherein the reinforcing fiber is selected from the group consisting of glass fibers and carbon fibers and the polymer matrix comprises at least semi-aromatic polyamides selected from the group consisting of PA 6T, PA 6I, PA 9T, PA 10T, PA 6T/6I, PA 6T/66 and PA 6T/6I/66, and 0.5 to 15.0 wt. % of at least one impact modifier selected from the group consisting of ethylene-higher alpha-olefin polymers and ethylene-higher alpha-olefin-diene polymers grafted or copolymerized with reactive carboxylic acids or their derivatives.

11. The composite of claim 1, wherein the composite is a unidirectional composite.

12. The composite of claim 1, wherein the composite is a multiaxial composite laminate.

13. The composite of claim 1, wherein the continuous reinforcing fibers are in a configuration selected from the group consisting of a woven fabric, a layered fabric, or a combination thereof.

14. An article comprising the composite of claim 1.

15. The article of claim 14, wherein the article is selected from the group consisting of an automotive component, a battery housing, an aerospace component, oil and gas drilling components, a component for Smart Devices, a medical housing or component for medical devices, an Urban Air Mobility device, and an Electronic Device.

16. The composite of claim 4, wherein the semi-aromatic polyamide polymers are selected from the group consisting of PA 4T, PA5T, PA 6T, PA 6I, PA 9T, PA 10T, PA6T/6I, PA 6T/66, PA 6T/6I/66, MXD6, copolymers thereof, and mixtures thereof.

17. The composite of claim 1, wherein the at least one impact modifier is selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride or their esters; ethylene-methyl acrylate-glycidyl methacrylate terpolymers, copolymers based on styrene and ethylene and/or butylene optionally grafted with maleic anhydride, and mixtures thereof.

18. The composite of claim 10, wherein the at least one impact modifier is selected from the group consisting of acrylic acid, methacrylic acid, maleic anhydride or their esters; ethylene-methyl acrylate-glycidyl methacrylate terpolymers, copolymers based on styrene and ethylene and/or butylene optionally grafted with maleic anhydride, and mixtures thereof.

Description

EXAMPLES

Raw Materials

[0101] Semi-aromatic Polyamide 1 (PPA1): Amodel A1006 (PA6T/6I/66) obtained from Solvay Specialty Polymers USA, L.L.C.

[0102] Semi-aromatic Polyamide 2 (PPA2): Genestar GC 98018 (PA9T) obtained from Kuraray, Co. Ltd.

[0103] PPS polymer (PPS): Ryton QA200P obtained from Solvay Specialty Polymers USA, L.L.C.

[0104] Impact modifier 1 (IM1): Kraton FG 1901 GT a linear triblock copolymer based on styrene and ethylene/butylene with a polystyrene content of 30% supplied by Kraton Polymers US, LLC.

[0105] Impact modifier 2 (IM2): Lotader AX8900 a random terpolymer of ethylene, acrylic ester and glycidyl methacrylate supplied by Arkema

[0106] Reinforcement fiber 1 (GF): TufRov 4510 fiberglass roving supplied by Nippon Electric Glass.

[0107] Reinforcement fiber 2 (CF): HexTow AS4D carbon fiber supplied by Hexcel

[0108] Heat Stabilizer (HS): HS Pellet Blend supplied by Ajay North America, LLC.

Manufacture of Composite Materials

[0109] Continuous filament carbon fiber unidirectional tape prepregs (Layer (L)) were formulated using polymer matrices, as described in Table 1. The amount by weight of the thermoplastic polymer and of the impact modifier are calculated based on the total weight of the polymer matrix. The amount of the reinforcing fibers in the prepreg is measured in ters of volume fraction with respect to the total volume of the prepreg.

[0110] Such unidirectional prepregs were made using a melt impregnation process as fundamentally described in EP 102158 (using different equipment). sufficient number of fibers were used to make a 76 mm wide unidirectional tape. The resulting tape prepregs had a nominal polymer matrix content of 38 wt. % and a fiber areal weight of 180 g/m.sup.2.

[0111] The prepreg tape was cut and manually laid up with the plies being lightly tacked together with a soldering iron into various lay-ups in preparation for autoclave consolidation. The lay-up consisted of 12 plies ([(0/90).sub.3].sub.s configuration). Sacrificial polyimide surface films were applied before the ply stack was loaded into steel picture frame style tooling. The tooling was loaded into a compression press at the desired consolidation temperature. 500 psi of pressure was applied and the laminate was held for two minutes. The temperature was cooled to room temperature at 8 C./minute with pressure still applied before the tooling was removed, and the laminate demoulded.

[0112] The test panels were removed from the autoclave and then ultrasonic scanned to ensure good consolidation (less than 2% void content) before machining the laminates into test coupons for the mechanical test to be performed.

[0113] Samples of unidirectional tape were cut perpendicular to the fibre direction before being stabilised and set with a two component epoxy resin (an example of a suitable casting resin is Epoxicure 2 from Buehler). After curing, the puck was progressively abraded and polished using first sandpaper, and then a diamond slurry on a felt pad. Sandpaper grits of 280/P320 to 1200/P4000 are appropriate for the initial abrasion, and then diamond slurries with a particle size of 3.0 m, then 1.0 m, and finally 0.1 m were usedfor polishing; a suitable slurry would be from the Glennel Diamond Suspension range from Electron Microscopy Sciences.

[0114] Imaging: The polished samples were imaged using an optical microscope under different magnification levels (100-300). The full tape cross-section image (30 mm wide) was inspected for the evidence of transverse cracks. Two samples per laminate were inspected. If present, these appear as dark jagged cracks running through fibre beds.

TABLE-US-00001 TABLE 1 Example No CE1 E1 CE2 E2 CE3 E3 CE4 E4 PPA1 (wt. %) 100 90 PPA2 (wt. %) 99 89 99 89 PPS (wt. %) 100 90 IM1 (wt. %) 10 10 IM2 (wt. %) 10 10 HS 1 1 1 1 Fibre (vol %) 50 50 50 50 50 50 50 50 GF GF GF GF CF CF CF CF Cracking Y N Y N Y N Y N

[0115] The results in Table 1 show that composite laminates of the invention (Examples 1 to 4) exhibit an increased resistance to cracking with respect to the laminates of Comparative Examples 1 to 4.