RESIN COMPOSITE

Abstract

A water-resistant composition 20 includes a graphene material 22 forming a matrix with a resin 23. The matrix can include reinforcing fibres such as glass fibres. The composition can include the graphene material 22, a polyester resin 23 and glass fibre reinforcement. Multiple forms of the composite can be provided in layers, such as a barrier layer containing the graphene material 22 in a resin 23 and a second layer containing reinforcing material. A cosmetic coloured gel coat can be applied to the composition and a clear gel coat applied over the cosmetic coating. The graphene material can include graphene platelets 22 dispersed within the resin. The graphene material can provide up to 5% by weight (% wt) of the composite, preferably up to 2% wt of the composite, more preferably between 1% wt and 2.5% wt of the composite and yet more preferably 2% wt of the composite. The composition can be applied to a boat hull, a pipe, a swimming pool, a spa or a tank, or a surface subject to prolonged contact with or submersion in water.

Claims

1. A material composition comprising at least a combination of a resin and a graphene material.

2. The composition of claim 1, further comprising a reinforcing material.

3. The composition of claim 2, wherein the reinforcing material comprises one or more of: a glass fibre material; a carbon fibre material; a poly-paraphenylene terephthalamide and/or other synthetic material; fibers; matting; and mesh.

4. The composition of claim 1, wherein the resin is or includes at least one of a polyester resin (PE), vinyl ester resin, an epoxy resin and any other resin base.

5. The composition of claim 1, wherein the graphene material comprises one or more of: an osmotic barrier material; graphene; functionalised graphene; graphene oxide; graphene nano particles; oxygen; and at least one oxygen-containing group.

6. The composition of claim 5, wherein the graphene material has a volumetric lateral size in the range 100 nanometres to 100 microns.

7. The composition of claim 5, wherein the oxygen or the at least one oxygen-containing group: is bonded to or intercalated at the edges of graphene platelets; or includes at least one of: a carboxylate; an ester; an epoxy; and a carbonyl group.

8. The composition of claim 5, wherein the at least one oxygen containing group is present in the graphene material in quantities of 0.5% to 10% wt.

9. The composition of claim 1, wherein the graphene material provides: up to 5% by weight (% wt) of the composition; up to 2% wt of the composition; between 1% wt and 2.5% wt of the composition; or 2% wt of the composition.

10. A product comprising a composition according to claim 1.

11. The product of claim 10, comprising a boat hull, a pipe, a swimming pool, a spa or a tank.

12. The product according to claim 11, wherein the product is a pipe, the pipe comprising: a lining of the composition; and a cementitious or concrete material; wherein the composition is in multiple layers.

13. A method of producing a product for prolonged immersion or submersion in water, the method comprising: providing a composition according to claim 1; coating the composition with a coloured gel coat; and subsequently coating the coloured gel coat with a protective top coat.

14. The method of claim 13, wherein: the composition is provided as at least a first layer and a second layer; at least one of the first layer and the second layer is provided as a barrier layer; and the composition is applied by at least one of spraying, painting, rollering and pouring.

15. The method of claim 13, wherein the composition is created by applying the resin with the graphene material dispersed therein to a reinforcing material.

16. A water-resistant composite including a matrix of a graphene material and a resin.

17. The water-resistant composite of claim 16, wherein: the water-resistant composite further includes a reinforcing material; and the graphene material comprises one or more of the list consisting of: functionalised graphene; oxygen; an oxygen-containing group; and graphene platelets that are dispersed within the resin.

18. The water-resistant composite of claim 17, wherein the graphene platelets are between 100 nanometres to 100 microns in a lateral dimension of the platelets.

19. The water-resistant composite of claim 16, wherein the graphene material provides up to 5% by weight (% wt) of the composite.

20. The water-resistant composite of claim 16, wherein: the composite is part of a swimming pool, a spa, a boat hull, a tank, a water tank or waste water tank, piping, a storage vessel, cladding or roofing material; and the composite is provided in at least one layer having an additional reinforcing material and at least one other layer not having the reinforcing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0072] One or more forms of the present invention will hereinafter be described with reference to the accompanying drawings, in which:

[0073] FIG. 1a shows a representation of moisture diffusion into a composite results in degradation.

[0074] FIG. 1b shows a representation of resistance to degradation by presence of graphene material within the composite.

[0075] FIG. 2 shows a chart of moisture absorption data from comparative trials of at least one embodiment of the present invention relative to a base sample having Reinforced Fibre (RF) Polyester (PE) resin.

[0076] FIG. 3 shows a chart of sorption curves from comparative testing of at least one embodiment of the present invention relative to a base sample having Reinforced Fibre (RF) Polyester (PE) resin.

[0077] FIGS. 4a, 4b and 4c show representations of the cross-section of composite structures showing respective layers. FIG. 4a shows the cross-section of a current composite structure for a pool, spa or boat hull or the like, and FIG. 4b represents an embodiment of the present invention with a resin incorporating a graphene material. FIG. 4c shows an alternative structure with a composite layer as a water barrier and a second layer as a structural layer.

[0078] FIG. 5 shows a histogram of flexural stress versus sample grade and concentration of graphene material (platelets in this example) in the composition/composite.

[0079] FIG. 6 shows a histogram of flexural modulus versus grade and concentration of graphene material (platelets in this example) in the composition/composite.

DETAILED DESCRIPTION

[0080] In the following detailed description, reference is made to accompanying drawings which form a part of the detailed description. The illustrative embodiments described in the detailed description, depicted in the drawings and defined in the claims, are not intended to be limiting. Other embodiments may be utilised and other changes may be made without departing from the spirit or scope of the subject matter presented. It will be readily understood that the aspects of the present disclosure, as generally described herein and illustrated in the drawings can be arranged, substituted, combined, separated and designed in a wide variety of different configurations, all of which are contemplated in this disclosure.

[0081] An osmotic cracking process can occur by the following mechanism: [0082] Microcavities present in the system are filled by water. [0083] Small molecules or salts, initially present in the matrix (e.g. catalyst residues) or formed during hydrolysis, are dissolved by water and accumulate into microcavities. [0084] The material layer separating a microcavity and the water bath is permeable to water, but considerably less permeable to larger molecules. [0085] This causes it to act as a semi-permeable membrane, leading to osmotic pressure developing in the cavity.

[0086] The following stages of an osmotic cracking process have been identified (see ‘Humid Ageing of Organic Matrix Composites’—X. Colin and J. Verdu, as published in ‘Durability of Composites in a Marine Environment’, P. Davies and Y. D. S. Rajapakse (eds.), Solid Mechanics and Its Applications 208): [0087] 0 to t.sub.1—physical water sorption. The system reaches an equilibrium based on water solubility at t.sub.1. [0088] t.sub.1 to t.sub.2—system is at a pseudo-equilibrium. Hydrolysis occurs, but the conversion ratio remains low. [0089] Time>t.sub.2—propagation of osmotic cracks. The increased rate of mass uptake corresponds to the increase of volume created by cracking. The time to t.sub.2 is representative of the material stability. [0090] Time=t.sub.3—crack coalescence. The solutes responsible for osmosis are transferred out of the system, causing a rapid reduction in mass after t.sub.3.

[0091] There are two main matrix categories: [0092] Polymers which react chemically with water, for instance polyesters. Failure is considered to result from the following causal chain: Polymer+water->water absorption->polymer hydrolysis->degradation of the macromolecular backbone->embrittlement->failure: [0093] Non-reactive polymers, for instance amine cured epoxies. Failure results from the following causal chain: Polymer+water->water absorption->polymer swelling->stress state->failure.

[0094] For uncoupled fibres, there are various possible causes of a specific attack of water in the interfacial region: [0095] The presence of interfacial voids allowing a fast penetration of water in deep layers [0096] Glass fibers have an alkaline character, which may be able to play a catalytic role on ester hydrolysis.

[0097] Hydrolysis is accelerated in the presence of glass, due to basic catalysis, and the coupling agent displays a limited but significant stabilizing effect. Coupling agents are expected to have a positive effect on the composite stability in humid ageing conditions.

[0098] Accelerated immersion testing was conducted using a pressure vessel at temperature to reduce testing time. Accelerated test results are achieved within 10 to 100 hrs compared to months using a conventional testing standard of months. The following Table 1 shows samples 1-3 that were tested:

TABLE-US-00001 TABLE 1 Relative to base Sample Description Gradient D (120° C.) D (25° C.) (120° C.) 1 5 mm Base 0.0016 5.02655E−07 1.71768E−07 100%  RF PE sample 2 5 mm 1% PG 0.0013 3.31831E−07 1.13394E−07 66% 20 RF PE sample 3 5 mm 2% PG 0.0012 2.82743E−07 9.66196E−08 56% 20 RF PE sample

[0099] FIG. 1a shows a known composite structure/system 10 wherein water molecules 14 are able to penetrate into the composite 10 at a water-structure interface T due to poor or limited water barrier characteristics of the composite. Water molecules 14 can collect in voids 16 in the resin matrix 12 and can aggregate at fibre reinforcements 13 (e.g. glass fibre strands)

[0100] Water penetrating into the composite causes blistering/cracking 18, leading to structural and/or aesthetic degradation of the composite/product.

[0101] FIG. 1b shows a composite structure/system 20 according to at least one embodiment of the present invention, wherein graphene material 22, such as in the form of graphene platelets, and a resin 24 form a composite structure matrix 25 that reduces or prevents significant water molecule 14 diffusion into the composite structure/system 20, thereby avoiding or at least reducing degradation and enhancing mechanical strength of the product. Water molecules 14 have reduced penetration into the matrix at the water-matrix interface ‘I’. The composite 20 preferably includes reinforcing 23, such as reinforcing fibres e.g. glass fibres.

[0102] The product may be, for example, a swimming pool, a spa, a boat hull, tank (such as a water tank), cladding or roofing, such as formed using reinforcing fibres e.g. glass reinforced composites.

[0103] FIG. 2 shows examples (samples 2 and 3) of embodiments of the present invention compared to the base sample of 5 mm base reinforce glass fibre (RF) polyester (PE) resin structure (sample 1).

[0104] A composition of at least one embodiment of the present invention includes the graphene material combined with

[0105] The same data of FIG. 2 is represented in FIG. 3 as sorption curves.

[0106] Curve 1 represents the 5 mm base RF PE sample. Curve 2 represents the 5 mm 1% graphene material (˜20 nanometre particles) in RF PE sample. Curve 3 represents a 5 mm 2% graphene material (˜20 nanometre particles).

[0107] From the curves in FIG. 3, the following conclusions can be drawn: [0108] There is a two-stage absorption process, consistent with that reported in the literature. [0109] The gradient of Stage 1 (diffusion control) allows estimation of the diffusion coefficient for the systems. These are shown below. [0110] For Stage 2, the overlap between the base sample curve (curve 1) and the invention embodiment curves (curves 2 and 3) suggest no difference in the rate of osmosis/change to the system.

[0111] As shown in FIG. 4b, one or more embodiments of the present invention can incorporate graphene material in the structure designed for prolonged immersion in water and therefore otherwise at risk of premature delamination, cracking, bubbling etc., due to osmosis of the water into the structure (e.g. of a boat hull, pool, spa tank or the like).

[0112] It will be appreciated that the inventive structure includes use of a composition including a graphene material forming a matrix with a resin and reinforcing fibres.

[0113] According to the embodiment represented in FIG. 4b, the composition can include the graphene material, a polyester resin and glass fibre reinforcement.

[0114] As shown in FIG. 4c, multiple forms of the composite can be provided in layers, such as a barrier layer containing the graphene material in a resin and a second layer containing reinforcing material.

[0115] Other arrangements and configurations falling within the scope of the present invention are possible.

[0116] A cosmetic coloured gel coat can be applied to the composition and a clear gel coat applied over the cosmetic coating.

[0117] Table 2 shows results for tests as depicted in the chart of Ultimate Flexural Stress vs Sample Grade and Concentration in FIG. 5.

TABLE-US-00002 TABLE 2 % graphene Graphene platelets Ultimate Sample platelets lateral size Flexural No. to resin (microns) Stress 1 0 N/A 188 2 0 N/A 172 3 0 N/A 200 4 0 N/A 187 5 0.5 20 228 6 0.75 20 215 7 1.0 20 234 8 0.75 10 250 9 0.5 10 286

[0118] Base samples 1-4 do not contain graphene platelets in the resin of the composite matrix, demonstrating significantly lower ultimate flexural stress compared with samples 5-9 containing graphene platelets according to embodiments of the present invention. The baseline average flexural stress from samples 1-4 is 186.5 MPa. The flexural stress in the samples containing graphene ranges from 215 MPa to 286 MPa.

[0119] Table 3 shows results of tests as depicted in the chart of Flexural Modulus (MPa) vs Grade and Concentration of graphene platelets in FIG. 6:

TABLE-US-00003 TABLE 3 % graphene Graphene platelets Flexural Sample platelets lateral size Modulus No. to resin (microns) (MPa) 1 0 N/A 8325 2 0 N/A 7460 3 0 N/A 7797 4 0 N/A 7803 5 0.5 20 8564 6 0.75 20 8750 8 1.0 20 10046 9 0.75 10 11174 10 0.5 10 11245

[0120] Base samples 1-4 do not contain graphene platelets in the resin of the composite matrix, demonstrating significantly lower flexural modulus (MPa) compared with samples 5-9 containing graphene platelets according to embodiments of the present invention.

[0121] Baseline average flexural modulus is 7846 MPa from samples 1-4 and the flexural modulus ranges from 8564 MPa to 11245 MPa for samples 5-9 loaded with graphene according to embodiments of the present invention.

[0122] Structures incorporating one or more embodiments of the present invention can include Interface/Internal surface (immersed/water facing) such as having a clear gel coat 26, a cosmetic layer—coloured gel coat 28, structural—glass fibre/resin layer 30, compressive strength/water resistance—ceramic-filled polyester resin 32, outer layer—calcium carbonate filler with resin 34.

[0123] An alternative structure incorporating one or more embodiments of the present invention can include an Interface/Internal surface (immersed/water facing)—clear gel coat 26, a cosmetic layer—coloured gel coat 28, a multi-functional layer—polyester resin/graphene material/reinforcing material 36 having structural, chemical resistance barrier properties, higher thermal conductivity.

[0124] An alternative structure incorporating one or more embodiments of the present invention can include an Interface/Internal surface (immersed/water facing)—clear gel coat 26, a cosmetic layer—coloured gel coat 28, a composite barrier layer incorporating graphene material 38, a structural composite layer incorporating resin and a reinforcing material 40, (optional graphene material 22).

[0125] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.