Process for the incorporation of carbon nanomaterials into a fbe polymeric matrix in solid phase, product and use
Patent Information
- Application Number
- BR102020015342
- Authority / Receiving Office
- BR · BR
- Patent Type
- Patents
- Current Assignee / Owner
- Publication Date
- 2026-08-11
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Abstract
Description
1 / 13 “PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A SOLID-PHASE FBE POLYMERIC MATRIX, PRODUCT AND USE”
[01] The present technology refers to an efficient process for mixing, dispersing, and integrating reduced graphene oxide (RGO) or carbon nanomaterials or nanostructured materials into a fusion-bonded epoxy (FBE) matrix. The polymeric material consists of a mixture of particulate solid epoxy with a curing agent, catalyst, pigments, and inorganic additives. It allows the integration of particulate nanometric additives into the FBE, using FBE in the solid state. Mixtures of the FBE + RGO powder system are produced using a planetary ball mill or a high-energy planetary ball mill with internal ball addition, with time and rotation control. The mixtures show little or no sign of RGO aggregation after application of the composite as a coating on metals.The FBE + RGO mixture can be applied to metallic surfaces for protection against abrasive processes and corrosion without compromising the properties of FBE applied without the nanomaterials. Increases of up to 11% in abrasion resistance were observed, along with improved material resistance to accelerated tests such as immersion in a hot water bath, and a significant increase in adhesion, approximately 100% after a hot water bath immersion test.
[02] Polymer coatings have been used to protect metal parts and were initially used to mitigate corrosion in metals. Technological advances in formulations and processes have improved the performance of these materials, increasing the service life of pipelines, valves, and metal structures in the sugar and ethanol, sanitation, mining, oil, construction, and general industries. Petition 870200093905, dated 07 / 28 / 2020, pp. 41 / 59 2 / 13
[03] Epoxy resins have been widely used as matrices for polymer-based composites due to their unique stiffness, dimensional stability, chemical resistance, and strong adhesion to metallic substrates. Fusion-Bonded Epoxy (FBE) resin has been used as a coating since the 1960s for various purposes, including electrical insulation and corrosion protection. In pipelines, the applied FBE promotes a smooth surface that reduces friction with the walls, increasing hydraulic efficiency, reducing energy costs, and reducing investments in pumps and compressors.
[04] Polymers reinforced with nanometer-sized materials, known as nanocomposites, have aroused great interest among researchers and developers due to the significant improvement in material properties with a very low amount of the nano-dispersed component.Up to now, a variety of epoxy-based composites with different particles, such as silica (RODRIGUES, T. Formation of CaCO3 deposits on surfaces coated with epoxy matrix nanocomposites with the addition of SiO2 nanoparticles, Master's thesis, UFRJ, 2016 and SALIBA, PA, MANSUR, AA P, MANSUR, HS Advanced Nanocomposite Coatings of Fusion Bonded Epoxy Reinforced with Amino-Functionalized Nanoparticles for Applications in Underwater Oil Pipelines Journal of Nanomaterials, 2016), clay (MORGAN, AB Polymer-Clay Nanocomposites: Design and Application of Multi-Functional Materials Material Matters, 2 2011) and carbon nanotubes (JEON, H. PARK, J. SHON, M. Corrosion protection by epoxy coating containing multi-walled carbon nanotubes Journal of Industrial and Engineering Chemistry, 19 2012 and MITTAL, G., DHAND, V., RHEE, KY, PARK, S., LEE, WRA review on carbon nanotubes and graphene as fillers in reinforced polymer nanocomposites Journal of Industrial and Engineering chemistry,21, 2015), were. Petition 870200093905, dated 07 / 28 / 2020, pp. 42 / 59 3 / 13 were successfully prepared and their properties were well explored. More recently, graphene and graphene oxide (GO) sheets have also been used as nanoadditives for epoxy-based composites (XIAO, W., LIU, Y., GUO, S., Composites of graphene oxide and epoxy resin assuming a uniform 3D graphene oxide network structure, RSC Advances, 2016).
[05] Among the most studied carbon materials for nanocomposites are carbon nanotubes and graphene. Graphene oxide (GO) is also a carbon-based nanomaterial with excellent performance and low cost. Nanocomposites with GO can be proposed for uses in the civil, mechanical and aerospace industries (ABDULLAH, SI, ANSARI, MNM Mechanical properties of graphene oxide (GO) / epoxy composites HBRC Journal, 11 (2014).
[06] Graphene oxide (GO) and graphite oxide (GrO) are promising precursors for the large-scale fabrication of graphene. Oxygenated functional groups covalently bonded to the GO structure can be thermally or chemically treated to obtain reduced graphene oxide (RGO), which partially restores the hydrophobicity and electrical conductivity of natural graphite for use as a filler material in 2D composites or conductive films.
[07] Reduced graphene oxide is so named because not all oxygenated groups in the GO structure are reduced. Therefore, RGO should not be called graphene, which corresponds to a high-quality graphitic monolayer without defects or functionalizations. If thermal reduction is compared to the chemical reduction of GO, it can be concluded that it is an interesting alternative for the synthesis of graphene materials due to the simplicity and scalability of the process. Petition 870200093905, dated 07 / 28 / 2020, pp. 43 / 59 4 / 13
[08] The thermal expansion of GrO to obtain RGO occurs when the rate of decomposition of the oxygenated groups of GrO exceeds the rate of diffusion of the evolved gases, thus producing pressures that exceed the van der Waals forces that hold the sheets together, being essential for the success of the reduction process, minimizing the harmful effects of water vapor present in GrO and eliminating the spacing between the graphene layers associated with native graphite during the oxidation stage.
[09] Mechanical means, such as planetary, vibratory or centrifugal ball mills, are frequently used for mixing powdered constituents, where mixing occurs through the kinetic energy of the balls impacting the powder particles. Mills are used both on a laboratory and industrial scale. Different final particle sizes can be obtained by varying the amount of feed and rotational speeds (which influence the impact energy). Other variables in the grinding process are: mill type, grinding time, type and size of grinding media, container fill level, process control agents used for temperature control.
[010] Document WO2010096345, from 2009, entitled “Fusion bonded epoxy coating compositions that include magnesium oxide, comprises an epoxy powder coating composition with about 60 to 75% by weight of at least one epoxy resin; and about 1 to 4% by weight of at least one catechol novolac type adhesion promoter; about 15 to 35% by weight of an inorganic filler; Petition 870200093905, dated 07 / 28 / 2020, pp. 44 / 59 5 / 13
[011] The 2008 document WO2009112824, entitled “Coated metal pipe joints”, refers to polymer-coated metal pipe joints as well as methods for forming coated metal pipe joints. In particular, it refers to composite materials for forming bonds between a coating that is applied as a liquid and a polymer-coated pipe element, methods for forming coated metal pipe joints, and uses of said composite material. It describes the use of epoxy layered coating, but the same technology does not involve the addition of carbon particles.
[012] Document WO2009073716, from 2007, entitled “Multi-layer anticorrosive coating”, describes a multi-layer coating for metal pipes comprising a first layer of metallic coating, a second layer of metal and polymer coating, and a third layer of polymeric coating. The metallic material comprises various metal alloys and the polymeric material comprises a mixture of a thermosetting polymer (FBE) with some thermoplastic polymer (polyethylene, polypropylene, nylon, polytetrafluoroethylene (PTFE), ethylene methacrylate copolymer (EMAA)). The invention describes the use of coating various surfaces from different polymers, including FBE, but the same technology does not involve the addition of carbon particles.
[013] Document WO2011163100, from 2010, entitled “Powder coatings compositions”, discloses a composition useful for the preparation of cured coatings comprising a formulation of at least one divinylarene dioxide resin (fusion-bonded epoxy) and at least one curing component. The composition is prepared from solid epoxy resins (SERs), phenolic epoxy resins (PERs) and poly(hydroxyl ethers) (PHEs). The invention describes the use of surface coatings from mixtures of different epoxy resins with Petition 870200093905, dated 07 / 28 / 2020, pp. 45 / 59 6 / 13 different curing agents, but the same technology does not involve the addition of carbon particles.
[014] The 2012 document WO2013187962, “Low application temperature powder coating”, describes FBE-type powder coating compositions that include an epoxy resin composition and a curing agent. The powder coating compositions can be applied at low application temperatures of approximately 165 °C to 185 °C. Mixing techniques can be performed by any available mechanical mixer or by manual mixing. The work does not describe the use of carbon nanomaterials, nor the parameters required for mixing and incorporating solid materials in the high-energy planetary ball mill.
[015] US patent 2012 - Lithographic printing plate precursors and methods of use - discloses a lithographic printing plate precursor that is sensitive to infrared radiation, whose components comprise thermoset hydrophobic particles (FBE) and comprise at least one pigment which may be carbon black. The invention describes the manufacture of a plate from FBE resin using carbon particles (carbon black) as a pigment for the plate along with other pigments, but the same technology does not include the addition of carbon nanoparticles.
[016] The 2012 document US4157273A, entitled “Bonding with a poly(arylene sulfide)-polytetrafluoroethylene adhesive”, describes the application of a ball or rod mill for mixing polymers (arylene polysulfide and polytetrafluoroethylene), but preferentially uses a diluent to aid mixing and subsequent application to the surfaces to be bonded. It also mentions the use of long mixing times (24 hours). The work does not describe the use of FBE epoxy and carbon nanomaterials, nor parameters. Petition 870200093905, dated 07 / 28 / 2020, pp. 46 / 59 7 / 13 of the energy required for mixing and incorporating solid materials in a planetary ball mill, let alone in a high-energy planetary ball mill.
[017] The present technology aims to solve the difficulties of integrating carbon nanomaterials into FBE, which allows its application in coatings of metallic substrates with improved mechanical performance and chemical resistance to corrosion, for example.
[018] In the technology for which protection is sought, a preliminary study of the mixing and integration process of the two solid matrices was carried out using times of less than 10 minutes and rotations of less than 230 rpm in a planetary ball mill, obtaining a mixture that, after application to heated steel, led to the formation of a composite whose average size distribution of agglomerates present in the coating was around 5 to 15 μm in diameter, values lower than those found in patent document RU2654959, of 2016, entitled “Superconcentrate of carbon nanotubes and the method of its production” where the mixture is made between CNTs and liquid epoxy resin. The use of liquid epoxy resin facilitates the mixing and dispersion of the matrices due to the greater interaction between the components, a fact that does not occur when the process is carried out with two solid components, as is the technical difficulty overcome with the method proposed in the present technology.
[019] The presence of agglomerates in composites can be a detrimental factor to the material, potentially leading to crack formation and weakening. In order to optimize the mixing and integration process of these two solid materials, an original strategy was the use of a high-energy planetary ball mill. After mixing and integrating the materials, a highly dispersed material was obtained, whose composite did not present agglomerates in the coating. This result is presented Petition 870200093905, dated 07 / 28 / 2020, pp. 47 / 59 8 / 13 as a technological advancement with regard to the production of composites from solid powders of the starting components.
[020] A combination of a specific mixing process and effective integration results was obtained for an extremely challenging solid-solid dispersion system. The combined use of larger-sized balls together with smaller-sized balls presented an optimized dispersion response of the solid nanofiller in the solid polymer matrix. This unique combination of parameters with reduced operating ranges (time and rotation) and efficient dispersion results for a solid-solid system (consisting of a nanofiller and an FBE epoxy matrix) is a surprising effect compared to what was expected from the literature, which was obtained by the synergistic effect with the ball distribution in a high-energy mill.
[021] Due to the intrinsic properties of FBE and RGO, both in the solid state, the resulting composite also exhibits unique properties. Composites produced with different RGO concentrations (0.1, 0.3, 0.5, and 1.0% w / w) were tested to evaluate the adhesion between the coating and the metallic substrate, according to ASTM D 4541 method D, obtaining adhesion increases of approximately 100% for some of the tested composites. Electrochemical tests showed improvements in corrosion protection for the FBE / RGO composite materials compared to the coating with FBE without added fillers, due to the improved barrier mechanism promoted by the insertion of the nanofiller. These simultaneous property gains demonstrate multifunctional advantages, which are not obtained with conventional additives.
[022] The proposed technology presents an effective method for mixing and integrating carbon nanomaterials in an FBE epoxy matrix, which is not reported in the prior art. The process of integrating the solid materials involves a short mixing time in a planetary ball mill. Petition 870200093905, dated 07 / 28 / 2020, pages 48 / 59 9 / 13 or high-energy planetary ball mill, ensuring high uniformity of the additives added to the polymer matrix. Applying the composite as a coating for metallic surfaces provides gains in abrasion resistance and adhesion to the metallic substrate. BRIEF DESCRIPTION OF THE FIGURES
[023] Figure 1 shows scanning electron microscopy images for the RGO-ET (A) and RGO-RT (B) samples.
[024] Figure 2 shows images obtained with a stereoscopic microscope or microscopic magnifying glass of the surface of composite coatings prepared from the dispersion of RGO in FBE, at two rotations (2230rpm and 2000rpm), with the addition of 0.1% w / w (A), 0.3% w / w (B), 0.5% w / w (C) and 1.0% w / w (B) of RGO-RT.
[025] Figure 3 presents a bar graph of pull-off adhesion before and after immersion in a hot bath. DETAILED DESCRIPTION OF THE TECHNOLOGY
[026] The present technology relates to an efficient process for mixing, dispersing, and integrating reduced graphene oxide (RGO) or carbon nanomaterials or nanostructured materials into a fusion-bonded epoxy (FBE) matrix. The single-component polymer material consists of a mixture of particulate solid epoxy with a curing agent, catalyst, pigments, and inorganic additives. The present technology allows the integration of particulate nanometric additives into the FBE by an efficient method of obtaining it using solid-state FBE. Mixtures of the FBE + RGO powder system are produced using a planetary ball mill or a high-energy planetary ball mill with internal ball addition, with time and rotation control. The mixtures show little or no sign of RGO aggregation after application of the composite as a coating on metals. The FBE + RGO mixture can be applied to metal surfaces for Petition 870200093905, dated 07 / 28 / 2020, pages 49 / 59 10 / 13 protection against abrasive processes and corrosion without compromising the properties already presented by the FBE applied without the nanomaterials. Increases of up to 11% in abrasion resistance, improved material resistance to accelerated tests such as immersion in a hot water bath, and a significant increase in adhesion of approximately 100% after immersion testing in a hot bath were observed after adding RGO to the FBE using the proposed method.
[027] The process for incorporating carbon nanomaterials into a polymer matrix results from applying the following steps: a. To produce reduced graphene oxide (RGO); b. Sift the RGO obtained in step “a”; c. Incorporate the RGO produced in step “a” into the fusion-bonded epoxy polymer matrix (FBE) in powder form, at a ratio of 1 g / Kg to 10 g / Kg of RGO relative to FBE, using a planetary ball mill or a high-energy planetary ball mill, for a period of 1 to 10 minutes, at a speed between 200 and 2000 rpm.
[028] In step “a” RGO is produced by thermal reduction of graphene oxide (GO) in a heating oven or furnace for a period of time between 10 and 100 minutes, at an internal furnace temperature between 120°C and 200°C.
[029] RGO can also be produced in step “a”, via reduction and thermal expansion of graphite oxide (GrO) in a microwave oven for a period of time between 1 and 5 minutes, using an oven heating power between 50 and 100%.
[030] The graphene oxide to be reduced may have a degree of oxidation between 25 and 50%, assessed by the mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere. Petition 870200093905, dated 07 / 28 / 2020, pp. 50 / 59 11 / 13
[031] Obtaining reduced graphene oxide via thermal reduction in an oven (RGO-RT) can present a degree of oxidation between 6 and 13%, evaluated by the mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere.
[032] The graphite oxide to be reduced and expanded may have a degree of oxidation between 25 and 50%, assessed by the mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere.
[033] Obtaining reduced graphene oxide via reduction and thermal expansion in a microwave oven (RGO-ET) can present a degree of oxidation between 6 and 13%, evaluated by the mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere.
[034] In step “c” the use of a system composed of a set of balls with a diameter between 5 and 10 mm and balls with a diameter between 10 and 20 mm.
[035] The number of balls with a diameter between 5 and 10 mm is 1.5 to 3 times greater than the number of balls with a diameter between 10 and 20 mm.
[036] In step “c” the incorporation of carbon nanomaterials into the FBE polymer matrix in powder form.
[037] Fusion bonded epoxy (FBE) nanomodified by dispersing reduced graphene oxide, in the proportion of 0.1% to 1.0% w / w of graphene relative to FBE.
[038] The composite can be used bonded to metallic surfaces for protection against corrosion and abrasive processes. Preferably, the composite can be applied to metallic surfaces with a thickness between 200 and 500 μm, for a curing time between 25 and 100 minutes, at a curing temperature between 160 and 220 °C.
[039] The present technology is best understood through the examples described below, which are not limiting. Petition 870200093905, dated 07 / 28 / 2020, pages 51 / 59 12 / 13 EXAMPLE 1 - Process of incorporating carbon nanomaterials into a polymeric matrix.
[040] Fusion-Bonded Epoxy (FBE) material is widely used in the Valspar Pipeclad 2000 thermosetting epoxy coating system, imported from the United States, used for corrosion protection in steel pipelines exposed to more demanding operating environments.
[041] Samples of GO were dried in a freeze dryer and the resulting solid was taken to a knife mill. The material was separated using a sieve until the powders were obtained with the same particle size as the epoxy (diameter less than 0.25 mm).
[042] The ground GO was placed in a glass beaker sealed with aluminum foil (semi-open system), and this system was placed in an oven for 20 min at 180°C, for thermal reduction and production of reduced graphene oxide via thermal reduction (RGO-RT). Figure 1B shows a representative scanning electron microscopy (SEM) image of the wrinkled morphology of the RGO-RT nanosheets.
[043] GrO was added to a quartz crucible with a lid and the material was microwaved for 5 min at 70% power. A process of heating, drying, reduction and thermal expansion of GrO was carried out, and subsequently reduced graphene oxide via thermal expansion (RGO-ET) was obtained. Figure 1A shows a representative scanning electron microscopy (SEM) image of the wrinkled morphology of the RGO-ET nanosheets.
[044] The reduced graphene oxides (RGO-RT and RGO-ET) and epoxy used in this work were processed in powder form. The materials were sieved using a 0.25 mm diameter sieve, i.e., the grain size used is less than 0.25 mm. The mixtures were prepared in a planetary ball mill or planetary mill. Petition 870200093905, dated 07 / 28 / 2020, pp. 52 / 59 13 / 13 high-energy balls, using 6 balls, with 2 balls having a diameter between 10-20 mm and 4 balls having a diameter of 5-10 mm. The mill was operated at a rotation speed between 230 and 2000 rpm for a period of 10 minutes.
[045] All mixtures were produced at different concentrations of RGO-RT nanofiller (0.1%, 0.3%, 0.5% and 1.0% w / w) and RGOET (0.1%, 0.3%, 0.5% and 1.0% w / w). The same milling process was performed with FBE without the addition of nanofiller. Figure 2 shows representative images obtained under a microscope of the surface of the FBE composite coatings with RGO-RT produced with ball mills at two rotation speeds (230 rpm and 2000 rpm).
[046] The mixtures obtained after processing in a planetary ball mill were applied to SAE 1020 steel sheets measuring 100 x 100 mm, with a coating thickness between 200 and 400 μm. The coated sheets were tested to evaluate the adhesion between the coating and the metallic substrate, according to ASTM D 4541 method D. The same adhesion test was performed on samples immersed in a hot water bath (hot immersion, temperature of 80°C) for 48 h. The immersion was performed according to ISO 21809-1. Improvements in the adhesion of the coating to the metallic substrate were observed, with increases of approximately 100% for the FBE / RGO-RT 1% w / w and FBE / RGO-ET 0.5% w / w composites (Figure 3). Petition 870200093905, dated 07 / 28 / 2020, pages 53 / 59
Claims
1 / 3 CLAIMS 1. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, characterized by comprising the following steps: a. Producing reduced graphene oxide (RGO); b. Sieving the RGO obtained in step “a”; c. Incorporate the RGO produced in step “a” into a fusion-bonded epoxy (FBE) polymer matrix in powder form, with a ratio of 1 g / Kg to 10 g / Kg of RGO relative to FBE, using a high-energy planetary ball mill, with a system composed of a set of balls with a diameter between 5 and 10 mm and balls with a diameter between 10 and 20 mm, where the number of balls with a diameter between 5 and 10 mm is 1.5 to 3 times greater than the number of balls with a diameter between 10 and 20 mm, for a period of time from 1 to 10 minutes, at a speed between 200 and 2,000 rpm.
2. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, according to claim 1, characterized in that, in step “a”, the RGO is produced by thermal reduction of graphene oxide (GO) in an oven or heating furnace for a period of time between 10 and 100 minutes, at an internal furnace temperature between 120°C and 200°C.
3. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, according to claim 1, characterized in that, in step “a”, the RGO is produced via reduction and thermal expansion of graphite oxide (GrO) in a microwave oven for a period of time between 1 and 5 minutes, using an oven heating power between 50 and 100%. Petition 870260049619, dated 05 / 25 / 2026, page 10 / 12 2 / 3 4. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, according to claim 2, characterized by the graphene oxide (GO) to be reduced having a degree of oxidation between 25 and 50%, evaluated by mass loss between 100 and 400°C in thermogravimetric analysis with a synthetic air atmosphere.
5. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, according to claim 2, characterized by obtaining reduced graphene oxide via thermal reduction in an oven (RGO-RT) exhibiting a degree of oxidation between 6 and 13%, evaluated by mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere.
6. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, according to claim 3, characterized by the graphite oxide (GrO) to be reduced and expanded having a degree of oxidation between 25 and 50%, evaluated by the mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere.
7. PROCESS FOR INCORPORATING CARBON NANOMATERIALS INTO A POLYMERIC MATRIX, according to claim 3, characterized by obtaining reduced graphene oxide via reduction and thermal expansion in a microwave oven (RGO-ET) exhibiting a degree of oxidation between 6 and 13%, evaluated by mass loss between 100 and 400 °C in thermogravimetric analysis with a synthetic air atmosphere.
8. A composite of carbon nanomaterials incorporated into a polymeric matrix obtained by the process defined in claim 1, characterized by comprising fusion-bonded epoxy (FBE) nanomodified by dispersion of reduced graphene oxide, in the proportion of 0.1% to 1.0% w / w of graphene relative to the FBE.
9. USE OF THE COMPOSITE defined in claim 8, characterized by being adhered to metallic surfaces for protection against corrosion and abrasive processes.
10. USE, according to claim 9, characterized by the application of the composite on metallic surfaces comprising a thickness between 200 and 500 μm, for a curing time between 25 and 100 minutes, at a curing temperature between 160 and 220 °C. Petition 870260049619, dated 05 / 25 / 2026, page 12 / 12