Polymer Compositions Containing Graphene

Abstract

A polymer composition is provided, comprising, based on the total weight of the polymer composition, a) 40% to 99% by weight of a polyalkenamer derived from at least one cycloalkene having 5 to 12 carbon atoms, the polyalkenamer having a trans isomer content greater than 50% by weight, based on the weight of the polyalkenamer; and b) 1% to 60% by weight of graphene. A molded article can be produced from the polymer composition, and the molded article can be a plate, film, bristles, or foam. Use of the molded article as a clothing element, a sporting goods element, a sealant, a conductive article, a friction control element, a transportation element, or a structural element is also provided.

Description

[Technical field]

[0001] The present disclosure relates to polymer compositions comprising graphene, methods for their production and uses.

[0002] background Graphene is a two-dimensional allotrope of carbon in which the carbon atoms form a honeycomb-like structure. It has outstanding properties, including a high elastic modulus and excellent electrical and thermal conductivity. Graphene has been proposed as a versatile filler and modifier for polymers.

[0003] It has been shown that graphene can be compounded into various polymers, such as polyethylene, polypropylene, polystyrene, etc. However, graphene, especially graphene nanosheets, tend to aggregate, and the dispersibility of graphene in polymers is a bottleneck in some applications that require polymers with different properties simultaneously, such as high electrical conductivity and high mechanical strength.

[0004] Korean Patent Publication No. 2012091709 discloses a polynorbornene / graphene oxide composite material formed by covalently bonding modified graphene oxide and norbornene polymer. The modified graphene oxide is obtained by modifying the surface of graphene oxide with a compound having an amine group at one end capable of reacting with an epoxy group present on the surface of the graphene oxide and a functional group at the other end capable of reacting with an anhydride group of the norbornene polymer. Polynorbornene is produced by a ring-opening reaction using a catalyst.

[0005] Felix Kirschvink, in his doctoral dissertation entitled “Semicrystalline Blockcopolymere, Graphen- und Gibbsit Nanocomposite durch Kettenuebertragung bei der ringoeffnenden Metathesepolymerisation von cis-Cycloocten” (http: / / d-nb.info / 1125905557 / 34, available from KATALOG DER DEUTSCHEN NATIONALBIBLIOTHEK), teaches the synthesis of polymer-graphene nanocomposites by chain transfer using in situ ring-opening metathesis polymerization of cis-cyclooctene. Different nanocomposites including thermally reduced graphite oxide, undecanoic acid functionalized thermally reduced graphite oxide, or crushed graphite are obtained by in situ polymerization of cis-cyclooctene. In this synthesis, transition metal compounds are used as catalysts and toluene is used as solvent. Polyoctenamers with or without graphene as a filler were reported to have melting points below 0 °C, indicating a predominance of the cis isomer. Furthermore, the weight percentage of the filler in the composites was very low: the filler content was less than 7 wt% for thermally reduced graphite oxide, less than 9 wt% for undecanoic acid modified thermally reduced graphite oxide, and only 5 wt% for crushed graphite.

[0006] It is also known in the art to disperse graphene or exfoliated graphite in a polymer using a solvent, but this approach is not suitable for industrial applications due to the resource and / or energy consumption involved in dissolving the graphene and polymer in the solvent and then removing the solvent.

[0007] Graphene has been recognized as a promising modifier for various polymer applications, and it is desirable to produce polymer compositions with high concentrations of graphene that can be easily dispersed in various polymer matrices. However, powdered graphene is very dispersible, so its addition to polymers remains a technical challenge.

[0008] overview Therefore, the objective of the present disclosure was to provide a polymer composition containing graphene in a high concentration.

[0009] This problem has been solved by a polymer composition comprising, relative to the total weight of the polymer composition, a) 40% to 99% by weight of a polyalkenamer derived from at least one cycloalkene having 5 to 12 carbon atoms, and b) 1% to 60% by weight of graphene, said polyalkenamer having a trans isomer content of more than 50% by weight, relative to the weight of the polyalkenamer.

[0010] In a preferred embodiment, the graphene is selected from exfoliated graphene, thermally reduced graphene oxide, functionalized graphene oxide, mechanochemically produced graphene, or a mixture thereof.

[0011] In one preferred embodiment, the polyalkenamer comprises a polyoctenamer.

[0012] In a preferred embodiment, the polyalkenamer has a melting point greater than 5°C, preferably greater than 15°C, more preferably greater than 30°C.

[0013] In a preferred embodiment, the polymer composition comprises 10 6 Less than Ωcm, preferably 10 4 It has a volume resistivity of less than Ωcm, more preferably less than 100 Ωcm.

[0014] In a preferred embodiment, the polymer composition further comprises at least one additive, preferably selected from light stabilizers, heat stabilizers, flame retardants, plasticizers, fillers, nanoparticles, antistatic agents, dyes, pigments, mold release agents, flow aids, or any mixture thereof.

[0015] In a preferred embodiment, the graphene has a content of 4% to 50% by weight, preferably 9% to 45% by weight, more preferably 19% to 40% by weight, relative to the total weight of the polymer composition.

[0016] In a preferred embodiment, the graphene is in the form of granules, flakes, powder, films, sheets, nanoribbons, fibers, or mixtures thereof.

[0017] In a preferred embodiment, the graphene has a density of 0.01 g / cm 3 ~0.10g / cm 3 , preferably 0.01 g / cm 3 ~0.08g / cm 3 , more preferably 0.01 g / cm 3 ~0.05g / cm 3 The bulk density is in the range of

[0018] In one preferred embodiment, the polyalkenamer has a crystallinity greater than 10%, preferably greater than 20%, more preferably greater than 25%.

[0019] The present disclosure further provides a molded article made from the polymer composition.

[0020] In a preferred embodiment, the molded article is preferably a molding, a film, a bristles, or a foam.

[0021] In a preferred embodiment, the molded article is made from a polymer matrix comprising at least one selected from polyethylene, polypropylene, polystyrene, natural rubber, polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene-styrene, ethylene-propylene-diene monomer rubber, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyoxymethylene, polyketone, polyetherketone, polyetheretherketone, polyethylene terephthalate, polyethylene naphthalate, polylactic acid, polycarbonate, ethylene vinyl acetate, poly(methyl methacrylate), polyamide, polyether block amide, polyimide, polyoxymethylene, polysulfone, polyethersulfone, polyphenylene sulfide, polyurethane, and polyurea.

[0022] In a preferred embodiment, the molded article is produced by fused filament fabrication, stereolithography, binder jetting, material jetting, powder bed fusion, calendaring, compression molding, foaming, extrusion, coextrusion, blow molding, 3D blow molding, coextrusion blow molding, coextrusion 3D blow molding, coextrusion suction blow molding, or injection molding.

[0023] In a preferred embodiment, the present disclosure further provides for the use of the molded article as a clothing element, a sporting goods element, a sealant, a conductive article, a friction control element, a transportation element, or a structural element.

[0024] Throughout this specification, reference is made to the accompanying drawings. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 shows five thermogravimetric curves for a composition containing 44.87 wt % graphene, a composition containing 29.31 wt % graphene, a composition containing 19.53 wt % graphene, a composition containing 9.90 wt % graphene, and a composition containing 4.98 wt % graphene, from top to bottom, respectively.

[0026] Detailed Description The following description is for illustrative purposes only and is not intended to limit the scope of the present disclosure.

[0027] The term "polymer" refers to, but is not limited to, oligomers, homopolymers, copolymers, terpolymers, etc. Polymers can have a variety of structures, including, but not limited to, regular, irregular, alternating, periodic, random, block, graft, linear, branched, isotactic, syndiotactic, atactic, etc.

[0028] The term "graphene" refers to single- or few-layer graphite, whether pristine or chemically functionalized (e.g., graphene oxide, graphene oxide), including graphite exfoliated by mechanical, solvothermal, ultrasonic, or thermal reductive methods, single- or few-layer sp 2 These include, but are not limited to, carbon, or grown on a substrate.

[0029] [Graphene] The graphene used herein is preferably selected from exfoliated graphene, thermally reduced graphene oxide, functionalized graphene oxide, mechanochemically produced graphene, or a mixture thereof. More preferably, the graphene is exfoliated graphene, thermally reduced graphene oxide, functionalized graphene, or a mixture thereof. Among various functionalized graphenes, graphene having halogen atoms or amino groups, amide groups, mercapto groups, carboxyl groups, carboxyl ester groups, carbonyl groups, epoxy groups, or hydroxy groups is preferably used in the polymer composition. These functional groups are preferably introduced into the graphene by, for example, halogenation, oxidation, amino substitution, mercapto substitution, esterification, ester exchange, reduction, hydrogenation, or a combination thereof.

[0030] The graphene used in the present disclosure has a carbon content of greater than 80% by weight, preferably greater than 90% by weight, and even more preferably greater than 95% by weight.

[0031] The graphene according to the present disclosure is a single-layer or few-layer graphene. Among the few-layer graphenes, those having a coplanar carbon-carbon network of 2 to 10 layers are preferably used. The graphene has a thickness of less than 10 nm, preferably less than 5 nm, more preferably less than 3 nm.

[0032] Graphene as used herein preferably has a density of 0.01 g / cm 3 ~0.10g / cm 3 , more preferably 0.01 g / cm 3 ~0.08g / cm 3 , and even more preferably 0.01 g / cm 3 ~0.05g / cm 3 The bulk density is in the range of

[0033] The graphene is preferably in the form of granules, flakes, powder, films, sheets, nanoribbons, fibers, or mixtures thereof.

[0034] Graphene can be purchased commercially from a variety of vendors under a variety of trade names, such as, for example, "graphene," "graphene oxide," "graphene oxide," "single layer graphene film," "graphene nanoplatelets," etc.

[0035] [Polyalkenamer] The polyalkenamers according to the present disclosure are prepared by ring-opening polymerization of one or more cycloalkenes in the presence of a catalyst. Preferably, the polyalkenamers contain a trans isomer content in which the double bonds are in the trans position. The trans isomer content is greater than 50% by weight, preferably greater than 60% by weight, more preferably greater than 70% by weight, based on the weight of the polyalkenamer.

[0036] Examples of polyalkenamers include polypentenamer, polyheptenamer, polynorbornene, polyoctenamer, polydecenamer, polydicyclopentadiene, and polydodecenamer. They are also commercially available, for example, under the trade names Vestenamer® 6213 and Vestenamer® 8012 from Evonik Resource Efficiency GmbH, or Norsorex® from Astrotech Advanced Elastomerproducts GmbH. A preferred species is the polyoctenamer under the trade name Vestenamer® 8012 from Evonik Resource Efficiency GmbH.

[0037] Preferably, according to the present disclosure, the polyalkenamer has a melting point above 5°C, preferably above 15°C, more preferably above 30°C.

[0038] The polyalkenamer has a crystallinity greater than 10%, preferably greater than 20%, more preferably greater than 25%.

[0039] As used herein, trans isomer content refers to the weight percentage of the trans isomer relative to the total weight of the polyalkenamer. In general, the trans isomer content in a polyalkenamer affects the crystallinity of the polyalkenamer. The higher the trans isomer content, the higher the crystallinity and, as a result, the higher the resulting melting temperature.

[0040] Preferably, the polyalkenamer has a number average molecular weight greater than 100,000, more preferably greater than 120,000, and even more preferably greater than 140,000. Number average molecular weight can be measured using a variety of methods, such as gel permeation chromatography.

[0041] [Polymer composition] The polymer composition according to the present disclosure comprises, relative to its total weight, 1% to 60% by weight of graphene, preferably 4% to 50% by weight, more preferably 9% to 45% by weight, even more preferably 19% to 40% by weight. Correspondingly, the polymer composition comprises, relative to its total weight, 40% to 99% by weight of polyalkenamer, preferably 50% to 96% by weight, more preferably 55% to 91% by weight, even more preferably 60% to 81% by weight. The high concentration of graphene means that less storage space is required and also that the loading amount of polyalkenamer is significantly reduced when the graphene masterbatch is used to modify the target polymer.

[0042] The polymer composition according to the present disclosure can be achieved by various methods. A two-roll mill, a kneader, or a twin screw extruder can be used. However, other known techniques or processes for compounding polymers or rubbers are contemplated by those skilled in the art.

[0043] In one particular embodiment, a two-roll mill was used to compound graphene and polyalkenamer. The two-roll mill was preheated to a temperature range of 30° C. to 50° C. A precalculated amount of polyalkenamer in the form of pellets was then added to the mill and formed into a sheet. Graphene powder was added batchwise to the mill and the temperature was raised to about 40° C. to 70° C. A black sheet was obtained, which was then fed into a pelletizer to produce pellets containing graphene.

[0044] According to the present disclosure, the polymer composition is 6 Less than Ωcm, preferably 10 4 It has a volume resistivity of less than Ωcm, more preferably less than 100 Ωcm. The low resistivity makes it promising for a wide range of applications in the field of conductive polymer systems.

[0045] The polymer composition according to the present disclosure may comprise as constituents, in addition to the components according to a) and b), further additives preferably selected from light stabilizers, heat stabilizers, flame retardants, plasticizers, fillers, nanoparticles, antistatic agents, dyes, pigments, mold release agents or flow aids, in a total amount of up to 10% by weight, preferably up to 5% by weight, relative to the total weight of the polymer composition.

[0046] Preferably, the polymer composition according to the present disclosure consists of the components defined above.

[0047] [Master batch] The polymer composition according to the present disclosure can function as a graphene masterbatch for introducing graphene into a polymer matrix. A masterbatch is a concentrated mixture of additives or modifiers that are encapsulated in a carrier resin during heat treatment, which is then cooled and cut into granules or pelletized. The masterbatch allows processors to economically modify raw polymers during the manufacturing process. Because graphene is typically in the form of powder, flakes, platelets, nanoribbons, or other low density forms, the use of graphene masterbatches offers many advantages, such as reducing the space required to store graphene, simplifying and speeding up the compounding process, and / or facilitating homogenization of the final mixture.

[0048] In polymer compositions where the presence of graphene is desired, the masterbatch can be added to and compounded into a polymer matrix to achieve homogeneous and convenient dispersion of graphene. The polymer matrix can be polyethylene (PE), polypropylene (PP), polystyrene (PS), natural rubber (NB), polybutadiene (butadiene rubber, BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene-styrene (ABS), ethylene-propylene-diene monomer rubber (EPDM), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polytetrafluoroethylene (PTFE), polyoxymethylene (POM), polyketone, polyetherketone (PEK), polyetherether, and polyetherether. The graphene masterbatch may be formed of one or more polymers such as polyether ketone (PEEK), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polylactic acid (PLA), polycarbonate (PC), ethylene vinyl acetate (EVA), poly(methyl methacrylate) (PMMA), polyamide (PA), polyether block amide (PEBA), polyimide (PI), polyoxymethylene (POM), polysulfone, polyethersulfone (PES), polyphenylene sulfide (PPS), polyurethane (PU), polyurea, etc. Graphene masterbatches can introduce excellent performance in electrical conductivity, thermal conductivity, and mechanical strength into polymer matrices. The low melting point of polyalkenamers and their high dispersibility in many polymers allow graphene to be uniformly dispersed in polymer mixtures and agglomeration can be controlled and reduced.

[0049] In addition to the good dispersion of polyalkenamers in many polymers, the masterbatch can provide the elasticity and resilience of the polyalkenamer to the polymer matrix to which it is added. In some cases, the polyalkenamer reduces the adverse effects of graphene on the elongation, elasticity, resilience, or other mechanical properties of the polymer matrix. The addition of the masterbatch can improve the processability of the final composition, since the polyalkenamer also functions as a processing aid or plasticizer.

[0050] The polymer composition of the present disclosure, specifically in the form of graphene masterbatch pellets, can be compounded with the polymer by various methods, such as dry blending, Banbury type mixing, co-rotating twin screw extrusion, or any other suitable method. During the compounding process, equipment such as mixers, extruders, or blenders can be used. During compounding, the graphene masterbatch pellets can be added batchwise or all at once. Finally, a molding composition containing graphene is obtained.

[0051] Compounding can be accomplished using dispersion equipment for plastics or rubber processing, such as an internal mixer, high shear mixer, dynamic in-line mixer, homogenizer, intensive in-line mixer, two-roll mixing mill, homomixer, ball mill, bead mill, high pressure homogenizer, ultrasonic homogenizer, colloid mill, mixing nozzle, or melt blender.

[0052] After compounding, the molding composition can be used to make molded articles such as plates, films, bristles, foams, or any other shape or form.

[0053] Preferably, the molded article is made of polyethylene (PE), polypropylene (PP), polystyrene (PS), natural rubber (NB), polybutadiene (butadiene rubber, BR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene-styrene (ABS), ethylene-propylene-diene monomer rubber (EPDM), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polytetrafluoroethylene (PTFE), polyoxymethylene (POM), polyketone, polyether ketone (PEK), polyether ether ketone (PE The graphene masterbatch is made from a polymer matrix containing at least one selected from the group consisting of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polylactic acid (PLA), polycarbonate (PC), ethylene vinyl acetate (EVA), poly(methyl methacrylate) (PMMA), polyamide (PA), polyether block amide (PEBA), polyimide (PI), polyoxymethylene (POM), polysulfone, polyethersulfone (PES), polyphenylene sulfide (PPS), polyurethane (PU), and polyurea. The graphene masterbatch can be added to the above polymers as a modifier or additive.

[0054] Manufacturing can be accomplished by one or more methods such as fused filament deposition modeling, stereolithography, binder jetting, material jetting, powder bed fusion, calendaring, compression molding, foaming, extrusion, co-extrusion, blow molding, 3D blow molding, co-extrusion blow molding, co-extrusion 3D blow molding, co-extrusion suction blow molding, or injection molding.

[0055] The molded articles can be used as apparel elements (fabrics, shoe soles, etc.), sporting goods elements (personal protective equipment, helmets, top sheets for skis or snowboards, pneumatic balls such as footballs or basketballs, golf balls), seals (O-rings, support rings, lip seals, etc.), conductive articles (wires, conductive films, conductive plates, etc.), friction control elements (glide rings, bushings, bearings, wear parts), transportation elements (tires, belts, ropes, gaskets, ABS airbags, seat mats), or structural elements (frames, rods, blocks, foams, etc.).

[0056] The present disclosure is illustrated below by examples according to the invention and comparative examples.

[0057] [Example] Five samples were prepared from Vestenamer® 8012 and KNG®-G2 graphene, with different concentrations of graphene in the polyoctenamer. Volume resistivity tests and thermogravimetric analysis (TGA) were performed on these five samples. The graphene content of each sample was determined by the residual mass It is determined according to TGA by measuring

[0058] Vestenamer® 8012, available from Evonik Resource Efficiency GmbH, is a semi-crystalline polyoctenamer containing predominantly trans isomers and a high proportion of macrocyclic polymers.

[0059] KNG (registered trademark)-G2 is a graphene product manufactured by Xiamen Knano Graphene Technology Corporation Limited, and is composed mostly of single-layer sheets, with a small amount of few-layer graphene with a high aspect ratio. The manufacturing method is based on exfoliation, and since no oxidation / reduction treatment is performed, the planar honeycomb structure of graphene is well preserved, resulting in good electrical conductivity and stability. The bulk density is approximately 0.01-0.02 g / cm 3 The average carbon content is about 98% by weight.

[0060] Samples of graphene-containing polyamide 12 and rubber compositions were prepared along with their comparison samples. All samples were tested for mechanical and electrical properties.

[0061] Vestamid® L1600 is a low viscosity polyamide 12 manufactured by Evonik Resource Efficiency GmbH.

[0062] Buna® VSL 4526-2 is a high performance tire solution manufactured by Arlanxeo Deutschland GmbH. polymerization It is styrene-butadiene rubber (S-SBR).

[0063] Taipol® BR 0150 is a 1,3-polybutadiene rubber obtained by solution polymerization using a Ziegler cobalt catalyst from Taiwan Synthetic Rubber Corporation. It is 96% in the cis configuration and contains non-staining stabilizers.

[0064] Ultrasil® 7000 GR is a precipitated silica used as a reinforcing filler in the rubber industry manufactured by Evonik Resource Efficiency GmbH.

[0065] Irganox® 1098 is the trade name for benzenepropanamide, N,N′-1,6-hexanediylbis[3,5-bis-4-hydroxy], manufactured by BASF SE, and is used primarily for the stabilization of polymers, especially polyamides.

[0066] Production of polyamide composite granules containing graphene 1. Compounding graphene masterbatch with PA12: Commercially available polyamide 12, 29.31 wt% graphene masterbatch, and heat stabilizer were dry blended and fed into the main port of a Coperion co-rotating twin screw extruder ZSK26mc, then mixed at 250° C. The mixture was sent to a pelletizer and pelletized to obtain polyamide composite granules.

[0067] 2. Compounding graphene powder with PA12: Graphene powder was very friable and could not be fed directly into the extruder. First, 10 parts (by weight) of graphene powder was dry blended with 90 parts of polyamide powder. This mixture was then fed into the extruder through a side feeder. Other granules and heat stabilizers were dry blended and fed into the main port of the extruder and melted at 250°C. After pelletizing the mixture, polyamide composite granules were obtained.

[0068] Production of graphene-containing rubber composite granules Step 1. Compounding graphene masterbatch and rubber Phase 1 Commercially available rubber BUNA® VSL 4526-2, Taipol® BR 0150, 19.53 wt% graphene masterbatch, ULTRASIL® 7000 GR silica, antioxidants, and other auxiliaries were dry blended and fed into a W & P Model GK 1.5N Internal Rotor Mixer (Banbury type mixer) and then mixed at 150°C-160°C. The rotor speed was 80 rpm. The first stage was for 12 hours-48 hours.

[0069] After the first stage, the mixer discharged a black rubber sheet, which was then used in the second stage.

[0070] Second Phase The rubber sheets and vulcanization additives produced in the first stage were mixed in the same mixer as in the first stage. The rotation speed was increased to 95 rpm and the temperature remained approximately the same. The second stage lasted from 2 hours to 48 hours.

[0071] Third Stage In this stage, sulfur and accelerators were added to the rubber sheets for vulcanization. The batch temperature was around 90°C-120°C. The mixer discharged the final rubber sheets. The mixture was kept for 12 hours before vulcanization. The rubber sheets were hot pressed to obtain the rubber composite samples.

[0072] Step 2. Compounding graphene powder and rubber The process for preparing rubber composite samples from graphene powder and rubber was similar to process 1, except that the graphene masterbatch was replaced with graphene powder.

[0073] Step 3. Compounding of graphene powder, polyoctenamer and rubber The process for preparing rubber composite samples from graphene powder, polyoctenamer and rubber was similar to process 1, except that the graphene masterbatch was replaced with graphene powder and polyoctenamer.

[0074] [Test procedure] Thermogravimetric analysis was performed on each graphene masterbatch sample using a thermogravimeter. The samples were continuously heated from room temperature to approximately 650°C at a rate of 10°C / min under a nitrogen atmosphere to measure the thermal stability and the weight percentage of graphene.

[0075] For all masterbatch samples, plates of 2 mm thickness were produced by hot pressing. These plates were cut into 60 mm × 60 mm × 2 mm (high resistivity) plates depending on the range of resistivity of the sample. rate ) or 80mm x 10mm x 2mm (low resistance rate ) was cut.

[0076] High resistance 60mm x 60mm x 2mm rate The measurement standard for the sample was IEC 62631-3-1 using the ZC46A high insulation resistance test equipment. Rate The measurement standard of the samples is ISO 3915 with a volume resistivity tester for semiconductive rubber and plastic materials.

[0077] For the PA12 composition, a 60 mm x 60 mm x 2 mm plate was produced by injection molding and measured in accordance with the IEC 62631-3-1 standard using the same equipment as for the graphene masterbatch. On the other hand, for the rubber composition, a 2 mm thick sample was produced by hot compression and then cut into a 60 mm x 60 mm x 2 mm plate for testing, and the volume resistivity was measured in accordance with the IEC 62631-3-1 standard using the same equipment as for the graphene masterbatch.

[0078] Tensile modulus, tensile yield stress, tensile break stress and elongation at break were measured on ISO 1A type tensile specimens of 170 mm x 10 mm x 4 mm at a temperature of (23 ± 2) °C and a relative humidity of (50 ± 10) % according to ISO 527 using a Zwick Z020 materials testing machine. Notched impact strength was measured at the point of complete break as described in ISO 179-1. destruction type was used.

[0079] The Mooney viscosity of rubber was measured using a Mooney viscometer. The rubber compound, including the vulcanization system, is formed into a sheet 6-8 mm thick in a mill. A circular specimen with a diameter of 45 mm is cut from this sheet. A hole is drilled in the center of the specimen so that the rotor shaft can pass through. Before the measurement begins, the instrument is heated to the required temperature. After the introduction of the sample, the sample is allowed to reach thermal equilibrium for 1 minute, and then the rotor is started.

[0080] Mooney viscosity measurements ML(1+4) were carried out at 100°C using a large rotor and the torque was recorded as the rotor rotated for 4 minutes. Before starting the rotor, raw material was preheated at 100° C. for 1 min. This value generally indicates the processing behavior of the rubber compound.

[0081] Scorch time MS t5 is the time required for an increase of 5 Mooney units in the Mooney scorch measurement at 130°C. It is used as an indicator of the rate at which a compound's viscosity will increase during processing such as extrusion. The t5 value is thought to indicate the compound's tendency to pre-vulcanize.

[0082] [result] Thermogravimetric analysis (TGA) was performed on each sample to measure the weight loss at each temperature. Figure 1 suggests that after heating below 500 °C, the polyoctenamer components decompose or vaporize, leaving only graphene in the solid phase. The analysis also confirmed the graphene concentration in the samples. Graphene is neither volatile nor thermally unstable, so there is no residual graphene after temperatures reach above 600 °C. mass was graphene. The TGA curve also shows the excellent thermal stability of the polymer composition of the present disclosure below 300°C.

[0083] The masterbatch results are shown in Table 1.

[0084] [Table 1]

[0085] From the above table, comparing Example E5 according to the present invention with Comparative Example CE1, it is clear that when the concentration of graphene is low, the volume resistivity of the masterbatch does not deviate from that of the polyoctenamer. With the increase in the graphene concentration, the volume resistivity of the polymer composition decreases significantly. When the graphene content reaches about 30 wt%, the volume resistivity is comparable to that of semiconductors and seawater. Considering that the graphene is not uniformly dispersed in the polyoctenamer, especially at a high concentration of 30 wt%, there is a significant change in electrical conductivity, which is expected to lead to new applications, especially in the electrical industry.

[0086] To investigate the compatibility with other polymers, the graphene masterbatch was added to two different polymers, polyamide and polybutadiene. Mechanical testing was performed to analyze the effect of the graphene masterbatch on the polymer matrix. Specifically, 29.31 wt% of the graphene masterbatch was added to polyamide Vestamid® L1600 to produce two polyamide compositions with approximately 1 wt% and 2 wt% graphene, respectively. 19.53 wt% of the graphene masterbatch was added to polybutadiene to produce a rubber composition with approximately 1 wt% graphene.

[0087] Polyamide molding composition containing graphene Table 2 shows the formulations and properties of the polyamide molding compositions.

[0088] [Table 2]

[0089] Example E6 is made by blending a pre-blended graphene-polyoctenamer masterbatch with polyamide, whereas Example CE4 is made by blending the same amounts of graphene, polyoctenamer and polyamide simultaneously, but both Examples E6 and CE4 have almost the same chemical composition. The same is true for Examples E7 and CE5.

[0090] After the introduction of graphene in the form of graphene alone or a graphene masterbatch, the elongation at break of the polymer composition is significantly reduced (data for unmodified polyamide Vestamid® L1600 is not shown here). However, the elongation at break of examples E6 or E7 is higher than that of examples CE4 or CE5, indicating better resilience.

[0091] The notched impact strength increases with increasing graphene content in the polymer composition. Moreover, the notched impact strength of Example E6 or E7 is higher than that of Example CE4 or CE5, indicating higher impact resistance.

[0092] Without wishing to be bound by theory, it is believed that the higher resilience and impact resistance is due to the high dispersion of graphene within the polyamide matrix due to pre-blending of the polyoctenamer with graphene.

[0093] Rubber molding composition containing graphene Table 3 shows the formulations and properties of the rubber molding compositions.

[0094] [Table 3]

[0095] Example E8 is prepared by blending a pre-blended graphene-polyoctenamer masterbatch with rubber and other additives, while Example CE8 is prepared by blending the same amounts of graphene, polyoctenamer, rubber and other additives simultaneously, but both Examples E8 and CE8 have almost the same chemical composition.

[0096] After the introduction of graphene in the form of graphene alone or graphene masterbatch, the tensile strength of the polymer composition is significantly increased compared to Example CE6. However, the tensile strength of Example E8 is slightly higher than that of Example CE8. Viscosity data confirms that the addition of graphene masterbatch does not adversely affect the viscosity or dynamic properties.

[0097] Without wishing to be bound by theory, it is believed that the high tensile strength is due to the high dispersion of graphene within the rubber matrix due to pre-mixing of the polyoctenamer with graphene.

[0098] Although the present disclosure has been described in detail, various modifications and alterations to the embodiments will be apparent to those skilled in the art without departing from the spirit and scope of the present disclosure. It should be understood that the present disclosure is not limited to the exemplary embodiments described herein.

Claims

1. A polymer composition comprising, based on a total weight of the polymer composition: a) 55% to 96% by weight of a polyalkenamer which is a polyoctenamer and has a trans isomer content of greater than 50% by weight based on the weight of said polyalkenamer; b) 4% to 45% by weight of graphene selected from exfoliated graphene; 1. A polymer composition comprising:

2. The polymer composition of claim 1 , wherein the polyalkenamer has a melting point greater than 5° C.

3. The polymer composition is ６ 3. The polymer composition of claim 1 or 2, having a volume resistivity of less than Ω cm.

4. 4. The polymer composition of claim 1, further comprising at least one additive selected from light stabilizers, heat stabilizers, flame retardants, plasticizers, fillers, nanoparticles, antistatic agents, dyes, pigments, mold release agents, flow aids, or any mixture thereof.

5. 5. The polymer composition of claim 1, wherein the graphene is in the form of granules, flakes, powder, films, sheets, nanoribbons, fibers, or a mixture thereof.

6. The graphene has a density of 0.01 g / cm ３ ~0.10g / cm ３ 6. The polymer composition of claim 1 having a bulk density in the range of

7. 7. The polymer composition of claim 1, wherein the polyalkenamer has a crystallinity greater than 10%.

8. 8. A molded article made from the polymer composition of claim 1, wherein the molded article is made from a polymer matrix comprising at least one selected from natural rubber, polybutadiene, styrene-butadiene rubber, acrylonitrile-butadiene-styrene, ethylene-propylene-diene monomer rubber, and polyamide.

9. The molded article according to claim 8 , wherein the molded article is a plate, a film, a bristles, or a foam.

10. 10. The molded article of claim 8 or 9, wherein the molded article is produced by fused filament deposition modeling, stereolithography, binder jetting, material jetting, powder bed fusion, calendaring, compression molding, foaming, extrusion molding, co-extrusion molding, blow molding, 3D blow molding, co-extrusion blow molding, co-extrusion 3D blow molding, co-extrusion suction blow molding, or injection molding.

11. 11. Use of the molded article according to any one of claims 8 to 10 as a clothing element, a sporting goods element, a sealant, an electrically conductive article, a friction control element, a transport element or a structural element.

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