Sustainable high density polyethylene and method for its production

Abstract

Disclosed are high density polyethylene polymers, including high molecular weight and ultra-high molecular weight polyethylene polymers, made at least in part from bio-based feedstocks selected to produce high purity monomers that can produce high density polymers for use in high purity applications, such as the production of porous membranes for implants and lithium ion batteries.

Description

[Technical field]

[0001] Related Applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 272,456, having a filing date of October 27, 2021, which is incorporated herein by reference. [Background technology]

[0002]

[0002] High density polyethylene polymers, particularly high molecular weight polyethylene polymers and ultra-high molecular weight or linear polyethylene polymers, are valuable engineering plastics that possess a unique combination of abrasion resistance, surface lubricity, chemical resistance, tensile strength and impact strength. High density polyethylene polymers are used in numerous and diverse fields where the properties of the polymers can be tailored to specific applications.

[0003] For example, certain high density polyethylene particles having high molecular weight can be sintered together and formed into a variety of different filter devices, including filter funnels, dip filters, filter crucibles, porous sheets, pen nibs, marker nibs, ventilators, air diffusers, and lightweight molded parts.

[0004]

[0004] High density polyethylene particles can also be combined with one or more plasticizers and gel extruded into films and fibers. For example, high density polyethylene polymers can be used to produce porous membranes. Porous membranes made with high and ultra-high molecular weight polyethylene polymers have gained significant importance and value due to the emergence of electric vehicles. For example, porous membranes can be used as battery separators placed between the anode and cathode in lithium ion batteries. Membranes made from high density polyethylene polymers not only have optimal porosity characteristics, but also present a shutdown temperature that provides safety for the battery in which the membrane is incorporated. Furthermore, conventional high molecular weight polyethylene polymers can be formed with very low impurity levels so that the polymer membrane never reacts with the chemical components contained in the battery.

[0005]

[0005] Additionally, high density polyethylene polymers are often used in conjunction with biomedical devices. High density polyethylene polymers, particularly ultra-high molecular weight polyethylene polymers, have sufficient purity for use in, for example, biological environments. For example, the polymers can be produced with minimal concentrations of residual catalysts and other impurities. As a result, high density polyethylene polymers can be used as load-bearing components in artificial knee joints, artificial hip joints, and other replacement artificial joints for the human body.

[0006]

[0006] High density polyethylene polymers are typically produced by polymerizing ethylene monomer in the presence of a catalyst. Historically, ethylene monomer has been produced from crude oil via a catalytic cracking process. Over the years, this process used to produce ethylene monomer has led to the production of high purity monomers that are well suited to producing higher molecular weight polyethylene, where exposure to the catalyst and reaction times are longer. However, recently, companies large and small have committed to becoming carbon neutral within a certain time period. To become carbon neutral, a company must achieve net zero carbon emissions by removing the same amount of carbon dioxide as it emits into the atmosphere. On the other hand, carbon negative companies remove more carbon from the atmosphere than they emit into the atmosphere.

[0007]

[0007] In view of the significant efforts of companies around the world to become carbon neutral or carbon negative, there is a need for processes to produce high density polyethylene polymers in a more sustainable manner without significantly altering the amount of impurities in the polymer or other properties of the polymer. There is also a need for polymer compositions and polymer products made from sustainable high density polyethylene polymers. Summary of the Invention

[0008]

[0008] The present disclosure is generally directed to producing high density polyethylene polymers, including high molecular weight polyethylene polymers and ultra-high molecular weight polyethylene polymers, in a manner that creates carbon offsets.

[0009] In one aspect, the present disclosure is directed to a polymer composition containing polymer particles comprising a high density polyethylene polymer. The high density polyethylene polymer can have a molecular weight greater than about 300,000 g / mol and a viscosity of about 0.92 g / cm 3The high density polyethylene polymer may have a density of greater than 100%. The high density polyethylene polymer is produced from ethylene monomer. In accordance with the present disclosure, at least a portion of the ethylene monomer comprises bio-based ethylene made from one or more carbon negative or carbon neutral components. The bio-based content may be determined in one embodiment using a mass balance approach. Alternatively, the bio-based content may be determined according to ASTM test D6866-21. The portion of the polymer made from carbon negative or carbon neutral components may be at least about 1%, such as at least about 10%. Alternatively, the bio-based content may be at least about 1%, such as at least about 10%, based on radiocarbon dating of the total organic carbon content.

[0010] For example, a high density polyethylene polymer can be produced from a mixture of fossil-based ethylene monomer and bio-based ethylene monomer. The resulting high density polyethylene polymer can have a bio-based content or contain carbon negative or carbon neutral components in an amount of at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, such as at least about 60%, and generally less than about 90%, such as less than about 80%, such as less than about 70%. In one embodiment, the high density polyethylene polymer can be produced exclusively from bio-based ethylene monomer or exclusively from carbon negative or carbon neutral components.

[0011] The high density polyethylene polymer has a molecular weight of greater than about 500,000 g / mol, such as greater than about 700,000 g / mol, for example greater than about 1,000,000 g / mol, for example greater than about 1,300,000 g / mol, such as greater than about 1,700,000 g / mol, for example greater than about 2,000,000 g / mol, for example greater than about 2,500,000 g / mol, for example greater than about 3,000,000 g / mol, for example greater than about 3,500,000 g / mol, for example greater than about 4,000,000 g / mol. The average molecular weight of the polymer may be greater than about 0,000 g / mol, such as greater than about 4,500,000 g / mol, such as greater than about 5,000,000 g / mol, such as greater than about 5,500,000 g / mol, such as greater than about 6,000,000 g / mol, such as greater than about 6,500,000 g / mol, such as greater than about 7,000,000 g / mol, such as greater than about 7,500,000 g / mol, such as greater than about 8,000,000 g / mol, and less than about 12,000,000 g / mol. For purposes herein, the molecular weights referred to herein are determined according to the Margolies formula ("Margolies molecular weight").

[0012]

[0012] The ethylene monomer used to produce the polyethylene polymer can come from a variety of different sources, so long as the monomer remains highly pure and does not otherwise interfere with the ability of the monomer to be polymerized into high density polyethylene, including high molecular weight and ultra-high molecular weight polyethylene polymers. Bio-based ethylene can be produced, for example, from carbon negative or carbon neutral components. In one aspect, the carbon negative or carbon neutral component includes methane, for example, derived from biomass. The methane can be subjected to a pyrolysis or partial oxidation process to produce acetylene. The acetylene can then be hydrogenated to ethylene. Alternatively, the carbon negative or carbon neutral component can include ethanol, which is converted to ethylene. For example, the ethanol can be a fermentation product. In yet another embodiment, the carbon negative or carbon neutral component can include vegetable oil or animal lipid. The vegetable oil or animal lipid can be converted to ethylene by hydrodeoxygenation. In another embodiment, the carbon negative or carbon neutral component can include tall oil, which can be converted to ethylene.

[0013] The high density polyethylene polymer may be a Ziegler-Natta catalyzed polymer. In one embodiment, the polymer particles may have an average particle size D50 of about 10 microns to about 1,000 microns. The polymer particles may have a mass density of about 0.2 g / cm 3 to about 0.54 g / cm 3 The high density polyethylene polymer may have a bulk density of about 0 g / 10 min (not measurable) to about 20 g / 10 min. The high density polyethylene polymer may be a polyethylene homopolymer or a polyethylene copolymer. For example, the polyethylene polymer may be a copolymer of ethylene and at least one comonomer including butene, propylene, hexene, or a mixture thereof. The butene, hexene, and / or propylene may be bio-based.

[0014] A variety of different articles can be made with the polymer composition. For example, the polymer composition is well suited for the production of medical implants. In one embodiment, the polymer is used to produce a battery separator that includes a porous membrane. The porous membrane can optionally include a coating on one side of the membrane. The coating can include an inorganic coating or a polymer coating. The battery separator can be disposed between the anode and cathode in the battery.

[0015] In yet another embodiment, the polymer composition can be used to form a sintered article, such as a filter element.

[0016] Other features and aspects of the disclosure are discussed in more detail below.

[0016]

[0017] A full and enabling disclosure of the present disclosure is set forth in more detail in the remaining portions of the specification, including reference to the accompanying figures. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view of a membrane for a battery made according to the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the present invention.

[0019] It should be understood by those skilled in the art that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of the present disclosure.

[0019]

[0020] In general, the present disclosure is directed to a method for producing high density polyethylene polymers in a more sustainable manner and polymer compositions made from high density polyethylene polymers. At least a portion of the feedstock used to produce the high density polyethylene polymers can be derived from biomass or other sustainable resources instead of from fossil fuels, such as crude oil. The high density polyethylene polymers are produced from ethylene monomers. In accordance with the present disclosure, the ethylene monomers can be derived from bio-based components, such as biogas, fermentation products, vegetable by-products, animal by-products, cellulosic by-products, and the like. The bio-based feedstocks are converted to ethylene and can then generally also be used to produce high density polymers having high molecular weights. The high density polyethylene polymers produced in accordance with the present disclosure have a much smaller carbon footprint and can also be produced to be carbon neutral or negative overall.

[0020]

[0021] High density polyethylene polymers, including high molecular weight and ultra-high molecular weight polyethylene polymers, are commonly used in very specific applications where the purity of the polymer can be just as important as the mechanical properties. For example, high density polyethylene polymers used in biomedical applications must have ultra-high purity properties. Therefore, in the past, there has been resistance to changing the monomers used to make the polymer, especially when the monomers are derived from other sources, such as by-products. However, due to certain advantages, high density polyethylene polymers can be produced according to the present disclosure without sacrificing impurity levels or mechanical properties.

[0021]

[0022] The high density polyethylene polymer made according to the present disclosure can meet the sustainability needs of many manufacturers and consumers. The high density polyethylene polymer can be used to produce all kinds of products and articles in all fields. For example, the high density polyethylene polymer can be used to produce molded parts and articles for use in the medical field, the automotive field, the electrical field, the food handling industry, the water purification field, etc. Manufacturers can incorporate the high density polyethylene polymer into their products to achieve their renewable or bio-based content goals. Overall, the high density polyethylene polymer made according to the present disclosure can help manufacturers reduce their carbon footprint without sacrificing quality or mechanical properties in any way.

[0022]

[0023] Finally, the high density polyethylene polymers made according to the present disclosure can be certified according to any suitable standard. One such certification is the International Sustainability Carbon Certification (ISCC). The ISCC is a globally applicable sustainability certification system that covers all sustainable feedstocks, including agricultural and forestry biomass, circular and bio-based materials, and renewable energy. The ISCC follows a mass balance approach where the renewable content of the polymer can be verified. In the mass balance, renewable feedstocks are attributed to the selected products according to their own individual formulations that take into account all yields and losses. Only raw materials (not for energy) used as feedstock for its production are considered for the mass balance. Important criteria used to apply the mass balance approach include the suitability of the feedstock, the chain of custody, and product claims.

[0023]

[0024] The mass balance approach allows for tracking the amount and sustainability attributes of recycled and / or bio-based feedstocks in the value chain and attributing it to the end product in a verifiable manner. In one embodiment, the high density polyethylene of the present disclosure can be made entirely from carbon negative or carbon neutral components in a mass balance approach. Alternatively, the high density polyethylene can be made from at least 20% carbon negative or carbon neutral components, such as from at least about 30% carbon negative or carbon neutral components, such as from at least about 40% carbon negative or carbon neutral components, such as from at least about 50% carbon negative or carbon neutral components, such as from at least about 60% carbon negative or carbon neutral components, such as from at least about 70% carbon negative or carbon neutral components, such as from at least about 80% carbon negative or carbon neutral components, and up to 100% carbon negative or carbon neutral components, such as from less than about 80% carbon negative or carbon neutral components, such as from less than about 60% carbon negative or carbon neutral components, such as from less than about 40% carbon negative or carbon neutral components.

[0024]

[0025] To produce high density polyethylene polymers according to the present disclosure, bio-based feedstocks are collected, optionally converted, and purified to produce monomers, specifically bio-based ethylene monomers that are carbon negative or at least carbon neutral according to the mass balance approach described above. Bio-based ethylene can be produced in a variety of different ways from a variety of different feedstocks. The following processes for producing bio-based ethylene are exemplary and are believed to be capable of producing ethylene at the purity levels required for many end use applications, including using the resulting high density polyethylene polymers in biomedical applications.

[0025]

[0026] In one embodiment, biogas is collected and / or produced from biomass resources and converted to ethylene. In one aspect, biogas is methane produced from solid waste landfills and anaerobic digestion plants. Alternatively, methane can be collected as recycled gas from industrial processes. For example, methane is typically collected and not recycled, but rather vented to the environment or incinerated. By collecting by-product gases from industrial processes, the carbon footprint of the resulting monomer is significantly reduced.

[0026]

[0027] Using biogas as a starting feedstock for ethylene monomer production can provide a variety of advantages and benefits depending on the particular application. For example, biogas can contain very little impurities, preventing them from even appearing in the final product.

[0027]

[0028] The conversion of methane biogas to ethanol can be carried out using different processes and steps. In one embodiment, for example, methane can be directly converted to ethanol via partial oxidation of methane in the presence of a metal-containing zeolite catalyst. In this embodiment, 2 moles of methane are reacted with 0.5 moles of molecular oxygen to produce ethanol.

[0028]

[0029] In an alternative embodiment, the methane of the biogas may be converted to syngas, which is produced by steam reforming the methane. For example, the syngas may contain carbon monoxide or carbon dioxide. Ethanol can then be produced from the carbon monoxide or carbon dioxide.

[0029]

[0030] Ethylene monomer can then be produced from the ethanol. There are a variety of different processes and technologies for converting ethanol to ethylene. In one embodiment, the ethanol can be dehydrated to produce ethylene. For example, in one embodiment, the resulting ethanol product can be optionally filtered and fed to a concentrator, which may include one or more distillation columns. The distillation columns can produce an ethanol-rich stream that can then be converted to ethylene. For example, the ethanol-rich stream can be fed to a dehydrator. The dehydration can be done at high temperatures to produce water and ethylene together. As the product cools, the water blended with the ethylene can be condensed and removed. The ethylene can then be condensed to a liquid form if necessary. The condensed ethylene can also be fed to a distillation column for further purification.

[0030]

[0031] In alternative embodiments, biogas such as methane can be converted to ethylene without first being converted to ethanol. For example, in one embodiment, bio-based methane can first be converted to acetylene. The acetylene can then be converted to ethylene via a reaction other than catalytic hydrogenation.

[0031]

[0032] Methane can be converted to acetylene, for example, by a pyrolysis or partial oxidation process. For example, methane can be preheated in substoichiometric amounts at a temperature of about 500° C. to about 800° C. and combined with oxygen. The mixture can be fed to a pyrolysis zone at a temperature above about 1,400° C., for example above about 1,500° C. Acetylene is then produced and cooled by partial quenching. The acetylene, at a temperature of about 750° C. to about 950° C., is then hydrogenated, optionally in the presence of ethane, which may also be biobased, to produce ethylene.

[0032]

[0033] In yet another embodiment, ethanol is produced from a carbonaceous, e.g., biomass, feedstock. In one aspect, for example, biomass can be fed to a fermentation process to produce ethanol from microorganisms. For example, the biomass can be any suitable plant, such as sugar cane. The biomass can be any suitable cellulosic-derived material or by-product.

[0033]

[0034] In one embodiment, a carbonaceous feedstock is first reformed to produce carbon dioxide, carbon monoxide, and / or hydrogen. The resulting gas stream can then be subjected to bacterial fermentation to produce ethanol. Microorganisms that can be used for ethanol production include anaerobic bacteria. The anaerobic bacteria may be from the Clostridium species, such as C. ljungdahlii, C. carboxydivorans, C. ragsdalei, and / or C. autoethanogenum.

[0034]

[0035] Once ethanol is produced, it can be converted to ethylene as described above using a dehydration step.

[0036] In yet another embodiment, biomass can be fermented to directly produce ethanol. For example, cellulose, sugars and starch can be directly converted to ethanol using fermentation processes.

[0035]

[0037] In yet another embodiment, biomass-derived oils can be converted to ethylene. For example, vegetable oils or animal lipids can be subjected to a hydrodeoxygenation process. More specifically, vegetable oils and / or animal lipids can be hydrodeoxygenated in a manner that converts triglycerides and other molecules to paraffinic hydrocarbons, in particular ethylene. The ethylene can be purified, for example, via filtration and distillation, and then used to produce the high density polyethylene polymers of the present disclosure.

[0036]

[0038] In yet another embodiment, gaseous ethylene can be produced from bio-based feedstocks using microorganisms, such as genetically engineered microorganisms. Metabolic pathways that can be used to produce gaseous ethylene can include the S-adenosylmethionine pathway, the 4-(methylsulfanyl)-2-oxobutanoate pathway, and / or the 2-oxoglutarate pathway. Producing ethylene gas directly can, in some embodiments, facilitate the production of subsequent polymers as well as the reduction of impurities.

[0037]

[0039] In yet another embodiment, tall oil can be collected from a biomass feedstock and converted to ethylene. For example, in one embodiment, tall oil can be derived from a cellulosic derived feedstock.

[0038]

[0040] Once the bio-based monomers are synthesized and purified, a high density polyethylene polymer is produced from the monomers. The high density polyethylene polymer can be produced exclusively from bio-based monomers. However, in alternative embodiments, the high density polyethylene polymer can be produced from a mixture of monomers including bio-based monomers combined with fossil-based ethylene monomers. For example, when fossil-based ethylene monomers are used, the weight ratio between the bio-based monomers and the fossil-based monomers can be from about 1:95 to about 95:1.

[0039]

[0041] High density polyethylene is approximately 0.92 g / cm 3 More than 0.94g / cm 3 More than 0.95g / cm 3 or more, and generally about 1 g / cm 3 The ion exchange resin may have a density of less than 100 nm.

[0040]

[0042] High density polyethylene may be high molecular weight polyethylene, very high molecular weight polyethylene, and / or ultra-high molecular weight polyethylene. "High molecular weight polyethylene" refers to polyethylene having a molecular weight of at least about 2×10 5 "Molecular Weight" refers to a polyethylene composition having an average molecular weight in grams per mole, and as used herein is intended to include very high molecular weight polyethylene and ultra-high molecular weight polyethylene. For purposes of this specification, molecular weights referenced herein are determined according to the Margolies formula ("Margolies molecular weight").

[0041]

[0043] "Very high molecular weight polyethylene" is about 1 × 10 6 g / mol to about 3 × 10 6Refers to a polyethylene composition having a molecular weight in g / mol.

[0044] "Ultra-high molecular weight polyethylene" is at least about 3 × 10 6 This refers to a polyethylene composition having an average molecular weight of about 3×10 6 g / mol to about 30 × 10 6 g / mol, or approximately 3 x 10 6 g / mol to about 20 × 10 6 g / mol, or approximately 3 x 10 6 g / mol to about 10 × 10 6 g / mol, or approximately 3 x 10 6 g / mol to about 6 × 10 6 g / mol.

[0042]

[0045] In one embodiment, the high density polyethylene is a homopolymer of ethylene. In another embodiment, the high density polyethylene may be a copolymer. For example, the high density polyethylene may be a copolymer of ethylene and another olefin containing 3 to 16 carbon atoms, such as 3 to 10 carbon atoms, such as 3 to 8 carbon atoms. These other olefins include, but are not limited to, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methylpent-1-ene, 1-decene, 1-dodecene, 1-hexadecene, and the like. Also usable herein are polyene comonomers such as 1,3-hexadiene, 1,4-hexadiene, cyclopentadiene, dicyclopentadiene, 4-vinylcyclohex-1-ene, 1,5-cyclooctadiene, 5-vinylidene-2-norbornene, and 5-vinyl-2-norbornene. However, the amount of non-ethylene monomer in the copolymer, if present, may be less than about 10 mol%, such as less than about 5 mol%, for example less than about 2.5 mol%, for example less than about 1 mol%, where mol% is based on the total moles of monomer in the polymer. In accordance with the present disclosure, the comonomer may be a bio-based comonomer.

[0043]

[0046] In one embodiment, the high density polyethylene may have a monomodal molecular weight distribution. Alternatively, the high density polyethylene may exhibit a bimodal molecular weight distribution. For example, a bimodal distribution generally refers to a polymer having a distinct higher molecular weight and a distinct lower molecular weight (e.g., two distinct peaks) in a size exclusion or gel filtration chromatography curve. In another embodiment, the high density polyethylene may exhibit more than two molecular weight distribution peaks, such as a polyethylene exhibiting a multimodal (e.g., trimodal, tetramodal, etc.) distribution. Alternatively, the high density polyethylene may exhibit a broad molecular weight distribution, the polyethylene being composed of a blend of higher and lower molecular weight components such that a size exclusion or gel filtration chromatography curve does not exhibit at least two distinct peaks, but rather one distinct peak that is broader than the peaks of the individual components.

[0044]

[0047] Any method known in the art can be utilized for the synthesis of polyethylene. Polyethylene powder is typically produced by catalytic polymerization of ethylene monomer, or optionally with one or more other 1-olefin comonomers, using heterogeneous catalysts and organoaluminum or magnesium compounds as cocatalysts, such that the 1-olefin content in the final polymer is 10% or less of the ethylene content. Ethylene is usually polymerized in gas or slurry phase at relatively low temperatures and pressures. The polymerization reaction may be carried out at temperatures between 50° C. and 100° C., and at pressures in the range of 0.02 to 2 MPa.

[0045]

[0048] The molecular weight of the polyethylene can be adjusted by hydrogenation. Varying the temperature and / or the type and concentration of cocatalyst may also be used to fine-tune the molecular weight. Additionally, the reaction may take place in the presence of an antistatic agent to avoid fouling and product contamination.

[0046]

[0049] Suitable catalyst systems include, but are not limited to, Ziegler-Natta type catalysts. Typically, Ziegler-Natta type catalysts are derived from the combination of a transition metal compound from Groups 4 to 8 of the Periodic Table with a metal alkyl or hydride derivative from Groups 1 to 3 of the Periodic Table. The transition metal derivatives used usually include metal halides or esters or combinations thereof. Exemplary Ziegler-Natta catalysts include catalysts based on the reaction products of organoaluminum or magnesium compounds, such as, but not limited to, aluminum or magnesium alkyls, with titanium, vanadium or chromium halides or esters. Heterogeneous catalysts may or may not be supported on a porous particulate material, such as silica or magnesium chloride. Such supports may be added during the synthesis of the catalyst or may be obtained as a chemical reaction product of the catalyst synthesis itself.

[0047]

[0050] In one embodiment, a suitable catalyst system may be obtained by reaction of a titanium(IV) compound with a trialkylaluminum compound in an inert organic solvent at a temperature in the range of -40°C to 100°C, preferably -20°C to 50°C. The concentrations of the starting materials are in the range of 0.1 to 9 mol / L, preferably 0.2 to 5 mol / L for the titanium(IV) compound and 0.01 to 1 mol / L, preferably 0.02 to 0.2 mol / L for the trialkylaluminum compound. The titanium component is added to the aluminum component over a period of 0.1 to 60 minutes, preferably 1 to 30 minutes, such that the molar ratio of titanium to aluminum in the final mixture is in the range of 1:0.01 to 1:4.

[0048]

[0051] In another embodiment, a suitable catalyst system is obtained by one or two stage reaction of a titanium(IV) compound with a trialkylaluminum compound in an inert organic solvent at a temperature ranging from -40°C to 200°C, preferably from -20°C to 150°C. In one stage, the titanium(IV) compound is reacted with the trialkylaluminum compound at a temperature ranging from -40°C to 100°C, preferably from -20°C to 50°C, using a titanium to aluminum molar ratio ranging from 1:0.1 to 1:0.8. The concentrations of the starting materials are in the range of 0.1 to 9.1 mol / L, preferably 5 to 9.1 mol / L for the titanium(IV) compound and 0.05 to 1 mol / L, preferably 0.1 to 0.9 mol / L for the trialkylaluminum compound. The titanium component is added to the aluminum component over a period of 0.1 to 800 minutes, preferably 30 to 600 minutes. In the second stage, if applicable, the reaction product obtained in the first stage is treated with a trialkylaluminum compound at a temperature in the range of from -10°C to 150°C, preferably from 10°C to 130°C, using a molar ratio of titanium to aluminum in the range of from 1:0.01 to 1:5.

[0049]

[0052] In yet another embodiment, a procedure for obtaining a suitable catalytic system comprises reacting, in a first reaction stage, a magnesium alcoholate with titanium chloride in an inert hydrocarbon at a temperature between 50° and 100° C. In a second reaction stage, the reaction mixture formed is subjected to a heat treatment at a temperature between 110° and 200° C. for between about 10 and 100 hours, accompanied by the evolution of alkyl chlorides until no further alkyl chlorides are evolved, after which the solid is liberated from the soluble reaction products by washing several times with a hydrocarbon.

[0050]

[0053] Each of the above catalysts may further comprise an internal electron donor. Such donors may be selected from the group of linear and cyclic ethers; esters and diesters, such as aromatic esters; nitrogen-containing compounds; and sulfur-containing compounds, such as thioethers. In one embodiment, the internal electron donor may be a derivative of succinic acid. In an alternative embodiment, the internal electron donor may be a substituted phenylene diester.

[0051]

[0054] The Ziegler-Natta catalysts are used together with an activator. Suitable activators are alkyl metal compounds, in particular alkyl aluminum compounds. These compounds include alkyl aluminum halides such as ethyl aluminum dichloride, diethyl aluminum chloride, ethyl aluminum sesquichloride, dimethyl aluminum chloride. They also include trialkyl aluminum compounds such as trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, trihexyl aluminum and tri-n-octyl aluminum. They further include alkyl aluminum oxy compounds such as methyl aluminum oxane (MAO), hexaisobutyl aluminum oxane (HIBAO) and tetraisobutyl aluminum oxane (TIBAO). Other alkyl aluminum compounds such as isoprenyl aluminum may also be used. Particularly preferred activators are trialkyl aluminum, of which triethyl aluminum, trimethyl aluminum and triisobutyl aluminum are particularly used.

[0052]

[0055] The amount of activator used will depend on the particular catalyst and activator. Typically triethylaluminum is used in an amount such that the molar ratio of aluminum to transition metal, such as Al / Ti, is from 1 to 1000, preferably from 3 to 100, especially from about 5 to about 30 moles / mole.

[0053]

[0056] It is possible to use external donors together with the catalyst. The use of such donors is known in the art. They may be selected from linear and cyclic ethers, esters, silicon ethers, nitrogen-containing compounds, etc.

[0054]

[0057] Utilizing the above-described catalyst system, high density polyethylene polymer can be produced in a slurry polymerization process. For example, the catalyst can be introduced into a slurry containing ethylene and a diluent.

[0055]

[0058] The slurry polymerization step to produce ultra-high molecular weight polyethylene is carried out at a temperature of 30 to 110° C. Preferably, the temperature is 35 to 75° C., more preferably 40 to 70° C., e.g., 42 to 70° C. or 45 to 70° C. The molecular weight of the polymer produced in the process tends to be higher when operating at the lower end of the temperature range. On the other hand, the polymerization rate tends to increase with increasing temperature. The above ranges provide a good compromise between molecular weight capability and productivity.

[0056]

[0059] The pressure in the slurry polymerization step for producing ultra-high molecular weight polyethylene is not critical and may be freely selected within the range of about 1 to about 100 bar (absolute). The choice of operating pressure depends, among other things, on the choice of diluent used in the polymerization.

[0057]

[0060] The diluent in the slurry polymerization step to produce ultra-high molecular weight polyethylene may be any suitable diluent that dissolves ethylene but not high density polyethylene at the reaction conditions. Additionally, the diluent should not react with the polymerization catalyst. Preferably, the diluent is selected from alkanes having 2 to 8 carbon atoms and mixtures thereof. More preferably, the diluent is selected from the group consisting of propane, isobutane, n-butane and mixtures thereof.

[0058]

[0061] Slurry polymerization to produce ultra-high molecular weight polyethylene may be carried out batchwise or continuously.

[0062] The ethylene content in the fluid phase of the slurry may be from 1 to about 50 mol%, preferably from about 2 to about 20 mol%, and particularly from about 2 to about 10 mol%. The advantage of having a high ethylene concentration is that the productivity of the catalyst is increased, but the disadvantage is that more ethylene then needs to be recycled than if the concentration were lower.

[0059]

[0063] The slurry polymerization to produce ultra-high molecular weight polyethylene may be carried out in any known reactor used in slurry polymerization. Such reactors include continuous stirred tank reactors and loop reactors. It is particularly preferred that the polymerization is carried out in a loop reactor. In such reactors, the slurry is circulated at high velocity along a closed pipe using a circulation pump.

[0060]

[0064] The average residence time in the slurry polymerization step is typically from 20 to 120 minutes, preferably from 30 to 80 minutes. As is known in the art, the average residence time T in a continuous process can be calculated from

[0061]

number

[0062] In the above formula, V R is the volume of the reaction space (in the case of a loop reactor, the volume of the reactor), and Q O is the volumetric flow rate of the product stream (including the polymer product and the fluid reaction mixture).

[0065] High density polyethylene polymers generally have a molecular weight of more than about 200,000 g / mol, for example more than about 300,000 g / mol. For example, the polyethylene polymer may have a molecular weight of more than about 500,000 g / mol, for example more than about 700,000 g / mol, for example more than about 1,000,000 g / mol, for example more than about 1,300,000 g / mol, for example more than about 1,700,000 g / mol, for example more than about 2,000,000 g / mol, for example more than about 2,500,000 g / mol, for example more than about 3,000,000 g / mol, for example more than about 3,500,000 g / mol, for example more than about 4,000,000 g / mol. 00 g / mol, such as greater than about 4,500,000 g / mol, for example greater than about 5,000,000 g / mol, for example greater than about 5,500,000 g / mol, such as greater than about 6,000,000 g / mol, for example greater than about 6,500,000 g / mol, such as greater than about 7,000,000 g / mol, for example greater than about 7,500,000 g / mol, for example greater than about 8,000,000 g / mol, and less than about 12,000,000 g / mol.

[0063]

[0066] The polyethylene polymer may have a melt flow rate of about 0.1 g / 10 min to about 50 g / 10 min. The melt flow rate of the polymer is determined according to ASTM test D1238 at 190° C. and a load of 21.5 kg. In one embodiment, the high density polyethylene polymer has a relatively low melt flow rate, for example less than about 30 g / 10 min, for example less than about 20 g / 10 min, for example less than about 10 g / 10 min, for example less than about 5 g / 10 min, for example less than about 4 g / 10 min, for example less than about 3 g / 10 min, for example less than about 2 g / 10 min, for example less than about 1 g / 10 min. In one embodiment, the melt flow rate is so low that it cannot be measured according to the above-mentioned ASTM test.

[0064]

[0067] In addition to the mass balance approach, high density polyethylene polymers produced according to the present disclosure can then be subjected to ASTM test D6866 (2021) to determine their biobased content. The analytical test described above was developed to determine the biobased content of solid, liquid or gas samples using radiocarbon dating. ASTM test D6866 distinguishes between carbon derived from modern biomass-based inputs and carbon derived from fossil-based inputs. More specifically, this method uses radiocarbon dating isotopes in the polymer. 14 The method relies on determining the amount of carbon (5,730 years half-life) in the polymer. This method identifies whether the carbon contained in the polymer comes from a biological source, such as a modern plant or animal, or a fossil source, or a mixture of these. In general, the carbon from fossil sources is very close to zero. 14 C content of high density polyethylene polymer 14 Measuring the amount of C isotope can confirm that all or part of a material or article is derived from a biological source. ASTM test D6866 comprises methods A to C. In one embodiment, method B may be used.

[0065]

[0068] The high density polyethylene polymer made according to the present disclosure may have a bio-based content of at least 10% based on radiocarbon dating of the total organic carbon content when tested according to ASTM test D6866. For example, the high density polyethylene polymer may have a bio-based content of more than about 20%, such as more than about 30%, such as more than about 40%, such as more than about 50%, such as more than about 60%, such as more than about 70%, such as more than about 80%. In one embodiment, the high density polyethylene polymer may be made exclusively from bio-based feedstocks and have a bio-based content of 100%. In other embodiments, the high density polyethylene polymer may be made partially from fossil-based ethylene such that the bio-based content is less than about 90%, such as less than about 80%, such as less than about 70%, such as less than about 60%, such as less than about 50%, such as less than about 40%, such as less than about 30%.

[0066]

[0069] Generally, the high density polyethylene polymer produced in accordance with the present disclosure is collected in the form of particles for use in making a variety of different products and articles.

[0070] In one embodiment, the polyethylene particles are made from a polyethylene polymer having a relatively low bulk density as measured according to DIN 53466. For example, in one embodiment, the bulk density is generally about 0.4 g / cm 3 Less than about 0.35 g / cm 3 Less than about 0.33 g / cm 3 Less than about 0.3 g / cm 3 Less than about 0.28 g / cm 3 Less than about 0.26 g / cm 3 Generally, the bulk density is about 0.1 g / cm 3 More than about 0.15 g / cm 3 In one embodiment, the polymer has a viscosity of greater than about 0.2 g / cm 3 to about 0.27 g / cm 3 It has a bulk density of

[0067]

[0071] In one embodiment, the polyethylene particles may be a free-flowing powder. The particles may have a volume median particle size (d50) of less than 250 microns. For example, the median particle size (d50) of the polyethylene particles may be less than about 150 microns, such as less than about 125 microns. Typically, the median particle size (d50) is greater than about 10 microns. The particle size of the powder may be measured using laser diffraction according to ISO 13320.

[0068]

[0072] In one embodiment, 90% of the polyethylene particles may have a particle size less than about 250 microns. In another embodiment, 90% of the polyethylene particles may have a particle size less than about 200 microns, such as less than about 170 microns.

[0069]

[0073] The polyethylene may have a viscosity number, determined according to ISO 1628 part 3 utilizing a concentration in decahydronaphthalene of 0.0002 g / mL, of at least 100 mL / g, such as at least 500 mL / g, for example at least 1,500 mL / g, such as at least 2,000 mL / g, for example at least 4,000 mL / g to less than about 6,000 mL / g, such as less than about 5,000 mL / g, for example less than about 4000 mL / g, such as less than about 3,000 mL / g, for example less than about 1,000 mL / g.

[0070]

[0074] The high density polyethylene may have a crystallinity of at least about 40% to 85%, such as 45% to 80%.

[0075] In producing products and articles, the high density polyethylene polymers may be combined with a variety of additives, such as heat stabilizers, light stabilizers, UV absorbers, acid scavengers, flame retardants, lubricants, colorants, and the like.

[0071]

[0076] In one embodiment, a heat stabilizer may be present in the composition, including, but not limited to, a phosphite, an amine antioxidant, a phenolic antioxidant, or any combination thereof.

[0072]

[0077] In one embodiment, antioxidants may be present in the composition, including, but not limited to, secondary aromatic amines, benzofuranones, sterically hindered phenols, or any combination thereof.

[0073]

[0078] In one embodiment, light stabilizer can be present in the composition.Light stabilizer includes but is not limited to 2-(2'-hydroxyphenyl)-benzotriazole, 2-hydroxy-4-alkoxybenzophenone, nickel-containing light stabilizer, 3,5-di-tert-butyl-4-hydroxybenzoate, sterically hindered amine (HALS), or any combination thereof.

[0074]

[0079] In one embodiment, a UV absorber may be present in the composition instead of or in addition to the light stabilizer. The UV absorber may include, but is not limited to, benzotriazole, benzoate, or any combination thereof, or any combination thereof.

[0075]

[0080] In one embodiment, halogenated flame retardants may be present in the composition. Halogenated flame retardants include, but are not limited to, tetrabromobisphenol A (TBBA), tetrabromophthalic anhydride, dodecachloropentacyclooctadecadiene (dechlorane), hexabromocyclododecane, chlorinated paraffins, or any combination thereof.

[0076]

[0081] In one embodiment, non-halogenated flame retardants may be present in the composition. Non-halogenated flame retardants include, but are not limited to, resorcinol diphosphate tetraphenyl ester (RDP), ammonium polyphosphate (APP), phosphinic acid derivatives, triaryl phosphate, trichloropropyl phosphate (TCPP), magnesium hydroxide, aluminum trihydroxide, and antimony trioxide.

[0077]

[0082] In one embodiment, a lubricant may be present in the composition, including, but not limited to, silicone oil, wax, molybdenum disulfide, or any combination thereof.

[0078]

[0083] In one embodiment, a colorant may be present in the composition. Colorants include, but are not limited to, inorganic and organic based color pigments.

[0084] In one aspect, an acid scavenger may be present in the polymer composition. The acid scavenger may include, for example, an alkali metal salt or an alkaline earth metal salt. The salt may include a salt of a fatty acid, such as a stearate. Other acid scavengers include carbonates, oxides, or hydroxides. Specific acid scavengers that may be incorporated into the polymer composition include metal stearates, such as calcium stearate. Still other acid scavengers include zinc oxide, calcium carbonate, magnesium oxide, and mixtures thereof.

[0079]

[0085] These additives may be used alone or in any combination thereof. Generally, each additive may be present in the polymer composition or the resulting polymer article in an amount of at least about 0.05% by weight, such as at least about 0.1% by weight, such as at least about 0.25% by weight, such as at least about 0.5% by weight, such as at least about 1% by weight, and generally less than about 20% by weight, such as less than about 10% by weight, such as less than about 5% by weight, such as less than about 4% by weight, such as less than about 2% by weight. The sum of the weight percentages of all components utilized in the polymer composition and article, including any additives, if present, equals 100% by weight.

[0080]

[0086] High density polyethylene polymers made according to the present disclosure can be used in numerous and diverse applications to produce all kinds of products and articles. The manner in which the high density polyethylene polymer is formed into various articles can also vary. In one embodiment, for example, high density polyethylene particles can be combined with a plasticizer and fed through a gel extrusion process to produce articles, such as fibers and films. During gel extrusion, a significant amount of plasticizer is combined with the high density polyethylene polymer to form a gel that can be extruded through a die. Once the polymer article is formed, the plasticizer is then removed from the final product.

[0081]

[0087] When forming a gel extrusion article, the high density polyethylene polymer is combined with a plasticizer to form a polymer composition.

[0088] Generally, the high density polyethylene particles are present in the polymer composition in an amount of up to about 50% by weight. For example, the high density polyethylene particles can be present in the polymer composition in an amount of less than about 45% by weight, such as less than about 40% by weight, such as less than about 35% by weight, such as less than about 30% by weight, such as less than about 25% by weight, such as less than about 20% by weight, such as less than about 15% by weight. The polyethylene particles can be present in the composition in an amount of more than about 5% by weight, such as more than about 10% by weight, such as more than about 15% by weight, such as more than about 20% by weight, such as more than about 25% by weight. During gel processing, the plasticizer is combined with the high density polyethylene particles and can be substantially or completely removed during the formation of the polymer article. For example, in one embodiment, the resulting polymeric article may contain high density polyethylene polymer in an amount greater than about 70% by weight, such as greater than about 80% by weight, such as greater than about 85% by weight, such as greater than about 90% by weight, such as greater than about 95% by weight.

[0082]

[0089] Generally, any suitable plasticizer can be used during the gel extrusion process. The plasticizer may include, for example, a hydrocarbon oil, an alcohol, an ether, an ester, such as a diester, or a mixture thereof. For example, suitable plasticizers include mineral oil, paraffinic oil, decalin, and the like. Other plasticizers include xylene, dioctyl phthalate, dibutyl phthalate, stearyl alcohol, oleyl alcohol, decyl alcohol, nonyl alcohol, diphenyl ether, n-decane, n-dodecane, octane, nonane, kerosene, toluene, naphthalene, tetralin, and the like. In an embodiment, the plasticizer may include a halogenated hydrocarbon, such as monochlorobenzene. Cycloalkanes and cycloalkenes may also be used, such as camphene, methane, dipentene, methylcyclopentadiene, tricyclodecane, 1,2,4,5-tetramethyl-1,4-cyclohexadiene, and the like. The plasticizer may also include any mixtures and combinations of any of the above.

[0083]

[0090] The plasticizer is generally present in the composition used to form the polymeric article in an amount greater than about 50% by weight, such as greater than about 55% by weight, such as greater than about 60% by weight, such as greater than about 65% by weight, such as greater than about 70% by weight, such as greater than about 75% by weight, such as greater than about 80% by weight, such as greater than about 85% by weight, such as greater than about 90% by weight, such as greater than about 95% by weight, such as greater than about 98% by weight. In fact, the plasticizer may be present in an amount up to about 99.5% by weight.

[0084]

[0091] The high density polyethylene particles and the plasticizer form a homogeneous gel-like material. To form a polymeric article according to the present disclosure, the high density polyethylene particles are combined with the plasticizer and extruded through a die of a desired type. In one embodiment, the composition can be heated in the extruder. For example, the plasticizer can be combined with the particle mixture and fed into the extruder. In accordance with the present disclosure, the plasticizer and particle mixture form a homogeneous gel-like material before leaving the extruder to form a polymeric article with little or no impurities.

[0085]

[0092] In one embodiment, an elongated article is formed during a gel spinning or extrusion process. The polymer article may be in the form of, for example, a fiber or a film, such as a membrane.

[0093] During this process, at least a portion of the plasticizer is removed from the final product. The process of plasticizer removal may occur by evaporation when a relatively volatile plasticizer is used. Otherwise, an extraction liquid can be used for plasticizer removal. The extraction liquid may include, for example, a hydrocarbon solvent. For example, one example of an extraction liquid is dichloromethane. Other extraction liquids include acetone, chloroform, alkanes, hexenes, heptenes, alcohols, or mixtures thereof.

[0086]

[0094] If necessary, the resulting polymeric article can be stretched at an elevated temperature below the melting point of the polymer mixture to enhance strength and modulus. Suitable temperatures for stretching are in the range of about ambient temperature to about 155°C. Generally, the stretch ratio can be greater than about 4, such as greater than about 6, such as greater than about 8, such as greater than about 10, such as greater than about 15, such as greater than about 20, such as greater than about 25, such as greater than about 30. In certain embodiments, the stretch ratio can be greater than about 50, such as greater than about 100, such as greater than about 110, such as greater than about 120, such as greater than about 130, such as greater than about 140, such as greater than about 150. Generally, the stretch ratio is less than about 1,000, such as less than about 800, such as less than about 600, such as less than about 400. In one embodiment, a lower stretch ratio is used, such as from about 4 to about 10. The polymeric article can be stretched uniaxially or biaxially.

[0087]

[0095] The polymeric articles made according to the present disclosure have many uses and applications. For example, in one embodiment, the process is used to produce membranes. The membranes can be used, for example, as separators for batteries. Alternatively, the membranes can be used as microfilters. When producing fibers, the fibers can be used to produce nonwovens, ropes, nets, etc. In one embodiment, the fibers can be used as filler materials in ballistic clothing.

[0088]

[0096] Referring to FIG. 1, an embodiment of a lithium-ion battery 10 made according to the present disclosure is shown. The battery 10 comprises an anode 12 and a cathode 14. The anode 12 can be made of, for example, lithium metal. Meanwhile, the cathode 14 can be made of sulfur or intercalated lithium metal oxide. In accordance with the present disclosure, the battery 10 further comprises a porous membrane 16 or separator disposed between the anode 12 and the cathode 14. The porous membrane 16 allows the passage of ions, for example lithium ions, while minimizing electrical shorts between the two electrodes. As shown in FIG. 1, in one embodiment, the porous membrane 16 is a single layer polymer membrane and does not comprise a multilayer structure. In one aspect, the single layer polymer membrane may comprise a coating. The coating may be an inorganic coating made, for example, of aluminum oxide or titanium oxide. Alternatively, the single layer polymer membrane may comprise a polymer coating. The coating may provide an increase in thermal resistance.

[0089]

[0097] In alternative embodiments, high density polyethylene polymers can be used to produce a variety of different biomaterials, such as implants. For example, high density polyethylene polymers can be biocompatible, making them well suited for producing knee, hip, and other replacement prostheses for the human or animal body. For example, in one embodiment, high density polyethylene can be used as a lining for the acetabular cup of an artificial hip joint.

[0090]

[0098] When used as a biomaterial, the high density polyethylene polymer should have little or no impurities. In this regard, the high density polyethylene polymer may have an ash content of less than about 500 ppm, such as less than about 250 ppm, such as less than about 100 ppm, such as less than about 50 ppm, such as less than about 10 ppm. Indeed, in certain embodiments, the ash content may be less than about 8 ppm, such as less than about 5 ppm, such as less than about 2 ppm. As used herein, ash content is determined according to ASTM test D5630-13.

[0091]

[0099] High density polyethylene polymers can be used to produce any type of biomedical product, including any type of implant. The implants can be designed for the human body or for animal bodies, including all vertebrates. The polymers can be used to produce implants for dogs, cats, sheep, horses, cows, etc.

[0092] [000100] In one embodiment, sintered products can be made from high density polyethylene polymers, particularly porous articles. The porous articles can be formed by a free sintering process, which involves introducing the polyethylene polymer powder described above into a partially or totally confined space, such as a mold, and heating the molding powder sufficiently to soften, stretch, and bring the polyethylene particles into contact with each other. Suitable processes include compression molding and injection molding. The mold can be made of steel, aluminum, or other metals. The polyethylene polymer powder used in the molding process is generally post-reactor grade, which means that the powder is not screened or crushed before being introduced into the mold. Of course, the additives described above can be mixed together with the powder.

[0093] [000101] The mold is heated in a convection oven, hydraulic press or infrared heater to a sintering temperature of between about 140°C and about 300°C, for example between about 160°C and about 300°C, for example between about 170°C and about 240°C, to sinter the polymer particles. The heating time and temperature vary and depend on the size of the mold and the shape of the molded article. However, the heating time is typically within the range of about 25 to about 100 minutes. During sintering, the surfaces of the individual polymer particles fuse at their contact points to form a porous structure. The mold is then cooled and the porous article is removed. Generally, no molding pressure is required. However, if adjustment of the porosity is required, a proportionally lower pressure can be applied to the powder.

[0094] [000102] The porous substrate made according to the present disclosure is known to have excellent blending properties.For example, the porous substrate made according to the present disclosure can have relatively low pressure loss, exhibit excellent filter properties, and exhibit a less fragile and more flexible product in combination with a relatively high level of bending strength.For example, the porous substrate made according to the present disclosure can have a pressure loss of less than 10 mbar, for example less than about 8 mbar, for example less than about 6 mbar, for example even less than about 4 mbar.In one embodiment, for example, the pressure loss can be about 0.1 mbar to about 3.5 mbar.

[0095] [000103] Furthermore, the porous substrate can have a relatively high bending strength. The bending strength can be determined, for example, according to DIN ISO178. Generally, the bending strength of the porous substrate made according to the present disclosure can be greater than about 1.5 MPa, for example greater than about 2 MPa, for example greater than about 2.2 MPa, for example greater than about 2.4 MPa, for example greater than about 2.6 MPa, for example greater than about 2.8 MPa, for example greater than about 3 MPa. Generally, the bending strength is less than about 8 MPa.

[0096] [000104] In addition to the above properties, the porous substrate made according to the present disclosure may have various other advantageous physical properties. For example, the porous substrate may have a porosity of more than about 30%, such as more than about 35%, such as more than about 40%. Generally, the porosity is less than about 80%, such as less than about 60%, such as less than about 55%. The porosity can be determined according to DIN test 66133. Also, the average pore size, which can be determined according to DIN test 66133, can generally be more than about 80 microns, such as more than about 85 microns, such as more than about 90 microns, such as more than about 95 microns, such as more than about 100 microns, such as more than about 105 microns, such as more than about 110 microns, such as more than about 115 microns, such as more than about 120 microns, such as even more than about 125 microns. Generally, the average pore size is less than about 180 microns.

[0097] [000105] Porous substrates made according to the present disclosure can be used in numerous and diverse applications, specific examples include wastewater aeration, capillary applications, and filtration. [000106] Aeration is a method of decomposing wastewater using microorganisms and vigorous agitation. The microorganisms work by coming into intimate contact with the dissolved and suspended organic matter. Aeration is practically carried out through the use of "aerators" or "porous diffusers." Aerators are made from many different materials and come in widely accepted types and shapes. The three main types of materials currently used in the manufacture of aerators are ceramics (including aluminum oxide, aluminum silicate, and silica), membranes (mainly elastomers such as ethylene / propylene dimer - EPDM), and plastics (mainly HDPE).

[0098] [000107] The porous article offers an attractive alternative to ceramic, membrane and HDPE vents due to the fact that tighter control of particle size distribution and bulk density leads to the production of vents with tightly controlled pores, uniform flow rates, larger cell sizes and less pressure loss. Furthermore, the incorporation of UV stabilizers and / or antimicrobial additives should allow the performance of the sintered porous polyethylene vents to be further improved over that of existing vents. Thus, the incorporation of UV stabilizers can be used to extend the expected lifespan of the vents in outdoor environments, while the addition of antimicrobial agents should prevent fouling on the vent surface, thereby allowing the vents to function at maximum efficiency for longer periods of time.

[0099] [000108] Capillary applications of the present porous sintered articles include writing instruments such as highlighters, colored sketch pens, oil-based markers, and erasable whiteboard markers, which utilize the capillary action of the porous nib to transport ink from a reservoir to the writing surface. Currently, porous nibs formed from ultra-high molecular weight polyethylene are often used in highlighters and colored sketch pens, while oil-based and whiteboard markers are commonly produced from polyester (polyethylene terephthalate), polyolefin hollow fibers, and acrylic porous materials. The large pore size of the present sintered articles makes them attractive for use in capillary transport of the high viscosity alcohol-based inks used in oil-based and whiteboard markers.

[0100] [000109] With regard to filtration applications, the porous sintered article is useful, for example, in filtering produced water (drilling injection water). Thus, in crude oil production, water is often injected into reservoirs near shore to maintain pressure and hydraulically drive the oil toward the production wells. The injected water must be filtered so as not to plug the reservoir or the equipment used for this purpose earlier than normal. Furthermore, as oil fields mature, the generation of produced water increases. The porous tubes made from the polyethylene powder are oleophilic, backwashable, abrasion-resistant, chemical-resistant, and can form a strong and stable filter element with a long service life, making them an ideal filtration medium for filtering produced water.

[0101] [000110] The present porous sintered articles also find utility in other filtration applications where oil needs to be separated from water, such as filtration of turbine and boiler water in power plants, filtration of cooling water emulsions, de-oiling of wash water from car washes, filtration of process water, removal of oil spills from seawater, separation of glycol from natural gas and aviation fuel filters.

[0102] [000111] Another application of the present porous sintered articles is in irrigation, where filtration of inflowing water is necessary to remove fine sand particles that can clog sprinkler systems and damage other irrigation equipment including damaging pumps. Traditional approaches to this problem are the use of stainless steel screens, composite disc filters, sand media filters and cartridge filters. One of the key requirements for these filters is pore size, which is usually required to be in the range of 100μ to 150μ. Other considerations are high flow rate, low pressure drop, good chemical resistance, high filter strength and long service life. The properties of the present porous sintered articles make them particularly suitable for such uses.

[0103] [000112] Further filtration applications include replacement of sediment filters used as prefilters to remove rust and large sediments in multi-stage drinking water applications, where sintered polyethylene filters have shown extended life over more expensive carbon blocks, reverse osmosis membranes, and hollow fiber cartridges. Until now, the required sintered part strength of such filters could only be achieved by blending LDPE or HDPE with UHMWPE powder. However, these blends have some drawbacks in that the pore size of the sintered filters is small and existing UHMWPE powders cannot produce filters with pore sizes greater than 20μ and adequate part strength. On the other hand, the present polyethylene powders facilitate the design of sediment filters that exhibit adequate part strength with pore sizes >30μ and excellent pore size maintenance during high velocity water use.

[0104] [000113] Other filtration applications of the present porous sintered articles include medical fluid filtration, such as filtration of blood outside the human body, filtration to remove solids in chemical and pharmaceutical manufacturing processes, and filtration of hydraulic oils for removal of solid contaminants.

[0105] [000114] In a further filtration embodiment, the polyethylene powder can be used in the production of carbon block filters. Carbon block filters are produced from granular activated carbon particles blended with about 5% to about 80% by weight, typically about 15% to about 25% by weight, of a thermoplastic binder. The blend is poured into a mold, usually a hollow cylindrical mold, and compressed to pack the blended material as tightly as possible. The material is then heated to a point where the binder softens or melts and bonds the carbon particles together. Carbon block filters are used in a wide variety of applications, including, for example, water filtration for refrigerators, air and gas filtration, removal of toxic organic pollutants from, for example, cigarette smoke, organic vapor masks, and gravity flow filtration devices.

[0106] [000115] These and other modifications and variations to the present invention may be made by those skilled in the art without departing from the spirit and scope of the present invention, as more particularly set forth in the appended claims. Moreover, it should be understood that aspects of the various embodiments may be interchanged in whole or in part. Moreover, those skilled in the art will recognize that the foregoing description is merely exemplary and is not intended to limit the invention, as further set forth in the appended claims.

Claims

1. 1. A polymer composition comprising: polymer particles comprising a high density polyethylene polymer; The high density polyethylene polymer has an average molecular weight greater than about 200,000 g / mol and a molecular weight of about 0.92 g / cm ３ (ISO 1183) and is produced from ethylene monomer, at least a portion of which contains or is derived from a carbon-negative or carbon-neutral component; The polymer composition.

2. The high density polyethylene is greater than about 500,000 g / mol, such as greater than about 700,000 g / mol, for example greater than about 1,000,000 g / mol, such as greater than about 1,300,000 g / mol, for example greater than about 1,700,000 g / mol, such as greater than about 2,000,000 g / mol, for example greater than about 2,500,000 g / mol, for example greater than about 3,000,000 g / mol, such as greater than about 3,500,000 g / mol, for example greater than about 4,000,000 g / mol, e.g.

2. The polymer composition of claim 1, wherein the polymer composition has an average molecular weight of, for example, greater than about 4,500,000 g / mol, such as greater than about 5,000,000 g / mol, for example greater than about 5,500,000 g / mol, such as greater than about 6,000,000 g / mol, for example greater than about 6,500,000 g / mol, such as greater than about 7,000,000 g / mol, for example greater than about 7,500,000 g / mol, such as greater than about 8,000,000 g / mol, and less than about 12,000,000 g / mol.

3. 10. The polymer composition of claim 1, wherein the ethylene monomer is produced from the carbon negative or carbon neutral component.

4. 4. The polymer composition of claim 3, wherein the carbon-negative or carbon-neutral component comprises methane, the methane being subjected to a pyrolysis or partial oxidation process to produce acetylene, and the acetylene being hydrogenated to ethylene.

5. 4. The polymer composition of claim 3, wherein the carbon negative or carbon neutral component comprises ethanol that is converted to ethylene.

6. 4. The polymer composition of claim 3, wherein the carbon-negative or carbon-neutral component comprises a vegetable oil or an animal lipid, and the vegetable oil or animal lipid has been converted to ethylene by hydrodeoxygenation.

7. 4. The polymer composition of claim 3, wherein the carbon negative or carbon neutral component comprises tall oil, and the tall oil has been converted to ethylene.

8. 10. The polymer composition of claim 1, wherein the polymer particles have an average particle size D50 of about 10 microns to about 1,000 microns.

9. 10. The polymer composition of claim 1, wherein the high density polyethylene polymer is catalyzed with a Ziegler-Natta catalyst.

10. The high density polyethylene polymer has a density of about 0.2 g / cm ３ to about 0.54 g / cm ３ 10. The polymer composition of claim 1 having a bulk density of

11. 10. The polymer composition of claim 1, wherein the high density polyethylene polymer has an MFR of from about 0 g / 10 min to about 10 g / 10 min.

12. 10. The polymer composition of claim 1, wherein the high density polyethylene polymer comprises a polyethylene copolymer of ethylene and at least one comonomer comprising hexene, butene, propylene, or a mixture thereof.

13. The polymer composition of claim 1 , wherein the high density polyethylene polymer is crosslinked.

14. 10. The polymer composition of claim 1, wherein the high density polyethylene polymer is produced from a mixture of fossil-based and bio-based ethylene monomers.

15. A medical implant formed from the polymer composition of any of claims 1 to 14.

16. A separator for a battery comprising a porous membrane formed from the polymer composition of any one of claims 1 to 14.

17. 17. The battery separator of claim 16, wherein the porous membrane comprises a coating, the coating comprising an inorganic coating or a polymer coating.

18. 17. A battery comprising an anode, a cathode, and the battery separator of claim 16, wherein the battery separator is disposed between the anode and the cathode.

19. 15. A filter element formed from the polymer composition of any of claims 1 to 14, the filter element comprising a sintered product.

20. 1. A polymer composition comprising: polymer particles comprising a high density polyethylene polymer; The high density polyethylene polymer has an average molecular weight greater than about 300,000 g / mol and a molecular weight of about 0.93 g / cm ３ and formed from ethylene monomers, at least a portion of the ethylene monomers comprise bio-based ethylene, such that the high density polyethylene polymer has a bio-based content of at least 10% based on radiocarbon dating of the total organic carbon content when tested in accordance with ASTM test D6866-21; The polymer composition.

21. 21. The polymer composition of claim 20, wherein the high density polyethylene polymer has 100% bio-based content.

22. 21. The polymer composition of claim 20, wherein the high density polyethylene polymer is formed from a mixture of fossil-based and bio-based ethylene monomers.

23. 23. The polymer composition of claim 20 or 22, wherein the high density polyethylene polymer has a bio-based content of at least 20%, such as at least 30%, for example at least 40%, such as at least 50%, for example at least 60%, and has a bio-based content of less than about 90%, such as less than about 80%, for example less than about 70%.

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