Sintered porous polypropylene media and uses

Abstract

A composition comprising a sintered porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight exceeding 500,000, an average pore size ranging from 10 [mu] m to 200 [mu] m, and a porosity ranging from 20% to 60%. Devices and methods including such compositions.

Description

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 472,658, filed June 13, 2023, entitled “Sintered Porous Polypropylene Media and Applications”. The contents of the foregoing application are relied upon and are incorporated herein by reference in their entirety.

[0002] field Embodiments of the present invention are found in the field of polymer processing and applications. In particular, embodiments relate to incorporating sintered porous thermoplastic media into various applications.

[0003] background Sintered porous polymer materials have applications and play a crucial role in numerous fields. They are widely used in filtration, absorption, adsorption, ventilation, and fluid barrier applications. Currently, only a limited number of sintered porous polymer materials with a wide range of pore sizes and porosities that meet the requirements of filtration, absorption, adsorption, ventilation, application, wicking, and fluid barriers are available. Therefore, components made of sintered porous polymer materials are often assembled with or incorporated into product components made of different polymer materials to meet the overall application requirements of the product. However, products comprising assembled components and components of different polymer materials make recycling difficult and expensive. Therefore, it would be desirable to use the same polymer material for both the sintered porous polymer component and the non-porous component in assembled components, products, or devices.

[0004] Overview In view of the above-mentioned problems, it would be desirable to provide sintered porous polymer compositions that share a common polymer composition (e.g., the same repeating subunit molecules) with the non-porous components to improve the recyclability and sustainability of filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier products. In particular, polypropylene is one of the most widely available thermoplastics, serving as a filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier medium in filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier products, and possesses desirable material properties superior to other widely available thermoplastics (e.g., polyethylene). When compared to other widely available thermoplastics, polypropylene is characterized by high impact resistance, strong corrosion resistance, strong chemical stability, and strong thermal stability (e.g., a higher melting point than polyethylene), which allows polypropylene to withstand a wider range of conditions (e.g., sterilization, autoclaving, etc.). Furthermore, ultra-high molecular weight polypropylene (“UHMWPP”) with extremely long polymer chains and enhanced intermolecular interactions exhibits improved material properties compared to conventional polypropylene. By subjecting UHMWPP particles to a sintering process, the resulting sintered porous UHMWPP disclosed herein achieves satisfactory porosity and average pore size as a medium for filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier applications, thereby enabling more efficient recycling of polypropylene-based products for filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier applications.

[0005] This invention provides compositions comprising sintered porous polymeric materials to give the compositions porosity and average pore size suitable for use as filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier media in a variety of products. This invention also provides devices comprising such compositions.

[0006] In one aspect, compositions are provided. An example composition of this aspect comprises a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight of more than 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0007] On the other hand, pipette tips are provided. An example pipette tip includes a tubular tip defining a reservoir for receiving a sample, wherein the tubular tip comprises polypropylene; and a porous thermoplastic stopper mounted in the tubular tip, wherein the porous thermoplastic stopper comprises a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight exceeding 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0008] On the other hand, a solid-phase extraction column is provided. An example solid-phase extraction column includes a barrel defining a sample reservoir, wherein the barrel comprises polypropylene; and a plurality of sieves disposed within the barrel, wherein the plurality of sieves comprises a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight of more than 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0009] On the other hand, multi-well devices are provided. An example multi-well device includes a housing comprising a plurality of pores, wherein the housing and the plurality of pores comprise polypropylene; and a plurality of filters disposed within the housing, wherein the plurality of filters comprise a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight exceeding 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0010] On the other hand, a writing instrument is provided. An example writing instrument includes a cylinder containing a solution, wherein the cylinder comprises polypropylene; and a tip (nib) attached to the cylinder, wherein the tip comprises a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight of over 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0011] On the other hand, a liquid applicator is provided. An example liquid applicator includes a housing containing a solution, wherein the housing comprises polypropylene; and a filter disposed within the housing, wherein the filter comprises a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight of more than 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0012] On the other hand, liquid dispersing devices are provided. An example liquid dispersing device includes a housing containing a solution, wherein the housing comprises polypropylene; and a core fluidly connected to the solution and disposed within the housing, wherein the core comprises a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight exceeding 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%. In some instances, the solution contains fragrance or pesticide.

[0013] On the other hand, an apparatus comprising the above-described composition is provided. Example apparatuses include a liquid collection device and a diagnostic device, the liquid collection device comprising a polypropylene housing and a filter comprising the composition described herein, and the diagnostic device comprising a polypropylene housing and components comprising the composition described herein.

[0014] On the other hand, an example method for recycling is provided. The example method involves reprocessing the device by melting the device without separating the device components, wherein the device components include a shell comprising polypropylene and functional components comprising sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight of more than 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%.

[0015] On the other hand, a recycling method is provided. An example recycling method includes placing a recyclable article in a recycling chamber, wherein the recyclable article is thermoplastic, wherein the recyclable article comprises components containing porous sintered polymeric material, wherein each component of the recyclable article comprises the same repeating subunit molecules; depolymerizing the recyclable article by heating the recycling chamber to obtain a plurality of subunit molecules; purifying the plurality of subunit molecules to obtain a plurality of purified subunit molecules; and repolymerizing the plurality of purified subunit molecules to form a recycled polymer. In some examples, the sintered polymeric material has a porosity ranging from 20% to 60%, wherein the sintered polymeric material is polypropylene, and the sintered polymeric material has a viscosity-average molecular weight exceeding 500,000 or 1,000,000.

[0016] Not wishing to be bound by any particular theory, this document may contain discussions of beliefs or understandings of the fundamental principles relating to this invention. It should be recognized that, regardless of the ultimate correctness of any mechanistic explanation or assumption, embodiments of this invention can still be effective and useful. Brief description of the attached diagram Figure 1 The sintering process of ultra-high molecular weight polypropylene is shown according to some examples.

[0018] Figure 2 A schematic diagram of a pipette tip according to some examples is shown, the pipette tip comprising a porous plastic plug having a sintered porous ultra-high molecular weight polypropylene material.

[0019] Figure 3 A schematic diagram of a writing instrument according to some examples is shown, the writing instrument comprising a sintered porous polymer material tip having a sintered porous ultra-high molecular weight polypropylene material.

[0020] Figure 4 A simplified schematic diagram of the top portion of a writing instrument according to some examples is shown, the top portion comprising a sintered porous ultra-high molecular weight polypropylene tip.

[0021] Figure 5A schematic diagram of a liquid dispersing device according to some examples is shown, the liquid dispersing device comprising a sintered porous ultra-high molecular weight polypropylene core.

[0022] Detailed Explanation Currently available sintered porous polymer materials for use as filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier media are limited to polyethylene, especially ultra-high molecular weight polyethylene (“UHMWPE”). However, most polymer devices that include filtration and fluid barrier media use housings made of polypropylene. Since polypropylene and polyethylene (especially UHMWPE) are incompatible materials, they cannot be reprocessed together as a single unit. Furthermore, separating components made of different materials (e.g., polypropylene, polyethylene, UHMWPE, etc.) is often prohibitively expensive. As previously mentioned, many polymer devices (e.g., pipette tips, solid-phase extraction columns, porous devices, writing instruments, liquid applicators, etc.) consist of a housing made of polypropylene and filtration and fluid barrier media made of polyethylene. To avoid the high cost of separating components made of different materials (e.g., housing and barrier media), these polymer devices (e.g., pipette tips, solid-phase extraction columns, porous devices, writing instruments, liquid dispensing devices, liquid applicators, etc.) are often disposed of as landfills, raising environmental problems and concerns. If the sintered porous filtration, absorption, adsorption, application, wicking, ventilation, and fluid barrier media in these polypropylene-based devices are made of ultra-high molecular weight polypropylene, the entire device can be remelted and reprocessed into new products without separating the device components. Therefore, the device will not become landfill material and cause environmental problems.

[0023] A better understanding of the nature and advantages of embodiments of the present invention can be obtained by referring to the following detailed description and accompanying drawings.

[0024] Figure 1A sintering process for ultra-high molecular weight polypropylene (UHMWPP) according to several examples is illustrated. Similar to the sintering process for polyethylene and / or UHMWPE, the example sintering process involves compacting and forming a solid block of porous material by heating a mixture of sintered particles without completely melting the mixture. That is, the sintered particles are heated to soften them without melting them. For the invention disclosed herein, the mixture of sintered particles comprises a plurality of ultra-high molecular weight polypropylene (“UHMWPP”) particles 112. In an initial stage 110, the mixture of sintered particles (e.g., a plurality of UHMWPP particles 112) is placed in a mold 115 that holds the mixture of sintered particles in the shape or geometry desired for the final product. The plurality of UHMWPP particles 112 can be in any desired form. In some examples, the plurality of UHMWPP particles 112 can be in powder form. In some examples, the plurality of UHMWPP particles 112 in powder form can be characterized by an average particle size. In some instances, multiple UHMWPP particles 112 in powder form can have an average particle size ranging from 10 μm to 300 μm. For example, the average particle size can be in the range of 10-50 μm, 50-100 μm, 100-150 μm, 150-200 μm, 200-250 μm, and / or 250-300 μm. In some instances, UHMWPP can have a viscosity-average molecular weight exceeding 500,000. For example, the viscosity-average molecular weight can be in the range of 500,000-600,000, 600,000-700,000, 700,000-800,000, 800,000-900,000, 900,000-1,000,000, 1,000,000-1,100,000, 1,100,000-1,200,000 or higher.

[0025] In some instances, the mixture of sintered particles may optionally include a plurality of additive particles 113, which are intentionally added to the mixture of sintered particles to control microstructure and size development during sintering. In some instances, the plurality of additive particles 113 may also alter the hydrophilicity, hydrophobicity, absorption, adsorption, recyclability, and / or color variability of the mixture of sintered particles or any substance produced by the sintering process. In some instances, the additive may be a filter or catalyst for absorbing unwanted gases. In some instances, the additive may promote the maintenance of porosity during the sintering process. In some instances, the additive may include an absorbent that inhibits or prevents the passage of liquids. In some instances, the absorbent may include carboxymethyl cellulose (“CMC”), cellulose gum, hydrolyzed acrylonitrile graft copolymer, neutralized starch-acrylic acid graft copolymer, acrylamide copolymer, modified crosslinked polyvinyl alcohol, neutralized self-crosslinked polyacrylic acid, crosslinked polyacrylate, or neutralized crosslinked isobutylene-maleic anhydride copolymer, or a salt or mixture thereof. In some instances, the additive may include a color change indicator comprising a dye, including but not limited to inorganic or organic dyes such as food colorings, azo compounds, or azo dyes. In some instances, the additive may include a pigment. Details relating to porous barrier media comprising color change indicators are illustrated in U.S. Patent No. 8,187,534, co-owned by Mao et al., entitled “POROUS BARRIERMEDIA COMPRISING COLOR CHANGE INDICATORS,” which is owned by a co-assignee of this disclosure and is incorporated herein by reference in its entirety for all purposes. The additive may be in any desired form. In some instances, the additive may be in powder form. In some instances, the plurality of additive particles 113 may include activated carbon particles.

[0026] In a first intermediate stage 120, a mixture of sintered particles comprising a plurality of UHMWPP particles 112 is heated to a sintering temperature at which the plurality of UHMWPP particles 112 soften but do not melt. As discussed above, the mixture of sintered particles may optionally include a plurality of additive particles 113. As the softened UHMWPP particles 112 fuse into a dense mass, a plurality of pores 116 are formed. The mixture of sintered particles is continued to be heated until a sintered mass with satisfactory properties (e.g., porosity, pore size) is obtained. In other examples, said properties may be any material properties, including but not limited to composition, density, melting point, strength, electrical conductivity, translucency, thermal conductivity, pore size uniformity, etc.

[0027] In the second intermediate stage 130, the sintered block is separated from the mold 115. For example... Figure 1As illustrated, the sintered bulk material may include multiple UHMWPP particles 112 and multiple pores 116 as needed. Optionally, the sintered bulk material may also include multiple additive particles 113.

[0028] In the final stage 140, a sintered bulk may be prepared by any means or method as needed to place the sintered bulk under conditions suitable for any downstream processing. The sintered bulk in the final stage 140 may be referred to as the "finally sintered bulk". In some instances, the finally sintered bulk may have a porosity ranging from 20% to 60%. For example, the porosity may be 20% to 25%, 25% to 30%, 30% to 35%, 35% to 40%, 40% to 45%, 45% to 50%, 50% to 55%, or 55% to 60%. In some instances, the finally sintered bulk may have an average pore size ranging from 10 μm to 200 μm. In some instances, the finally sintered bulk may have a bulk density ranging from 0.2–0.3 g / ml, 0.3–0.4 g / ml, and / or 0.4–0.5 g / ml. In some instances, the final sintered block may have a melting temperature of at least 150°C. In other instances, the final sintered block may have a higher softening or melting temperature than the polyethylene product to withstand the required sterilization conditions. In some instances, the sintered block has an infinitesimal melt flow index at 230°C and a load of 21.6 kg for 10 minutes. In some instances, the sintered block has a flow index ranging from 0-1, 1-2, 2-3, 3-4, 4-5, and 5-6 kg / 230°C at a load of 21.6 kg for 10 minutes. In some instances, the sintered block may not contain polyethylene. In some instances, the sintered block may include both flexible and rigid regions.

[0029] For example, regarding Figure 1 The final sintered bulk or composition can be incorporated into various devices as needed. The final sintered bulk or composition can be a sintered porous UHMWPP material having a viscosity-average molecular weight exceeding 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%. Example devices include, but are not limited to, porous devices comprising a polypropylene housing further comprising a plurality of polypropylene pores, and a plurality of filters disposed within the housing and made of sintered porous UHMWPP material; a liquid applicator comprising a housing made of polypropylene and a tip made of sintered porous UHMWPP material; a liquid collection device comprising a polypropylene housing and filters made of sintered porous UHMWPP material; or a diagnostic device comprising a polypropylene housing and components comprising sintered porous UHMWPP material.

[0030] Figure 2 A schematic diagram of a pipette tip according to some examples is shown, the pipette tip comprising a porous plastic plug having a sintered porous ultra-high molecular weight polypropylene material. Pipette device 200 includes a pipette tip 210 in which a porous plastic plug 220 is mounted. In some examples, pipette tip 210 may include a tubular tip 230 defining a reservoir for receiving samples. In some examples, pipette tip 210 and tubular tip 230 may comprise polypropylene. In some examples, the porous plastic plug 220 may comprise a sintered porous ultra-high molecular weight polypropylene material having a viscosity-average molecular weight exceeding 500,000, an average pore size ranging from 10 μm to 200 μm, and a porosity ranging from 20% to 60%. Pipette tip 210 can be used as a liquid and / or aerosol barrier.

[0031] In addition to the description set forth herein, further details of the pipette device can be found in U.S. Patent No. 5,364,595, co-owned by Smith and entitled “PIPETTE DEVICE CONSTRUCTED TO PREVENT CONTAMINATION BY AEROSOLS OROVERPIPETTING,” which is owned by a co-assignee of this disclosure and whose entire contents are incorporated herein by reference for all purposes.

[0032] Figure 3 A schematic diagram of a writing instrument according to some examples is shown, the writing instrument comprising a sintered porous polymer material tip having a sintered porous ultra-high molecular weight polypropylene material. The use of the term "pen" in this invention is not intended to refer to a device for applying ink to a surface as a writing instrument, but rather to a device that can be held like a pen and used as a sample collection device. The term "pen" is used interchangeably with the term "writing instrument." Figure 3As illustrated, the writing instrument 300 may include a cylinder 310 containing a solution and a tip 320 connected to the cylinder 310. In some instances, the cylinder 310 may comprise or be made of a first polymer material. The tip 320 may be made of a second polymer material, and the second polymer material may be a sintered porous polymer material. In some instances, the sintered porous polymer material contained in the tip 320 is formed by heating polypropylene particles having a particle size of less than 300 μm. In some instances, the first polymer material and the second polymer material contain the same repeating subunit molecules (e.g., propylene). The tip 320 (used in some instances for collecting samples) may be connected or otherwise fixed at one or both ends and included in the cylinder 310. The tip 320 may be frictionally fitted into the cylinder 310 such that the tip 320 can be pressed into and firmly connected to an opening at the end of the writing instrument 300. In some instances, the tip 320 may be fixed to (or shaped with) a nib stem, which can then be frictionally fitted into the barrel 310. For example, the tip and / or nib stem may have a geometry and shape that matches the internal geometry of the barrel 310 and the shape of the writing instrument 300, such that the tip 320 and / or nib stem can be securely attached within the barrel 310. The nib stem may have a cross-sectional shape that is typically circular, square, flat or rectangular, star-shaped, or any other suitable shape. In this and other embodiments, it is possible to provide a protrusion at the end of the nib stem that engages in a recess in the barrel 310, or vice versa, such that an additional male / female connection holds the tip 320 and / or nib stem in place. Examples of alternative tip shapes and writing instruments are illustrated by U.S. Patent No. 8,852,122, entitled "Liquid Sampling, Storage, Transfer and Delivery Device," co-owned by Mao et al., which is owned by a co-assignee of this disclosure and whose entire contents are incorporated herein by reference for all purposes. Examples and details of alternative tips and sintered polymeric materials are illustrated by U.S. Patent No. 8,141,717, entitled "Sintered Polymeric Materials and Applications Thereof," co-owned by Wingo et al., which is owned by a co-assignee of this disclosure and whose entire contents are incorporated herein by reference for all purposes.

[0033] As shown in Figure 301, in some instances, the cylinder 310 may have a body, a reservoir, and a cap. The reservoir may be provided as a separate element, or it may be incorporated into the pen body. In some instances, all components, parts, and components of the writing device 300 comprise polypropylene or ultra-high molecular weight polyethylene (“UHMWPP”), allowing the writing device 300 to be recycled without incurring additional preparation, sorting, or disassembly steps.

[0034] In some instances, tip 320 may comprise sintered porous UHMWPP with a viscosity-average molecular weight exceeding 500,000. For example, the viscosity-average molecular weight range may be 500,000-600,000, 600,000-700,000, 700,000-800,000, 800,000-900,000, 900,000-1,000,000, 1,000,000-1,100,000, 1,100,000-1,200,000 or higher. In some instances, the UHMWPP powder particles used to manufacture the sintered porous UHMWPP may have an average size ranging from 10 to 300 μm. In some instances, the sintered porous UHMWPP may have an average pore size ranging from 10 μm to 200 μm. In some examples, sintered porous UHMWPP can have a porosity ranging from 20% to 60%. In some examples, sintered porous UHMWPP can have an infinitely small melt flow index at a temperature of 230°C and a load of 21.6 kg for 10 minutes. In some examples, sintered porous UHMWPP can have flow indices ranging from 0-1, 1-2, 2-3, 3-4, 4-5, and 5-6 kg / 230°C at a load of 21.6 kg for 10 minutes. In some examples, sintered porous UHMWPP can further include activated carbon particles. In some examples, sintered porous UHMWPP can further include surfactants.

[0035] Figure 4A simplified schematic diagram of the top portion of a writing instrument according to some examples is shown, the top portion comprising a sintered porous ultra-high molecular weight polypropylene tip. The top portion 400 of the writing instrument may include a tip 420 connected to a body 410. The body 410 is made of polypropylene. The tip 420 is made of sintered porous ultra-high molecular weight polypropylene (“UHMWPP”) material. The sintered porous UHMWPP material may have a viscosity-average molecular weight exceeding 500,000. The sintered porous UHMWPP material has an average pore size ranging from 10 μm to 200 μm and a porosity ranging from 20% to 60%. In some examples, the sintered porous UHMWPP material is manufactured from UHMWPP powder having an average particle size ranging from 10 μm to 300 μm.

[0036] Figure 5 A schematic diagram of a liquid dispensing device according to some examples is shown, the liquid dispensing device comprising a sintered porous ultra-high molecular weight polypropylene core. In some examples, the liquid dispensing device may be a fragrance dispensing device or an insecticide dispensing device. Liquid dispensing device 500 includes a core 510 in fluid communication with a solution 530 and a housing 520 disposed therein. The core 510 is made of sintered porous ultra-high molecular weight polypropylene (“UHMWPP”) material. The sintered porous UHMWPP material has an average pore size ranging from 10 μm to 200 μm and a porosity ranging from 20% to 60%. The sintered porous UHMWPP material may have a viscosity-average molecular weight exceeding 500,000. In some examples, the sintered porous UHMWPP material is made from UHMWPP powder having an average particle size ranging from 10 μm to 300 μm. The housing 520 is made of polypropylene material. In some examples, the solution 530 may contain fragrance or insecticide.

[0037] As will be apparent to those skilled in the art upon reading this disclosure, each individual embodiment described and illustrated herein has discrete parts and features that can be readily separated from or combined with features of any of the other several embodiments without departing from the scope or spirit of this disclosure.

[0038] For purposes of illustration and description, the foregoing description of exemplary embodiments of the present disclosure has been presented and set forth in order to provide those skilled in the art with a complete disclosure and description of how to make and use embodiments of the present disclosure. It is not intended to be exhaustive or to limit the disclosure to the precise forms described, nor is it intended to represent that the experiments described are all or only the experiments performed. Although the present disclosure has been described in some detail by way of illustration and example for the purpose of clarity, it will be apparent to those skilled in the art, based on the teachings of the present disclosure, that certain changes and modifications may be made therein without departing from the spirit or scope of the appended claims.

[0039] Therefore, the foregoing merely illustrates the principles of the invention. It will be understood that those skilled in the art will be able to conceive of various arrangements, which, although not explicitly described or shown herein, embody the principles of the invention and are included within its spirit and scope. Furthermore, all embodiments and conditional language described herein are primarily intended to assist the reader in understanding the principles of this disclosure and are not intended to limit the scope to such specifically described embodiments and conditions. Moreover, all statements herein regarding the principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to cover both structural and functional equivalents. Additionally, such equivalents are intended to include both currently known equivalents and future-developed equivalents, i.e., any element developed to perform the same function, regardless of its structure. Therefore, the scope of the invention is not intended to be limited to the exemplary embodiments shown and described herein. Rather, the scope and spirit of the invention are embodied in the appended claims.

[0040] Unless explicitly stated otherwise, the use of "a / kind" or "the / described" is intended to mean "a / kind or more / kinds". Unless explicitly stated otherwise, the use of "or" is intended to mean "inclusive or", not "exclusive or". A reference to the "first" component does not necessarily require the provision of the second component. Furthermore, unless explicitly stated otherwise, a reference to the "first" or "second" component does not limit the referenced component to a particular location. The term "based on" is intended to mean "at least partially based on".

[0041] Claims may be drafted to exclude any optional elements. Therefore, this statement is intended to serve as a basis for the use of such exclusive terms as “alone,” “only,” etc., or the use of “negative” limitation in relation to the description of the claim elements.

[0042] Where a numerical range is provided, it should be understood that each intermediate value between the upper and lower limits of the range (accurate to one-tenth of the lower limit unit unless the context clearly indicates otherwise) is also specifically disclosed. Each smaller range between any stated value or intermediate value in the range and any other stated value or intermediate value in the range is included within embodiments of this disclosure. The upper and lower limits of these smaller ranges may independently include or exclude them from the range, and each range—where any limit value, no limit value, or both limit values ​​are included in the smaller range—is also included in this disclosure, except for any specifically excluded limit values ​​in the range. Where the range includes one or two limit values, the range excluding any one or both of those included limit values ​​is also included in this disclosure.

[0043] All patents, patent applications, publications, and descriptions mentioned herein are incorporated herein by reference in their entirety for all purposes, as if each individual publication or patent were specifically and individually indicated to be incorporated herein by reference, and are incorporated herein by reference to disclose and describe methods and / or materials relating to the cited publications. None of them are acknowledged as prior art.

Claims

1. A composition comprising: a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

2. A pipette tip comprising: a tubular tip defining a reservoir for receiving a sample, wherein the tubular tip comprises polypropylene; and a porous thermoplastic plug mounted in the tubular tip, wherein the porous thermoplastic plug comprises a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

3. A solid phase extraction column comprising: a barrel defining a sample reservoir, wherein the barrel comprises polypropylene; and a plurality of frits disposed in the barrel, wherein the plurality of frits comprises a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

4. A porous device comprising: a housing comprising a plurality of pores, wherein the housing and the plurality of pores comprise polypropylene; and a plurality of filters disposed in the housing, wherein the plurality of filters comprises a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

5. A writing instrument comprising: a barrel containing a solution, wherein the barrel comprises polypropylene; and a tip connected to the barrel, wherein the tip comprises a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

6. A liquid applicator comprising: a housing containing a solution, wherein the housing comprises polypropylene; and a filter disposed in the housing, wherein the filter comprises a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

7. A liquid dispensing device comprising: a housing containing a solution, wherein the housing comprises polypropylene; and a wick in fluid connection with the solution and disposed in the housing, wherein the wick comprises a sintered, porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight in excess of 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

8. The dispensing device of claim 7, wherein the solution comprises a fragrance or a pesticide.

9. A device comprising the composition of claim 1.

10. The device of claim 9, wherein the device is a liquid collection device comprising a polypropylene housing and a filter comprising the composition of claim 1 or a diagnostic device comprising a polypropylene housing and a component comprising the composition of claim 1.

11. A recycling method comprising: reprocessing a device by melting the device without separating device components, wherein the device components include a housing comprising polypropylene and a functional component comprising a sintered porous ultra-high molecular weight polypropylene material having a viscosity average molecular weight exceeding 500,000, an average pore size ranging from 10 pm to 200 pm, and a porosity ranging from 20% to 60%.

12. A recycling method comprising: placing a recyclable article in a recycling chamber, wherein the recyclable article is thermoplastic, wherein the recyclable article includes a component comprising a porous sintered polymeric material, wherein each component of the recyclable article comprises the same repeating subunit molecule; depolymerizing the recyclable article by heating the recycling chamber to obtain a plurality of subunit molecules; purifying the plurality of subunit molecules to obtain a plurality of purified subunit molecules; and re-polymerizing the plurality of purified subunit molecules to form a recycled polymer.

13. The method of claim 12, wherein the sintered polymeric material has a porosity ranging from 20% to 60%, wherein the sintered polymeric material is polypropylene, and the sintered polymeric material has a viscosity average molecular weight exceeding 500,000 or 1,000,000.

14. The method of claim 12, wherein the recyclable article is any one of the pipette tip of claim 2, the porous device of claim 4, the writing instrument of claim 5, the liquid applicator of claim 6, the liquid collection device or diagnostic device of claim 10. ​

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