Polymer compositions containing zeolite for enhanced water adsorption

Abstract

To provide zeolites and polymer compositions with zeolites having enhanced adsorption capacity for adsorption of water, ammonia and other similar compounds, particularly to provide aluminosilicate zeolites and methods for preparing zeolite entrained polymer compositions having enhanced water adsorption properties, and also to provide improved packaging materials having enhanced water adsorption properties incorporating the polymer compositions containing zeolites.SOLUTION: The present invention provides a process for producing a polymer composition having enhanced adsorption.SELECTED DRAWING: Figure 7A

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority under 35 U.S.C. § 119(e) from U.S. Provisional Patent Application No. 62 / 961,024, filed on January 14, 2020, entitled "ZEOLITE WITH ENHANCED WATER ADSORPTION"; U.S. Provisional Patent Application No. 62 / 961,038, filed on January 14, 2020, entitled "COMPOSITES CONTAINING ZEOLITE FOR ENHANCED WATER ADSORPTION"; and U.S. Provisional Patent Application No. 62 / 827,332, filed on April 1, 2019, entitled "ZEOLITE WITH ENHANCED WATER ADSORPTION", and the entire contents of all three of these applications are hereby incorporated by reference in their entirety.

[0002] The present invention generally relates to zeolites and polymer compositions having zeolites with improved adsorption capacities for the adsorption of water, ammonia, nitrogen, and oxygen. The present invention particularly relates to aluminosilicate zeolites and methods for preparing zeolite - incorporated polymer compositions having improved water adsorption characteristics. The present invention also relates to improved packaging materials having improved water adsorption characteristics incorporating polymer compositions containing zeolites.

Background Art

[0003] The adsorption of water by materials is important for many applications that require the capture and release of water, such as dehumidifiers, adsorption heat pumps, and various specialty packaging. One of the most promising adsorption heat pump technologies in this context is based on the evaporation and continuous adsorption of water under specific conditions. The water content in natural gas is an important concern in adsorption heat pumps because it can cause corrosion and hydrate formation leading to pipeline blockages.

[0004] A high-humidity environment promotes the breeding of house dust mites and provides an environment suitable for the growth of fungi and various harmful bacteria. The relative humidity of the atmosphere is an important factor affecting health. There is a continuing need for dehumidifying materials for home and commercial environments to control moisture conditions and reduce the levels of harmful microorganisms.

[0005] The need for moisture removal technology and moisture management packaging is also important for improving the quality and safe storage of processed foods, pharmaceuticals, and cosmetics. The transportation and storage of moisture-sensitive materials such as electronic components and ammunition also require moisture management packaging.

[0006] The use of adsorption technology is also required for environmental pollution removal and purification efforts, and the demand for such clean technologies continues to increase as the number and complexity of industrial processes worldwide increase. Therefore, there is a continuing need to control humidity, and there is a need to develop highly efficient adsorbent technologies including novel and effective adsorbent materials.

[0007] Several strategies involving the use of solid or liquid desiccants, membranes, cooling, and supersonic methods have been used to remove water vapor from gas streams. One of the most effective strategies is the use of solid porous beds incorporating porous desiccants with effective properties for removing water vapor from gas mixtures. Various porous materials such as zeolites, metal-organic frameworks, clays, carbon-based adsorbents, and organic polymers have been explored for various applications. Polymer membranes for gas separation such as natural gas sweetening, landfill gas recovery, hydrogen recovery and purification, flue gas, and air separation are one of the most important applications using inorganic porous and non-porous materials dispersed in a polymer matrix. Fillers such as metal-organic frameworks (MOFs), activated carbon (AC), mesoporous silica (MS), and zeolites have been incorporated into polymers to confer some degree of adsorption, permeability, and selectivity to the composite materials.

[0008] Zeolites are compounds that act as molecular sieves and are widely used due to their high adsorption properties as well as their thermal, chemical, and mechanical stability. Zeolites are known for their moisture absorption properties. Zeolites are used not only for drying solutions, dehumidifying enclosed spaces, but also for drying fabrics after the washing process and as drying components for tableware in dishwashers. U.S. Patent No. 8,904,667 teaches a drying solution and its production based on a zeolite material with thermal management containing titano-alumino-phosphate as an adsorbent for energy-improved drying of objects such as fabrics. The first prototypes of adsorption heat or cooling pumps used an adsorption bed made from zeolite free particles. Zeolite-based materials are also used in powder form to remove contaminant cations present in wastewater. The selectivity of zeolites is particularly used for odor removal due to its ability to adsorb trace levels of volatile organic compounds in the atmosphere. Therefore, zeolite-based composites for water removal present a large area of interest.

[0009] Zeolites are crystalline aluminosilicates having a three-dimensional open anion framework consisting of oxygen-sharing SiO4 and AlO4 - tetrahedral structures. Essentially all zeolites are aluminosilicates, but some contain more alumina and others contain more silica. Alumina-rich zeolites are attracted to polar molecules such as water, while silica-rich zeolites act better with non-polar molecules. Each silicon ion has its +4 charge balanced by four tetrahedral oxygens, and thus the silica tetrahedron is electrically neutral. Since trivalent aluminum is bonded to four oxygen anions, each alumina tetrahedron has a residual charge of -1. Therefore, each alumina tetrahedron requires a +1 charge from extra-framework cations in its microporosity to maintain electrical neutrality.

[0010] Sodium cations typically exist within the zeolite structure in their natural or synthetic form. Sodium ions can be exchanged by monovalent, divalent, or trivalent cations. In some studies, the roles of cations such as Na+, K+, Li+, Mg2+, Ca2+, Zn2+, Mn2+, and Fe3+ in increasing the affinity between the adsorbate and the adsorbent or modifying the separation characteristics of zeolites have been discussed. Furthermore, aluminosilicate zeolites containing compensating cations in their frameworks are known to exhibit high hydrophilicity, especially those with a low Si / Al ratio that gives them a strong affinity for water.

[0011] The most common zeolites used for water adsorption in the industry are the LTA-type zeolites 3A (potassium or KA) and 4A (sodium or NaA) zeolites, as well as the FAU-type zeolite 13X (sodium or NaX) zeolite. LTA (Linde Type A) is also known as zeolite A. The main building unit of zeolite A is the sodalite cage connected by four-membered rings that form a three-dimensional (3D) network structure. The aluminosilicate framework of zeolite A (LTA type) can be further explained from the perspective of two types of polyhedra. One is the simple cubic arrangement of eight polyhedra (double four-rings), and the other is the truncated octahedron of 24 tetrahedra, also called the β-cage. In LTA zeolite, the sodalite cages are connected via double four-rings, creating an α-cage at the center of the unit cell. Alternatively, the framework can be described as the basic cubic arrangement of α-cages connected via a single eight-ring. Zeolite A has a three-dimensional pore system, and molecules can diffuse in all three directions. Usually, zeolite A exists or is synthesized in its sodium form with a pore aperture of approximately 0.4 nm.

[0012] The FAU-type (faujasite) zeolite is another common form of zeolite used for water adsorption. The faujasite framework consists of supercages or sodalite cages connected via hexagonal prisms. The pores are formed by twelve-membered rings and have a relatively large diameter of 7.4 Å. The internal cavities have a diameter of 12 Å and are surrounded by ten sodalite cages. The unit cell is cubic. Due to its structure, the FAU-type zeolite is one of the main components of cracking catalysts on an industrial scale and is used to convert high-boiling fractions of petroleum crude oil into more valuable gasoline, diesel, and other products.

[0013] Water adsorption in zeolites has been reported to be mainly directed by the interaction between water, charge-compensating cations, and the zeolite framework. Depending on the charge (monovalent or divalent cations) and kinetic diameter of the compensating cations, the available microporous volume and proximity to the pores are modified, resulting in different adsorption behaviors and adsorption capacities. LTA and FAU-type zeolites exhibit attractive adsorption uptake and high hydrophilicity, but their overall performance regarding water adsorption is still not optimal, mainly due to the nature, size, and affinity of the compensating cations towards water molecules.

[0014] Furthermore, although zeolites are excellent candidates for water adsorption as a result of their shape and pore distribution, the processing of zeolites into composite materials such as polymers has proven to pose challenges in the industry. There are problems with the use of zeolites in powder form in polymer manufacturing. There is a significant need for the improvement of zeolite adsorbents for application to adsorptive polymer materials that can be incorporated into existing polymer manufacturing processes such as extrusion. It remains a challenge to find high-performance materials that combine high water uptake, precise operating pressure range control, stability, recyclability, and cost suitability.

[0015] Examples of polymers incorporating moisture sorbing desiccants are disclosed in U.S. Patent Nos. 6,174,952 and 6,316,520, which teach a process for producing a modified polymer having interconnected channels and the resulting structure. The interconnected channels function as controlled permeation pathways through the polymer. The hydrophilic agent is blended into the polymer so as to be dispersed therein. In one embodiment, a water sorbing material such as zeolite is blended into the polymer so that the water sorbing material is dispersed within the product. The polymer product is solidified such that the hydrophilic agent forms channels within the product, through which a desired composition can communicate with the water sorbing material incorporated within the product. The solidified product may be used to form desired molded articles such as plug type inserts and liners for sealed containers, or may be formed into films, sheets, beads or pellets.

[0016] Hodgkin and Solomon considered how the chemical reactivity of fillers and pigments used in commercially available polymer formulations often causes detrimental polymer-filler interactions unless compensating additives are applied during compounding. They described a method for reducing these interactions by forming a stable, inert magnesium-silicate gel-coating on the surface of the mineral filler. Various methods for measuring this reduction in chemical activity were considered. (Magnesium-Silicate Coated Minerals as Polymer Fillers and Pigments, Journal of Macromolecular Science: Part A-Chemistry, J.H. Hodgkin & D.H. Solomon, Vol. 8, Issue 3, 1974)

[0017] The present invention involves a method for preparing a zeolite material having improved water adsorption characteristics. The present invention relates to a composite material incorporating zeolite as a filler, which not only retains the zeolite performance within the polymer composition but also improves its water adsorption capacity. The polymer material of the present invention has the advantages of a high surface area for water adsorption, a high adsorption capacity, measurable mechanical strength, relative cost-effectiveness, and being non-corrosive, non-toxic, and chemically inert. A further important advantage of the process of the present invention is its operability within existing polymer manufacturing processes.

Summary of the Invention

[0018] Disclosed herein is a polymer composition comprising LTA-type and FAU-type aluminosilicate zeolites in powder form exchanged with lithium and magnesium cations, which functions to improve the water adsorption or sorption characteristics of the polymer composition. Specifically, disclosed herein is a process for making a polymer composition that improves sorption, comprising: (a) providing a crude aluminosilicate zeolite; (b) treating the crude zeolite with a solution containing monovalent, divalent, or trivalent cations to form a treated cation-exchanged zeolite; (c) optionally, repeating step (b) one or more times; (d) drying the treated cation-exchanged zeolite to provide a dried cation-exchanged zeolite having a water adsorption capacity greater than that of the crude zeolite before the cation exchange treatment; (e) optionally, repeating steps (b) and (c) one or more times; (f) adding and blending the dried cation-exchanged zeolite with a base polymer; and (g) forming a polymer composition having a water adsorption capacity per gram of zeolite greater than that of the crude zeolite. Also disclosed are the polymer compositions prepared by the method and packaging materials containing the polymer compositions.

[0019] Furthermore, a polymer composition for improving pick-up is disclosed, the polymer composition comprising (a) a monovalent, divalent or trivalent cation exchange aluminosilicate zeolite and (b) a base polymer, the polymer composition having a water adsorption capacity per gram of zeolite greater than that of a reference crude sodium zeolite.

Brief Description of the Drawings

[0020] The following detailed description of the technology disclosed herein will be better understood when read in conjunction with the accompanying drawings. For the purpose of exemplifying the technology disclosed herein, various exemplary embodiments are shown in the drawings. However, it goes without saying that the technology disclosed herein is not limited to the detailed arrangements and means shown. The present invention will be described in conjunction with the following drawings, and the same reference numerals refer to the same elements.

[0021]

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6A

Fig. 6B

Fig. 6C

Fig. 7A

Fig. 7B

Fig. 7C

Mode for Carrying Out the Invention

[0022] Water adsorption onto hydrophilic zeolites such as LTA and FAU types mainly depends on the available porous volume, interaction with the oxygen atoms of the framework, and interaction with the compensating cations (solvation layer). Since the hydrophilic zeolite framework and water molecules are polarized, electrostatic attraction can occur. The present invention provides an increase in the available microporous volume and increased water adsorption of a polymer composition mixed with the exchanged zeolite by the substitution of sodium cations by smaller monovalent cations such as lithium or smaller divalent cations such as magnesium, and their incorporation into the polymer material (+15% and +22% respectively for the available microporous volume of FAU-type zeolites exchanged with magnesium and lithium, compared to the crude sample). The larger available microporous volume and less crowded pore openings increase the proximity of water (or other substances) (N2 in LTA) to the pores within the zeolite particles, improving the storage of water (or other substances). Furthermore, by the method of the present invention, divalent cations bring about a higher degree of order of water molecules around them, whereby the improved spatial structure further contributes to the increase in water adsorption capacity. According to the method of the present invention, the most significant increase in water adsorption is observed for sodium zeolite samples that have undergone cation exchange with magnesium, resulting in an increase of more than 30% in the adsorption volume of the composite material for both LTA-type and FAU-type zeolites compared to the polymer material containing crude sodium zeolite without cation exchange. Preferred zeolites used in the present invention are aluminosilicate zeolites containing sodium, magnesium, lithium, potassium, calcium, zinc, iron, and manganese cations.

[0023] As mentioned herein, the zeolite compounds according to the present invention include not only aluminosilicates containing compensating cations, but also silicoaluminophosphate zeolites. In various embodiments, prior to incorporation of the prepared zeolite into the base polymer, a solution containing cations of sodium, magnesium, lithium, potassium, calcium, zinc, manganese and iron is used in the cation exchange pretreatment and preparation process of the present invention to impart improved water adsorption properties to the prepared zeolite. Optional embodiments include LTA-type or FAU-type zeolites used in the polymer compositions of the present invention. In a preferred embodiment, the crude zeolite is a sodium zeolite and is treated with a solution containing Mg2+, Li+, K+, Ca+, Zn2+, Mn2+ and Fe3+ cations, or combinations thereof.

[0024] In addition to its water sorption properties, in an alternative embodiment, the polymer compositions of the present invention also function to absorb or adsorb ammonia (NH3), nitrogen (N2) and oxygen (O2).

[0025] Generally, the term "adsorption" refers to the adhesion of atoms, ions or molecules from a gas, liquid or dissolved solid to a surface. The adsorption process creates a film of adsorbate on the surface of the adsorbent. Adsorption is a surface phenomenon. The term "absorption" refers to the physical or chemical phenomenon or process by which atoms, molecules or ions enter a liquid or solid material. Absorption is a state in which the absorbed substance is dissolved or penetrated by the liquid or solid (absorbent) respectively. Absorption involves the volume of the material. In the process of absorption, the molecules undergoing absorption are taken up by the volume rather than the surface, whereas in adsorption, the molecules undergoing adsorption are taken up by the surface. The term "sorption" encompasses both the processes of absorption and adsorption, as well as the process of ion exchange. According to the present invention, the terms "absorption", "adsorption" and "sorption" are used herein with the same meaning. Whenever one of these terms is used throughout this specification and the claims, such term is intended to include and encompass all three processes of absorption, adsorption, and ion exchange.

[0026] As used herein, the term "base polymer" is optionally a polymer having a gas permeation rate such that the gas permeability of the selected material is significantly lower than, lower than, or substantially equivalent to that of the channeling agent. By way of example, in embodiments where the selected material is moisture and the activating agent is an antibacterial gas releasing agent activated by moisture, such permeability is the water vapor permeability. The activating agent may include an active ingredient and other ingredients in a formulation configured to release an antibacterial gas. The primary function of the base polymer is to provide structure to the incorporated polymer and zeolite.

[0027] In certain embodiments, the channeling agent has a water vapor permeability of at least 2 times that of the base polymer. In other embodiments, the channeling agent has a water vapor permeability of at least 5 times that of the base polymer. In other embodiments, the channeling agent has a water vapor permeability of at least 10 times that of the base polymer. In still other embodiments, the channeling agent has a water vapor permeability of at least 20 times that of the base polymer. In yet another embodiment, the channeling agent has a water vapor permeability of at least 50 times that of the base polymer. In still other embodiments, the channeling agent has a water vapor permeability of at least 100 times that of the base polymer.

[0028] As used herein, the term "channeling agent(s)" is defined as a material that is immiscible with the base polymer and has an affinity to transport gaseous substances at a faster rate than the base polymer. Optionally, the channeling agent can form channels through the incorporated polymer when formed by mixing the channeling agent with the base polymer. Optionally, such channels can propagate a selected material, such as water, through the incorporated polymer at a faster rate than the base polymer alone.

[0029] As used herein, the terms "channel" or "interconnecting channel" are defined as passages formed by a channeling agent that penetrate the base polymer and may be interconnected with each other.

[0030] As used herein, the terms "container" or "packaging material", and "packaging" may be used interchangeably herein to refer to a structure that holds or contains a good or product. Optionally, the packaging material may include a container in which the product is stored. Non-limiting examples of containers, packaging materials, and packaging include boxes, trays, cartons, bottles, vessels, pouches, and bags. The packaging material or container may be closed, covered, and / or sealed using various mechanisms, such as, for example, covers, lids, lid seals, adhesives, and / or heat seals. The packaging material or container may be composed or constructed of various materials, such as plastics, metals, resins, glass, wood, combinations thereof, and any other materials.

[0031] As used herein, the term "adulterated polymer" is defined as a monolithic material formed from a base polymer in which at least an activator and optionally a channeling agent are admixed or dispersed throughout. Thus, adulterated polymers include two-phase polymers (without a channeling agent) and three-phase polymers (with a channeling agent).

[0032] As used herein, the terms "monolithic", "monolithic structure", or "monolithic composition" are defined as a composition or material that does not consist of two or more separate macroscopic layers or parts. Thus, "monolithic compositions" do not include multilayer composites.

[0033] As used herein, the term "phase" is defined as a part or component of a monolithic structure or composition that is uniformly distributed throughout so as to impart its monolithic properties to the structure or composition.

[0034] As used herein, the term "selected material" is defined as a material that acts on, is acted upon by, or interacts or reacts with an active agent and can propagate through the channels of the incorporated polymer. For example, in embodiments where the release material is the active agent, the selected material may be moisture that reacts with or otherwise attracts the active agent.

[0035] As used herein, the term "three-phase" is defined as a monolithic composition or structure that includes three or more phases. An example of a three-phase composition according to the present invention is an incorporated polymer formed from a base polymer, an active agent, and a channeling agent. Optionally, the three-phase composition or structure may include additional phases, such as a colorant, but is still considered "three-phase" due to the presence of the three main functional components.

[0036] The zeolite-incorporated polymer composition of the present invention functions to remove, reduce, capture, control, or modify the amount of water in the environment. In an optional embodiment, the polymer composition herein is preferably placed in a sealed environment, such as a sealed chamber, container, or packaging material, to cause sorption of moisture within the space of the sealed environment.

[0037] Conventionally, to control the internal environment of packaging materials, desiccants, sorbents, oxygen absorbers, and other active agents have been used in their as-received form, for example, as loose particles contained in bags or canisters within the packaging material. For many applications, such loose-stored active substances are undesirable. Accordingly, the present application provides an active incorporated polymer that includes zeolite as an active agent, and such polymers can be extruded, molded, or heat-melted into various desired forms, such as containers, container liners, plugs, film sheets, pellets, covers, seal rings, and other such structures, to assist in water adsorption and thereby extend the shelf life of many products.

[0038] The polymer composition of the present invention may be prepared by any known conventional manufacturing process such as extrusion, injection molding, blow molding, thermoforming, vacuum forming, continuous compounding, and hot melt dispensing, in which zeolite is added to the base polymer during the manufacturing process, the materials are combined, and generally mixed or blended to some extent with each other. The combination of the base polymer mixed with the generated zeolite becomes the incorporated polymer composition. According to the present invention, it is not necessary to uniformly distribute the zeolite throughout the base polymer in order to imbue the incorporated polymer composition with moisture replenishment and capture properties. In an optional embodiment, the zeolite may be uniformly or essentially uniformly distributed within the base polymer such that the incorporated polymer composition is homogeneous or essentially homogeneous.

[0039] Optionally, the incorporated polymer composition of the present invention may include a channeling agent that forms channels between the surface and the interior of the incorporated polymer to propagate (adsorb moisture) a selected material (e.g., moisture) to the incorporated zeolite activator. As described above, optional embodiments of the present invention include an incorporated polymer composition that may be a two-phase formulation (i.e., including a base polymer and an activator and not including a channeling agent) or a three-phase formulation (i.e., including a base polymer, an activator, and a channeling agent). Incorporated polymers are described, for example, in U.S. Pat. Nos. 5,911,937, 6,080,350, 6,124,006, 6,130,263, 6,194,079, 6,214,255, 6,486,231, 7,005,459, and U.S. Patent Publication No. 2016 / 0039955, each of which is incorporated herein by reference as if fully set forth.

[0040] One aspect of the present invention is that a zeolite composition to be mixed or blended with a base polymer herein is first prepared by treating a crude zeolite with a solution containing monovalent, divalent or trivalent cations to form a treated cation-exchanged zeolite, and optionally repeating the treatment one or more times depending on the desired degree and amount of cation exchange, and then drying the treated cation-exchanged zeolite to provide a dried cation-exchanged zeolite, the dried cation-exchanged zeolite having a water adsorption capacity greater than that of the crude zeolite before the cation exchange treatment, and then optionally repeating these steps one or more times again. As used herein, the term "crude" refers to the raw or unchanged state of the zeolite material prior to ion exchange, generally cation exchange herein, according to the method of the present invention. In an optional preferred embodiment, the crude zeolite used herein is a zeolite containing sodium.

[0041] Referring now to the figures in detail, like reference numerals refer to like parts throughout. Shown in FIGS. 1-4 are exemplary incorporated polymers 10 that can be used in conjunction with aspects of the present invention. Each of the incorporated polymers 10 includes an activator that is a base polymer 25, a channeling agent 35, and a zeolite 30. As shown, the channeling agent 35 forms interconnected channels 45 through the base polymer 10. At least a portion of the zeolite 30 is contained within these channels 45 such that the channels 45 communicate between the zeolite 30 and the exterior of the incorporated polymer 10 via channel openings 48 formed in the outer surface of the incorporated polymer 25. Although a channeling agent, such as 35, is preferred, in an optional aspect, the present invention includes incorporated polymers that do not include a channeling agent.

[0042] Suitable base polymers include thermoplastic polymers such as polyolefins like polypropylene and polyethylene, polyhydroxyalkanoates (PHA), polylactic acid (PLA), polybutylene succinate (PBS), polyisoprene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, poly(vinyl chloride), polyvinyl pyrrolidone, polystyrene, polyester, polyanhydride, polyacrylianitrile, polysulfone, polyacrylate, acrylic, polyurethane, and polyacetal, or copolymers or combinations thereof.

[0043] Suitable channeling agents include polyglycols such as polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerin polyamine, polyurethane, and polycarboxylic acids including polyacrylic acid or polymethacrylic acid. Alternatively, the channeling agent 35 can be a water-insoluble polymer such as a propylene oxide polymerisate-monobutyl ether such as Polyglykol B01 / 240 manufactured by Clariant Specialty Chemicals. In other embodiments, the channeling agent can be a propylene oxide polymerisate monobutyl ether such as Polyglykol B01 / 20 manufactured by Clariant Specialty Chemicals, a propylene oxide polymerisate such as Polyglykol D01 / 240 manufactured by Clariant Specialty Chemicals, ethylene vinyl acetate, 6 nylon, 66 nylon, or any combination of the foregoing.

[0044] Generally, it is considered that the higher the concentration of the activator in the polymer composition, the greater the sorption of the final composition. However, if the concentration of the zeolite is too high, the incorporated polymer becomes more brittle, and the molten mixture of the activator, base polymer, and channeling agent may become more difficult to thermoform, extrude, injection mold, or hot melt.

[0045] In embodiments of the present invention, the filling level of the zeolite in the incorporated polymer composition can be in the range of 10 wt% to 80 wt%, preferably 20 wt% to 70 wt%, more preferably 30 wt% to 60 wt%, and even more preferably 25 wt% to 55 wt% based on the total weight of the incorporated polymer. Optionally, the base polymer can be in the range of 10 wt% to 90 wt%, preferably 20 wt% to 80 wt% of the total composition. When an optional channeling agent is used, the channeling agent can be provided in the range of 2 wt% to 15 wt%, optionally in the range of 2 wt% to 10 wt%, and preferably about 5 wt%.

[0046] Referring to FIG. 1, an insert 20 composed of the incorporated polymer of the present invention is shown. The insert 20 can be in the form of a plug 55 that may be placed within the packaging material or chamber of the container to capture moisture from the moisture products stationary within the container.

[0047] Referring to FIG. 2, a cross-sectional view of a plug 55 composed of an incorporated polymer 10 including a base polymer 25 uniformly blended with zeolite 30 and an optional channeling agent 35 is shown. In the illustration of FIG. 2, the incorporated polymer is solidified such that interconnected channels 45 are formed throughout the incorporated polymer 10 and passages are established throughout the solidified plug 55. As can be understood from both FIGS. 1 and 2, the passages terminate at channel openings 48 on the outer surface of the plug 55, creating a larger surface area for the zeolite to capture moisture from the environment surrounding the polymer composition.

[0048] Figure 3 shows an embodiment of plug 55 having a configuration and composition similar to plug 55 in Figure 2, where the interconnect channels 45 are very fine compared to those in Figure 2. This can be brought about by using a dimerizing agent (i.e., a plasticizer) together with the channeling agent 35. The dimerizing agent can improve the compatibility between the base polymer 25 and the channeling agent 35. This improvement in compatibility is facilitated by a decrease in the viscosity of the blend, thereby promoting a more complete blend of the base polymer 25 and the channeling agent 35, which may be difficult to mix into a homogeneous solution under normal conditions. When the polymer blend 10 with the added dimerizing agent solidifies, the interconnect channels 45 formed throughout have a greater dispersion and a smaller porosity, thereby establishing a higher density of interconnect channels throughout the plug 55.

[0049] Figure 4 shows an embodiment of the polymer blend 10 according to the invention, which includes zeolite as the activator 30. The arrows indicate the path of the moisture-containing gas, or optionally a liquid, from outside the polymer blend 10, through the channels 45, to the particles of zeolite 30 that absorb or adsorb moisture.

[0050] Interconnect channels 45, such as those disclosed herein, generally facilitate the permeation of moisture through a base polymer 25 that is difficult for gases or liquids to penetrate and thus functions as a barrier thereto. For this reason, the base polymer 25 itself functions as a barrier material into which an activator 30 can be incorporated. The interconnect channels 45 formed by the channeling agent 35 provide a path for gases or liquids to move through the incorporation polymer 10. In the absence of these interconnect channels 45, it is thought that only a relatively small amount of the desired material would permeate through the base polymer 25 to or from the activator 30. Thus, gases or liquids are permeated into the zeolite 30, and the zeolite absorbs or adsorbs a much larger amount than the material without the incorporated zeolite. Accordingly, in one aspect, a zeolite as a sorbent and an incorporation polymer comprising a base polymer are used in embodiments of the present invention. In another aspect, an incorporation polymer comprising a zeolite as a sorbent, a base polymer, and a channeling agent may be used in embodiments of the present invention.

[0051] Figure 5 shows a sheet or film 75 formed of an incorporation polymer 20 used in combination with a barrier sheet 80 to form a composite, according to an optional aspect of the present invention. The properties of the sheet or film 75 are similar to those described with respect to the plug 55. The barrier sheet 80 may be a substrate such as a foil and / or polymer having low moisture or oxygen permeability. The barrier sheet 80 is compatible with the incorporation polymer sheet or film 75 and is thus configured to thermally adhere to them when the sheet or film 75 solidifies after dispensing.

[0052] In one embodiment, the filling level of the zeolite is in the range of 10 wt% to 80 wt%, optionally 20 wt% to 70 wt%, optionally 30 wt% to 60 wt%, optionally 40 wt% to 50 wt%, optionally 45 wt% to 65 wt%, optionally 45 wt% to 60 wt%, optionally 45 wt% to 55 wt%, optionally 50 wt% to 70 wt%, optionally 50 wt% to 60 wt%, optionally 55 wt% to 65 wt%, optionally 55 wt% to 60 wt% based on the total weight of the polymer incorporated.

[0053] In one embodiment, the concentration of the base polymer is in the range of 10 wt% to 80 wt%, optionally 20 wt% to 70 wt%, optionally 30 wt% to 60 wt%, optionally 40 wt% to 50 wt%, optionally 45 wt% to 65 wt%, optionally 45 wt% to 60 wt%, optionally 45 wt% to 55 wt%, optionally 50 wt% to 70 wt%, optionally 50 wt% to 60 wt%, optionally 55 wt% to 65 wt%, optionally 55 wt% to 60 wt%, 15 wt% to 75 wt%, optionally 25 wt% to 70 wt%, optionally 35 wt% to 60 wt%, optionally 45 wt% to 55 wt%, optionally 20 wt% to 50 wt%, optionally 20 wt% to 40 wt%, optionally 20 wt% to 35 wt%, optionally 25 wt% to 60 wt%, optionally 25 wt% to 50 wt%, optionally 25 wt% to 40 wt%, optionally 25 wt% to 30 wt%, optionally 30 wt% to 60 wt%, optionally 30 wt% to 50 wt%, optionally 30 wt% to 45 wt%, optionally 40 wt% to 60 wt%, optionally 40 wt% to 50 wt% of the polymer incorporated.

[0054] In one embodiment, the optional channeling agent ranges from 2 wt% to 25 wt%, optionally from 2 wt% to 15 wt%, optionally from 5 wt% to 20 wt%, optionally from 5 wt% to 15 wt%, optionally from 5 wt% to 10 wt%, optionally from 8 wt% to 15 wt%, optionally from 8 wt% to 10 wt%, optionally from 10 wt% to 20 wt%, optionally from 10 wt% to 15 wt%, or optionally from 10 wt% to 12 wt% based on the total weight of the incorporated polymer.

[0055] In one embodiment, the incorporated polymer may be a two-phase blend comprising 20 wt% to 50 wt% adsorbent and 50 wt% to 80 wt% base polymer (such as polypropylene). The base polymer is not particularly limited.

[0056] In one embodiment, the incorporated polymer may be a three-phase blend comprising 20 wt% to 45 wt% adsorbent, 30 wt% to 75 wt% base polymer (such as polypropylene), and 2 wt% to 12 wt% channeling agent. The base polymer and the channeling agent are not particularly limited.

[0057] The method for producing the incorporated polymer 10 according to the present invention is not particularly limited. By way of example, blending the base polymer 25 and the channeling agent 35 may be mentioned. The activator 30 is blended into the base polymer 25 either before or after the addition of the channeling agent 35. All three components are uniformly distributed within the incorporated polymer 10 mixture. The incorporated polymer thus prepared contains at least two or three phases.

[0058] The form of the incorporated polymer is not limited. Optionally, such an incorporated polymer may be formed into a component in the form of a film, sheet, disk, pellet, packaging material, container, cover, plug, cap, lid, insert, stopper, cork, gasket, seal, washer, liner, or ring.

[0059] The polymer composition of the present invention can be incorporated into any type of packaging material such as plastics, paper, glass, metal, ceramics, synthetic resins, or combinations thereof, and is not limited thereto. As described above, containers and packages having water adsorption characteristics are highly desired in various industries, and the polymer composition of the present invention can address and meet many packaging needs such as food packaging.

[0060] Further methods and materials for utilizing the zeolite-incorporated polymer compositions disclosed herein for water or ammonia adsorption are fully described by the embodiments for carrying out the invention and the examples described in detail below, and will be apparent to those skilled in the art from these.

Examples

[0061] Polymer composite films containing cation-exchanged LTA-type and FAU-type zeolites were prepared using aqueous solutions of MgCl2 and LiCl. Cation selection was made to have the minimum monovalent and divalent cations in order to maximize the available microporous volume. Next, the prepared samples were fully characterized using the following property evaluation techniques, and their adsorption performance was systematically evaluated by comparing their nitrogen and water adsorption isotherms. The cation-exchanged zeolites were shown as follows. In "cAy" or "cXy", "c" refers to the main compensating cation, and "y" refers to the number of exchange steps. For example, MgA-1 designates zeolite A exchanged once with Mg2+ cations.

[0062] Property Evaluation Techniques (1) X-ray fluorescence (XRF): Chemical analysis was performed on samples pre-pressed into 13 mm diameter pellets at a pressure of 5 tons for 10 minutes using an X-ray fluorescence (XRF) analyzer (PANalytical Zetium (4kW)) to determine the exchange ratio of cations in the samples.

[0063] (2) Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES): The sample was acid-digested at room temperature for 24 hours (0.05 grams of sample + 3 ml of 48.9% hydrofluoric acid (HF)). The solution thus obtained was diluted to 30 mL and then filtered at 0.45 μm before analysis using a Thermo ICAP 6300 DUO instrument.

[0064] (3) X-ray Diffraction (XRD): X-ray diffraction patterns were recorded on a PANalytical MPD X’Pert Pro diffractometer operating with Cu Kα radiation (Kα = 0.15418 nm) equipped with an X’Celerator real-time multi-strip detector (effective length = 2.12° 2θ). The XRD powder patterns were collected stepwise at 2θ with 0.017° and stepwise over a time of 220 seconds in the range of 3° < 2θ < 50° at 22 °C.

[0065] (4) Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX): SEM and EDX mapping were obtained on a Philips XL 30 FEG microscope. Prior to analysis, the samples were coated with a fine carbon layer using a BAL-TEC SCD004 sputter coating system to improve electrical conductivity. Composite samples (granules and molded parts) were immersed in a polymer resin before analysis. After curing, the polymer resin was polished in one plan until the sample was cut to obtain a depiction of the distribution of zeolite crystals.

[0066] (5) Solid-state nuclear magnetic resonance (solid NMR): 29Si solid magic angle spinning (MAS) NMR spectra and 1H decoupling were recorded on a Bruker AVANCE II 300WB spectrometer (B0 = 7.1 T) operating at 59.59 MHz with a pulse duration of 2.4 microseconds corresponding to a flip angle of π / 6 and a recycling delay of 80 seconds. The sample was filled into a 7 mm cylindrical zirconia rotor and rotated at a rotation frequency of 4 kHz. The 29Si chemical shift was referenced to tetramethylsilane (TMS). 27Al MAS NMR spectra were recorded on a Bruker AVANCE II 400WB spectrometer (B0 = 9.4 T) operating at 104.2 MHz using a 4 mm cylindrical zirconia rotor rotated at a rotation frequency of 12 kHz. The 27Al chemical shift was given relative to an aqueous solution of aluminum nitrate (Al(NO3)3). Typical acquisition parameters included a pulse duration of 0.5 microseconds corresponding to a flip angle of π / 12 and a waiting time of 1 second. Decomposition of the NMR spectra to extract the proportion of the corresponding species was performed using DMfit software.

[0067] (6) Tensile test measurement: Tensile tests were performed on a modernized INSTRON ZWICK dynamometer equipped with a 1 kN force cell. The specimens were tested at 10 mm / min until failure. The average value of the Young's modulus was determined for each sample.

[0068] (7) N2 adsorption / desorption measurement: The texture properties of the as-synthesized zeolite and ion-exchanged zeolite samples were determined from N2 adsorption / desorption isotherms measured at -196 °C using a Micromeritics ASAP2420 instrument. Prior to the sorption measurements, the samples (50 - 100 mg) were degassed under vacuum at 90 °C for 1 h and 300 °C for 15 h to remove any physically adsorbed water. The Brunauer - Emmett - Teller specific surface area (SBET) was calculated using the BET method, and the micropore volume (Vm) of the samples was determined using the t-plot method.

[0069] (8) Water adsorption measurement: The water adsorption isotherms of the raw zeolite and the prepared zeolite samples were carried out at 25 °C using a Micromeritics ASAP 2020 instrument. Before the water adsorption measurement, water (analyte) was rapidly frozen under liquid nitrogen and then evacuated at least 5 times under dynamic vacuum to remove any gas in the stored water. The sample (50 - 100 mg) was degassed under vacuum at 90 °C for 1 hour and 300 °C for 24 hours to remove physically adsorbed water. The water adsorption capacity of the sample was determined from the water adsorption isotherm.

[0070] The water adsorption kinetics of the raw materials, the exchanged zeolites and the composite materials (NaA - 0, LiA - 1 and MgA - 1) containing the raw zeolite and the exchanged zeolite were carried out at 30 °C and 80% relative humidity by tracking the weight change using a Memmert HCP 108 humidity chamber. The samples were taken out from the sealed bags in which they were stored after production to avoid moisture uptake and used directly for the measurement.

[0071] Example 1 Materials: (a) Zeolites: LTA - type zeolite (NaA) and FAU - type zeolite (NaX) were provided in powder form by CSP Technologies. Lithium chloride (LiCl, ACS Reag.Ph.Eur>99%) and magnesium chloride (MgCl2·6H2O, ACS - ISO for analysis>99%) salts were purchased from Merck and Carlo Erba, respectively. (b) Polymers: Polypropylene, polyethylene glycol (relative molar mass 4000 g / mol) and titanium dioxide were obtained from Aptar CSP Technologies.

[0072] Cation exchange: Zeolites for incorporation into the polymer composites according to the present invention were prepared by ion exchange of NaA and NaX zeolites. The sodium (Na+) compensating cations present in the parent zeolite were exchanged with magnesium (Mg2+) or lithium (Li+) cations by a cation exchange process in aqueous solutions of MgCl2 and LiCl. The starting zeolite (20 g) was blended with a 1 M aqueous cation solution prepared by mixing LiCl salt (16.96 g) or MgCl2 salt (81.32 g) with 400 mL of deionized water. Next, the reaction mixture was heated at 80 °C for 2 h with stirring. The mass ratio of the reaction mixture was 1 g of zeolite to 20 mL of the electrolyte aqueous solution. The pH value of this mixture was between 7 and 9. Next, the zeolite was filtered by centrifugation (8000 rpm, 5 min) and washed three times with cold deionized water (ca. 200 mL) with stirring (10 min). Next, all samples were dried at 80 °C for at least 24 h. The cation exchange process was repeated four times. After each cation exchange, the samples were fully characterized using the above techniques.

[0073] Results and Discussion: 1.1 X-ray fluorescence analysis and results were reported in Tables 1 and 2. [Table 1] a Experimental error 3% b The ratio is corrected from the small amount of extra-framework aluminum.

[0074] According to the chemical analysis in Table 1, the obtained Si / Al ratios were about 1 (1) for the as-made LTA-type zeolite and about 1.20 for the as-made FAU-type zeolite. As shown in Table 1, the loss of sodium and the increase of magnesium that occur simultaneously as the cation exchange proceeds indicate the success of the cation exchange. (A slight change in the Si / Al ratio was observed as the cation exchange step proceeded, resulting in negligible aluminum extraction.) Since the LTA-type and FAU-type zeolites differ in terms of structure and cation positions, only the trends should be compared and only the trends should be compared.

[0075] The overall charge ratio (Na / Al + 2Mg / Al) required to compensate for the negative charge generated by the presence of aluminum atoms was larger than that of the raw material. Due to the small cage openings, the exchange of sodium cations present in the sodalite cage microstructure may be difficult, so complete cation exchange was not observed. In particular, the cation exchange process occurred without causing a modification to the overall Si / Al molar ratio of both zeolites, which is an efficient technique for the chemical modification of zeolites.

Table 2

[0076] Table 2 shows the successful preparation of lithium-form zeolites. For the LTA-type zeolites, for the LiA-1 to LiA-4 samples, the simultaneous loss of sodium (Na / Al molar ratio 1.07 to 0.12) and the increase in lithium (Li / Al molar ratio 0 to 0.93) indicated the success of the exchange process. A similar trend was observed for the FAU-type zeolites.

[0077] Unlike magnesium exchange, the overall charge ratio (Na / Al + Li / Al) required to compensate for the negative charge generated by the presence of aluminum atoms and thus maintain the neutrality of the framework was lower than expected. For the LTA-type zeolites, the values of these ratios were equal to 0.78, 0.75, and 0.89 for LiA-1, LiA-2, and LiA-3, respectively, and equal to 0.75, 0.87, 0.89, and 0.95 for the FAU-type zeolites LiX-1 to LiX-4.

[0078] 1.2 X-ray diffraction property evaluation. Raw zeolite as well as Li + and Mg 2+The XRD patterns of the LTA-type zeolite cation-exchanged were analyzed. The unit cell parameters (a, b, and c) of the LTA-type zeolite having a cubic crystal system and the space group Fm-3c were determined with X’Pert HighScore and STOE Win XPOW software according to the Werner algorithm. In the control crude LTA zeolite sample, a = b = c was equal to 24.57 Å. After cation exchange, the unit cell parameters were a = b = c = 24.25 Å and 24.53 Å for LiA-1 and MgA-1, respectively. After cation exchange, the smaller the cation radii of lithium (0.69 Å) and magnesium (0.72 Å) compared to sodium (1.02 Å), the more it led to the shrinkage of the structure. These results also indicated the success of cation exchange in the prepared zeolite materials. No impurities were detected by XRD analysis. All XRD patterns of the prepared samples were similar to the XRD pattern of the parent material, indicating that cation exchange did not significantly affect the structure of the zeolite, thereby maintaining the water absorption properties of the zeolite in the preparation of subsequent incorporation into the composite material.

[0079] 1.3 Characterization of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Images of the crude materials were compared with samples of LTA-type and FAU-type zeolites (with Li+ and Mg2+) prepared according to the method of the present invention. The images showed a crystallized phase with the cubic crystal form characteristics of the LTA-type zeolite having a particle size in the range of 1 to 5 μm each. The FAU-type zeolite prepared according to the method of the present invention was expected to have a bi-conical form, but showed interconnected bi-conical crystals with a pseudo-spherical form. The particle size was in the range of about 1 to 4 μm. Regarding the samples prepared with magnesium cations, for both LTA-type and FAU-type zeolites, it was observed that the crystal form was preserved, but small particles seemed to cover the surface of the crystals. The XRF and EDX analyses shown in Table 1 indicated the loss of sodium cations after the preparation process favorable for the selected new cation Mg2+.

[0080] Using the EDX mapping with the above SEM images, the elemental distributions of Si, Al, Na, and Mg in the samples were examined. Each white pixel on the image indicated the presence of the corresponding atom. The loss of sodium cations, which are favorable for the exchanged cations (Li+ or Mg2+), was confirmed by the loss of intensity (whiteness) between the EDX Na mappings shown in the prepared materials compared to the samples of the raw materials. The image also showed a uniform distribution of magnesium atoms in the particles, indicating the success of the exchange process. As described above, both the LTA-type and FAU-type zeolites exchanged with magnesium cations were coated with small nanoparticles.

[0081] 1.4 Solid-state nuclear magnetic resonance (NMR) MAS NMR was carried out to examine the local environments and corresponding atoms of 29Si and 27Al after cation exchange of the NaA-0 as well as the related MgA-1 to MgA-4 samples and LiA-1 to LiA-4 samples. It was observed that the local environment of aluminum atoms was less affected after Li exchange than after Mg exchange. The conditions of cation exchange were the same for magnesium and lithium, indicating that the lithium solution did not significantly affect the zeolite structure. Five characteristic resonances indicated that the characteristic structure of the FAU-type zeolite was maintained after ion exchange. It was pointed out that cation exchange seemed to be favorable for the formation of octahedral aluminum atoms. A slight increase in the Si / Al ratio suggested that a slight extraction of aluminum atoms from the zeolite framework occurred as the exchange rate increased from 1 to 3. The MgX-4 sample showed the same Si / Al ratio and the same amount of extra-framework species as the parent sample, which might be due to variations during the washing process.

[0082] 1.5 N2 adsorption-desorption isotherm property evaluation. The nitrogen adsorption isotherms of the crude zeolite and the cation-exchanged zeolite were analyzed. N2 adsorption was not observed due to the position of Na+ cations near the pore openings, which hindered the approach of N2 to the microporous structure of the zeolite framework.

[0083] In contrast, the ion-exchanged samples of MgA-1, 2, 3, and 4 enabled nitrogen diffusion due to the porosity of the LTA-type zeolite. The large adsorption capacity of all samples indicated the ability of the experimentally prepared zeolite to adsorb even trace amounts of nitrogen. Just one cycle of ion exchange was sufficient to obtain the highest microporous volume. This first exchange corresponded to the replacement of 59% of the sodium initially present in the test environment. Since the samples were in powder form, the adsorption observed at p / p0 = 0.9 - 1 was considered to be due to the interparticle porosity. Repeating the steps is thought to result in further exchange and replacement of sodium ions.

[0084] The samples prepared with magnesium showed a maximum capacity of 210 cm3.g-1, representing a 24% increase in the adsorption volume compared to the crude samples with a 15% increase in the microporous volume (0.27 - 0.31 cm3.g-1). For all samples, the BET surface increased along with the microporous volume, reaching approximately 550 - 600 m2.g-1 for the LTA-type zeolite samples, approximately 738 m2.g-1 for the crude FAU-type zeolite samples, and approximately 860 m2.g-1 for the magnesium-prepared samples.

[0085] Although not limited to the mechanism of action, the increase in the amount of adsorbed nitrogen between the sodium and magnesium forms could be due to the position of the cations within the microscopic cage structure. The same behavior was observed for the LTA-type zeolite exchanged with lithium cations. After sodium exchange with magnesium, nitrogen molecules can reach the porous structure. All these parameters enabled an increase in the available microporous volume and adsorption capacity (see Table 3).

[0086] When the FAU-type zeolite sample was exchanged with lithium, the capacity of 205 cm3.g-1 - 210 cm3.g-1 (microporous volume of 0.32 - 0.33 cm3.g-1) showed an increase in the adsorption volume of 21% - 24% and an increase in the microporous volume of 19% - 22% compared to the crude NaX-0 sample.

[0087] 1.6 Adsorption Isotherm Property Evaluation The water adsorption capacity was determined at p / p0 = 0.2 (representing adsorption in the microporous structure of the sample) and reported in Table 3 for each sample. Consistent with the nitrogen adsorption analysis, an increase in the water adsorption capacity was observed for each exchanged sample compared to their related starting samples.

Table 3

[0088] According to Table 3, the NaA - 0 sample had a water adsorption capacity of 21.1 wt%. When the sample was cation - exchanged with magnesium, the capacity increased to 26.5 wt% (MgA - 1) - 27.5 wt% (MgA - 4), representing an increase in the adsorption volume of 26% - 30% compared to NaA - 0. Even when the number of cation - exchange steps was increased from 1 to 4, although slight variations were observed, the water adsorption capacity of the sample did not increase significantly. The adsorption observed at p / p0 = 0.9 - 1 was due to the inter - particle porosity.

[0089] From the water adsorption isotherm of the NaX - 0 zeolite, a water adsorption capacity of 25.3 wt% was estimated. When the sodium sample was exchanged with magnesium, the water capacity increased from 31.2 wt% (MgX - 1) to 32.8 wt% (MgX - 3), i.e., an increase in adsorbed water of 23% - 30% compared to NaX - 0.

[0090] For the lithium-exchanged LTA-type samples, a water adsorption capacity of 24.7 wt% was observed for the LiA-4 sample, while Exchanges 1, 2, and 3 showed adsorption capacities of 22.8 wt%, 22.9 wt%, and 23.3 wt%, respectively. The overall water adsorption increased by 8% - 17% compared to NaA-0.

[0091] The lithium form of the FAU-type zeolite shown in Fig. 11d showed a water adsorption capacity of 29.5 wt% for LiX-1, while Exchanged LiX-2, LiX-3, and LiX-4 showed adsorption capacities of 29.9 wt%, 30.4 wt%, and 32.4 wt%, respectively. The overall water adsorption increased by 17% - 28%, indicating that using lithium for cation exchange with LTA-type or FAU-type zeolites is less effective than magnesium for water adsorption optimization. These results show that the modification of the charge-compensating cations of LTA-type and FAU-type zeolites changes the water adsorption behavior.

[0092] The water adsorption capacity was improved by up to 30% of the adsorption volume for LTA-type and FAU-type zeolites exchanged with magnesium, up to 24% for LTA-type zeolites exchanged with lithium, and up to 28% for FAU-type zeolites exchanged with lithium. The lithium-exchanged samples showed an increase in the water adsorption volume compared to the crude sodium samples. Magnesium as a compensating cation seemed to show a higher water adsorption capacity despite the surface coating of the particles.

[0093] Example 2 Materials: (a) Zeolites: Zeolite LTA (NaA) and zeolite FAU (NaX) were provided in powder form by CSP Technologies. Lithium chloride (LiCl, ACS Reag. Ph. Eur > 99%) salt and magnesium chloride (MgCl2·6H2O, ACS-ISO for analysis > 99%) salt were purchased from Merck and Carlo Erba, respectively. (b) Polymers: Polypropylene, polyethylene glycol (relative molar mass 4000 g / mol) and titanium dioxide were obtained from Aptar CSP Technologies.

[0094] Large-scale cation exchange: The NaA zeolite was modified by exchanging the sodium-compensating cations present in the parent zeolite framework with magnesium (Mg2+) or lithium (Li+) cations, respectively, by a cation exchange process using 1 M aqueous solutions of MgCl2 and LiCl. Ten hours before the experiment, a container (10 L polypropylene bottle) containing a reaction mixture with 7.5 L of demineralized water was placed in a dedicated apparatus and heated to a stable temperature of 80 °C. On the day of the experiment, a 1 M salt solution of MgCl2 or LiCl was prepared by adding the LiCl salt (317.93 g) or MgCl2 salt (1524.83 g) to the heated 7.5 L of demineralized water with stirring. The pH values of these aqueous electrolyte solutions were measured to be approximately 5.8 and 5.5 for the LiCl and MgCl2 salt solutions, respectively. Next, 468.75 g of each crude hydrated zeolite was blended with the 1 M electrolyte aqueous solution. The mass ratio of the reaction mixture was 1 g of dehydrated zeolite per 20 mL of the electrolyte aqueous solution. The pH values of the mixtures were approximately 8.5 and 10.9 for the MgCl2 and LiCl salt solutions, respectively. Next, the reaction mixture was maintained at 80 °C for 2 h with stirring. After 2 h, all of the reaction mixtures (30 L = 4 bottles per sample) were washed with cold demineralized water (60 L) in a 100 L polypropylene container under mechanical stirring (10 min). Next, the mixture was filtered using a Rousselet-Robatel RC40VXR centrifuge (3000 rpm, 5 - 10 min until no wastewater was observed). For further washing, 60 L of additional demineralized water was sprayed onto the aggregated zeolite. Centrifugation was stopped after no wastewater was observed, indicating that the zeolite powder was essentially completely dry. Next, all samples were dried at 100 °C for 3 days. The obtained cation-exchanged zeolite samples were designated as follows. c in cA-y is the major compensating cation and y is the number of the exchange experiment. The samples were fully characterized.

[0095] Activation of the zeolite powder used for composite production: Before using in the preparation of the polymer composite, the zeolite powder was dehydrated to activate their adsorption properties. The zeolite powder was placed in a PYREX® glass tray (Corning Inc.) (1.8 kg of zeolite per glass tray), and the temperature criteria described in Table 4 were applied using a Nabertherm Controller B170 oven. After dehydration, the zeolite powder was transferred to each moisture-proof aluminum bag to retain the adsorption properties, and then the bags were sealed. Next, each aluminum bag was transferred to a second sealed aluminum bag for additional protection against moisture as a precautionary measure. [Table 4]

[0096] Composite material components: The composite formulations containing the prepared zeolite powder samples shown in Table 5 were prepared the day before the manufacturing date of the composite material by mixing the required amounts of each component into aluminum bags that were sealed to retain the adsorption properties of the zeolite and stored until use. 2 kg of each composite formulation was prepared and separated into two aluminum bags (2 x 1 Kg). For each formulation, a precision balance with a readability of 0.001 g was used to weigh the insensitive components (polypropylene, polyethylene glycol, and titanium dioxide), and a precision balance with a readability of 10 g was used in a moisture-protected area (relative humidity less than 10%) for weighing the moisture-sensitive zeolite. Before forming into the composite form, the contact of the components in the aluminum bag, especially the zeolite powder, with the atmosphere was minimized to limit potential losses in adsorption performance. [Table 5] 1 Filling (wt%) = introduced mass compared to the total mass of each component 2 Titanium dioxide is added to the formulation in the form of polypropylene pellets containing 50% TiO2. *The formulation type of A-101 is based on a specific formulation by our company.

[0097] A polymer material containing sodium, lithium, and magnesium compensating cations was prepared by extruding it into pellets / granules. The polymer material in the form of molded parts was formed from the pellets into molded parts. All formulations showed similar behavior during both the extrusion and injection processes. No significant differences were observed among the samples in terms of size, color, or texture. Each sample was transferred to a sealed aluminum bag to avoid potential environmental contamination. Next, all the prepared polymer materials were fully characterized.

Table 6

[0098] Preparation of composite materials: Using each of the above formulations, a composite material was produced in the form of granules using an extrusion process with a Clextral BC21 mini extruder (extruder die = 3 mm). Next, the granules were used in the production of a composite material in the form of molded parts using an injection process (mold cavity, length = 208 mm and thickness = 0.8 mm) with a Billion Dixit 2 Proxima H120-500 injection molding machine. The obtained composite material samples were shown as follows. For cA-y-Cg or cA-y-Cmp, c is the main compensating cation of the zeolite contained, y is the number of cation exchange experiments with the zeolite, C = composite, g = granular form, and mp = molded part form. For example, MgA-1 means zeolite A exchanged once with an aqueous MgCl2 solution, and MgA-1-Cg means a composite material in granular form containing zeolite A exchanged once with an aqueous MgCl2 solution. After the production of the composite materials of the present invention, the samples were fully characterized using the above characterization techniques.

[0099] Zeolite Filling into Composite Material Complexes The filling of the raw materials contained in the composite material and the exchanged zeolite samples was determined using a Nabertherm Controller B170 oven. Samples were taken from sealed aluminum bags that had stored and protected the composite material directly after its production. To determine the zeolite filling, a firing program was executed according to the conditions shown in Table 7. When the composite samples were heated, decomposition of the organic matter occurred. The samples were heated to 300 °C and then transferred to a desiccator containing phosphorus pentoxide (P2O5) to avoid water capture by the zeolite. After 10 minutes, the samples were weighed. The inorganic content corresponding to the zeolite and titanium dioxide in the formulation was obtained by measuring the weight difference. After correcting for the titanium dioxide content, the zeolite filling was estimated. [Table 7]

[0100] Results (1) H2O Adsorption Isotherm Property Evaluation The water adsorption isotherms of the crude LTA-type zeolite and the LTA-type zeolite exchanged with Li+ and Mg2+ are shown in Figures 6A, 6B, and 6C. The water adsorption capacity was determined at p / p0 = 0.2 (representing adsorption in the microporous structure of the sample) and reported for each sample in Table 8. No adsorption was observed for the sodium and lithium forms because the cations block the pore openings. However, for both exchanged samples, an increase in water adsorption (28.8 wt% and 22.7 wt% for the MgA-1 and LiA-1 samples, respectively) occurred compared to the sodium form. [Table 8] X → Not Porous to Nitrogen Molecules a Exchange rate of sodium cations. Value determined by XRF measurement. b Value determined by the BET method (average of 3 measurements). c Value determined by the t-plot method. (Average of 3 measurements). d Value determined from the water sorption isotherm (measured at p / p 0 = 0.2) (average of two measurements). e Value obtained by multiplying the amount of adsorbed water in mmol / g by the molecular weight of water MW = 18.02 g / mol (average of two measurements). f Standard deviation.

[0101] The results shown in Table 8 represent an increase in water uptake of 32% and 4% respectively, compared to the relevant crude samples of the MgA-1 and LiA-1 samples. The difference in the size of the lithium atom compared to the sodium atom (Li+: 0.69 Å, Na+: 1.02 Å) is thought to result in an increase in the available microporous volume and consequently an increase in the water sorption capacity. This effect was also observed in the case of exchange with magnesium cations (0.72 Å), but due to the divalency of the cation, only half of the substituted monovalent cations were required. Thus, both the difference in size and the difference in the number of cations required contribute to the increase in the accessible microporous volume and are thought to explain the significant increase in water uptake of the MgA-1 sample. The MgA-1 sample provided the highest water sorption performance.

[0102] (2) Firing of the composite material Since the adsorption characteristics of the composite material are related to the zeolite content, zeolite filling is one of the most important points to be managed. To determine the zeolite filling, a firing test was carried out. The zeolite filling (inorganic matter) of the granular material and the molded parts was determined by the weight difference after firing. The theoretical zeolite filling and the experimentally determined zeolite filling were recorded. The maximum deviation observed compared to the target filling was 3.2 wt% (LiA-1-cg sample). From a macroscopic perspective, the polymer material was seen as homogeneous in terms of the dispersion of zeolite in the polymer matrix. Scanning electron microscopy (SEM) was performed on each sample to analyze the homogeneity of the sample from a microscopic perspective. SEM and EDX analyses showed a homogeneous distribution of zeolite particles into the polymer matrix. Furthermore, a tensile test was carried out to evaluate the mechanical properties of different samples. The results are summarized in Table 9.

Table 9

[0103] According to Table 9, the Young's moduli of the activated molded part composite forms containing the NaA-0, LiA-1, and MgA-1 zeolite samples were similar across all samples, indicating no significant effect of the nature of the compensating cations on the mechanical properties of the composite material.

[0104] (3) Water adsorption into the composite material: Before testing the adsorption characteristics of the polymer composite material samples of the present invention, the related zeolite powder samples were analyzed under the same conditions as the reference materials. The adsorption kinetic curves of the zeolites and their corresponding composites are shown in FIGS. 6A, 6B, and 6C. The adsorption capacities are summarized in Table 10. FIGS. 6(A-C) show the water adsorption kinetics of (A) the forms of LTA-type zeolites (NaA-0), (LiA-1), and (MgA-1), and their related composites, (B) the NaA-0-cg, LiA-1-cg, and MgA-1-cg samples, and (C) the NaA-0-cmp, LiA-1-cmp, and MgA-1-cmp samples. As expected from the water adsorption isotherms of the zeolite materials shown in FIGS. 6(A-C), all samples showed water adsorption with similar behavior. For all samples, a saturation plateau was reached after about 3 hours, but MgA-1 still showed a slight water uptake (+1 wt%) after 3 hours until the final water uptake was reached.

Table 10

[0105] Figures 7(A - C) show the water adsorption kinetics of the incorporated polymer compositions of the present invention in which the zeolite was treated and exchanged, showing (A) NaA - 0, NaA - 0 - cg and NaA - 0 - cmp, (B) LiA - 1, LiA - 1 - cg and LiA - 1 - cmp and (C) MgA - 1, MgA - 1 - cg and MgA - 1 - cmp samples. As described above, cation exchange improved the water adsorption capacity of the zeolite when incorporated into a polymer composite that retained the water absorption capacity after incorporating the exchanged zeolite into the polymer composition according to the method of the present invention.

[0106] According to Table 10 and Figures 7(A - C), all the composite materials according to the present invention showed a water adsorption capacity equivalent to that of the parent zeolite, which means that the adsorption capacity of the zeolite was not affected by the incorporation of the zeolite into the matrix of the base polymer when preparing the incorporated polymer composition by the method according to the present invention. The similarity in the adsorption capacity between the SEM images and the corresponding composite materials of the zeolite powder suggests that water is most likely adsorbed onto the zeolite crystals.

[0107] Generally, this study showed that while the NaA - 0 and LiA - 1 powders and their corresponding incorporated polymer compositions containing NaA - 0 and LiA - 1 zeolites showed similar water adsorption capacities, the MgA - 1 samples in both the zeolite powder and its corresponding incorporated polymer composite form showed a significant increase in water adsorption capacity compared to the sodium form.

[0108] Figures 6(A - C) and 7(A - C) also show that each sample has its own adsorption kinetics. The powder form shows a faster adsorption kinetics in all cases compared to its related composite sample.

[0109] Furthermore, FIGS. 7(A - C) and Table 10 also show that the molded part samples exhibited a slightly lower adsorption kinetics than the granular polymer composites (this factor was not very prominent for the LiA - 1 sample). This observation may be due to the molding of the samples and the applied test method. This may also be attributed to the fact that a larger surface of the polymer granule samples was exposed to atmospheric humidity compared to the polymer molded part samples where only one side of each sample was exposed to atmospheric humidity. Furthermore, it is possible that the granular samples were shaken during each measurement, enabling overall adsorption on the granular surface compared to the molded part samples.

[0110] X - ray fluorescence (XRF), inductively coupled plasma optical emission spectrometry (ICP - OES), and energy - dispersive X - ray spectroscopy (EDX) reported that a significant amount of the introduced cations was uniformly distributed in the zeolite framework, which is an indication of the success of cation exchange. Scanning electron micrographs emphasized the cubic morphology of the LTA crystals, while XRD and NMR analyses confirmed that the exchanged zeolites did not undergo significant structural changes.

[0111] The substitution of sodium cations by smaller monovalent cations such as lithium or smaller divalent cations such as magnesium results in an increase in the available microporous volume, which, in addition to less crowded pore apertures, increases the proximity to the pores (N2 in LTA), leading to an improvement in the storage of host molecules such as water. Furthermore, divalent cations bring about a higher degree of order of water molecules around them, and the better spatial structure also contributes to the improvement of water adsorption. According to the results of the water adsorption isotherms, for the lithium - and magnesium - exchanged samples, an increase in water adsorption capacity of 4% and 32% respectively was observed compared to the parent material, indicating that magnesium provides the best performance.

[0112] In the second part of the experiment, these exchanged zeolites were mixed with the polymer and composite materials in granular form and molded part form were produced using an extrusion process and an injection process, respectively. The determination of the zeolite filling in each composite formulation showed results consistent with the amount of components introduced into the formulation that showed a uniform and viable molding process. This was confirmed by SEM analysis showing that the zeolite crystals were uniformly distributed in the polymer matrix for both the granular form and the molded part form with a selective orientation of the polymer fibers and zeolite crystals. Water adsorption was observed for each composite regardless of the nature of the charge-compensating cations contained in the molding and zeolite. For the composite materials, the granules containing the exchanged zeolites showed similar results with respect to water adsorption compared to the parent samples. The water adsorption of the molded part form was also similar for the exchanged zeolites compared to the parent material.

[0113] This study confirmed that the developed composite materials with zeolite as a filler retain the adsorption characteristics of the zeolite crystals. These exchanged zeolites, especially the zeolites exchanged with Mg2+ as the charge-compensating cation, are promising for use in water purification applications because they provide increased protection against water or require less adsorbent to capture the same amount of water compared to their sodium counterparts.

Claims

1. A process for producing a polymer composition with improved storage, comprising: (a) providing a crude aluminosilicate zeolite; (b) treating the crude zeolite with a solution containing monovalent, divalent or trivalent cations to form a treated cation-exchanged zeolite; (c) optionally repeating step (b) one or more times; (d) drying the treated cation-exchanged zeolite to provide a dried cation-exchanged zeolite, wherein the dried cation-exchanged zeolite has a water adsorption capacity greater than that of the crude zeolite before cation exchange treatment; (e) optionally repeating steps (b) and (c) one or more times; (f) adding and blending the dried cation-exchanged zeolite into a base polymer; (g) forming a polymer composition having a water adsorption capacity per gram of zeolite greater than that of the crude zeolite. A process comprising the steps.

2. The process according to claim 1, wherein the zeolite is an aluminosilicate or silicoaluminophosphate containing a compensating cation and is selected from the group consisting of sodium, magnesium, lithium, potassium, calcium, zinc, manganese and iron.

3. The process according to claim 2, wherein the crude zeolite is an LTA-type or FAU-type zeolite.

4. The crude zeolite is sodium zeolite, and Mg 2+ , Li + , K. + , Ca 2+ , Zn 2+ , Mn 2+ and Fe 3+ 4. The process of claim 3, wherein the surface is treated with a solution containing a cation, a cation, or a combination thereof.

5. The zeolite solution contains MgCl 2 or LiCl, the process according to claim 4.

6. The crude zeolite and the MgCl 2 or LiCl solution is in a ratio of 0.5 g / 20 mL to 2 g / 20 mL, the process according to claim 5.

7. The process according to any one of claims 1 to 6, wherein the dried cation-exchanged zeolite is added to the base polymer in powder form.

8. The crude zeolite is sodium zeolite, and the solution for cation exchange contains Mg 2+ cations and Li + cations or combinations thereof, and the water adsorption capacity of the polymer composition is at least 1% to 33% greater than the water adsorption capacity of the crude sodium zeolite. The process according to any one of claims 1 to 7.

9. The process according to any one of claims 1 to 8, wherein the zeolite polymer composition is used for the sorption of at least one of water, ammonia, nitrogen, oxygen, or combinations thereof.

10. The process according to any one of claims 1 to 9, wherein the concentration of zeolite in the polymer composition ranges from 1 wt% to 74 wt% based on the total weight of the polymer composition.

11. The process according to any one of claims 1 to 10, wherein the distribution of zeolite in the base polymer of the polymer composition is essentially uniform when observed by scanning electron microscopy (SEM).

12. The process according to any one of claims 1 to 11, wherein the base polymer is selected from polypropylene, polyethylene, polyhydroxyalkanoate (PHA), polylactic acid (PLA), polybutylene succinate (PBS), polyisoprene, polyhexene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, polyvinyl chloride (PVC), polystyrene, polyester, polyanhydride, polyacrylanitrile, polysulfone, polyacrylate ester, acrylic, polyurethane, polyacetal, polyvinyl pyrrolidone (PVP), copolymer, or a combination thereof.

13. The process according to any one of claims 1 to 12, further comprising adding a channeling agent to the base polymer, wherein the zeolite is incorporated into the polymer composition.

14. The process according to claim 13, wherein the amount of the channeling agent ranges from 1 wt% to 25 wt%, optionally 2 wt% to 15 wt%, optionally 5 wt% to 20 wt%, optionally 8 wt% to 15 wt%, optionally 10 wt% to 20 wt%, optionally 10 wt% to 15 wt%, or optionally 10 wt% to 12 wt% based on the total weight of the polymer composition.

15. The process according to claim 13, wherein the channeling agent is selected from polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerin polyamine, polyurethane, polycarboxylic acid, propylene oxide polymerisate - monobutyl ether, propylene oxide polymerisate, ethylene vinyl acetate, 6 nylon, 66 nylon, or a combination thereof.

16. The process according to claim 13, wherein the polymer composition is a monolithic material and is at least two-phase or at least three-phase.

17. The process according to any one of claims 1 to 16, wherein the polymer composition is formed by extrusion molding, injection molding, blow molding, thermoforming, continuous compounding, vacuum molding or hot melt dispensing.

18. The process according to claim 17, wherein the polymer composition is formed into granules, pellets, films, sheets, disks, covers, plugs, caps, lids, inserts, stoppers, gaskets, seals, washers, liners, rings, containers or packaging materials.

19. The process according to any one of claims 1 to 18, further comprising adding the polymer composition to a packaging material selected from plastics, paper, glass, metal, synthetic resin, ceramic or combinations thereof.

20. A polymer composition prepared by the method according to any one of claims 1 to 19.

21. The polymer composition according to claim 20, for use as a desiccant.

22. The polymer composition according to claim 21, for use in a dehumidifier or an adsorption heat pump.

23. A packaging material comprising the polymer composition according to any one of claims 20 to 22.

24. The packaging material according to claim 23, wherein the material is selected from plastics, paper, glass, metal, ceramic, synthetic resin or combinations thereof.

25. A polymer composition for enhanced sorption, comprising: (a) a monovalent, divalent or trivalent cation exchange aluminosilicate zeolite; and (b) a base polymer, wherein the polymer composition has a water adsorption capacity per gram of zeolite greater than that of a reference crude sodium zeolite.

26. The polymer composition according to claim 25, wherein the zeolite is an aluminosilicate or silicoaluminophosphate containing a compensating cation selected from the group consisting of sodium, magnesium, lithium, potassium, calcium, zinc, manganese and iron.

27. The polymer composition according to claim 25 or claim 26, wherein the zeolite is an LTA-type or FAU-type zeolite.

28. The polymer composition according to any one of claims 25 to 27, wherein the zeolite contains magnesium, lithium or both, and the water adsorption capacity of the polymer composition is at least 1% to 33% greater than the water adsorption capacity of the reference crude sodium zeolite.

29. The polymer composition according to any one of claims 25 to 28, wherein the polymer composition is used for the sorption of at least one compound selected from water, ammonia, nitrogen, and oxygen or combinations thereof.

30. The polymer composition according to any one of claims 25 to 29, wherein the concentration of zeolite in the polymer composition ranges from 1 wt% to 74 wt% based on the total weight of the polymer composition.

31. The polymer composition according to any one of claims 25 to 30, wherein the distribution of zeolite in the base polymer of the polymer composition is essentially uniform when observed by scanning electron microscopy (SEM).

32. The base polymer is selected from polypropylene, polyethylene, polyhydroxyalkanoate (PHA), polylactic acid (PLA), polybutylene succinate (PBS), polyisoprene, polyhexene, polybutadiene, polybutene, polysiloxane, polycarbonate, polyamide, ethylene-vinyl acetate copolymer, ethylene-methacrylate copolymer, polyvinyl chloride (PVC), polystyrene, polyester, polyanhydride, polyacrylonitrile, polysulfone, polyacrylate ester, acrylic, polyurethane, polyacetal, polyvinyl pyrrolidone (PVP), copolymer, or combinations thereof. The polymer composition according to any one of claims 25 to 31.

33. The polymer composition according to any one of claims 25 to 32, further comprising a channeling agent, wherein the zeolite is incorporated into the polymer composition.

34. The amount of the channeling agent ranges from 1 wt% to 25 wt%, optionally 2 wt% to 15 wt%, optionally 5 wt% to 20 wt%, optionally 8 wt% to 15 wt%, optionally 10 wt% to 20 wt%, optionally 10 wt% to 15 wt%, or optionally 10 wt% to 12 wt% based on the total weight of the polymer composition. The polymer composition according to claim 33.

35. The polymer composition according to claim 33 or claim 34, wherein the channeling agent is selected from polyethylene glycol (PEG), ethylene-vinyl alcohol (EVOH), polyvinyl alcohol (PVOH), glycerin polyamine, polyurethane, polycarboxylic acid, propylene oxide polymethacrylate-monobutyl ether, propylene oxide polymethacrylate, ethylene vinyl acetate, 6 nylon, 66 nylon, or a combination thereof.

36. The polymer composition according to any one of claims 25 to 35, wherein the polymer composition is a monolithic material and is at least two-phase or at least three-phase.

37. The polymer composition according to any one of claims 25 to 36, wherein the polymer composition is formed by extrusion molding, injection molding, blow molding, thermoforming, continuous compounding, vacuum molding, or hot melt dispensing.

38. The polymer composition according to any one of claims 25 to 37, wherein the polymer composition is formed into powder, granules, beads, pellets, film, sheet, disk, cover, plug, cap, lid, insert, stopper, gasket, seal, washer, liner, ring, container, or packaging material.

39. The polymer composition according to any one of claims 25 to 38, provided in the form of a bag, packet, or gel pack.

40. A packaging material comprising the polymer composition according to any one of claims 25 to 39, selected from plastic, paper, glass, metal, ceramic, synthetic resin, or a combination thereof.

Images