Polymeric articles comprising a blend of PBAT, PLA, and a carbohydrate-based polymer material

Abstract

Composite blends of PBAT (or another similar polyester) with PLA and a carbohydrate-based polymeric material. While PLA is not compostable by itself under home composting conditions (e.g., at a temperature of 28°C), when blended in the manner described herein, it is compostable under such conditions. Because PBAT itself is quite flexible, making it problematic for use in takeout bags and the like, the addition of PLA increases the rigidity of the composite blend. Exemplary blends may include 30-55% by weight of the carbohydrate-based polymeric material, up to 20% by weight, or up to 15% by weight of PLA, with the remainder of the polymer content being PBAT (e.g., 30-60% PBAT). Other ingredients (e.g., inorganic fillers such as calcium carbonate) may also be included in the blend.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Patent Application Nos. 62 / 872,589 (21132.28) and 62 / 875,872 (21132.28.1), filed July 10, 2019 and July 18, 2019, respectively. This application is also a continuation-in-part of U.S. Patent Application No. 16 / 425,397 (21132.20.1), filed May 29, 2019, which claims the benefit of U.S. Patent Application No. 62 / 677,368 (21132.20), filed May 29, 2018. U.S. Patent Application No. 16 / 425,397 (21132.20.1) is also a continuation-in-part of U.S. Patent Application No. 15 / 691,588 (21132.7), filed August 30, 2017, which is a continuation-in-part of U.S. Patent Application No. 14 / 853,725 (21132.8), filed September 14, 2015, which claims the benefit of U.S. Provisional Patent Application No. 62 / 187,231, filed June 30, 2015. U.S. Patent Application No. 15 / 691,588 (21132.7) is also a continuation-in-part of U.S. Patent Application No. 14 / 853,780 (21132.6), filed September 14, 2015, and a continuation-in-part of U.S. Patent Application Nos. 15 / 481,823 (21132.2) and 15 / 481,806 (21132.1), both filed April 7, 2017. U.S. Patent Application No. 15 / 691,588 (21132.7) also claims the benefit of U.S. Provisional Patent Application No. 62 / 440,399 (21132.10), filed December 29, 2016, and U.S. Provisional Patent Application No. 62 / 442,432 (21132.11), filed January 4, 2017. The entire contents of each of the foregoing are incorporated herein by reference.

[0002] Other applications are also incorporated by reference herein, for example, U.S. Patent Application No. 62 / 483,219 (21132.4), filed April 7, 2017, U.S. Patent Application No. 15 / 836,555 (21132.4.1), filed December 8, 2017, U.S. Provisional Patent Application No. 62 / 483,109 (21132.5), filed April 7, 2017, U.S. Patent Application No. 62 / 610,615 (21132.9) and U.S. Patent Application No. 16 / 456,303 (21132.9.1), filed December 27, 2017 and June 28, 2019, respectively, U.S. Patent Application No. 62 / 610,618 (21132.9), filed December 27, 2017 and June 28, 2019, respectively. Nos. (21132.12) and 16 / 456,295 (21132.12.1), U.S. patent application Ser. No. 16 / 391,909 (21132.14.1), filed April 23, 2019, U.S. patent application Ser. No. 63 / 033,676 (21132.31), filed June 2, 2020, PCT application Ser. No. PCT / US2017 / 068492 (21132.1A), filed December 27, 2017, and two additional non-provisional patent applications of the applicant bearing attorney docket numbers 21132.27.1.1 and 21132.30.1, filed on the same date as the present application, are each incorporated herein by reference in their entirety. [Background technology]

[0003] Conventional petrochemical-based plastics are formulated to be strong, lightweight, and durable. However, these plastics are typically not biodegradable, resulting in hundreds of millions of tons of plastic occupying landfills or floating in the ocean. In an effort to reduce the amount of plastic waste, some items typically made using petrochemical-based plastics are being manufactured using bioplastic materials, which are defined as plastics made from renewable resources or that are biodegradable.

[0004] Large amounts of petrochemical-based plastic materials such as polyethylene and polypropylene, as well as many other plastics (e.g., polyethylene terephthalate, polystyrene, ABS, polyvinyl chloride, polycarbonate, nylon, etc.), typically do not readily biodegrade in typical land-based disposal environments (e.g., in landfills), or even more so when disposed of in the marine environment. This is typically true even for so-called "green" plastics, where a portion of such materials may be sourced from renewable or sustainable sources rather than petrochemical feedstocks.

[0005] There are several specialized plastic materials that can exhibit some degree of compostability and / or biodegradability under certain disposal conditions. For example, polylactic acid ("PLA") and polybutylene adipate terephthalate ("PBAT") (also known as poly(butylene adipate-co-terephthalate)) have been shown to exhibit some degree of compostability under industrial composting conditions. While such disposal conditions may allow some biodegradation of PLA or PBAT under some conditions where the composting temperature is elevated (e.g., 58°C), PLA does not exhibit compostability in typical home composting environments, where the composting temperature is significantly lower. In other words, while PBAT may exhibit some biodegradability under such home composting conditions (e.g., 28°C according to EN13432), PLA does not exhibit any significant biodegradability when disposed of in such environments. Furthermore, PBAT itself is a very flexible material, so flexible that bags made from it may bend significantly under load when filled with items, making it particularly unsuitable for use alone in bags or other film materials. PLA is more rigid but does not exhibit the desirable home compostability characteristics.

[0006] It would be an improvement in the art to provide a film that could address at least some of the above-identified problems. Summary of the Invention

[0007] The present disclosure is directed to polymer blends suitable for use as films or rigid materials that meet home compostability requirements (e.g., depending on thickness). The blends include a carbohydrate-based polymer material (e.g., a modified polysaccharide, such as NuPlastiQ®, available from the applicant) blended with PBAT and PLA. NuPlastiQ® and PBAT typically biodegrade in home compost environments, but PLA does not. PLA, even when blended with PBAT alone, similarly does not biodegrade under home composting conditions. However, when NuPlastiQ® is included in the blend, PLA biodegrades under home composting conditions (e.g., at 28°C, otherwise in line with conditions specified by EN 13432).

[0008] Film materials containing PBAT would be desirable for use in applications such as take-out bags, where, unfortunately, significant littering still occurs, even in the United States and other developed countries. The rationale for using PBAT in such articles is that PBAT exhibits biodegradable properties, even under relatively low-temperature home composting conditions, for example. By comparison, the vast majority of such take-out bags (and other film articles) are formed from polyethylene, which essentially exhibits negligible biodegradability under any standardized testing or actual disposal conditions. The problem with using PBAT in such films, for example, is that bags formed from PBAT are extremely elastomeric, to the point that when various items are placed inside the bag, rather than generally maintaining their shape and retaining the items, the bag may actually stretch significantly. Naturally, such properties result in poor overall flexibility and toughness, which is problematic for take-out bags or other film articles, as well as other non-film articles where increased strength and stiffness may be desirable.

[0009] Blending PBAT with PLA increases the stiffness of the resulting material, allowing the blend to be used to form films for use as takeout bags or other articles where a good balance of strength, stiffness, flexibility, and toughness is desired. The problem with such PLA addition is that the PLA in such blends does not biodegrade under low-temperature "home" composting conditions (similar to ASTM D-5338, but e.g., at 28°C ± 2°C as specified by EN 13432), resulting in films or other articles that are only partially biodegradable (i.e., the PBAT biodegrades, but the PLA does not).

[0010] Applicant has discovered that by adding Applicant's NuPlastiQ® material, not only does the PBAT in the blend biodegrade under such low-temperature home composting conditions, but the PLA, in turn, also biodegrades under such low-temperature conditions. Naturally, because the NuPlastiQ® carbohydrate-based polymeric material also biodegrades, all of the polymeric materials in such a blend exhibit compostability under low-temperature home composting conditions. Such a result is particularly advantageous.

[0011] Additionally, NuPlastiQ® materials are formed from renewable sourced components (e.g., starch and glycerin) and are relatively inexpensive compared to other polymeric materials (e.g., PBAT and PLA) included in the blend. At least some of the components used to produce PBAT (e.g., butanediol, adipic acid, terephthalic acid) or PLA (e.g., lactic acid) may also be formed from renewable sourced components.

[0012] Because PBAT exhibits low stiffness, high flexibility, and / or high toughness (and low strength), it can benefit from blending with PLA or the like to increase stiffness, and if a carbohydrate- or starch-based polymeric material, such as NuPlastiQ®, is also included in the blend, it ensures that all polymeric materials in the blend are compostable. In one embodiment, the blend of the present invention comprises a first polyester plastic material (e.g., comprising PBAT) having a first stiffness and a second polyester (e.g., comprising PLA), where the first polyester plastic material has a lower stiffness (and / or higher flexibility) than that of the second polyester (e.g., PLA). The blend also includes a carbohydrate-based polymeric material.

[0013] Exemplary embodiments may include PBAT in an amount of at least 30% by weight of the blend, PLA in an amount of up to 20% by weight of the blend, and a carbohydrate-based polymeric material in an amount of up to 60% by weight of the blend, e.g., 5% to 60% by weight, or 10% to 60% by weight. For example, the carbohydrate-based polymeric material may more typically be present in an amount of 30% to 60% by weight of the polymer blend. PLA may be present in an amount of up to 15% or up to 12% by weight of the polymer blend, with PBAT comprising the remainder of the polymer content (e.g., 30 to 70% by weight). In one embodiment, PLA may be present in an amount of at least 10% by weight of the blend, or greater than 10% by weight. In addition to the polymeric components, inorganic fillers such as calcium carbonate, talc, etc. may also be included. The inclusion of such filler materials can further reduce the amount of polymeric components required to manufacture a particular bag, other film, or other article, and can also help reduce any tendency of bags formed from such films to exhibit "blocking" or clumping, which can result in the sides of such bags tending to stick to one another, making the bag somewhat difficult to actually open. In one embodiment, such inorganic fillers can be included in an amount of, for example, 0% to 30% by weight of the article.

[0014] Any of a variety of other additives may also be included, if desired, including, but not limited to, for example, slip aids and / or processing aids. Such composite plastic blends can be processed according to a wide variety of known manufacturing methods to form extruded plastic products, injection molded plastic products, blow molded plastic products, blown film plastic products, extruded or cast sheet or film, thermoformed plastic products, foamed plastic products, and the like.

[0015] Further features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments. [Brief explanation of the drawings]

[0016] So that the above and other advantages of the invention are obtained, a more particular description of the invention, briefly described above, will be rendered by reference to specific embodiments thereof which are illustrated in the accompanying drawings. The invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, with the understanding that these drawings illustrate only typical embodiments of the invention and therefore should not be considered as limiting its scope. [Figure 1] 1 shows a flow diagram of an exemplary process for forming an article according to the present invention. [Figure 2] 2 illustrates components of an exemplary manufacturing system for producing an article according to FIG. 1. [Figure 3] The X-ray diffraction (XRD) pattern of NuPlastiQ® GP, a commercially available carbohydrate-based polymer material from BioLogiQ, is shown in comparison to the XRD patterns of the native corn starch and native potato starch used to form NuPlastiQ® GP. The significant reduction in crystallinity is readily apparent. [Figure 4] 1 shows dart drop impact strength data for exemplary blends of PBAT and PLA with NuPlastiQ®. [Figure 5] FT-IR spectral data for NuPlastiQ® GP, as well as native corn starch and native potato starch are shown. Starch is hydrophilic, while NuPlastiQ® GP is hydrophobic. [Figure 6] Photographs showing the relative hydrophobic properties of a film comprising NuPlastiQ® blended with another polymer material compared to another film comprising conventional starch blended with another polymer material, illustrating how NuPlastiQ® is much more hydrophobic when tested with a dyne pen at a given weight fraction of starch-based component relative to the same polyolefin matrix material. [Figure 7] 1 shows DSC melting temperature profile data for conventional starch materials. [Figure 8] 1 shows TGA temperature stability data for exemplary NuPlastiQ® materials compared to glycerin and starch. [Figure 9]

[0033] Figure 1 shows the biodegradation rates measured over 179 days in accordance with EN 13432 at home compost conditions intended to mimic home compost conditions at ambient temperature (28°C) for various samples made in accordance with the present disclosure, as described in Example 1, and a positive control. [Figure 10A]

[0023] Figure 1 shows the results of disintegration testing from initiation to 26 weeks based on ISO 20200 standards, intended to mimic compost conditions at ambient temperature (28°C), for sample BC27240 made in accordance with the present disclosure, as described in Example 2. [Figure 10B] 1 shows photographs of test samples BC27130 and BC27251 at the start of the study, as described in Example 3. [Figure 10C] 1 shows a photographic comparison of test sample BC27130 at the start of the study and after 4 weeks, as described in Example 3. [Figure 10D] 1 shows a photographic comparison of test sample BC27251 at the start of the study and after 4 weeks, as described in Example 3. [Figure 10E]1 shows a photograph of the contents of a composting reactor containing test sample BC27130 after 8 weeks, as described in Example 3. [Figure 10F] 1 shows a photograph of the contents of a composting reactor containing test sample BC27251 after 8 weeks, as described in Example 3. [Figure 10G] 1 shows a photographic comparison of test sample BC27130 at the start of the study and after 12 weeks, as described in Example 3. [Figure 10H] 1 shows a photographic comparison of test sample BC27251 at the start of the study and after 12 weeks, as described in Example 3. [Figure 10I] 1 shows a photograph of the contents of a composting reactor containing test sample BC27130 after 14 weeks, as described in Example 3. [Figure 10J] 1 shows a photograph of the contents of a composting reactor containing test sample BC27251 after 14 weeks, as described in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0017] I. Definition All publications, patents, and patent applications cited in this specification, whether supra or infra, are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

[0018] The term "comprising," which is synonymous with "including," "containing," or "characterized by," is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.

[0019] The term "consisting essentially of" limits the scope of a claim to the particular materials or steps of the claimed invention and "that do not materially affect the basic and novel characteristics."

[0020] As used herein, the term "consisting of" excludes any element, step, or ingredient not specified in the claim. As used in the context of describing features of the present invention (particularly in the context of the claims that follow), the terms "a," "an," "the," and similar referents should be construed to encompass both the singular and the plural, unless otherwise specified herein or clearly contradicted by context. Thus, for example, reference to "starch" may include one, two, or more starches.

[0021] As used herein, "film" refers to a thin continuous article comprising one or more polymeric materials that can be used to separate areas or volumes, hold items, act as a barrier, and / or serve as a printable surface.

[0022] As used herein, "bag" refers to a container made of relatively thin, flexible film that can be used to contain and / or transport goods. As used herein, "bottle" refers to a container that can be made from the presently disclosed plastic, which is typically thicker than a film and typically includes a relatively narrow neck adjacent to an opening. Such bottles can be used to hold a wide variety of products (e.g., beverages, personal care products such as shampoos, conditioners, lotions, soaps, detergents, etc.).

[0023] Unless otherwise specified, all percentages, ratios, parts and amounts used and described herein are by weight. Unless otherwise specified, molecular weight values ​​relate to weight average molecular weight.

[0024] As will be understood by those skilled in the art, numbers, percentages, ratios, or other values ​​described herein may include that value and other values ​​that are about or approximately the described value. Thus, a described value should be interpreted broadly enough to encompass values ​​at least sufficiently close to the described value and / or values ​​that are rounded to the nearest whole number to perform the desired function or achieve the desired result. The described value includes at least expected variations in a typical manufacturing process and may include values ​​within 25%, 15%, 10%, 5%, 1%, etc., of the described value. Furthermore, as used herein, the terms "substantially," "similarly," "about," or "approximately" refer to an amount or condition that is close to the described amount or condition that still performs the desired function or achieves the desired result. For example, the terms "substantially," "about," or "approximately" may refer to an amount that is within 25%, 15%, 10%, 5%, or 1% of the described amount.

[0025] Several ranges are disclosed herein. Additional ranges may be defined between any values ​​disclosed herein as examples of particular parameters. All such ranges are contemplated and within the scope of the present disclosure. Furthermore, the recitation of ranges of values ​​herein is intended to serve as a simple method of individually referring to each individual value within the range. Unless otherwise specified herein, each individual value is incorporated herein as if it were individually set forth herein.

[0026] All numbers expressing quantities of ingredients, components, conditions, and the like used in the specification and claims should be understood as being modified in all instances by the term "about." Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0027] As used herein, the phrase "free" or similar phrases means that the composition contains 0% of the recited component, i.e., the component has not been intentionally added to the composition. However, it will be understood that such components may form accidentally under appropriate circumstances and may be accidentally present in another included component, for example, as an accidental contaminant.

[0028] As used herein, the phrase "substantially free" or similar phrases means that the composition preferably contains 0% of the listed component, although it is understood that very low concentrations may be present, for example, due to accidental formation, accidental contamination, or even intentional addition. Such components, if present at all, may be present in amounts of less than 1%, less than 0.5%, less than 0.25%, less than 0.1%, less than 0.05%, less than 0.01%, less than 0.005%, or less than 0.001%. In one embodiment, the disclosed compositions may be free of any component not specifically disclosed as being contained therein.

[0029] The term "non-biodegradable," as used herein with respect to a material, means that a natural material (without additives added to make it biodegradable) does not break down (particularly biodegrade) to a significant extent, e.g., into carbon dioxide and / or methane, within a reasonable time limit (e.g., 1 year, 3 years, or 5 years) when exposed to various simulated disposal conditions (e.g., EN 13432, ASTM D-5338, ASTM D-5511, and / or ASTM D-6691). As described herein, home compostability standards based on EN 13432 may be similar to those based on ASTM D-5338, but are performed at lower temperatures. In a similar manner, any other such standards may be modified (e.g., performed at lower temperatures) to assess biodegradability under more stringent conditions (e.g., home compostability vs. industrial compostability). It should be further understood that given sufficient time and exposure to the conditions of sunlight, oxygen, and degrading microorganisms, most polymeric materials (e.g., even those typically considered "non-biodegradable") will eventually degrade or even biodegrade, usually to some limited extent, over an extended period of time (e.g., decades or centuries).

[0030] The term "biodegradable," as used herein with respect to a material, means that the material, including NuPlastiQ®, described herein, biodegrades into basic elements such as carbon dioxide, methane, and / or water under conditions as described herein. Typical home compostability standards require at least 90% biodegradation of an item's polymer content within 365 days (i.e., reaching 90% biodegradation when measured according to EN 13432 at 28°C (±2°C) rather than higher temperatures). Similar standards may be applicable under other certification bodies or regulatory authorities, e.g., biodegradability and / or disintegration standards under ISO 20200, or various similar standards for home compostability (e.g., NF T51-800 (2015), AS 5810 (2010), or TUV Austria Belgium's OK Compost Home certification scheme).

[0031] With respect to various standardized tests (e.g., ASTM or other tests), it will be understood that reference to any such standard refers to the most recent update (if any) of such standard.

[0032] The term "modified," as used to describe modified polysaccharides, e.g., "modified starch," refers to physical and / or chemical modifications, including converting the starting starch material to one containing a lower molecular weight. Such mechanical and / or chemical modifications may include mechanical modification of the amylopectin starch component to a more linear amylose structure. It will be understood that the foregoing description is merely exemplary, and that many modifications to such starch components are possible. Applicant's NuPlastiQ® material is one example of a modified starch.

[0033] While the NuPlastiQ® starch-based polymer described herein is one example of a starch-based material that can provide the benefits described herein, it will be understood that the scope of the invention extends broadly to other starches or starch-based materials (e.g., developed sometime in the future) that may exhibit similar small particle size characteristics, or even materials that may be synthesized from starting materials other than starch, that may achieve similar results due to the presence of the same or similar chemical structure or functional groups. For example, a material having a similar or identical chemical structure to NuPlastiQ® would also be within the scope of the invention if synthesized (e.g., in a reactor) starting from a non-starch material.

[0034] II. Introduction The present disclosure is directed to, among other things, blends of two polyester materials, such as PBAT and PLA, with a carbohydrate-based (e.g., starch-based) polymer material, which enhance the biodegradability of the PLA material in the blend. For example, PBAT is recognized as readily biodegradable even under relatively low ambient temperature composting conditions (e.g., "home composting conditions" rather than "industrial composting conditions"), while PLA does not exhibit such properties and is not compostable under such relatively low temperature home composting conditions. This is true even when blended with PBAT. For example, in such blends, PBAT biodegrades while PLA remains largely in its original form, and therefore such blends do not meet home composting standards, such as biodegradability and / or disintegration standards under ISO 20200 or various similar standards for home compostability (e.g., NF T51-800 (2015), AS 5810 (2010), or TUV Austria Belgium's OK Compost Home certification scheme). Applicant has discovered that while PLA does not biodegrade under such conditions by itself, by homogeneously blending PLA with certain carbohydrate-based (e.g., starch-based) polymeric materials available from Applicant, the biodegradability of PLA can be increased (e.g., in rate and / or extent), such that the entire blend in turn actually meets applicable home compostability standards.

[0035] Further explanation of the requirements necessary to meet the "home compostability" criteria is provided below. To meet the applicable criteria, a material must: (1) pass the heavy metal criteria (i.e., none of the constituent materials of the blend (e.g., PBAT, PLA, or carbohydrate-based polymeric materials) contain any prohibited heavy metals; (2) meet the applicable biodegradation criteria, such that at least 90% of the blend biodegrades under such home composting conditions (e.g., 28°C ± 2°C) within 365 days (as determined by applicable respirometry testing); (3) meet the applicable disintegration criteria (e.g., at least 90% of the tested material reduces in size to less than 2 mm at ambient temperature (e.g., 28°C ± 2°C) within 26 weeks); and (4) meet the applicable ecotoxicity criteria (i.e., each constituent material of the blend (e.g., PBAT, PLA, and carbohydrate-based polymeric materials) meets such ecotoxicity criteria).

[0036] The blends of the present invention meet such criteria and provide a viable alternative to polyethylene bags or other films that are not biodegradable to any significant degree, while addressing the softness, extreme flexibility, and lack of sufficient rigidity of bags or other films formed entirely from PBAT, or the limited biodegradability of bags formed from PBAT / PLA blends. Thus, the blends of the present invention can be used to form bags that provide good performance characteristics (e.g., a good balance of strength, rigidity, flexibility, etc.) while ensuring that each of the above home compostability criteria is met. Because contemplated carbohydrate-based polymer materials (e.g., NuPlastiQ®, available from the applicant) are generally cost-competitive with polyethylene (i.e., less expensive than PBAT and PLA), blends and bags or other films formed therefrom can also be manufactured more cost-competitively than if the bags were formed solely from PBAT and / or PLA.

[0037] Such blends are particularly beneficial in that they offer a viable alternative to the manufacture of many plastic products and allow such materials to advantageously biodegrade under home composting conditions within a reasonable time frame, rather than existing indefinitely in the stable state of plastic.

[0038] Furthermore, Applicant has observed that, like paper, biodegradation of such articles does not readily occur when the articles are stored in typical storage and use environments (e.g., in homes, offices, warehouses, etc.), but generally begins to occur only when the articles are placed in or exposed to an environment that mimics an aerobic or anaerobic digester, such as the conditions provided by the relevant ASTM or other biodegradability testing standards described herein. For example, such conditions often include (i) temperatures that may be at least somewhat higher than normal "use" or "storage" temperatures, (ii) exposure to high humidity levels, and (iii) exposure to specific classes of microorganisms that are lacking in composting or similar waste environments. While elevated temperature and humidity may cause degradation, they will not cause biodegradation of such articles unless the necessary microorganisms are also present. Such a combination of conditions will cause articles formed from such material blends to begin biodegrading. Third-party testing as described herein confirms that not only do carbohydrate-based polymeric materials and PBAT biodegrade under home composting conditions, but that PLA also biodegrades under such moderate conditions (PLA is otherwise resistant to biodegradation under home composting conditions at lower temperatures (i.e., 28°C)).

[0039] While the mechanism by which blending with carbohydrate-based polymeric materials enables such biodegradation of PLA may not be fully understood, it is likely that blending the two polyester plastic materials with a high degree of homogeneity, and perhaps coupling with specific properties of the carbohydrate-based polymeric material, somehow overcomes the moisture-wicking barrier associated with PLA, allowing microorganisms that biodegrade the carbohydrate-based polymeric material to not only biodegrade the carbohydrate-based polymeric material but also biodegrade adjacent polyester-linked PLA monomer units. Carbon and other bonds are broken, and biodegradation is confirmed based on third-party testing (i.e., respirometry-based testing) that captures and measures degassed carbon dioxide and methane. Such results are particularly advantageous. U.S. Patent Application Nos. 62,872,582 (21132.27) and 62 / 939,460 (21132.27.1), filed July 10, 2019 and November 22, 2019, respectively, which are incorporated by reference in their entireties, contain further description related to the uniformly blended small particle starch properties of such blends.

[0040] Previous literature in the field has shown that PLA exhibits biodegradation under industrial composting conditions (e.g., ASTM D-5338) where temperatures are significantly higher (e.g., 58°C vs. 28°C), but is notably resistant to biodegradation under home composting conditions at ambient temperatures.

[0041] It would clearly be advantageous to find ways to increase the rate and / or extent of biodegradability of PLA materials within a reasonable time frame (e.g., 365 days as applied in various standardized certification standards) when disposed of in a home composting-type environment. For example, the blends of the present invention may include blends of PBAT and PLA in combination with carbohydrate-based polymeric materials, thereby achieving improved physical properties while simultaneously providing full home compostability of the resulting bag, film, or other article.

[0042] Plastic articles can be made by blending a carbohydrate-based polymer material with two polyester plastic materials, heating the mixture, molding the mixture (e.g., injection molding), extruding the mixture, blow molding the mixture, blow molding the mixture (e.g., forming a blown film), thermoforming the mixture, etc. Various other plastic manufacturing processes will be apparent to those skilled in the art in light of this disclosure, applicant's other applications, and general knowledge in the art. Thermosetting materials can also be blended (e.g., such blending processes may or may not require heating).

[0043] The articles described herein can be produced in the form of any conceivable structure, including, but not limited to, bags, other films, and bottles, boxes, other containers, sheets, etc. Thin films for bags and film wraps (e.g., for wrapping around or over products) can be readily made using blown film equipment.

[0044] Examples of suitable carbohydrate- or starch-based polymeric materials that have been shown to render or enhance the biodegradability of polyester plastic materials that exhibit limited or no biodegradability are available from BiologiQ under the trade name NuPlastiQ®. Specific examples include, but are not limited to, NuPlastiQ® GP and NuPlastiQ® CG. The specific properties of such NuPlastiQ® materials are described in further detail herein. Other carbohydrate- or starch-based polymeric materials may also be capable of enhancing the biodegradability of PLA materials included in the blend and may be suitable for use, provided they are specifically selected for this purpose. To select such materials for this purpose, their ability to render or enhance the biodegradability of PLA must be recognized. Applicant is not currently aware of any such materials, other than NuPlastiQ®, that have been shown to function in this manner.

[0045] Applicant also offers masterbatch blends of NuPlastiQ® and conventional polymeric materials under the trade name BioBlend, including, but not limited to, BioBlend XP, BioBlend XD, BioBlend MB, BioBlend BC, and BioBlend CB. Such masterbatches may contain higher percentages of modified polysaccharide (NuPlastiQ®), which can be down-blended with other polymeric materials before forming the final product.

[0046] III. Exemplary Articles and Methods FIG. 1 illustrates an exemplary process 100 that can be used in accordance with the present invention. At 102, process 100 can include providing two or more polyester plastic (e.g., polymer) materials, such as PBAT and PLA, among others. While PBAT already exhibits home composting properties, PLA does not. Blending with a carbohydrate-based polymer material, such as those described herein, can impart home biodegradability to the overall blend (by enhancing the biodegradability of the PLA material). The presence of a carbohydrate-based polymer material, such as those described herein, intimately dispersed with the polyester material can also enhance the biodegradability (e.g., rate and / or extent) of PBAT or other polyester materials included in the blend. At 104, process 100 can include providing one or more carbohydrate-based polymer materials (e.g., NuPlastiQ®). While other materials may be suitable for use, in one embodiment, the selected carbohydrate-based polymer material can be specifically selected for blending with polyester due to its recognized ability to enhance the biodegradability of at least one of the polyester plastic materials (e.g., PLA) provided at 102. While one or more carbohydrate-based polymer materials can include starch-based polymer materials, typical, conventionally available carbohydrate-based polymer materials do not necessarily result in blends that meet home compostability requirements. Applicant's NuPlastiQ® material is an example of a specific carbohydrate-based polymer material that functions as described herein. NuPlastiQ® is particularly suitable because it can be incorporated while maintaining other desired physical properties, such as desired strength characteristics (e.g., particularly dart drop impact strength). The carbohydrate-based polymer material and polyester plastic material can be provided in a desired form, such as pellets, powder, nurdles, slurries, and / or liquids. In one embodiment, the materials can be in the form of pellets. The method further includes blending the polyester plastic material with the carbohydrate-based polymer material.

[0047] Surprisingly, Applicant has observed that such blending results in an overall blend that is home compostable, even though PLA itself (whether alone or blended with PBAT) would not normally meet such criteria. This is believed to be due, at least in part, to the uniform blending of the NuPlastiQ® material into the polyester component. In any event, such blends of materials meet applicable home compostability criteria tests, as evidenced by third-party testing included in the Examples section of this application.

[0048] Such blends can be formed into desired articles during manufacturing through any conceivable process. One such example would be an extrusion process. For example, a polyester plastic material (e.g., PBAT and PLA) and a carbohydrate-based polymer material can be fed into an extruder (e.g., into one or more hoppers thereof). The different materials can be fed into the extruder in the same chamber, in different chambers, at approximately the same time (e.g., through the same hopper), or at different times (e.g., through different hoppers, one introduced into the extruder earlier along the screw than the other), etc. It will be apparent that numerous configurations are possible.

[0049] The two polyester materials (e.g., PBAT and PLA) can be sourced from petrochemical sources or so-called "green" or sustainable sources (e.g., corn used to produce lactic acid, corn used to form PLA, etc.). Those skilled in the art will recognize that renewable or sustainable feedstocks refer to, for example, plant sources that are renewable within less than 100 years, rather than petrochemical feedstocks. Those skilled in the art will also appreciate the lower carbon content in carbon-containing renewable materials compared to, for example, materials sourced from fossil fuels. 14 Against C 12 Because of the high proportion of recycled content, you will understand that there are various tests to verify the sustainable or renewable content of plastic or other materials.

[0050] The carbohydrate-based polymeric material can be formed from multiple ingredients (e.g., a mixture) including one or more starches. For example, the one or more starches can be produced from one or more plants, such as corn starch, tapioca starch, cassava starch, wheat starch, potato starch, rice starch, sorghum starch, etc. In some embodiments, a mixture of different types of starch can be used, which can result in a synergistic increase in strength, as described, for example, in applicant's U.S. Patent No. 10,214,634 and U.S. Patent Application No. 16 / 287,884, filed February 27, 2019 (each of which is incorporated herein by reference in its entirety). A plasticizer is also present in the mixture of ingredients from which the carbohydrate-based polymeric material is formed. Water can also be used in forming the carbohydrate-based polymeric material (e.g., initially as a plasticizer), but only small to negligible amounts of water are present in the finished carbohydrate-based polymeric material.

[0051] One or more carbohydrate-based polymer materials may be formed predominantly from starch. For example, at least 65%, at least 70%, at least 75%, or at least 80% by weight of the carbohydrate-based polymer material may be attributable to one or more starches. In one embodiment, 65% to 90% by weight of the finished carbohydrate-based polymer material may be attributable to one or more starches. Other than negligible water content, the remainder of the finished carbohydrate-based polymer material may be attributable to plasticizers (e.g., glycerin). The finished carbohydrate-based polymer material, such as that exemplified by NuPlastiQ®, is not simply a mixture of starch and glycerin, as described below in connection with FIG. 3. Nevertheless, the NuPlastiQ® material is derived from a mixture of these materials.

[0052] The above percentages may represent the percentage of starch relative to the starting material from which the carbohydrate-based polymer material is formed, or the percentage of the finished carbohydrate-based polymer material that is derived or attributable to starch (e.g., at least 65% of the carbohydrate-based polymer material may be attributable to (formed from) starch as a starting material). While some water may be used in forming the carbohydrate-based polymer material, substantially the remainder of the carbohydrate-based polymer material may be attributable to glycerin or another plasticizer. Very little residual water (e.g., less than 2%, typically about 1% or less (e.g., 0.1-1.5%)) may be present in the finished carbohydrate-based polymer material.

[0053] For example, the material from which one or more carbohydrate-based polymeric materials are formed can contain at least 12% by weight, at least 15% by weight, at least 18% by weight, at least 20% by weight, at least 22% by weight, 35% by weight or less, 32% by weight or less, 30% by weight or less, 28% by weight or less, or 25% by weight or less of plasticizer. Such percentages can represent the proportion of the finished carbohydrate-based polymeric material that originates or is attributable to the plasticizer (e.g., at least 12% of the carbohydrate-based polymeric material can originate from (be formed from) the plasticizer as a starting material). Such percentages can also represent the proportion of the mixture of materials from which the finished carbohydrate-based polymeric material is formed, excluding any water initially present. Of course, it may be possible for carbohydrate-based polymeric materials to be produced using less than 12% (e.g., less than 12%, perhaps even 0%) of plasticizer.

[0054] Exemplary plasticizers include glycerin, polyethylene glycol, sorbitol, polyhydric alcohol plasticizers, hydrogen bond-forming organic compounds without hydroxyl groups, anhydrides of sugar alcohols, animal proteins, vegetable proteins, fatty acids, phthalates, dimethyl and diethyl succinates and related esters, glycerol triacetate, glycerol monoacetate and diacetate, glycerol mono-, di-, and tripropionate, butanoates, tearate, lactates, citrates, adipates, stearates, oleates, other acid esters, or combinations thereof. Glycerin may be preferred.

[0055] The finished carbohydrate-based polymer material may contain 5% or less, 4% or less, 3% or less, 2% or less, 1.5% or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, or 1% or less by weight of water. NuPlastiQ® material available from BiologiQ is an example of such a finished carbohydrate-based polymer material, although it should be understood that other materials available elsewhere (e.g., at some point in the future) may also be suitable for use.

[0056] In some embodiments, a mixture of different starches may be used to form the carbohydrate-based polymer material, and in such a mixture of starches, the starch may be present in the mixture in an amount of at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, up to 95%, up to 90%, up to 85%, up to 80%, up to 75%, up to 70%, up to 65%, up to 60%, up to 55%, up to 50%, or between 10% and 50% by weight, based on the total weight of the starches. Some non-limiting exemplary mixtures may include 90% of the first starch and 10% of the second starch, or 30% of the first starch and 70% of the second starch, or 50% of the first starch and 50% of the second starch. Mixtures of more than two starches (e.g., using three or four different starches) can also be used.

[0057] Examples of carbohydrate-based (e.g., starch-based) polymeric materials suitable for use in forming films and other articles are available from BioLogiQ, located in Idaho Falls, Idaho, under the trade name NuPlastiQ®. Specific examples include, but are not limited to, NuPlastiQ® GP and NuPlastiQ® CG. NuPlastiQ® may be provided in pellet form. The physical properties of two examples of NuPlastiQ® materials, formerly known as GS-270 and GS-300, are shown in Table 1 below.

[0058] [Table 1]

[0059] As mentioned above, the above basic properties shown for GS-270 and GS-300 are exemplary of the new NuPlastiQ® products available from BioLogiQ, although values ​​may vary somewhat. For example, suitable NuPlastiQ® products may generally have glass transition temperatures ranging from about 70°C to about 100°C. Those skilled in the art will appreciate that glass transition temperatures can be an indicator of crystallinity. Values ​​for melting temperature range, density, Young's modulus, and moisture content are similar to those shown in Table 1 above. Some properties may also vary somewhat (e.g., ±25% or ±10%) from the values ​​shown in Table 1. NuPlastiQ® has an amorphous structure (e.g., more amorphous than typical raw starch). For example, as described in more detail in connection with Figure 3 below, typical raw starch powders have a mostly crystalline structure (e.g., greater than 50%), while NuPlastiQ® has a mostly amorphous structure (e.g., less than 10% crystals).

[0060] Some properties may be similar to other thermoplastic starch materials, while other properties may be quite different from typical starch-based materials. For example, the density of such reactively extruded NuPlastiQ® materials is particularly high, e.g., greater than 1 g / cm 3 More than, at least 1.1g / cm 3 , at least 1.2 g / cm 3 , or at least 1.25 g / cm 3 , (e.g., 1.4 g / cm as shown in Table 1 above) 3 ) Various other properties may also differ substantially from superficially similar starch-based polymeric materials.

[0061] As described, NuPlastiQ® material has a low moisture content. As the material absorbs moisture, it exhibits plastic behavior and becomes flexible. When removed from the humid environment, the material dries and becomes rigid again (e.g., again exhibiting a moisture content of less than about 1%). Moisture present in NuPlastiQ® (e.g., in pellet form) can be released in the form of steam during processing (e.g., extrusion, blown film, injection molding, blow molding, etc.). As a result, films or other articles made from starch-based polymer materials blended with another plastic material may exhibit even lower moisture content; the PBAT, PLA, or other polyester materials used may exhibit negligible moisture content; any water in NuPlastiQ® will typically be released during the manufacture of the desired article.

[0062] The low water content of carbohydrate-based NuPlastiQ® polymer materials, and NuPlastiQ®'s hydrophobic rather than hydrophilic properties, can be important because significant water content (or hydrophilicity) can result in incompatibility with the polyester materials (typically considered hydrophobic, at least in the case of PBAT and PLA) with which the NuPlastiQ® material is blended. Water content is particularly problematic when the article requires the formation of a thin film. For example, evaporation of water can result in voids within the film or other article, as well as other problems. When blown into thin films, the carbohydrate-based polymer materials used may preferably contain no more than about 1% water. By matching the hydrophobicity between the NuPlastiQ® material and the polyester polymer material with which it is blended, this can also help achieve a uniform distribution of very small particle sizes of NuPlastiQ® material dispersed within the polyester material, as described in Applicant's Patent Application No. 62 / 872,582 (21132.27), filed July 10, 2019, which is incorporated herein by reference in its entirety.

[0063] The low water content in NuPlastiQ® materials is not achieved by esterification, as is common in some conventional TPS materials that may contain relatively low water contents. Such esterification can be expensive and complicated to implement. Furthermore, NuPlastiQ® materials, which are examples of carbohydrate-based polymeric materials employable herein, have been mechanically, physically, or chemically reacted and / or altered compared to the starting starch and glycerin materials. X-ray diffraction patterns of exemplary carbohydrate-based polymeric materials described below (e.g., shown in Figure 3) demonstrate such chemical or physical changes. Furthermore, while both the starch and glycerin starting materials are hydrophilic, NuPlastiQ® materials are hydrophobic. In other words, carbohydrate-based polymeric materials are not recognized as simple mixtures containing natural starch and glycerin. The low water content achievable in carbohydrate-based polymeric materials, and the hydrophobicity exhibited, can be attributed, at least in part, to the physical or chemical transformation of the starch and plasticizer materials into hydrophobic thermoplastic polymers that do not retain water like native starches, or conventional thermoplastic starches.

[0064] Nevertheless, processing at relatively high temperatures may result in the release of some volatilized glycerin (e.g., visible as smoke). If necessary (e.g., if stored pellets may have absorbed additional water), drying of the pellets can be accomplished by simply introducing warm, dry air, e.g., at 60°C, for 1-4 hours, which is sufficient to drive off any absorbed water. Pellets, especially those intended for film formation, should be dried to a moisture content of less than about 1% before processing. NuPlastiQ® pellets can be simply stored in a sealed container, with or without a desiccant, in a dry place away from heat to minimize water absorption and prevent unwanted decomposition.

[0065] In addition to being thermoplastic, NuPlastiQ® can also be thixotropic, meaning that the material is solid at ambient temperature but flows as a liquid when heat, pressure, and / or frictional movement are applied. Advantageously, NuPlastiQ® pellets can be used in standard plastic manufacturing processes in the same way as petrochemical pellets (any typical plastic resin pellets). NuPlastiQ® materials and products made therefrom may exhibit gas barrier properties. Products (e.g., films) made using such pellets exhibit oxygen gas barrier properties. NuPlastiQ® materials can be non-toxic and edible, and can be made using all edible raw materials. NuPlastiQ® and products made therefrom can be water-resistant, even hydrophobic, but also water-soluble. For example, NuPlastiQ® can resist swelling under moist heat conditions to the extent that pellets (e.g., 3-4 mm in size) of NuPlastiQ® may not completely dissolve in boiling water within 5 minutes, but the pellets dissolve in the mouth within about 10 minutes. That said, films containing NuPlastiQ® may still have a relatively low surface wettability (e.g., 40 mN / m (40 dynes / cm) or less), lower than that of conventional blends of TPS materials, as well as PBAT, PLA, or other polyester materials with which it is blended.

[0066] NuPlastiQ® materials also generally do not disintegrate or biodegrade under typical storage conditions, even in relatively humid conditions, due to the absence of other conditions typical of landfills, compost, or similar waste environments. Naturally, when such conditions exist, not only will NuPlastiQ® biodegrade, but PLA will also exhibit enhanced biodegradability to meet standards for home compostability.

[0067] NuPlastiQ® can be cost-competitive because it is manufactured at a cost competitive with conventional polyethylene or other inexpensive plastic resins. This is advantageous because polyester resins such as PBAT and PLA are significantly more expensive than polyethylene. The inclusion of NuPlastiQ® in the blends of the present invention can make them relatively less expensive than they would otherwise be. More specifically, PBAT can typically be about three times more expensive than polyethylene. Because NuPlastiQ® is cost-competitive with polyethylene, the blends of the present invention can actually be offered at a lower cost than conventional 100% PBAT films (or PBAT / PLA blends) or other articles. In addition to a potentially improved cost structure, the blends of the present invention also offer the advantage of a significant portion of the blended article being sourced from sustainable feedstocks (e.g., starch) that would otherwise often be considered waste.

[0068] As a further explanation, PLA is industrially compostable, i.e., it can decompose under high-temperature conditions (i.e., industrial composting conditions, i.e., 58°C), but strictly speaking, it is not "biodegradable" under less favorable conditions (e.g., 28°C). PBAT has been certified as home compostable under such less favorable conditions. Some polyesters (e.g., PBAT) may be compostable under relatively low-temperature conditions (e.g., 28°C), while other such materials do not meet such criteria. The degree to which a given polyester plastic material is biodegradable or compostable varies from material to material. For example, PHA and PBAT may be two of the more readily biodegradable polyester polymer materials. PLA and PCL, as well as various other polyesters, may exhibit low biodegradability under given conditions (e.g., less favorable conditions, such as 28°C). By homogeneously blending carbohydrate-based polymeric materials with specific properties (e.g., as exemplified by NuPlastiQ®), the degree and / or rate of biodegradability (especially under low-temperature home composting conditions) of PLA and possibly other similar polyester materials blended therewith is significantly increased. Current FTC Green guidelines stipulate that a plastic cannot be categorically claimed to be "degradable" unless it decomposes within a "reasonably short period of time" (most recently defined as within five years) "after normal disposal." The blends of the present invention provide the ability to meet applicable guidelines, allowing for "pass" certification of home compostability for the blends of the present invention (e.g., NF T51-800 (2015), AS 5810 (2010), or TUV Austria Belgium's OK Compost Home certification scheme).

[0069] In some embodiments, NuPlastiQ® can be provided in a masterbatch formulation, which can include one or more of a carbohydrate-based polymeric material, a polyester plastic material, and optionally a compatibilizer. Such a masterbatch can contain a high concentration of carbohydrate-based polymeric material, for example, specifically configured to be mixed with pellets of polyester material during further processing to form a given article, effectively reducing the concentration of carbohydrate-based polymeric material to a desired final value (e.g., the masterbatch can be about 50-80% NuPlastiQ®, while the finished article can contain 30-55% NuPlastiQ®). Depending on the desired percentages of NuPlastiQ® and / or compatibilizer and / or polyester plastic material in the finished article, any conceivable ratio can be used when mixing such different pellets.

[0070] The NuPlastiQ® materials described herein as suitable for use as carbohydrate-based (e.g., starch-based) polymeric materials are substantially amorphous. For example, raw starch powders (such as those used to make NuPlastiQ® and various other thermoplastic starch materials) have approximately 50% crystalline structure. The NuPlastiQ® materials available from BioLogiQ differ from many other commercially available thermoplastic starch (TPS) materials in terms of their crystallinity versus amorphous characteristics. For example, Kris Frost's doctoral dissertation, "Thermoplastic Starch Composites and Blends" (September 2010), pp. 62-63, states, "Of particular interest in TPS is the completeness of gelatinization during processing and any subsequent tendency toward retrogradation to form V-type amylose crystals." Frost continues, "Gelatinization involves the loss of granular and crystalline structure by heating with water and often the inclusion of other plasticizers or modifying polymers. Retrogradation is due to the rewinding of the amylose helical coil. Starch molecules that are broken during gelatinization slowly rewind into their original helical configuration, or a new single helical structure known as V-form, causing the TPS film to rapidly become brittle and lose optical clarity." Thus, conventional TPSs tend to reform their crystalline structure after the gelatinization process used to produce TPS from raw starch. In contrast, NuPlastiQ® material available from BioLogiQ remains amorphous virtually indefinitely and therefore rarely reverts to a crystalline structure.

[0071] In contrast to typical TPS materials, NuPlastiQ® material, which is a suitable example of a starch-based polymer material for use in forming the articles described herein, has an amorphous microstructure and physical properties. The difference in molecular structure between conventional TPS and NuPlastiQ® material is evidenced by the fact that NuPlastiQ® material is much less crystalline than conventional thermoplastic starch-based materials, as shown by the X-ray diffraction shown in Figure 3, when comparing the resulting diffraction pattern of NuPlastiQ® GP with the native raw corn starch and native raw potato starch from which NuPlastiQ® GP is formed. The diffraction pattern of NuPlastiQ®, as seen in Figure 3, is much less crystalline (e.g., about 7% crystallinity) than native corn and potato starches (about 42% and 31% crystallinity, respectively). The differences in the diffraction patterns demonstrate that conversion from native starch to NuPlastiQ® (e.g., by a reactive extrusion process) has resulted in substantial chemical changes to the material. For example, while native starch exhibits several prominent diffraction peaks between approximately 15 and 25°, the diffraction is quite different for the NuPlastiQ® material, exhibiting a much less intense "bell-curve" peak centered at approximately 20°. Interestingly, NuPlastiQ® exhibits a small peak at approximately 10°, whereas the starch material actually exhibits a trough at 10°, although the small peak at 10° for NuPlastiQ® is less intense than the trough for the native starch material. Across the spectrum, the diffraction intensity is higher for native starch than for NuPlastiQ®. The higher diffraction intensity across the broad spectrum indicates a higher degree of crystallinity in native starch compared to NuPlastiQ®. As can be seen, numerous differences exist.

[0072] For example, the carbohydrate-based (e.g., starch-based) polymeric material used in making films according to the present disclosure may have a crystallinity of less than about 40%, less than about 35%, less than about 30%, less than about 25%, less than about 20%, less than about 15%, less than about 10%, less than 9%, less than about 8%, less than 7%, less than about 6%, less than about 5%, or less than about 3%.Any suitable test mechanism for determining crystallinity can be used, including, but not limited to, FTIR analysis, X-ray diffraction, and symmetric reflection and transmission techniques.A variety of suitable test methods will be apparent to those skilled in the art.

[0073] In addition to differences in the chemical or microstructure of the finished NuPlastiQ® compared to the starting material, bags, other films, bottles, sheets, disposables, plates, cups, or other articles made from blends containing carbohydrate-based polymers differ from otherwise similar articles formed using only conventional TPS or starch powder, or polyester plastic materials. For example, articles formed by blending a carbohydrate-based polymer material, such as NuPlastiQ® described herein, with a polyester plastic material do not have the large "islands in the sea" particle size characteristic often seen when blending conventional TPS materials with other polymer materials. Rather, when Applicant's NuPlastiQ® material is used in the blend, a substantially uniform blend can be achieved. The uniform blending characteristics may be responsible for the observed accelerated or enhanced home compostability. Further details of the resulting uniform blend properties, including characterization of the small sized starch particles, can be found in Applicant's patent application Ser. No. 62 / 872,582 (21132.27), filed July 10, 2019, which has been previously incorporated by reference in its entirety.

[0074] As described herein, blending the carbohydrate-based polymeric materials described herein with blends of PBAT and PLA not only results in carbohydrate-based and PBAT materials that biodegrade under home composting conditions, but also allows the PLA to biodegrade under such home composting conditions, such that the entire blend can be certified under such applicable standards (e.g., NF T51-800 (2015), AS 5810 (2010), or TUV Austria Belgium's OK Compost Home Certification Scheme). While such a result would not necessarily occur when blending with a typical TPS material, it does occur with the blends of the present invention. As demonstrated by the various examples below, such different results clearly demonstrate significant structural and / or chemical differences in NuPlastiQ® materials and blends containing NuPlastiQ® compared to conventional TPS materials, as the entire composite structure (i.e., film or other structure) of the blend can now be substantially completely biodegraded under home composting conditions.

[0075] Without being bound by any particular theory, it is believed that carbohydrate-based polymer resins may reduce the crystallinity of the blended product, interfering with the crystallinity and / or moisture-wicking barrier properties of the PLA polyester plastic material in a manner that allows water and bacteria to degrade the otherwise stable plastic molecular arrangements and bonds of the PLA in the blend with the carbohydrate-based polymer resin material. In other words, when ester-linked PLA monomers or other components of the polymer are uniformly blended with certain carbohydrate-based polymer materials as contemplated herein, they can be more easily decomposed and ultimately digested by microorganisms present in such environments. Microorganisms naturally present in home compost environments can consume such small molecules, converting them back into their natural components (CO, CH, HO, etc.). While the PBAT in the blend is already capable of achieving this on its own without the addition of a carbohydrate-based polymer material, the rate and / or extent of biodegradation achieved under such conditions may be enhanced (e.g., faster and / or more extensive) when intimately blended with a carbohydrate-based polymer material.

[0076] For example, truly biodegradable plastics break down through microbial assimilation (e.g., microbial enzymatic action on plastic molecules) into naturally occurring elements or compounds such as carbon dioxide, methane, water, inorganic compounds, or biomass. Biodegradation of plastics is made possible by initially breaking down the polymer chains through either chemical or mechanical action, but can only be achieved completely through the breakdown of the remaining molecules through microbial assimilation.

[0077] Plastics made from petrochemical feedstocks or derived from plant sources begin life as monomers (i.e., single small molecules that can chemically react with other small molecules). When the monomers combine together, they become polymers ("many parts") known as plastics. Before combining together, the many monomers are readily biodegradable, but after combining together through polymerization, the molecules become so large that they combine in arrangements and linkages that microbial assimilation by microorganisms is impractical within any reasonable time frame under the contemplated conditions.

[0078] Polymers can be formed in both crystalline (orderly packed) and amorphous (randomly arranged) structures. Many polymers contain a high degree of crystallinity, with some amorphous regions randomly arranged and intertwined throughout the polymer structure.

[0079] NuPlastiQ® materials available from BiologiQ are formed from starting starch materials that are highly crystalline, but the finished NuPlastiQ® plastic resin material exhibits low crystallinity (i.e., is substantially amorphous). Such starch-based polymeric materials are used as starting materials in the manufacture of articles as described herein. NuPlastiQ® is therefore a plastic made from starch. As evidenced by the results of experimental testing contained herein, the molecules (size and bond) of plastics made with NuPlastiQ®, due to their natural starch-based origin and carefully controlled bond types, are highly susceptible to biodegradation by enzymatic reactions triggered by the introduction of water and bacteria or other microorganisms.

[0080] Like polyolefins such as polyethylene and polypropylene, polyesters typically have high crystallinity and are made by converting monomer molecules (whether derived from petroleum or from small building block molecules derived from lactic acid or other plant sources) into long-chain polymers. In polyesters, the bonds between monomers are naturally ester bonds. The bonds formed when connecting monomers to form long polymer chains can be relatively strong and difficult to break, with the degree of difficulty varying between different types of polyesters. For example, the bonds in PBAT (and PHA) are more easily broken than those in PLA. While many synthetic polyesters (including both PBAT and PLA) exhibit significant biodegradability under high-temperature composting conditions (e.g., 58°C), and PBAT also exhibits sufficient biodegradability to meet home compostability standards (e.g., 28°C), PLA cannot meet home compostability standards by itself or even when blended with PBAT. Blending such materials with applicant's NuPlastiQ® materials changes that.

[0081] In addition to enhanced home compostability, in some embodiments, the resulting polyester blends of the present invention may have a higher modulus (stiffness or strength) than one or both of the polyester plastic materials alone, allowing them to be used to make plastic films or other articles that are at least as strong as, or stronger than, the same article made from a given one of the pure polyester plastic materials alone. For example, PBAT alone exhibits relatively low stiffness but excellent elongation. PLA has a significantly higher modulus, and blending NuPlastiQ® and PLA with PBAT increases the modulus of the resulting blend compared to PBAT alone. In other embodiments, depending on the properties of the polyester materials blended together, strength properties may be reduced, but still sufficient for the desired purpose. By way of example, such blends may provide dart drop strengths of at least 130 g, at least 140 g, at least 150 g, at least 160 g, at least 175 g, at least 200 g, at least 225 g, at least 250 g, at least 275 g, or at least 300 g at a thickness of approximately 25 μm (1 mil). Strength generally increases with increasing thickness. The percentage of carbohydrate-based polymer material in the blend can be, for example, 1% to 70%, 10% to 65%, 20% to 55%, 30% to 55%, etc., as described herein or in Applicant's other applications. Figure 3A shows strength data for films of various thicknesses compared to various other materials (e.g., 100% PBAT, 100% LLDPE, and a 25% blend of NuPlastiQ® and LLDPE). The sample labeled BC27241 in Figure 3A contained 35% NuPlastiQ®, 11% PLA, and 54% PBAT. The sample labeled BC27251 in Figure 3A contained 41% NuPlastiQ®, 11% PLA, and 48% PBAT.

[0082] Figure 4 shows molecular weight data for an exemplary NuPlastiQ® (e.g., the same NuPlastiQ® GP as in Figure 3) material. As shown, the average molecular weight (i.e., weight average molecular weight) can be about 900,000 g / mol. For example, the weight average molecular weight can be greater than 200,000 g / mol, greater than 300,000 g / mol, greater than 400,000 g / mol, greater than 500,000 g / mol, greater than 600,000 g / mol, greater than 700,000 g / mol, 500,000 to 5,000,000 g / mol, 500,000 to 3,000,000 g / mol, 500,000 to 2,000,000 g / mol, 500,000 to 1,000,000 g / mol, or 800,000 to 1,000,000 g / mol.

[0083] Figure 5 shows the transmittance data for the same materials compared in the X-ray diffraction chart of Figure 3. The NuPlastiQ® material at 1653 cm -1 It is readily apparent that the peak of the OH scissor vibration at 1000 kJ / cm2 is significantly reduced compared to the native corn and potato starch materials. This reduction in the occurrence of OH groups is consistent with the low wettability shown in Figure 6.

[0084] Figure 6 shows a comparison of the wetting properties of a conventional blend of polyolefin and a conventional TPS material, having a wettability of greater than 46 mN / m (46 dynes / cm), compared to an exemplary blend of polyolefin and NuPlastiQ® GP (right), having a wettability of less than 34 mN / m (34 dynes / cm). In both examples, the starch-based polymer content is believed to be 20-25%. While this figure uses a polyolefin blend (rather than polyester), the comparison demonstrates the hydrophobicity of the NuPlastiQ® GP material compared to the hydrophilicity of the conventional starch material. The PBAT and PLA materials used in the blends described herein typically exhibit hydrophobic properties similar to those of polyolefins. For example, such materials often have wettability values ​​of less than 40 mN / m (40 dynes / cm), less than 38 mN / m (38 dynes / cm), less than 36 mN / m (36 dynes / cm), less than 34 mN / m (34 dynes / cm), or 30-40 mN / m (30-40 dynes / cm) when used in a dyne test. NuPlastiQ® materials exhibit wetting properties similar to those of hydrophobic polyesters, e.g., less than 40 mN / m (40 dynes / cm), less than 38 mN / m (38 dynes / cm), less than 36 mN / m (36 dynes / cm), or less than 34 mN / m (34 dynes / cm). Surface wettability dyne tests can be in accordance with, for example, DIN 53394 / ISO 8296. Such matched hydrophobicity between the NuPlastiQ® material and the polyester material with which it is blended may be responsible for its ability to achieve the biodegradable properties described herein.

[0085] FIG. 7 illustrates comparative DSC melting temperature data for conventional starch materials, showing a melting temperature of 287.7°C, much higher than that of NuPlastiQ®, which is about 170°C.

[0086] FIG. 8 shows the TGA temperature stability profile of the NuPlastiQ® GP material compared to the starting glycerin and native starch materials. Returning to FIG. 1 , at 106, the process 100 includes mixing a polyester plastic material with a carbohydrate-based polymer material to produce a material mixture. In some cases, mixing the polyester plastic material with the carbohydrate-based material can be performed using one or more mixing devices. In certain implementations, a mechanical mixing device can be used to mix the polyester plastic material with the carbohydrate-based polymer material. In implementations, at least a portion of the components of the material mixture can be combined in an apparatus such as an extruder, an injection molding machine, or the like. In other embodiments, at least a portion of the components of the material mixture can be combined before being fed into the apparatus.

[0087] The carbohydrate-based polymeric material can be present in the blend in an amount at least sufficient to enhance the biodegradability of the PLA polyester plastic material of the blend, such that the blend passes any of various applicable home compostability standards. Of course, amounts greater than such threshold amounts may be included (e.g., to further enhance biodegradability and / or increase the renewable content of the blend, etc.). By way of example, the carbohydrate-based polymeric material can be included in an amount of at least 1% by weight, at least 5% by weight, at least 10% by weight, up to 70% by weight, up to 60% by weight, between 1% and 70% by weight, between 10% and 65% by weight, between 20% and 55% by weight, or between 30% and 55% by weight of the blend of materials. If desired, more than one carbohydrate-based polymeric material and / or more than two polyester plastic materials can be included in the blend.

[0088] The first polyester plastic material (e.g., PBAT) can be present in the material blend in an amount of at least 20%, at least 25%, at least 30%, at least 35%, 20% to 85%, 30% to 70%, or 30% to 60% by weight of the material blend. The second polyester plastic material (e.g., PLA) can be present in the material blend in an amount of at least 1%, at least 3%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, or at least 10%, at least 11%, 50% or less, 40% or less, 30% or less, 20% or less, 15% or less, 1% to 20%, 1% to 15%, 1% to 12%, 3% to 15%, 5% to 15%, or about 10% to 15% by weight of the material blend.

[0089] The applicable home compostability standard will accept any test result that results in greater than 90% biodegradation, but the standard also requires that any ingredient present in the blend at 10% or less of the blend pass on its own, ensuring that this material, which may be present in trace amounts, actually passes the applicable standard.

[0090] A compatibilizer may be present in the mixture of materials, but is generally not required. In one embodiment, such a compatibilizer may not be included. If present, the compatibilizer may be blended with the polyester plastic material, blended with the carbohydrate-based polymeric material, blended with both, or provided separately. Often, the compatibilizer is provided with at least one of the polymeric materials, for example, in a masterbatch formulation. The compatibilizer may be a modified polyester such as a maleic anhydride-grafted polyester (e.g., maleic anhydride-grafted PBAT or PLA). The compatibilizer may also include an acrylate-based copolymer. Additionally, the compatibilizer may include a poly(vinyl acetate)-based compatibilizer. In one embodiment, the compatibilizer may be a grafted version of a polyester plastic material (e.g., a maleic anhydride-grafted polyester) or a copolymer (e.g., a block copolymer) in which one of the blocks is the same monomer as the polyester plastic material (e.g., a polyester copolymer). In at least some embodiments, a compatibilizer may not be required, and therefore is not present.

[0091] If included, the blend of materials may comprise at least 0.5%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, up to 50%, up to 45%, up to 40%, up to 35%, up to 30%, up to 25%, up to 20%, up to 15%, up to 10%, up to 9%, up to 8%, up to 7%, up to 6%, up to 5%, up to 4%, up to 3%, 0.5% to 12%, 1% to 7%, or 1% to 6% by weight of compatibilizer. For cost reasons, one may generally use the lowest effective amount of compatibilizer (or no compatibilizer at all).

[0092] While not necessarily required, and in at least some embodiments, it may be desirable to avoid including any of a variety of UV and / or OXO degradable additives, it is within the scope of the present invention. Further details of such additives are described in applicant's U.S. patent application Ser. No. 16 / 391,909 (21132.14.1), which is incorporated herein by reference in its entirety. Other additives may be included, for example, to enhance strength (e.g., DuPont's Biomax® Strong) or for other purposes.

[0093] The one or more additives may be included in the mixture of materials in an amount of at least 0.5%, at least 1%, at least 1.5%, at least 2%, at least 2.5%, at least 3%, at least 4%, 10% or less, 9% or less, 8% or less, 7% or less, 6% or less, 5% or less, 0.2% to 12%, 1% to 10%, 0.5% to 4%, or 2% to 6% by weight of the mixture.

[0094] Although primarily described in the context of mixtures of thermoplastic materials that can be melted together to form a desired blend, in some embodiments it may be possible to blend carbohydrate-based polymeric materials with plastic materials that are not thermoplastic (e.g., thermosetting polyesters or other thermosetting plastic materials that may be included in the blend). For example, a resin component that is a precursor to such a non-thermoplastic polyester plastic material may be blended with the carbohydrate-based polymeric material, and polymerization or other formation of the polyester material may occur in the presence of the carbohydrate-based polymeric material, resulting in a finished product that is a blend of the carbohydrate-based polymeric material and the thermosetting or other non-thermoplastic plastic material, and the carbohydrate-based polymeric material may enhance the biodegradability of a given polymeric component included in the blend.

[0095] 1 , at 108, the process 100 may include heating the mixture of materials, particularly if the materials are thermoplastic. In practice, the mixture of materials may be heated to a temperature of at least 100° C., at least 110° C., at least 115° C., at least 120° C., at least 125° C., at least 130° C., at least 135° C., at least 140° C., 200° C. or less, 190° C. or less, 180° C. or less, 175° C. or less, 170° C. or less, 165° C. or less, 160° C. or less, 155° C. or less, 150° C. or less, 95° C. to 205° C., 120° C. to 180° C., or 125° C. to 165° C. It will of course be understood that in some embodiments, the mixture may be heated to a temperature greater than 200° C.

[0096] Heating of such materials can be carried out, for example, in a multi-stage extruder in which progressive stages are heated to higher temperatures than previous stages, with each stage of the extruder heating the mixture of materials to a given temperature, as disclosed in various patent applications of the applicant previously incorporated by reference. In one embodiment, the temperature of the first stage of such an extruder for blending can be in the same range (e.g., 120-140°C) as the temperature of the carbohydrate-based polymer material (e.g., NuPlastiQ®) in the final stage of the reactive extrusion process from which it was produced, as described in the applicant's U.S. patent applications Ser. Nos. 62,872,582 (21132.27) and 62 / 939,460 (21132.27.1), filed July 10, 2019, and November 22, 2019, respectively. As described in those applications, Applicant discovered that controlling the conditions under which starch and other ingredients (such as plasticizers) are maintained during the preparation of NuPlastiQ® contributes to the desired formation of a starch-based polymer material that, when blended with other polymers, has a small particle size and tight distribution in the final blend of starch-based polymer material. Accordingly, during reactive extrusion of the starch-based polymer material, the material is maintained at a temperature of 110°C to 160°C, preferably 120°C to 140°C (e.g., about 130°C), in the final stage of the extruder before mixing with other polymers, such as polyesters, polyolefins, etc. It will be apparent that this careful temperature control in the final stage of the reactive extrusion step in forming the starch-based polymer material differs from the control of the temperature in the extruder when blending such already-formed starch-based polymer material with the other polymers with which it is blended. While such temperatures may be similar, the components present in such stages are entirely different (e.g., "other polymers," such as polyesters, are typically not present in the stages described herein).

[0097] The mixture of materials including the polyester plastic material and the carbohydrate-based polymer material can be heated in one or more chambers of the extruder. In some cases, one or more chambers of the extruder can be heated at different temperatures. The speed of one or more screws of the extruder can be set to any desired speed.

[0098] Of course, it is also possible to heat one material first and then add a second and / or third material in a subsequent (e.g., downstream) charge, which is heated after the previous material, so that all materials can be melt-blended together. Figure 1 is intended to cover all such conditions.

[0099] At 110, an article is manufactured using the mixture of materials. In some cases, the article can include a film. In other cases, the article can be formed from a film. In other embodiments, the article can have a shape based on the design of a mold (e.g., injection molding) or the like. Any conceivable article formed of plastic can be formed from the mixture, including, but not limited to, films, bags, bottles, caps, lids, sheets, boxes, plates, cups, utensils, etc. If the article is a film, the film can be formed using a die by injecting gas into a heated mixture of materials to form a film (i.e., blowing the film). Cast films are also possible. The film can be sealed and / or otherwise modified to form a bag or other article.

[0100] When the article is a film, the film can be composed of a single layer or multiple layers. The film or any individual layer can have a thickness of at least 0.001 mm, at least 0.002 mm, at least 0.004 mm, at least 0.01 mm, at least 0.02 mm, at least 0.03 mm, at least 0.05 mm, at least 0.07 mm, at least 0.10 mm, 2 mm or less, 1 mm or less, 0.5 mm or less, 0.1 mm or less, about 0.05 mm to about 0.5 mm, or 0.02 mm to 0.05 mm. While there may be some overlap in the thickness values ​​for film and sheet articles, it will be understood that sheet materials thicker than such film values ​​can of course be provided (e.g., 2 mm or more, e.g., 2 mm to 100 mm or 2 mm to 10 mm) and manufactured by any desired plastic manufacturing process.

[0101] The film or other article may have strength properties characterized by tests such as the Dart Drop Impact Test (ASTM D-1709), the Tensile Strength at Break Test (ASTM D-882), the Tensile Elongation at Break Test (ASTM D-882), the Secant Modulus Test (ASTM D-882), and / or the Elmendorf Tear Test (ASTM D-1922). Exemplary values ​​for such properties are provided in other applications of various applicants previously incorporated by reference herein.

[0102] When biodegradation tested under relatively cool, "home compost"-like conditions (e.g., EN 13432, which may be similar to the industrial composting test in ASTM Standard D-5338, but conducted at 28°C instead of 58°C), the blends of the present invention exhibit at least 90% (or more) biodegradation within 365 days, which is sufficient to satisfy the biodegradability portion of applicable "home compostability" standards, such as NF T51-800(2015), AS 5810(2010), and TUV Austria Belgium's OK Compost Home certification scheme. Such standards are incorporated herein by reference in their entirety. 90% or greater biodegradation may be achieved faster than the allowed 365 days, e.g., within 350 days, 325 days, 300 days, 275 days, 250 days, 200 days, or 180 days.

[0103] While biodegradation under home composting conditions is specifically contemplated, it will be understood that enhanced biodegradation may also be demonstrated under other waste environments, such as, for example, anaerobic digester environments (e.g., simulated by ASTM D-5511 or D-5526) or marine conditions (e.g., simulated by ASTM D-6691).

[0104] When subjected to biodegradation testing, articles having about 2% by weight or less (or preferably no biodegradation-promoting additive) and having the amounts of carbohydrate-based polymeric material and polyester plastic material described herein can exhibit enhanced home compostability as a result of incorporating the carbohydrate-based polymeric material into the article. For example, at least 90%, or even at least 95%, of the polyester polymeric material or blend (e.g., or their carbon atoms) may biodegrade over a period of 365, 300, 200, or even 180 days. In either case, the degree of degradation of the PLA material of the blend, and of the blend as a whole, will be greater than that exhibited by materials without the addition of NuPlastiQ® or other carbohydrate-based polymeric material. Such enhanced biodegradation is particularly advantageous because it allows for the formation of bags (e.g., takeout bags) or other films that can include PLA in the polyester blend while still meeting applicable home compostability standards.

[0105] Figure 2 illustrates components of an exemplary manufacturing system 200 for producing articles according to the present disclosure. In some cases, manufacturing system 200 can be used in process 100 of Figure 1. In an illustrative example, manufacturing system 200 is an extruder, such as a single-screw extruder or a twin-screw extruder.

[0106] In one embodiment, two or more polyester plastic materials (e.g., PBAT and PLA) and one or more carbohydrate-based polymer materials are provided via first hopper 202 and second hopper 204. More than two hoppers may be provided. A compatibilizer may optionally be included in either or both materials (e.g., in the masterbatch). In one embodiment, no compatibilizer is included, or a minimal amount thereof (e.g., less than 5%, less than 4%, less than 3%, less than 2%, less than 1%, or less than 0.5%). Calcium carbonate or other filler materials (e.g., whether inorganic fillers such as calcium carbonate or talc, or suitable organic fillers) can be added separately or included in the masterbatch. In a typical embodiment, the carbohydrate-based polymer materials can be compounded into the masterbatch (e.g., with any optional compatibilizer) before pellets of such masterbatch are placed in hopper 204. Such masterbatches, of course, can also include a portion of the polyester plastic material therein.

[0107] One or more carbohydrate-based polymeric materials and PBAT, PLA, or other polyester plastic materials can be mixed in the first chamber 206 to produce a mixture of materials. In some cases, the mixture of materials can include 5% to 60% by weight of one or more carbohydrate-based polymeric materials and 40% to 95% by weight of PBAT, PLA, or other polyester plastic materials. When inorganic or other filler materials (e.g., calcium carbonate and / or talc) are included, they can be present at 0% to 30% by weight, or up to 20% by weight. The percentage of polymeric material can be relative to the entire blend (e.g., including any fillers and / or compatibilizers) or relative to the polymeric material only. Of course, ranges can vary outside of the above or other ranges described herein depending on the desired properties.

[0108] One exemplary composition may include 30% to 55% carbohydrate-based polymeric material, at least 10%, at least 15%, at least 20%, at least 25%, up to 90%, up to 85%, up to 80%, 10% to 80%, 20% to 70%, or 30% to 60% PBAT, up to 60%, up to 50%, up to 40%, up to 30%, up to 20%, or up to 15% PLA (e.g., 1% to 15%, or 1% to 12% PLA), and 0% to 30% (e.g., 0%, 5%, 10%, 15%, 20%, 25%, or 30%) calcium carbonate or other filler. A compatibilizer may or may not be present. All else being equal, a higher percentage of PLA may biodegrade more slowly, but still meet the 90% threshold within 365 days. For example, including a PLA loading of up to 20% or up to 15% may result in a blend that can meet the standard's 90% threshold within 200 days, or even 180 days.

[0109] 2, the mixture of materials may pass through several chambers, such as a first chamber 206, a second chamber 208, a third chamber 210, a fourth chamber 212, a fifth chamber 214, and an optional sixth chamber 216. The mixture of materials may be heated in chambers 206, 208, 210, 212, 214, 216. In some cases, the temperature of one of the chambers may be different from the temperature of another chamber. In an illustrative example, first chamber 206 is heated to a temperature between 120°C and 140°C, second chamber 208 is heated to a temperature between 130°C and 160°C, third chamber 210 is heated to a temperature between 135°C and 165°C, fourth chamber 212 is heated to a temperature between 140°C and 170°C, fifth chamber 214 is heated to a temperature between 145°C and 180°C, and optional sixth chamber 216 is heated to a temperature between 145°C and 180°C.

[0110] The heated mixture can then be extruded using a die 218 to form an extrudate, such as a film or sheet. Injection molding, thermoforming, or other plastic manufacturing processes can be used to produce a variety of articles, such as bags (e.g., take-out bags), agricultural mulch (weed barriers), other films, utensils, plates, cups, bottles, caps, or lids. In blown-film extrusion, gas can be injected into the extrudate to expand it at pressures of 105 bar to 140 bar. The resulting tube 220 can be stretched by rollers 222 to produce a film 224, typically 0.02 mm (approximately 0.8 mil) to 0.05 mm (approximately 2 mil) thick. Even thinner films, e.g., having thicknesses of only 0.1 mil (0.004 mm), can be produced using the blends described herein. Of course, thicknesses greater than 2 mils can also be achieved. In some cases, the film 224 can be composed of a single layer. In other cases, the film 224 can be composed of multiple layers. When multiple layers are present, at least one of the layers may comprise a carbohydrate-based polymer material. In some embodiments, the carbohydrate-based polymer material may be present in one or more outer layers, an inner layer, or all layers.

[0111] The concepts described herein are further illustrated in the following examples, some of which demonstrate greater than 90% biodegradation of the composite blend and / or its polyester components (PBAT and / or PLA) within 365 days.

[0112] Biodegradation can be determined according to a carbon mass balance, as is customarily done in respirometry-based tests, whereby carbon atoms evolved in the materials of the blend (e.g., carbohydrate-based polymeric materials and / or polyesters) are accounted for in the off-gas products as CH4 and / or CO2 as a result of biodegradation. For example, at least 90% of the carbon atoms in either the polyester or the entire blend can become at least one of CO2 or CH4 within 365 days (or 300 days, or 200 days, or 180 days, etc.) in such simulated home composting conditions. To pass NF T51-800(2015), AS 5810(2010), or TUV Austria Belgium's OK Compost Home certification scheme, (1) a "pass" rating for certified solid heavy metals for all components in the blend (e.g., PBAT, PLA, and carbohydrate-based polymeric materials in the blend) according to, for example, ASTM D6400, (2) conversion of at least 90% of the carbon in the sample to CO or CH at 365 days according to EN 13432, (3) a "pass" rating for decay according to, for example, ISO 20200, and (4) a "pass" rating for exotoxicity for all components in the blend according to, for example, OECD Guideline 208, ASTM D6400, etc. The samples shown in the examples below meet these requirements. [Example]

[0113] Example 1 Films made from blends of NuPlastiQ®, PBAT, and PLA were tested according to standard controlled composting biodegradation tests over 195 days in accordance with ASTM D5338 and / or EN13432 at a temperature of 28±2°C, intended to mimic home composting conditions. The tested films are labeled BC27130 and BC27241 in Table 2 and Figure 9. Table 2 and Figure 9 show the results after 179 days of the 195-day test. After 179 days, samples BC27130 and BC27241 exhibited adjusted biodegradation values ​​of 75.3% and 81.8%, respectively (compared to the cellulose control). Specifically, sample BC27130 contained 30% NuPlastiQ® and 70% PBAT. Sample BC27241 contained 35% NuPlastiQ®, 11% PLA, and 54% PBAT. No compatibilizer was present in either sample. Both films had thicknesses of 38-51 μm (1.5-2 mils).

[0114] The biodegradation rate of the cellulose control, which exceeds 100%, can be explained by a synergistic effect called priming. In both cases, the absolute biodegradation of test samples BC27130 and BC27241 was measured at 79.2% and 86%, respectively. The notation in Figure 9 indicates that on day 46 of the test, 20% fresh vegetable, horticultural, and fruit waste (VGF) was reinoculated. The results in Table 2 and Figure 9 indicate that the samples are on track to reach greater than 90% biodegradation under home composting conditions within 365 days, thus meeting the criteria for home compostability.

[0115] [Table 2]

[0116] Example 2 To meet the home compostability standards NF T51-800 (2015), AS 5810 (2010), or TUV Austria Belgium's OK Compost Home certification scheme, sample films must also demonstrate disintegration under such home composting conditions within 26 weeks. Figure 10A shows the disintegration progression of sample BC27240 / 1 (similar to sample BC27241 in Example 1 above) over a 26-week (182-day) test. Test sample BC27240 / 1 (62 microns thick) was placed in a slide frame and mixed with compost inoculum. The resulting mixture was incubated in the dark at ambient temperature (28±2°C). The test was performed in two replicates. Figure 10A shows a photograph visualizing the disintegration progression of test material BC27240 / 1 during 26 weeks of composting at ambient temperature. After 20 weeks, only a small edge of the test material remained in the majority of the slide frame. Furthermore, it was noted that loose film fragments could be easily recovered from the composting reactors. To regenerate the microbial population and provide fresh nutrients, all reactors were re-inoculated with 5% fresh VGF waste after the 18-week incubation period. After 26 weeks, an average disintegration rate of at least 90% had been reached, based on any surface of test material still within the slide frame. After 26 weeks, no loose fragments of test material were found in the compost inoculum.

[0117] The French standard NFT51-800 Plastics - Specification for Plastics Suitable for Home Composting (2015) and the TUV AUSTRIA Belgium OK Compost Home certification scheme specify that a material demonstrates sufficient disintegration for home composting if it passes the 90% disintegration requirement in a quantitative test conforming to ISO 16929 (Plastics - Determination of the Degree of Disintegration of Plastic Materials under Specified Composting Conditions in Pilot-Scale Tests (2013)) and, in a qualitative test conforming to ISO 20200 at ambient temperature (20°C–30°C, e.g., 28°C ± 2°C), (1) after 26 weeks, at least 81% of the surface of the test material in the slide has disappeared, and (2) no discernible test material remains in the compost after the test.

[0118] According to Australian Standard AS5810 Biodegradable Plastics - Biodegradable Plastics Suitable for Home Composting (2010), the assessment criteria for disintegration in the slide frame test is that 90% of the test material disintegrates from the slide frame and any remaining residue is indistinguishable from other materials in the 500mm compost when observed with the naked eye.

[0119] Based on these results, and provided that the 90% disintegration requirement of EN 13432 Requirements for compostable and biodegradable recoverable packaging - Test schemes and evaluation criteria for final approval of packaging (2000) is met (100% disintegration is achieved), BC27240 / 1 of the tested thickness meets the disintegration requirements according to French standard NF T51-800 (2015), the OK Compost HOME conformity mark, and Australian standard AS 5810 (2010).

[0120] Example 3 Summary and Conclusion Figure 10B shows photographs of samples BC27130 and BC27251 (left and right, respectively) before the disintegration test began. Sample BC27251 contained 41% NuPlastiQ®, 11% PLA, and 48% PBAT. No compatibilizer was present. In a laboratory-scale composting test mimicking a home composting process, the disintegration of 49 μm-thick specimens BC27130 and 34 μm-thick specimens BC27251 was evaluated at ambient temperature (28°C). As with other examples herein, the test procedure was based on ISO 20200 (2015). Test materials BC27130 and BC27251 were added at a concentration of 0.5% as 2.5 cm x 2.5 cm pieces to an 80 / 20 mixture of less than 10 mm of mature compost and ground fresh vegetable, horticultural, and fruit waste (VGF). The test was carried out in three batches and lasted for 17 weeks. At the end of the composting test, the compost was sieved and assessed for disintegration.

[0121] Disintegration of 2.5 cm x 2.5 cm pieces of BC27130 (49 μm) and BC27251 (34 μm) proceeded very well. Disintegration of BC27130 proceeded somewhat faster than that of BC27251. After 14 weeks of composting, all test material for BC27130 appeared to be completely decomposed, and the same result was obtained for BC27251 after 2 weeks. At the end of the ambient temperature composting test (after 17 weeks), the entire contents of the test reactor were used for sieving, screening, further separation, and analysis. Disintegration is defined as size reduction to less than 2 mm. For both test articles, no test article fragments were recovered in the fraction greater than 2 mm. Disintegration rates of 100.0% were obtained for BC27130 at 49 μm thickness and BC27251 at 34 μm thickness.

[0122] The French standard NFT51-800 Plastics - Plastics - Specification for plastics suitable for home composting (2015), the Australian standard AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010) and TUV AUSTRIA Belgium's OK Compost HOME certification scheme ISO 20200 (2015) state that in a quantitative test according to ISO 20200 (2015) at ambient temperature (20°C-30°C), a material has demonstrated sufficient decomposition for home composting if at least 90% of the test material has shrunk to a size of less than 2 mm after 26 weeks of composting.

[0123] Introduction - Objectives and Test Methods For the 49 μm thick test material BC27130 and the 34 μm thick test material BC27251, complete disintegration was already obtained after a 17-week incubation period at ambient temperature, so it can be concluded that the 90% disintegration criteria of NF T51-800 (2015), AS 5810 (2010), and the OK Compost HOME certification scheme of TUV AUSTRIA Belgium were easily reached. Even at greater thicknesses, both materials have the potential to reach this requirement.

[0124] The purpose of this test was to evaluate the disintegration of materials at ambient temperatures in an 80 / 20 mixture of less than 10 mm mature compost and ground fresh vegetable, horticultural, and fruit waste (VGF). During home composting, the high temperatures (>50°C) obtained in industrial composting processes are not typically reached. Therefore, materials must demonstrate sufficient disintegration at ambient temperatures before home composting is possible.

[0125] Each test article was mixed with an 80 / 20 mixture of less than 10 mm of mature compost and ground fresh vegetable, horticultural, and fruit waste (VGF) and incubated in the dark at 28°C. Moisture content was checked periodically and adjusted as needed. The reactor contents were manually stirred periodically and the test articles were visually monitored. The maximum test period for which disintegration was to be demonstrated was 26 weeks.

[0126] At the end of the test, the compost from each reactor was sieved through a vibrating sieve (>2 mm) to recover the undecomposed test material residues in the >2 mm fraction. Decay was assessed very accurately by manual selection. If possible, a mass balance was calculated. The compost obtained at the end of the composting process could be used for further measurements, such as chemical and physical analyses.

[0127] The test procedure is based on ISO 20200 Plastics - Determination of the degree of disintegration of plastic materials under laboratory-scale simulated composting conditions, with the following deviations compared to ISO 20200(2015):

[0128] Incubation at 28°C ± 2°C to mimic home composting conditions. · Instead of 1 kg of synthetic solid waste per reactor, use a mixture of less than 10 mm mature compost and 2 kg of VGF per reactor.

[0129] Instead of the monitoring process specified in ISO 20200 (2015), visually monitor decay once a week, assess moisture status, and adjust as necessary. The test is considered valid (when performed with thermophilic and mesophilic incubation periods) if:

[0130] The degree of decay of the three replicates does not differ by more than 10%. Test item Test item 1 ·Name: BC27130 Description: Plastic film (Figure 10B) Color: Off-white Thickness: 49μm±2μm Total Solids (TS): 94.4% Volatile solids (VS): 99.1% of TS Sample preparation: Cut into 2.5cm x 2.5cm pieces Test item 2 ·Name: BC27251 Description: Plastic film (Figure 10B) Color: Off-white Thickness: 34μm±2μm Total Solids (TS): 90.9% Volatile solids (VS): 99.0% of TS Sample preparation: Cut into 2.5cm x 2.5cm pieces Analysis method Dry Matter or Total Solids Dry matter is determined by drying at 105°C for at least 14 hours and weighing as described in 'M_009. Determination of moisture content. Dry matter is expressed as a percentage of wet weight.

[0131] pH Measure the pH with a pH meter after calibration with standard buffers (pH=4.00, pH=7.00, and pH=10.00) as described in 'M_006. pH and conductivity measurements. Dilute the sample with distilled water in a 5:1 ratio (5 parts demineralized water to 1 part sample) and mix thoroughly before inserting the electrode as described in 'M_012. Preparation of extracts and solutions.

[0132] Thickness (plastic) After an acclimatization period of 24 hours at 23° C., 10 points on the specimen are measured. The measurements are carried out with a universal bench micrometer (accuracy 0.1 μm) according to ISO 4593 Plastics - Films and sheets - Measurement of thickness by mechanical scanning.

[0133] Total nitrogen (N) This analysis is performed as described in 'M_039. Total Organic Carbon and Total Nitrogen Determination - Total Carbon, Total Nitrogen, Inorganic Carbon Combustion Method. The sample is combusted at 950-1200°C and the nitrogen components are oxidized to nitrogen oxides (NOx) by briefly adding a controlled amount of extra oxygen. In the presence of a CuO catalyst and a copper reductant, the nitrogen oxides are converted to N2. The N2 formed is measured by a thermal conductivity detector (TCD). Results are given in grams per kilogram of total solids.

[0134] Volatile Solids-Ash Determine the volatile solids and ash content by heating the dried sample at 550°C for at least 4 hours and weighing as described in 'M_010. Determination of organic matter and carbon content. Results are given as percent of dry matter.

[0135] weight measurement Two types of balances are used during the test: a Sartorius AC 210S with internal calibration (max. 200 g; d = 0.1 mg) for the measurement of dry matter and volatile substances, and a Sartorius CPA 12001 S (max. 12100 g; d = 0.1 g) used to weigh the different components of the test article and inoculum.

[0136] result Test piece thickness The thickness measurement results for BC27130 and BC27251 are shown in Table 3.

[0137] [Table 3]

[0138] For each test article, three reactors measuring 30 cm x 20 cm x 13 cm (length, width, height) were set up for quantitative evaluation of disintegration. The reactors contained an 80 / 20 mixture of 16-week-old, <10 mm mature compost and ground fresh vegetable, horticultural, and fruit waste (VGF), as well as 2.5 cm x 2.5 cm pieces of 0.5% BC27130 or BC27251. A 0.5% test article concentration was used for the determination and quantitative evaluation of test article disintegration. Details of the test setup for the quantitative tests are shown in Table 4.

[0139] [Table 4]

[0140] Biowaste analysis The characteristics of the inoculum are shown in Table 5. The inoculum is characterized by an optimal moisture content for composting (56.7%), and a C / N ratio of 9 ensures sufficient nitrogen levels. A normal pH of 7.0 was measured.

[0141] [Table 5]

[0142] Vision During the composting process, the reactor contents were mixed weekly and water was added as needed to ensure optimal moisture conditions. During the test, the test material was carefully examined for disintegration.

[0143] Disintegration of 2.5 cm x 2.5 cm fragments of both 49 μm-thick BC27130 and 34 μm-thick BC27251 proceeded smoothly. Figures 10C and 10D show a visual comparison of 2.5 cm x 2.5 cm fragments of BC27130 and BC27251, respectively, at the beginning of composting at ambient temperature and after a 4-week incubation period. After 4 weeks, small holes were observed in both test materials. The amount of small holes was significantly greater in BC27130 (approximately 80% of the test material) compared to BC27251 (approximately 25% of the test material). After 4 weeks (i.e., at week 8), BC27130 began to disintegrate, and the average size of the resulting fragments was approximately 1.5 cm x 1.5 cm (Figure 10E). Figure 10F shows fragments obtained with BC27251 at week 8. We also noticed that both test materials had become brown in color. The breakdown continued, and after 12 weeks of composting, only a few fragments of BC27130 could be recovered from the composting reactor (Figure 10G), and BC27251 had also crumbled into small fragments (Figure 10H). Over the next few weeks, the amount and size of the remaining fragments further decreased. After 14 weeks of composting, no fragments of BC27130 could be found in the composting reactor (Figure 10I), and after 2 weeks (16 weeks), BC27251 had also completely decomposed (Figure 10J).

[0144] Sifting-Collapse At the end of the test (after 17 weeks), the reactor contents were dried. During the drying process, the compost clumps were gently broken down. The drying process was terminated when a constant mass was reached. The compost from each reactor was sieved through a vibrating sieve larger than 2 mm to recover any residual undecomposed test material in the fraction larger than 2 mm. Table 6 shows that for both test articles, no test material remained in the fraction larger than 2 mm in all replicates. The validity requirements of ISO 20200 (2015) were met.

[0145] [Table 6]

[0146] The French standard NFT51-800 Plastics - Specification for plastics suitable for home composting (2015), the Australian standard AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010) and TUV AUSTRIA Belgium's OK Compost HOME certification scheme ISO 20200 (2015) state that in a quantitative test according to ISO 20200 (2015) at ambient temperature (20°C-30°C), a material has demonstrated sufficient decomposition for home composting if at least 90% of the test material has reduced to a size of less than 2 mm after 26 weeks of composting.

[0147] For test materials BC27130 and BC27251, complete disintegration was obtained before 26 weeks, and therefore it can be concluded that the 90% disintegration criteria of NF T51-800 (2015), AS 5810 (2010), and the OK Compost HOME certification scheme of TUV AUSTRIA Belgium were easily reached.

[0148] Test materials BC27130 and BC27251 qualify for OK Compost HOME certification regarding disintegration requirements. chemical analysis Table 7 shows the results of the chemical analysis at the end of the test. Equivalent volatile solids were measured for the different replicates, resulting in normal pH values. The C / N ratio for the different replicates was 8.

[0149] [Table 7]

[0150] While the present invention has been described primarily in the context of PBAT as the primary or key component of the blend, it is understood that other polyester-based polymeric materials may be used, for example, instead of or in addition to PBAT. For example, other polyester-based polymeric materials with relatively low stiffness (modulus) include, but are not limited to, PCL and PBS. Where such materials may have similarly low stiffness, high flexibility, and / or high toughness (and low strength), they may similarly benefit from blending with PLA or a similarly stiff polyester to increase stiffness, and if a carbohydrate-based polymeric material such as NuPlastiQ® is also included in the blend, the overall blend will be guaranteed to meet home compostability requirements. In one embodiment, the blend of the present invention includes a first polyester plastic material (e.g., PBAT) having a first modulus of elasticity and a second polyester (e.g., including PLA), where the first polyester plastic material has a lower modulus (and / or higher flexibility) than the second polyester (e.g., PLA). The blend also includes a carbohydrate-based polymeric material.

[0151] Similarly, while this discussion is primarily focused on PLA as a component added to blends to enhance stiffness, it is understood that other polyester-based polymer materials may be used instead of, or in addition to, PLA. For example, PHA may have high stiffness similar to PLA and may be used to enhance the stiffness of PBAT, PBS, or PCL (all of which typically have low stiffness). By way of example, PLA may typically have a modulus of elasticity of about 3.5-4.0 GPa. PHA may typically have a modulus of elasticity of about 3-3.5 GPa. Both of these materials may exhibit relatively low elongation at break (e.g., about 200% or less for each, with PHA typically 100% or less). PBAT, PBS, and PCL typically exhibit much higher elongation at break (e.g., about 500-800%), but have relatively low moduli (e.g., less than 1 GPa, often less than 0.5 GPa). Therefore, the present invention contemplates blending one of the low stiffness (i.e., low modulus) materials exhibiting high elongation at break (e.g., PBAT, PCL, PBS, etc.) in combination with a carbohydrate-based polymer material with one of the polyester materials exhibiting high stiffness (high modulus) and low elongation at break, so that the overall blend meets home compostability requirements.

[0152] It should be understood that the embodiments of the inventive features disclosed herein are illustrative of the principles of the inventive features. Other variations that may be employed are within the scope of the inventive features. Thus, by way of example, but not limitation, alternative configurations of the inventive features may be utilized in accordance with the teachings herein, for example, at least as described in the preceding paragraphs.

Claims

1. A polyester-containing plastic material, the polyester-containing plastic material comprising: a first polyester plastic material having a first modulus comprising polybutylene adipate terephthalate (PBAT); a second polyester plastic material comprising polylactic acid (PLA); carbohydrate-based polymeric materials formed by chemically, mechanically, or physically modifying starch and plasticizers; Contains a blend of the plasticizer is selected from glycerin and sorbitol; the first polyester plastic material has a modulus of elasticity lower than the modulus of elasticity of the PLA; the PLA allows the blend to achieve a higher modulus than the first polyester plastic material alone; the carbohydrate-based polymeric material (1) has a crystallinity of less than 20% and is resistant to recrystallization; (2) has a moisture content of 2% by weight or less; and (3) does not exhibit an islands-in-a-sea structure when blended with the first polyester plastic material and the second polyester plastic material; A polyester-containing plastic material, wherein at least 90% by weight of said polyester-containing plastic material is home compostable at 28°C within 365 days.

2. 10. The material of claim 1, wherein the polyester-containing plastic material is substantially free of any compatibilizer.

3. 10. The material of claim 1, wherein the carbohydrate-based polymer material is present in an amount of 10% to 60% by weight of the blend.

4. 10. The material of claim 1, wherein the carbohydrate-based polymer material comprises from 30% to 60% by weight of the blend.

5. 10. The material of claim 1, wherein the PLA is present in an amount of at least 5% by weight of the blend.

6. 10. The material of claim 1, wherein the PLA is present in an amount of up to 20% by weight of the blend.

7. 10. The material of claim 1, wherein the PLA is present in an amount of up to 15% by weight of the blend.

8. The material described in claim 1, wherein the PBAT is contained in an amount of at least 30% by weight of the blend.

9. The material described in claim 1, wherein the PBAT is contained in an amount of 30% to 70% by weight of the blend.

10. 10. The material of claim 1, wherein the PLA exhibits compostability at 28°C in the blend, whereas the PLA when tested alone exhibits reduced compostability at 28°C within 365 days.

11. The material of claim 1 further comprising an inorganic filler within the blend.

12. 12. The material of claim 11, wherein the inorganic filler comprises calcium carbonate.

13. 12. The material of claim 11, wherein at least 90% by weight of the polyester-containing plastic material is home compostable within 365 days at 28°C ± 2°C as determined under EN 13432.

14. A polyester-containing plastic material comprising a blend of polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), and a carbohydrate-based polymeric material formed by chemically, mechanically, or physically modifying starch and a plasticizer; the plasticizer is selected from glycerin and sorbitol; the PBAT is present in an amount of at least 30% by weight of the blend; the PLA is in an amount of up to 20% by weight of the blend; the carbohydrate-based polymeric material comprises 10% to 60% by weight of the blend; the carbohydrate-based polymeric material (1) has a crystallinity of less than 20% and is resistant to recrystallization; (2) has a moisture content of 2% by weight or less; and (3) does not exhibit an islands-in-a-sea structure when blended with the PBAT and the PLA; 1. A polyester-containing plastic material, wherein at least 90% by weight of said polyester-containing plastic material is home compostable under EN 13432 at 28°C ± 2°C within 365 days.

15. 15. The material of claim 14, wherein the carbohydrate-based polymer material is present in an amount of 30% to 60% by weight of the blend.

16. 15. The material of claim 14, wherein the PLA exhibits compostability at 28°C ± 2°C in the blend, while the PLA alone exhibits reduced compostability at 28°C ± 2°C.

17. 15. The material of claim 14, wherein the PLA is present in an amount of up to 15% by weight of the blend.

18. 15. The material of claim 14, wherein the PBAT is present in an amount of 30% to 70% by weight of the blend.

19. 15. The material of claim 14, further comprising an inorganic filler within the blend.

20. 20. The material of claim 19, wherein the inorganic filler comprises calcium carbonate and is present at 5% to 30%, or 10% to 30% by weight of the material.

21. The material of claim 1 , wherein the plasticizer comprises sorbitol.

22. 10. The material of claim 1, wherein the starch comprises a mixture of two different starches, at least one of the starches comprising corn starch, potato starch, tapioca starch, or cassava starch.

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