Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
  • A01G9/02—Receptacles, e.g. flower-pots or boxes; Glasses for cultivating flowers
  • A01G9/029—Receptacles for seedlings
  • A01G9/0291—Planting receptacles specially adapted for remaining in the soil after planting
• • C—CHEMISTRY; METALLURGY
  • C05—FERTILISERS; MANUFACTURE THEREOF
  • C05G—MIXTURES OF FERTILISERS COVERED INDIVIDUALLY BY DIFFERENT SUBCLASSES OF CLASS C05; MIXTURES OF ONE OR MORE FERTILISERS WITH MATERIALS NOT HAVING A SPECIFIC FERTILISING ACTIVITY, e.g. PESTICIDES, SOIL-CONDITIONERS, WETTING AGENTS; FERTILISERS CHARACTERISED BY THEIR FORM
  • C05G5/00—Fertilisers characterised by their form
  • C05G5/40—Fertilisers incorporated into a matrix
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K11/00—Use of ingredients of unknown constitution, e.g. undefined reaction products
  • C08K11/005—Waste materials, e.g. treated or untreated sewage sludge
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
  • C08K5/0033—Additives activating the degradation of the macromolecular compound
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
  • C08L101/16—Compositions of unspecified macromolecular compounds the macromolecular compounds being biodegradable
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/04—Polyesters derived from hydroxycarboxylic acids, e.g. lactones
• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G9/00—Cultivation in receptacles, forcing-frames or greenhouses; Edging for beds, lawn or the like
  • A01G9/02—Receptacles, e.g. flower-pots or boxes; Glasses for cultivating flowers
  • A01G9/021—Pots formed in one piece; Materials used therefor
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
  • C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
  • C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2403/00—Characterised by the use of starch, amylose or amylopectin or of their derivatives or degradation products
  • C08J2403/02—Starch; Degradation products thereof, e.g. dextrin
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2467/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
  • C08J2467/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2467/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
  • C08J2467/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K2201/00—Specific properties of additives
  • C08K2201/018—Additives for biodegradable polymeric composition
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2201/00—Properties
  • C08L2201/06—Biodegradable
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2203/00—Applications
  • C08L2203/30—Applications used for thermoforming
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2205/00—Polymer mixtures characterised by other features
  • C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L3/00—Compositions of starch, amylose or amylopectin or of their derivatives or degradation products
  • C08L3/02—Starch; Degradation products thereof, e.g. dextrin

Definitions

• the present invention relates to biodegradable compositions and methods of manufacture and uses thereof.
• the present invention also relates to additives for use in enhancing the biodegradation of compositions.
• the present invention also relates to methods for adjusting the biodegradability of a composition.
• Plastic waste accumulation is a recognised problem that has yet to be addressed satisfactorily.
• Biodegradable polymers have gained popularity since the 1980s and have been used to replace some non-biodegradable materials. Some of the challenges that has yet to be satisfactorily addressed with such biodegradable polymers are that:
• poly-lactic acid is not recognised as being biodegradable under some certifying regimes (the American and European standards) since it does not biodegrade outside of artificial composting conditions.
• Some so-called "home compostable plastics” have been developed that meet standards developed by certain countries, but their application is limited and the standards are not universally accepted.
• the rate of biodegradation of the compositions of the invention under non-industrial composting conditions can be materially increased by providing the composition with a filler material that can be used to modulate the overall carbon to nitrogen ratio (C:N ratio) of the composition.
• the filler may provide a source of nitrogen to the composition that may otherwise be substantially deficient in nitrogen.
• the filler acts to nucleate biodegradation by providing a site of biodegradation that is favoured by microorganisms.
• the C:N ratio generally increases over time upon exposure to home compositing conditions. This suggests that microorganism growth is consuming nitrogen in situ over time.
• the invention provides a biodegradable composition including a polymer and a filler, such that the composition has an extractable phosphorous concentration of at least 5 mg/kg.
• the composition will have an extractable phosphorous concentration of at least 5 mg/kg prior to exposure to composting conditions.
• the rate of biodegradation of the compositions of the invention under non-industrial composting conditions can be materially increased by providing the composition with a filler material that can be used to modulate the extractable phosphorous concentration of the composition.
• the filler may provide a source of phosphorous to the composition that may otherwise be substantially deficient in phosphorous.
• the filler acts to nucleate biodegradation by providing a site of biodegradation that is favoured by microorganisms.
• the extractable phosphorous concentration of the composition may increase over time upon exposure to home compositing conditions. This suggests that microorganism growth may facilitate the release of phosphorous in situ over time and/or that microorganism growth may facilitate breakdown of the composition within the soil environment.
• the invention provides a biodegradable composition including a polymer and a filler, such that the composition has an extractable potassium concentration of at least 10 mg/kg.
• the rate of biodegradation of the compositions of the invention under non-industrial composting conditions can be materially increased by providing the composition with a filler material that can be used to modulate the extractable potassium concentration of the composition.
• the filler may provide a source of potassium to the composition that may otherwise be substantially deficient in potassium.
• the filler acts to nucleate biodegradation by providing a site of biodegradation that is favoured by microorganisms.
• the extractable potassium concentration of the composition may increase over time upon exposure to home compositing conditions. This suggests that microorganism growth may facilitate the release of phosphorous in situ over time and/or that microorganism growth may facilitate breakdown of the composition within the soil environment.
• the invention provides a biodegradable composition including a polymer and a filler, such that the composition has:
• the invention provides a biodegradable composition including a polymer and a filler, such that the composition has:
• the invention provides a biodegradable composition including a polymer and a filler, such that the composition has:
• the rate of biodegradation of the compositions of the invention under non-industrial composting conditions can be materially increased by providing the composition with a filler material that can be used to modulate the concentration(s) of extractable micronutrients of the composition.
• the filler may provide a source of the micronutrient(s) listed above to the composition that may otherwise be substantially deficient in the micronutrient(s).
• the filler acts to nucleate biodegradation by providing a site of biodegradation that is favoured by microorganisms.
• the extractable micronutrient(s) concentration of the composition may increase over time upon exposure to home compositing conditions. This suggests that microorganism growth may facilitate the release of micronutrient(s) in situ over time and/or that microorganism growth may facilitate breakdown of the composition within the soil environment.
• the invention provides a biodegradable composition including a polymer and a filler, such that the composition has:
• the present invention also provides a filler that may be used to modulate the properties of a polymer to enhance biodegradation.
• the invention provides a filler for incorporation in a biodegradable composition, the filler providing a source of at least one of: nitrogen; phosphorous; potassium; calcium; magnesium; sodium; manganese; iron; aluminium; zinc; copper; and boron, so that the biodegradable composition incorporating the filler has:
• the invention provides a method of increasing the rate of biodegradation of a composition including mixing (such as blending) a filler and a polymer so that the composition has:
• the C:N ratio of the polymer; and/or the concentration(s) in the polymer of the various elements outlined in the ninth aspect may be known before the filler is mixed (such as blended) into the composition. In such cases, the skilled person will be wellplaced to select a filler having the desired chemical composition to achieve the stated values.
• the C:N ratio of the polymer; and/or the concentration(s) in the polymer of the various elements outlined in the ninth aspect are not known before the filler is mixed (such as blended) into the composition, standard methodology (detailed further below) may be used to calculate those values. From that point, the skilled person will be well-placed to select a filler having the desired chemical composition to achieve the stated values.
• the step of mixing (such as blending) the filler and the polymer will include the step of thermoforming or injection moulding.
• Figure 1 is a front view of a plant container in accordance with one embodiment of the present invention.
• Figure 2 is a bottom view of a plant container in accordance with one embodiment of the present invention.
• Figure 3 is a cross-sectional view of a plant container in accordance with one embodiment of the present invention.
• Figure 4 is an exploded view of section "B" as shown in Figure 1.
• Figure 5 is a front view of one unit of a tray of individual plant containers in accordance with one embodiment of the present invention.
• Figure 6 is an exploded view of section "B" as shown in Figure 5.
• Figure 7 is a photograph of a plant container "A" used in the above ground degradation trial at day 60.
• Figure 8 is a photograph of a plant container "A" used in the above ground degradation trial at day 60.
• Figure 9 is a photograph of a plant container "B" used in the above ground degradation trial at day 60.
• Figure 10 is a photograph of a plant container "A" used in the underground degradation trial after approximately 7 weeks.
• Figure 11 is a photograph of a plant container "A" used in the underground degradation trial after approximately 7 weeks.
• Figure 12 is a photograph of a plant container "B" used in the underground degradation trial after approximately 7 weeks.
• Figure 13 is a photograph of a plant container "B" used in the underground degradation trial after approximately 7 weeks.
• FIG. 14 is a Scanning Electron Microscope (SEM) image of Sample ID#1, thermoforming
• FIG. 15 is a Scanning Electron Microscope (SEM) image of Sample ID#2, thermoforming
• Starch composite Starch granules are readily visible on the surface and in the interior.
• FIG. 16 is a Scanning Electron Microscope (SEM) image of Sample ID#3, thermoforming
• Figure 17 is a Scanning Electron Microscope (SEM) image of Sample ID#7, thermoforming
• Figure 18 is a Scanning Electron Microscope (SEM) image of Sample ID#12, thermoforming
• FIG 19 is a Scanning Electron Microscope (SEM) image of Sample ID#13, thermoforming
• Figure 20 is a Scanning Electron Microscope (SEM) image of Sample ID#21, injection moulding Blood & bone composite, showing a uniform surface after 6 months of soil exposure.
• SEM Scanning Electron Microscope
• Figure 21 is a Scanning Electron Microscope (SEM) image of Sample ID#22, injection moulding Starch composite showing pinholes after 6 months soil exposure.
• Figure 22 is a Scanning Electron Microscope (SEM) image of Sample ID#23 injection moulded Fish meal composite, showing cracking after 6 months of soil exposure.
• Figure 23-36 are photographs of samples of various compositions showing degrees of biodegradation under at home, soil conditions. Detailed Description of the Invention
• biodegradable composition refers to a composition which is biodegradable under at least non-industrial composting conditions, but may additionally be biodegradable under industrial composting conditions.
• biodegradable polymers are only biodegradable under very specific conditions that are not ubiquitous. Many geographical centres do not have access to industrial composting conditions which means that such "biodegradable polymers” essentially never biodegrade within a reasonable time period, thus contributing to landfill waste. Even where the geographical centre does have such industrial composting facilities, consumer preference (often laziness) or lack of ubiquitous collection points means that such biodegradable polymers end up in the landfill, again never biodegrading within a reasonable time period. In some cases, industrial composting facilities may be prohibited from recycling bio-based polymers (such as PLA) due to restrictive local regulations/by-laws, which may (for example) stipulate that the facility can only accept green matter.
• bio-based polymers such as PLA
• biodegradable compositions that are capable of biodegrading under non-industrial conditions such as home composting, in the soil or even as part of a landfill. This need is met, or at least met to some degree, such as a significant degree, by the biodegradable compositions of the present invention.
• the expression "industrial” in relation to composting conditions refers to those conditions that typically involve temperatures between 50 °C and 60 °C. Typically industrial composting conditions will be aerobic, rather than anaerobic. Typically industrial composting conditions involve two distinct phases: (i) active composting; followed by (ii) curing.
• the active composting phase may consist of a minimum period of 21 days where temperatures can reach
• non-industrial in relation to composting conditions refers to essentially all conditions that are not captured by industrial composting conditions as described herein. Typically such conditions would be considered “milder” and are characterised as operating at a substantially lower temperature than 50-60 °C. Typically such conditions will not include the conditions under which the biodegradable composition is kept for the duration of its functional life. For example, where the biodegradable composition is to be used to form a container, preferably the biodegradable composition will not substantially biodegrade while it is being used as a container.
• non-industrial composting conditions will refer to the conditions to which the biodegradable composition is exposed after the end of its functional life, typically through the conscious decision of the user to compost the product - namely the decision to place the biodegradable composition into a waste stream. Such a step will generally involve placing the biodegradable composition in contact with other waste products, although it is conceivable that the biodegradable composition is left alone.
• the non-industrial composting conditions may include being buried in the ground, although such conditions will preferably be aerobic. Specific examples of non-industrial composting conditions are those that relate to:
• “home composting conditions” such conditions involve biodegradation at ambient temperature or slightly above ambient temperatures, and are generally under aerobic conditions. Such conditions are typically used for the treatment of organic waste, especially garden waste. Such biodegradation typically occurs under uncontrolled conditions unlike industrial composting.
• Standards have been developed to test biodegradation under home composting conditions and include (each of which is incorporated herein by reference): o International - ISO 14855-1 (2012) - the test is performed at 25 °C under aerobic conditions. This test methodology is used in the examples used to support the present invention; o Australia - AS5810- biodegradable plastics suitable for home compositing. The test is performed at 25 °C +/- 5 °C; o France - NF T 51800; o Austria - prEN 17427-TUV
• the biodegradable compositions of the present invention are typically capable of biodegradation under at least one of the standards developed for non-industrial composting either listed here or elsewhere defined.
• the biodegradable compositions of the present invention are capable of biodegradation under at least ISO 14855-1 (2012).
• PBS poly(butylene succinate)
• PLA polylactic acid
• PLA of itself or in combination with PBS, is not considered capable of biodegradation under ISO 14855-1 (2012). It will be appreciated by the person skilled in the art that PLA degrades most efficiently at temperatures around 55 - 60°C.
• biodegradable composition of the invention is configured to undergo substantial biodegradation within 12 months of being exposed to non-industrial composting conditions.
• the biodegradable composition of the invention is configured to undergo substantial biodegradation within 6-12 months of being exposed to non-industrial composting conditions.
• the biodegradable composition of the invention is configured to fully biodegrade within 24 months of being exposed to non-industrial composting conditions. More preferably, the biodegradable composition of the invention is configured to fully biodegrade within 18-24 months of being exposed to non-industrial composting conditions.
• the biodegradable composition of the present invention has been shown, in preferred embodiments, to undergo at least 60% biodegradation within 60 days of being exposed to nonindustrial composting conditions.
• the biodegradable composition of the present invention has been shown, in preferred embodiments, to undergo about 80% biodegradation within 190 days of being exposed to non-industrial composting conditions.
• the positive control composition made of cellulose degraded about 82%, and so the preferred embodiments of the biodegradable composition of the invention were calculated to have a relative biodegradation of over 95%.
• a combination of PBS and PLA without the filler has been shown to biodegrade only about 10% over a similar time frame.
• Such rates of biodegradation make the biodegradable composition of the invention particularly well suited to those applications for which the functional life of the product is relatively short, such as take-away containers, food trays, beverage cups, etc. That said, without wishing to be bound by theory, it is believed that the rate of biodegradation may be modulated by increasing or decreasing the amount of filler and/or the chemical properties of the filler. Without wishing to be bound by theory, it is believed that the filler may act to nucleate biodegradation by providing a source of nutrition to the microorganisms that are responsible for the biodegradation. Scanning Electron Microscopy (SEM) indicates that for some fillers, there is a space/void between the filler and the polymer.
• SEM Scanning Electron Microscopy
• That space/void may also act as a depot for microorganism growth and/or leaching of nutrients from the filler to the surrounding areas.
• the more readily available the nutrition is such as where it is provided in increased quantity, has a high surface area:volume ratio such as provided by small particulate size, located on an exterior surface, etc) then the rate of biodegradation is likely to be higher.
• the filler of the present invention provides the user with the ability to configure the biodegradable composition to provide the desired rate of biodegradation.
• the biodegradable composition of the invention is used to form a container suitable for growing a plant in.
• the growing phase of the plant above ground lasts up to approximately 12 months depending on the plant matter growing.
• the biodegradable container formed from the biodegradable composition of the present invention may be configured to ensure that it does not degrade to a substantial degree before the container is likely to be ready to be planted. Such a container can be planted in situ at the site for which the plant is intended to continue to grow.
• the filler included in the biodegradable composition of the invention may be used to impart mechanical stiffness to the biodegradable composition for a time and under certain conditions
• a plant container made of the biodegradable composition of the present invention has been shown to maintain good mechanical stability and integrity during the growing phase of a plant in above ground degradation tests. It is believed that the use of the filler provides this advantage to the container. It is also envisaged that the use of a filler in the composition also provides nutrients to the soil upon degradation of the container in soil. It has also been surprisingly found that the filler greatly enhances the degradation of the composition.
• the term "polymer”, which forms part of the biodegradable composition refers to any polymeric material that is capable of biodegradation under industrial or non-industrial composting conditions.
• the incorporation of the filler of the invention into the biodegradable composition of the present invention increases the rate of biodegradation such that a polymer that may not, of itself, be considered to biodegrade satisfactorily under nonindustrial composting conditions is able to be formed into a biodegradable composition that is capable of biodegradation under non-industrial composting conditions.
• neat poly-lactic acid may typically be considered to exhibit poor biodegradation under non-industrial composting conditions, however when combined with the filler of the invention the composition so formed exhibits a satisfactory rate of biodegradation under nonindustrial composting conditions.
• Typical breakdown products of such polymers may include: naturally occurring gases (such as carbon dioxide and nitrogen); water; biomass (such as one or more components derived from a natural source that are used to form the polymer, such as polysaccharides); smaller subunits
• Such polymers will have a multitude of cleavable functional groups such as esters, amides, urethanes, and/or ethers. Such cleavable functional groups will typically be cleavable by hydrolysis and/or microbial action.
• polymers examples include agropolymers, and synthetic polymers.
• agro-polymers refers to polymers that are either naturally occurring, or are derived from naturally occurring polymers.
• synthetic polymers may include polymers produced wholly synthetically, and may also include polymers produced at least in part by natural processes such as fermentation, such as microbial fermentation.
• poly-lactic acid (PLA) may be formed from the (synthetic) polymerisation of a monomer derived from fermentation of plant starch.
• agro-polymers include: proteins (such as silk, wool, collagen); polysaccharides (such as starch, cellulose, chitin, chitosan, alginic acid, cellophane); polypeptides (such as gelatin, wheat gluten, casein, whey protein).
• proteins such as silk, wool, collagen
• polysaccharides such as starch, cellulose, chitin, chitosan, alginic acid, cellophane
• polypeptides such as gelatin, wheat gluten, casein, whey protein.
• Examples of synthetic polymers include:
• Aliphatic polyesters such as: polyglycolide/ poly(glycolic acid) (PGA) polycaprolactone (PCL) polydioxanone (PDO) polylactic acid (PLA) (including poly(L-lactic acid), poly(D-lactic acid), and poly(DL-lactic acid)) poly(lactic-co-glycolic acid) (RIGA) poly(trimethylene carbonate) (PTMC) poly(aIkyl succinates), this family includes:
• poly(butylene succinate-co-butylene adipate) (iv) is a biodegradable, semi-crystalline polyester produced by co-condensation of succinic and adipate acid with 1-4-butanediol.
• polyhydroxyalkanoates (PHA) this family includes:
• PHBV poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
• Aromatic polyesters such as poly(butylene adipate-co-terephthalate) (PBAT);
• Polyamides such as BAK 1095 and BAK 2195 (based on caprolactam, butanediol, and adipic acid;
• Polyurethanes that will typically include a biodegradable portion consisting of a polyester (such as PCI, PLA, and PGA), agro-polymer (such as chitin); and
• Vinyl alcohols such as polyvinylalcohol, and poly(vinyl acetate). Such polymers will typically be susceptible to oxidation and/or microbial degaradation.
• PBS is also used.
• PHB is used it is used in a minor component to another polymer selected from; PLA; PBAT; PHBV; PCL; PBS.
• PHB is not used.
• the polymer will be a synthetic polymer. Still more preferably the polymer will be a polyester.
• the polymer will be selected from polybutylene succinate (PBS), polylactic acid (PLA), a polyhydroxyalkanoates (PHA) (such as poly(3-hydroxybutyrate-co-3- hydroxyvalerate) (PHBV)), poly(butylene succinate-co-butylene adipate) (PBSA) and/or combinations thereof.
• PBS polybutylene succinate
• PLA polylactic acid
• PHA polyhydroxyalkanoates
• PHBV poly(3-hydroxybutyrate-co-3- hydroxyvalerate)
• PBSA poly(butylene succinate-co-butylene adipate)
• PBS is a thermoplastic polymer resin of the polyester family.
• PBS is a biodegradable aliphatic polyester with properties that are comparable to polypropylene.
• PBS is a relatively soft material and decomposes naturally into water and CO 2 and is a suitable material for use in the biodegradable compositions of the present invention.
• the material is soft which may be problematic in the processing/handling and particularly during manufacturing when used alone.
• PLA is a thermoplastic polyester and largely made from renewable resources. Contrary to other thermoplastics which are petroleum-based, some of the raw materials used for PLA's production include corn starch, tapioca roots, or sugarcane. PLA is bio-based and biodegradable but generally only under industrial composting conditions. Without industrial composting conditions it can take anywhere between 100 to 1000 years to decompose.
• the "type" of polymer will refer to the chemical constitution of the polymer backbone - eg whether it is an agro-polymer, polyester, polyamide, etc.
• polymers may be characterised in a number of different ways, not just by the chemical constitution of the polymer backbone (such as whether it is a polyester or polyamide, for instance).
• a polymeric material may be characterised by its degree of polydispersity (typically denoted as PD or PDI); its average molecular weight
• M n number average molecular weight
• M w weight average molecular weight
• M z Z-average molecular weight
• Tg thermogravimetric analysis
• the biodegradable composition will include a plurality of types of polymers.
• the biodegradable composition may include two types of polymers; the biodegradable composition may include three types of polymers.
• a plurality of polymers may be included for a number of reasons, including to provide the biodegradable composition with desirable mechanical properties suitable for the intended use.
• polymers individually have a wide range of mechanical properties, and that when combined such as in a composite material (such as a bilayer, or multilayer, or structural variants in which the plurality of polymers might be maintained separate locally), or in a mixture (such as a blend), that the mechanical properties of the combination may change, including that they may change dramatically.
• the present invention contemplates such combinations.
• the combination of a blend of polymers such as PLA and PBS
• a filler provides the advantage of the composition having improved mechanical properties such as stiffness and strength.
• PLA alone is a brittle substance.
• a filler such as the types described herein in a polymer blend of PLA and PBS has surprisingly produced a composition having improved mechanical strength and stiffness.
• Fillers of the types described herein may contribute stiffness to a product made from the biodegradable composition, but may slightly reduce strength (e.g. tensile strength, impact strength).
• the use of PBS is considered to add strength.
• the biodegradable composition of the present invention makes it well suited for a variety of different applications.
• the properties of the biodegradable composition may be modified as desired, by modifying the components, and the ratios of those components. For example, the amount of PLA in the composition can be increased as desired to produce more stiffness in the final composition. Increasing the stiffness of the composition would lead to a more rigid
• polymers that may be used in the biodegradable compositions of the present invention with a filler, such that the composition has a C:N ratio of from 30 to 200, include:
• a single grade of polymer may be used.
• the term "grade" in relation to a polymer will typically refer to a polymer that is commercially available and sold as having a defined set of characteristics such as average molecular weight, polydispersity, etc.
• PLA having an average molecular weight of 100 kDa may be used.
• that PLA grade may be blended with another PLA grade that might have a higher or lower average molecular weight, so that the polymer blend so formed may have characteristics different to either or both of the grades of PLA from which it is formed (such mixtures may have bi- or polymodal molecular weight distributions). All such combinations of grades and/or types are contemplated by the present invention.
• the amount of polymer in the biodegradable composition of the present invention should not be seen as limiting.
• the concentration of polymer may be chosen so as to achieve the desired C:N ratio of the biodegradable composition; and/or the concentration(s) in the polymer of the various elements so desired and referred to herein. As such the concentration of the polymer should not be seen as limiting. It may be convenient to provide the concentration of the polymer as a weight for weight basis, as a percentage (% w/w) of the total of the biodegradable composition.
• the polymer (which includes a plurality of polymers) may be present at up to 99.99% w/w, such as up to 99% w/w, such as up to 98% w/w, such as up to 97% w/w, such as up to 96% w/w, such as up to 95% w/w, such as up to 94% w/w, such as up to 93% w/w, such as up to 92% w/w, such as up to 91% w/w, such as up to 90% w/w, such as up to 89% w/w, such as up to 88% w/w, such as up to 87% w/w, such as up to 86% w/w, such as up to 85% w/w, such as up to 80% w/w, such as up to 75% w/w, such as up to 70% w/w, such as up to 65% w/w, such as up to 60% w/w, such as up to 55%
• the polymer is present at a concentration of at least 10% w/w, such as at least 15% w/w, such as at least 20% w/w, such as at least 25% w/w, such as at least 30% w/w, such as at least 35% w/w, such as at least 40% w/w, such as at least 45% w/w, such as at least 50% w/w, such as at least
• the polymer is present at a concentration of about 90% w/w, such as at a concentration of 90% w/w.
• the biodegradable composition includes PBS.
• PBS may be included in an amount from 20 to 99.99% w/w of the composition, such as from 20 to 95% w/w, such as from 20 to 80% w/w, such as from 20 to 75% w/w of the composition, such as from 30 to 75% w/w, such as from 40 to 75% w/w, such as from 45 to 65% w/w of the composition, such as about 60 % w/w, such as 60% w/w.
• the biodegradable composition includes PLA.
• PLA may be included in an amount from 10 to 99.99% w/w of the composition, such as from 10 to 95% w/w, such as from 10 to 80% w/w, such as from 15 to 60% w/w of the composition, such as from 15 to 50% w/w, such as from 25 to 45% w/w, such as about 30% w/w, such as 30% w/w.
• the biodegradable composition of the invention may be used in a variety of products.
• the biodegradable composition of the present invention may be used in the production of: pots
• the "filler" of the invention is a particulate material that is capable of incorporation into the biodegradable composition.
• the filler is added to the polymer of the invention and mixed (such as blended) with the polymer.
• the filler and the polymer are mixed prior to the polymer being formed into the desired article, however this should not be seen as limiting and the filler may be applied to the polymer (such as its surface) after it has been formed into the desired article.
• the filler will generally be chosen so as to achieve the desired C:N ratio of the biodegradable composition; and/or the concentration(s) in the biodegradable composition of the various elements so desired and referred to herein.
• the present invention is not limited to the use of any particular type or amount of filler. While the present invention contemplates the use of a single filler, in some embodiments a plurality of fillers will be used. Said plurality of fillers may be pre-mixed prior to mixing with the polymer, or may be added separately. Typically, where a plurality of filler is used, the fillers will be pre-mixed prior to mixing with the polymer.
• the use of a plurality of fillers enables the user to achieve the desired C:N ratio of the biodegradable composition; and/or the concentration(s) in the biodegradable composition of the various elements so desired and referred to herein.
• the filler is adapted to enhance the non-industrial biodegradation of the biodegradable composition.
• C:N ratio refers to the ratio of carbon to nitrogen within the object being referred to, such as the biodegradable composition or the polymer or the filler. Typically it will refer to the carbon to nitrogen ratio of the biodegradable composition.
• Total nitrogen can be considered to consist of organic nitrogen, ammonium nitrogen, nitrate and nitrite. In known solid materials, it can be assumed in some cases that nitrate and nitrite nitrogen are negligible.
• Total Kjehldahl nitrogen (TKN) measures organic nitrogen, and ammonium nitrogen.
• the Dumas method measures total nitrogen after converting organic nitrogen, ammonium nitrogen, nitrate and nitrite into gas.
• nitrogen for example total nitrogen in water where total nitrogen that can be dissolved in water after digestion.
• One such technique is the persulfate oxidation technique for nitrogen in water which is performed under heated alkaline conditions, where all organic and inorganic forms of nitrogen are oxidized to nitrate. Extractable nitrogen may generally be measured as extractable ammonium.
• the biodegradable composition of the invention will have a C:N ratio of from 15 to
• 200 such as from 30 to 200, such as from 15 to 150, such as from 30 to 150, such as from 15 to
• 100 such as from 30 to 100, such as from 50 to 100, such as from 60 to 85, such as from 75 to
• composition will have a C:N ratio of from 15 to
• the C:N ratio of the material may increase after exposure to composting conditions.
• extractable element values may be obtained using an extraction method such as Mehlich 3, which is well understood and is most commonly used to determine the availability of soil macronutrients (such as phosphorous, calcium, magnesium, and potassium) and soil micronutrients (such as copper, zinc, manganese, and iron).
• Mehlich 3 is well understood and is most commonly used to determine the availability of soil macronutrients (such as phosphorous, calcium, magnesium, and potassium) and soil micronutrients (such as copper, zinc, manganese, and iron).
• extractable phosphorous refers to phosphorous determined using a method such as Mehlich 3.
• the biodegradable composition has an extractable phosphorous concentration of at least 5 mg/kg, such as at least 50 mg/kg, such as at least 75 mg/kg, such as at least 90 mg/kg.
• the composition will have an extractable phosphorous concentration of at least 5 mg/kg prior to exposure to composting conditions. In some cases, the extractable phosphorous concentration of the material may increase after exposure to composting conditions.
• the or each filler used in the biodegradable composition of the invention will be substantially solid at room temperature, although in some embodiments the filler may include at least a part that is liquid at room temperature.
• the filler will itself be biodegradable.
• the filler may be derived from an animal (such as terrestrial, aerial, aquatic), fungi, plant (such as terrestrial, aquatic), or inorganic source, for example.
• the filler will be a processed material rather than a raw material.
• fillers examples include the following:
• Fungi derived mushroom powder Fungi derived mushroom powder; fungi powder;
• Plant derived - solid cottonseed meal ground seaweed; cork; seeds; peat; wood ash; wood flour; saw dust; wood fibers (eg from hardwood, softwood); fibers from grasses (including bamboo); flax; abaca; sisal; ramie; hemp; and bagasse; processed starch; cellulose; cellulose fibers; tea seed meal; cassava residue; distiller's grains; coffee grinds; rice hulls (rice husks); oat hulls; shells (including ground pecan shells, ground apricot seed, ground walnut shell, ground almond shell, coconut shell powder); maize meal; vinasse; sunflower seed husk; pea flour; soy protein; canola meal; soy bean meal; kiwifruit hair (which may be collected in the extractors/cyclones of kiwifruit packhouses); starch (although generally the use of starch will be less preferred);
• Plant derived - liquid soybean oil comprising of vegetable oil; sunflower oil; coconut oil; avocado oil; olive oil;
• Inorganic — ammonia/ammonium rich (nitrogen rich) and/or phosphorous/phosphate rich ammonium phosphate (diammonium phosphate, monoammonium phosphate); ammonium nitrate; ammonium chloride; ammonium sulphate; ammonium sulphate nitrate; ammonium thiosulfate; Inorganic - magnesium rich and/or ammonia/ammonium rich (nitrogen rich) and/or phosphorous/phosphate rich magnesium phosphate; magnesium nitrate; struvite (magnesium ammonium phosphate); wastewater mineral precipitates;
• the filler may, advantageously, provide a (secondary) function such as acting as a fertiliser, soil conditioner, soil enriching agent, weed suppressant, and/or a combination thereof.
• a (secondary) function such as acting as a fertiliser, soil conditioner, soil enriching agent, weed suppressant, and/or a combination thereof.
• the present invention allows the skilled person to select a filler, or combination of fillers, such as from the above list so as to achieve the desired C:N ratio of the biodegradable composition; and/or the concentration(s) in the biodegradable composition of the various elements so desired and referred to herein.
• the elemental composition of the polymer and/or the filler will be known from published information.
• the elemental composition will not be known, but can be derived using standard techniques known in the art. For instance, total phosphorous and total potassium may each be measured by a digestion method that involves solubilising the whole sample before quantitative analyses of those elements.
• Extractable nitrogen may generally be measured as extractable ammonium.
• Other extractable element values may be obtained using an extraction method such as Mehlich 3, which is well understood and is most commonly used to determine the availability of soil macronutrients (such as phosphorous, calcium, magnesium, and potassium) and soil micronutrients (such as copper, zinc, manganese, and iron).
• a mix ratio can be calculated so as to achieve the desired C:N ratio of the biodegradable composition; and/or the concentration(s) in the biodegradable composition of the various elements so desired and referred to herein.
• the filler will be typically be provided at a sufficient concentration so that the so as to achieve the desired C:N ratio of the biodegradable composition; and/or the concentration(s) in the polymer of the various elements so desired and referred to herein.
• the concentration of the filler should not be seen as limiting. It may be convenient to provide the concentration of the filler as a weight for weight basis, as a percentage (% w/w) of the total of the biodegradable composition.
• the filler may be present at up to 90% w/w, such as up to
• 80% w/w such as up to 70% w/w, such as up to 60% w/w, such as up to 50% w/w, such as up to
• w/w such as up to 30% w/w, such as up to 25% w/w, such as up to 20% w/w, such as up to
• the filler is present at a concentration of at least 0.01% w/w, such as at least 0.1% w/w, such as at least 1% w/w, such as at least 2% w/w, such as at least 3% w/w, such as at least 4% w/w, such as at least 5% w/w, such as at least 6% w/w, such as at least 7% w/w, such as at least 8% w/w, such as at least 9% w/w, such as at least 10% w/w.
• the filler is present at a concentration of about 10% w/w, such as at a concentration of 10% w/w.
• the particle size of the filler should not be seen as limiting, although generally the filler will have an average particle size from 1 nm to 5 mm. In some embodiments the filler will have an average particle size from 100 nm to 1 mm. Generally the filler will have a largest particle size from 10 nm to 5 mm. In some embodiments the filler will have a largest particle size from 100 nm to 1 mm, such as from 1 ⁇ m to 500 ⁇ m. In some embodiments the largest particle size of the filler will be about 500 ⁇ m, such as 500 ⁇ m. In some cases the source of the filler will be of a desired particulate size, although in some cases post-processing will be required.
• Techniques for generating particulate matter of the desired particle size will be well understood to the skilled person, and include both particle size reducing techniques such as grinding/milling (and optionally sieving) and particle size increasing techniques such as wet and dry granulation (and optionally sieving).
• the filler (such as blood and bone) can be graded by sieving through a sieve of the desired size, such as a sieve to select out those particles of greater than 1 mm, such as greater than 850 ⁇ m, such as an 850 ⁇ m sieve, so that the finer particles are utilised in the biodegradable compositions of the invention.
• the sieve may have even smaller apertures. It has been found that for some biodegradable compositions the finer particles of filler, such as from 1 ⁇ m to 500 ⁇ m, are better suited to forming techniques such as injection moulding.
• the biodegradable composition of the invention may be formed using a wide range of techniques, including 3D printing. In such modes of forming, the biodegradable composition may be passed through a nozzle having, for example, an aperture of 0.75 mm or less. It will be appreciated that the filler particle size should typically be (substantially) less than the aperture dimension of the nozzle. For example, a filler size of about 250 microns may be used to reduce or remove the likelihood of filler particle(s) clogging the nozzle.
• the source of the filler will undergo other post-processing steps such as being subject to: modulated temperature (such as being exposed to a temperature above ambient temperature for a period of time, such as to reduce moisture content); modulated pressure
• the biodegradable composition including a polymer and a filler comprises a mixture of PBS, PLA and a filler.
• the components PBS, PLA, and the filler may be present in:
• PBAT/PLA PBAT/PLA
• PHBV/PLA PHBV/PLA
• PCL/PLA PCL/PLA
• the expression "about 60:30:10" may refer to a range of (54 to 66) : (27 to 33) : (9 to 11), where
• the term "about” in relation to a specific numerical value (or plurality of values) refers to a range of values corresponding to those values rounded to the number of specified significant figures - for example, the expression “about 60:30:10” may refer to a range of (59.50 to 60.49) : (29.50 to 30.49) : (9.50 to 10.49).
• the biodegradable composition of the invention may be used in a variety of products.
• Techniques that may be used to blend the filler and the polymer and form it into the desired product include additive manufacture, extrusion, thermoforming, injection moulding, rotational moulding, injection blow moulding, vacuum casting, vacuum forming and/or compression moulding.
• the biodegradable composition of the present invention may be extruded into a desired product such as a container defining a cavity.
• a desired product such as a container defining a cavity.
• an additive layering manufacturing process could also be used to build the shape of a product, such as a container defining a cavity.
• a moulding process could be used such as a sacrificial moulding or injection moulding process or thermoforming.
• the biodegradable composition is processed through extrusion using a twin-screw extruder in order to reduce the production cost by process simplification, and to minimize the degradation of physical properties following the addition of the filler.
• the biodegradable compositions may be prepared using standard extrusion equi ⁇ ment - Labtech
• a mixture of the polymer and filler may be extruded into sheets using co-rotating extruder
• LTE26-40, 40L/D ratio set up with a slit die and a LabTech roller calendar.
• An exemplary die pressure is from 25 to 35 Bar. Sheets formed in such a manner may be collected as rolls from the extruder and then stored prior to thermoforming.
• 3D printed moulds of the desired product shape may be prepared for a thermoforming step.
• a sheet (such as an extruded sheet) may be thermoformed using standard vacuum former equi ⁇ ment such as Steele FS44.
• a series of vent holes may be included (such as drilled) in the moulds.
• the sheets may first be heated until soft, and then placed over the moulds to form the products
• the present invention also provides a method of selecting a filler to prepare a biodegradable composition including a polymer, the method including the steps of: i) selecting a polymer; ii) determining the C:N ratio of the polymer; iii) selecting a filler of known C:N ratio so that when combined with the polymer the
• C:N ratio of the combined filler and polymer is from 30 to 200.
• bespoke fillers may be created, including through combination of two or more conventional fillers, such as those shown above.
• a filler also provides improved manufacturability, namely during the extrusion/thermoforming process. It has been found the addition of a filler raises the Young's Modulus of the composition to a preferred level (about 1.298 GPa) to allow for improved processing.
• Initial testing suggested that a ratio of 60:30:10 (PBS :PLA:filler) provided a similar mechanical strength to HIPS (High Impact Polystyrene) and so could be used as a suitable biodegradable composition for replacing HIPS in products made of that polymer.
• Container suitable for biodegradation when buried in soil under non-industrial composting conditions
• the biodegradable composition may be formed into a plant container. It will be appreciated by the person skilled in the art that the shape and/or configuration of the plant container may be adapted to facilitate growth of the plant and/or enhance degradation of the container once planted in the soil.
• Figures 1-4 depict a plant container (100) that includes drain holes (20) on a base portion of the container to allow excess water to drain away.
• the drain holes are substantially circular in nature; however it will be appreciated that these holes should not be limited as such and any shaped holes can be used with the containers of the present invention.
• the container (100) may include a series of elongated slits (10) around the outer circumference of the container.
• the slits generally extend vertically from the base portion of the container and may vary in size in terms of length and width of the slits.
• the slits (10) are configured to enable the root system of the plant to penetrate through the walls of the container once the container is planted underground. Additionally, the slits provide segments in which to allow the container to break down once it has been planted to further speed up degradation.
• the number, size and location of the slits may vary depending on the size of the container.
• the container will be configured to retain soil and the plant within the container.
• FIG. 5-6 An alternative plant container/tray is also shown in Figures 5-6. Aspects of the container are similar to those of the plant container described above, therefore like references refer to like components.
• examples 7B and 8D were considered to be commercially viable of production by injection moulding. It should be appreciated by the person skilled in the art that different grades of starting materials may be used depending on the method of manufacture. For example, the grade of
• PLA, PBS or filler may be altered according to the method of manufacture utilised.
• a plant container prepared in accordance with the present invention was produced and tested in this trial.
• a plant container was prepared using compositions disclosed in examples 1 and 2.
• the purpose of the trial was to investigate the rate and type of breakdown of the plant container of the present invention under 'normal' in use conditions. Both above ground and below ground trials were conducted. The trials were conducted during New Zealand spring time conditions (from September to November).
• Figures 7-9 show degradation of the containers after approximately 60 days of use.
• composition Example 1 showed visual signs of degradation after 60 days. This suggests the composition may be useful for plants with shorter growth times above ground.
• composition Example 2 With reference to Figure 9, containers prepared from composition Example 2 showed minimal visual biodegradation after 60 days. This suggest that this composition may be suitable for plants having longer growth times above ground. An additional sample was sent to a testing facility around approximately the same time for further detailed testing of biodegradation. It was noted at the time that no signs of degradation were evident after 60 days, possibly because the conditions in the testing facility are more controlled than in a commercial nursery which may have a higher moisture level.
• Tomato seedlings were planted in both containers prepared from composition Examples 1 and 2, and both containers were subsequently planted.
• Figures 10-11 show the degradation of containers prepared from composition Example 1 after approximately 7 weeks underground.
• Figures 12-13 show the degradation of containers prepared from composition Example 2 after approximately 7 weeks underground.
• compositions with different fillers were tested in combination with a control sample.
• the two compositions included a polymer blend of PBS and PLA with different fillers comprising starch (sample 1) and blood and bone (sample 2) respectively.
• the control sample consisted of a mixture of PBS and PLA. Testing of each sample was conducted in triplicate with averages calculated from each sample, the results are as shown in table A and B below.
• biodegradable composition of the invention (examples 2 and 4) passed the 10-day and 45- day validation requirement, as outlined in ISO 14855-1 (2012), indicating the microbial activity of the composting inoculum is satisfactory.
• the tested materials can be considered biodegradable according to AS5810 (2010) when 90% has biodegraded within 365 days or when biodegradation has reached 90% of the maximum biodegradation for cellulose (positive control).
• the maximum percentage biodegradation of the positive control shall only be obtained after a plateau has been reached in the rate of biodegradation.
• the PBS/PLA composite and PBS/PLA/Starch composite biodegraded very little during the 190-day test period.
• the PBS/PLA/Blood and Bone composite did biodegrade much more effectively than either the PBS/PLA or PBS/PLA/Starch composites.
• the test material After 190 days, the test material has reached 97.5% of the biodegradability achieved by cellulose. Please note though that the positive control cellulose and the PBS/PLA/Blood and Bone composite have not yet reached a plateau value, so further degradation is expected to occur after 190 days.
• biodegradable compositions of the present invention showed vast improvement in biodegradation over that of the control, in particular the results demonstrate the level of biodegradation of the biodegradable compositions of the present invention (examples 2 and 4) was at least double the biodegradation of the control sample
• the level of biodegradation of the preferred biodegradable composition of the present invention that included blood and bone filler was substantially the same as the positive control (cellulose) which is remarkable given the inclusion of PLA which would not be expected to biodegrade substantially, even when co-formulated with PBS, as shown by the negative control.
• compositions were made and tested, some of which were exposed to soil for a period of 0, 2, 4, or 6 months to assess biodegradation under non-industrial composting conditions.
• thermoforming TF or injection-moulding (IM)
• PBS/ PLA/ filler ratios 65:35:0 (no filler), 60:30:10, or 45:45:10
• Types of filler materials (all at 10% w/w): starch, blood & bone, fish meal, canola, soymeal, and feather meal
• Thermoforming grade IM - Injection moulding grade.
• composites containing starch grains, blood & bone and fish meal were distinctive from the unfilled composite materials. Starch granules could easily be seen both inside and on the composite pellet surface. Likewise, composite pellets containing blood & bone or fish meal contained larger particles of variable size compared to the uniform starch granules.
• the samples After 4 to 6 months of soil exposure, the samples showed evidence of degradation in the form of cracking or pin holing.
• the filler at the surface may be degrading or affecting the degradation of the polymer.
• Filler at the composite surface appeared to be covered with polymer so the amount of direct exposure to soil may have been minimal. All three of the fillers (blood & bone, fish meal and starch) showed poor contact with the polymer with a void space surrounding the fillers in the matrix.
• Fourier-transform infrared spectroscopy Fourier transform infrared spectroscopy (FTIR) Fourier transform infrared spectroscopy provides a signature of the key chemical components of the test compositions. This signature would therefore only change considerably when the molecular components change significantly.
• Samples were analysed by Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) with 64 samples and background scans at 4 cm - 1 resolution from 4000-400 cm - 1 .
• FTIR-ATR Fourier transform infrared spectroscopy in attenuated total reflectance mode
• Table 3 The data in Table 3 has been derived from FTIR spectra obtained for the analysed samples.
• thermoforming grade formulation 60:30 PBS/PLA with blood & bone filler the PLA/PBS peak ratio increased over the first 4 months.
• the PBS degraded faster than PLA thus increasing the peak ratio.
• the peak ratio decreased, potentially signalling that PLA started to degrade too.
• thermoforming 45:45 PBS/PLA with blood & bone filler did not increase the peak ratio compared to thermoforming composite with no filler and the composite with 60:30:10 PBS/PLA with blood & bone filler (sample ID #3).
• the injection-moulding formulations were only measured at 0 and 6 months.
• the thermoforming 45:45 PBS/PLA with blood & bone filler did not increase the peak ratio compared to thermoforming composite with no filler and the composite with 60:30:10 PBS/PLA with blood & bone filler (sample ID #3).
• Quantitative analyses including peak picking of the 1711 cm - 1 peak and 1755 cm - 1 peak and additional FTIR analyses of the composites exposed for 2 and 4 month could give more detailed information about the degradability of those composites.
• GPC Gel Permeation Chromatography
• the parameters measured with GPC analyses that are most informative for this study are the mass-weighted molecular weight (Mw) and the dispersity index.
• Mw does not directly average the mass of individual polymers like the number-weighted molecular weight (Mn) does, but it takes account of the overall molecular weight of all the polymers in the sample. It is based on the fact that larger sized molecules contain more mass than smaller molecules and thus unduly contribute to the molecular weight average.
• the Mw average accounts for the molecular size of the polymers instead of just the number of polymers in the sample and thus gives a more informative representation of the sample's molecular weight.
• the dispersity index is the ratio between Mw/Mn and for a totally uniform sample would have a value of 1. The largerthe dispersity index the greater the size range of the polymers in a sample.
• the melt mass-flow rate also known as melt index, describes the flow properties of plastics at a defined temperature.
• the Melt Flow Rate is a measure of the ease of flow of melted plastic.
• the MFR is related to a polymer's relative molecular weight.
• the theoretical MFR for the biopolymers used in this study are shown in Table 4. In theory, if the MFR is higher for a given polymer, the molecular weight (Mw) is lower and vice versa. Therefore, based on MFR index in Table 4, and the actual measurements, the thermoforming grade exhibits a higher
• Table 4 Theoretical melt flow index (MFR), mass-weighted molecular weight (Mw), and dispersity index for the raw polymers used in the composite materials in this study.
• the Mw separated by process type grade, blend ratio and filler type showed that the before soil incubation composites with the various fillers all ranged between 101,115 g/mol for fish meal and 129,050 g/mol for blood & bone (Table 6).
• the Mw of the injection moulding type (45:45 blend ratio) starch composite decreased by 18%, the blood & bone composite by 21%, and the fish meal composite by 37%.
• the Mw of the thermoforming type (60:30 blend ratio) blood & bone composite decreased by 55%.
• the Mw did not decrease considerably with increased soil exposure time from 2 to 6 months for both injection moulding and thermoforming blood & bone composites while only small decreases were observed for the injection moulded fish meal and starch composites. This could indicate that the microbial activity and most of the degradation of the polymer chains is occurring within the first few months.
• the thermoforming blood & bone type composite with a blend ratio of 60:30:10 showed Mw value of about half the Mw value of the similar composite with a blend ratio of 45:45:10.
• a possible explanation for the higher Mw for the 45:45:10 blend could be that the amount of PLA present in the composites was greater.
• a PLA polymer is known to biodegrade slower than PBS polymer. Therefore, a greater proportion of PLA in the composite is likely to slow down the biodegradation process.
• thermoforming type starch composite approached the dispersity values of the injection moulded suited composites.
• the thermoforming type composites with other fillers all showed lower dispersity indices ranging from 8.9 for blood & bone to 10.0 for fish meal (Table 7).
• thermoforming blood & bone composite After 6 months of soil exposure, the lowest dispersity index was reached for the thermoforming blood & bone composite with a blend ratio of 60:30:10. All the 45:45:10 blend ratios showed greater dispersity indices ranging in order from low to high: injection moulding fish meal composite ⁇ injection moulding blood & bone composite ⁇ injection moulding starch ⁇ thermoforming blood and bone (Table 7). Table 7: The mean dispersity index and (standard deviation) of the different processing types, blend ratios, filler types and soil incubation period measured in this study, whereby "(-)" indicates "not measured”. Sample size is 2 for all except for soil incubated thermoforming 60:30
• Carbon and nitrogen ratios The carbon content of the composites with the various filler types ranged from 52.3 to 57.6%
• Table 8 The carbon content of the different processing types, blend ratios, filler types and soil incubation period measured in this study, whereby "(-)" indicates “not measured”. Standard deviations are given for the soil incubated thermoforming 60:30 Blood & bone composites, which were analysed in triplicate.
• Table 8 The carbon content of the different processing types, blend ratios, filler types and soil incubation period measured in this study, whereby "(-)" indicates “not measured”. Standard deviations are given for the soil incubated thermoforming 60:30 Blood & bone composites, which were analysed in triplicate.
• Table 10 The carbon to nitrogen ratio of the different processing types, blend ratios, filler types and soil incubation period measured in this study, whereby indicates "not measured”.
• Total and extractable nitrogen, phosphorus, and potassium concentrations were analysed by a digestion method that is able to solubilise the whole sample before quantitative analyses of those nutrients (Table 11).
• Total N can be determined using a furnace at extremely high temperatures.
• Extractable nitrogen will be measured as extractable ammonium.
• extractable nutrients (Tables 12) were analysed because they show the availability of those nutrients once composites are exposed to the soil.
• Mehlich 3 was selected. This method uses the acids acetic acid and nitric acid. The Mehlich 3 extraction procedure is most commonly used to determine the availability of soil macronutrients
• thermoforming and injection moulding end-application contained considerably more phosphorus than the other fillers (Table 11), while thermoforming type feather meal contained the most nitrogen (Table 9).
• the most total and extractable K and B was found in soymeal, while blood & bone contained considerably more Ca and Fe than the composites with other fillers.
• the composite with canola contained the most extractable Mg, Mn, Zn and Cu.
• thermoforming grade blood & bone filler increased more in extractable P and K percentages than the injection moulding grade blood & bone filler. This showed that with increased soil exposure more P and K become available (Table 11). Additionally, all other extractable nutrients except extractable sodium for thermoforming blood & bone also increased after soil exposure (Table 12). This provides evidence of composite material breakdown within the soil environment.
• Table 11 The total phosphorus (TP), extractable phosphorus (Extr. P), total potassium (TK), and extractable potassium (Extr. K) of the different processing types, blend ratios, filler types and soil incubation period measured in this study. Standard deviations are given for the soil incubated thermoforming grade 60:30 blood & bone composites, which were analysed in triplicate for TP and TK.
• Table 12 The extractable calcium (Ca), magnesium (Mg), sodium (Na), manganese (Mn), iron
• PBS polybutylene succinate
• PLA poly(lactic acid)
• the filler materials were: starch, blood & bone, fish meal, canola, soymeal, and feather meal.
• Microscopy showed that the fillers (blood & bone, fish meal and starch) exhibited poor contact with the polymer with a void surrounding the fillers in the matrix. This could be assisting with the degradation process. After 4 - 6 months of soil exposure, the composites showed evidence of degradation in the form of cracking or pin holing.
• FTIR Fourier transform infrared spectroscopy
• thermoforming plastics before compounding were higher than for injection moulding plastics, after processing the mean Mw for all fillers of each processing type were comparable. After 6 months of soil exposure, the Mw of the injection moulding (45:45 blend ratio) starch composite decreased by 18%, the blood & bone composite by 21%, and the fish meal composite by 37%. In the same period of soil exposure, the Mw of the thermoforming (60:30 blend ratio) blood & bone composite decreased by 55%. The lower decrease in Mw for the
• Feather meal composites contained the highest concentrations of nitrogen.
• Fish meal composites contained the second highest nitrogen concentration.
• both the carbon and nitrogen contents of the composite material decreased.
• the carbon content was stable with increasing soil exposure time, while the nitrogen kept decreasing with soil exposure time for both the injection moulding and thermoforming blood & bone fillers. This was also reflected in the C to N ratio that kept increasing over time for both blood & bone composites. This is a promising result suggesting that the nitrogen provided by the blood and bone was accessible to the microbial communities and has to some extent been metabolised by those microbial communities.
• thermoforming composite (60:30 blend ratio) with blood & bone filler increased more in extractable P and K percentages than the injection moulding (45:45 blend ratio) blood & bone filler composite. This indicated the thermoforming (60:30 blend ratio) blood & bone filler composite was further degraded than the injection moulding (45:45 blend ratio) blood & bone filler composite.
• compositions were made and tested, some of which were exposed to soil for a period of 0, 2, 4, or 6 months to assess biodegradation under non-industrial (home) composting conditions.
• the samples shown in the Figures 23 to 36 are the samples that had been inserted into soil on the 25th of June 2021.
• the sequence of numbers on the samples reflect when the samples were recovered from the soil, the lowest numbers are at 2 months, the middle numbers at 4 months and the highest at 6 months, there being three samples each month.
• Table D Average weather conditions by month and cumulative are shown in the table below.
• PLA/Blood and Bone, PLA/Fish meal, PLA/Feather meal, and PLA/Canola meal composites appeared structurally sound but showed granular discolourations from 2 months of soil exposure onwards. This could indicate that the fillers near the surface were starting to degrade but that the PLA was more resilient. In addition, there were some large cracks visible in the PLA/Fish meal test strips. This would suggest that the composite material was becoming more brittle over time.
• Canola meal filler showed large surface cracks and cavities indicating severe deterioration.
• the PLA with Feather meal filler also showed cracks indicating some deterioration.
• the PLA with Feather meal filler also showed cracks indicating some deterioration.
• the PBAT/PLA with Blood and Bone filler composite showed microbes colonising the Blood and
• PBS/PLA with Feathermeal composites showed weathered surfaces with cracks and cavities.
• Microbes might have also been present on the flat surfaces but have been washed/brushed off when samples were removed from the soil.
• the pure PLA with filler samples tended to show more straight-line cracks than the polymer/PLA composite samples, while the polymer/PLA composite samples showed more holes and rougher surfaces.
• the straight-line cracks in the pure PLA with filler samples are likely caused by mechanical force after the fillers near the surface had started to biodegrade.
• the PLA with filler composite only showed minor variations in the mass of the test strips after soil exposure and in some cases increased in mass possibly due to a small amount of moisture being absorbed into the test strips during the soil exposure period.
• the PBS/PLA composite with 10% or more Blood and Bone filler and the PCL/PLA composite with Blood and Bone filler achieved more than 2% mass loss after either 4 or 6 months of soil exposure.
• N Total nitrogen
• P total phosphorus
• K total potassium
• the carbon concentration of the various composites ranged from 48.2 to 55.9% and was somewhat influenced by the polymer type.
• the PCL/PLA composite contained the highest carbon concentration while the pure PLA polymer by itself showed the lowest carbon concentration.
• the highest nitrogen concentrations were found in the Feather meal and 20%
• the N concentration ranged from almost none (500 p ⁇ m) for the pure PLA without filler, to 13,000 p ⁇ m N for the composite with PBS/PLA and 20% Blood and Bone depending on the particular composite manufactured.
• the PLA with various fillers decreased in nitrogen and potassium concentration over time.
• the polymer/PLA composites with fillers also decreased after 6 months of soil exposure.
• Extractable nutrients were analysed because any increase over time would show the availability of those nutrients once composites are exposed to the soil. Extractable nitrogen was measured as extractable ammonium nitrogen while extractable Phosphorus (P), Calcium (Ca), Magnesium
• This Mehlich extraction uses acetic acid and nitric acid for the extraction process.
• the extractable ammonium, phosphorus, potassium, sodium, calcium and magnesium concentrations in the pure PLA samples were below the detection limit before soil exposure and after 6 months of soil exposure. This was expected since these pure PLA samples contained very low concentrations of total nitrogen, total phosphorus, and total potassium.
• the most extractable ammonium, phosphorus, potassium, sodium, calcium and magnesium was found in the PBS/PLA composite with 20% Blood and Bone filler, followed by the PBS/PLA composite with 15% Blood and Bone filler.
• the PBS/PLA composites with 5% and 10% Blood and Bone filler had much lower concentrations of extractable nutrients indicating that the extractable nutrient originated from fillers.
• the 10% filler formulations before soil exposure, the most extractable ammonium was found in the PCL/PLA/Blood and
• Bone composite while the most extractable phosphorus was found in the PLA/Blood and Bone composite, the most extractable sodium was found in the PLA/Fish meal composite, the most extractable potassium and magnesium were found in PLA/Canola meal composite, and the most extractable calcium was found in the PHBV/PLA/Blood and Bone composite.
• a composition including PBS:PLA:blood and bone such as at a ratio of 60:30:10 and/or
• a composition including PBS:PLA:starch such as at a ratio of 60:30:10 and/or 45:45:10; and/or
• composition including PBS:PLA:kiwifruit "hair", such as at a ratio of 60:30:10; and/or
• a filler that is selected from: blood and bone; starch; sheep pellets; kiwifruit "hair”; sanderdust; fertiliser; fishmeal; soil conditioner; soil enriching agent; weed suppressant; processed organic matter; processed animal matter (such as sourced from land or marine species); and/or processed biological matter obtained from an animal (such as comprising animal carcass); and/or
• a filler between 0.01-15% w/w of the composition, such as between 1-15%, such as between 5-15%, such as at least 10% w/w;
• PBS Polybutylene succinate
• PLA Polylactic acid
• PHA Polyhydroxyalkanoates
• PHA Polyhydroxyalkanoates
• PHB Polyhydroxyalkanoates
• PBV Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)
• PBS in an amount between 50-95% w/w of the composition, such as PBS in an amount between 60-90% w/w, such as PBS in an amount between 80-90% w/w of the composition;
• the invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features. Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth.

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• 2023
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