WO2024124291A1

WO2024124291A1 - Algal composite

Info

Publication number: WO2024124291A1
Application number: PCT/AU2023/051293
Authority: WO
Inventors: Lakshmi Krishnan; Unnikrishnan KUZHIUMPARAMBIL; Peter Ralph
Original assignee: University of Technology Sydney
Current assignee: University of Technology Sydney
Priority date: 2022-12-14
Filing date: 2023-12-13
Publication date: 2024-06-20
Anticipated expiration: 2025-06-14
Also published as: WO2024124294A1

Abstract

Algal composite The present disclosure relates to a composition comprising or consisting of about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives, wherein the algal biomass or algae-derived material are obtained from an algae selected from Kappaphycus alvarezii and Euchema denticulatum, and a method of preparation thereof.

Description

Algal composite

[0001 ] The present application claims priority to Australian Provisional Patent Application No. 2022903824, filed 14 December 2022, the entire disclosure of which is incorporated herein by cross-reference.

Field of the disclosure

[0002] The present disclosure broadly relates to plastic compositions comprising algae biomass or algae-derived materials.

Background of the disclosure

[0003] Any discussion of the prior art throughout this specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.

[0004] Plastics are used extensively in all areas of modern society. However, the manufacture of conventional plastics is energy intensive, relies on non-renewable resources and has a large carbon footprint. Plastic waste also represents an environmental problem as conventional plastics are not biodegradable.

[0005] Bioplastics seek to address some of these problems by forming plastics incorporating renewable materials, such as plant-derived materials. Such plastics may have a lower carbon footprint, utilise renewable resources, and be biodegradable. However, the high cost and inferior performance of bioplastics remain obstacles to their widespread adoption.

Summary of the disclosure

[0006] In a first aspect of the disclosure, there is provided a composition comprising or consisting of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives, wherein the algal biomass or algae-derived material are obtained from an algae selected from Kappaphycus alvarezii and Euchema denticulatum.

[0007] The following options may be used in conjunction with the first aspect of the disclosure, either individually or in any combination. [0008] The composition may consist of about 40-60% w/w of a non-algal polymer; and about 40-60% w/w of algal biomass or an algae-derived material.

[0009] The composition may consist of about 40% w/w of a non-algal polymer; and about 60% w/w of algal biomass or an algae-derived material.

[0010] The composition may consist of about 50% w/w of a non-algal polymer; and about 50% w/w of algal biomass or an algae-derived material.

[0011 ] The composition may consist of about 60% w/w of a non-algal polymer; and about 40% w/w of algal biomass or an algae-derived material.

[0012] The composition may consist of about 20-80% w/w of a non-algal polymer; about 20- 80% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

[0013] The composition may consist of about 30-70% w/w of a non-algal polymer; about 30- 70% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

[0014] The composition may consist of about 30-70% w/w of a non-algal polymer; about 30- 70% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

[0015] The composition may consist of about 60-70% w/w of a non-algal polymer; about 30- 40% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

[0016] The composition may consist of about 60% w/w of a non-algal polymer; about 35% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

[0017] The algae-derived material may be a sulfated polysaccharide. The sulfated polysaccharide may be selected from the group consisting of carrageenan, ulvan, and fucoidan. The sulfated polysaccharide may be ulvan. The sulfated polysaccharide may be carrageenan.

[0018] The non-algal polymer may be selected from the group consisting of polycaprolactone (PCL), poly(lactic acid) (PLA), low density polyethelene (LDPE), polypropylene (PP) and poly(hydroxybutyrate) (PHB). The non-algal polymer may be PCL. The PCL may have a number average molecular weight of between about 50,000 and 100,000. The PCL may have a number average molecular weight of about 80,000.

[0019] The one or more additives may be selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid. The one or more additives may be a beeswax product. The one or more additives may be palmitic acid.

[0020] The composition may not be in the form of a film, a microbead, a nanoparticle or a fiber. The composition may be in the form of a block or a pellet.

[0021 ] The composition may have a tensile strength of at least 3 MPa measured according to ASTM D638.

[0022] The composition may have an elongation at break of at least 2% measured according to ASTM D638.

[0023] In a second aspect of the disclosure, there is provided a method of preparing a composition comprising a non-algal polymer, algal biomass or an algae-derived material, and optionally one or more additives, the method comprising:

(i) mixing the non-algal polymer, algal biomass or algae-derived material, and optionally one or more additives, at elevated temperature to form the composition, wherein the algal biomass or algae-derived material are obtained from an algae selected from Kappaphycus alvarezii and Euchema denticulatum.

[0024] The following options may be used in conjunction with the second aspect of the disclosure, either individually or in any combination.

[0025] Step (i) may be carried out in a twin screw extruder.

[0026] The elevated temperature may be between about 80 °C and about 150 °C.

[0027] The method may further comprise:

(ii) extruding the composition; and

(iii) forming the composition into pellets.

[0028] The method may further comprise (iv.a.) compression moulding, injection moulding, thermoforming, blow moulding, calendaring, or extruding the composition in a desired shape. [0029] The method may further comprise (iv.b.) 3D printing the composition in a desired shape.

[0030] The composition may comprise or consist of about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives.

[0031 ] The composition may consist of about 40-60% w/w of a non-algal polymer; and about 40-60% w/w of algal biomass or an algae-derived material.

[0032] The composition may consist of about 40% w/w of a non-algal polymer; and about 60% w/w of algal biomass or an algae-derived material.

[0033] The composition may consist of about 50% w/w of a non-algal polymer; and about 50% w/w of algal biomass or algae-derived material.

[0034] The composition may consist of about 60% w/w of a non-algal polymer; and about 40% w/w of algal biomass or an algae-derived material.

[0035] The composition may consist of about 20-80% w/w of a non-algal polymer; about 20- 80% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

[0036] The composition may consist of about 30-70% w/w of a non-algal polymer; about 30- 70% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

[0037] The composition may consist of about 30-70% w/w of a non-algal polymer; about 30- 70% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

[0038] The composition may consist of about 60-70% w/w of a non-algal polymer; about 30- 40% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

[0039] The composition may consist of about 60% w/w of a non-algal polymer; about 35% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

[0040] The algae-derived material may be a sulfated polysaccharide. The sulfated polysaccharide may be selected from the group consisting of carrageenan, ulvan, and fucoidan. The sulfated polysaccharide may be ulvan. The sulfated polysaccharide may be carrageenan.

[0041 ] The non-algal polymer may be selected from the group consisting of polycaprolactone (PCL), poly(lactic acid) (PLA), low density polyethelene (LDPE), polypropylene (PP), and poly(hydroxybutyrate) (PHB). The non-algal polymer may be PCL. The PCL may have a number average molecular weight of between about 50,000 and 100,000. The PCL may have a number average molecular weight of about 80,000.

[0042] The one or more additives may be selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid. The one or more additives may be a beeswax product. The one or more additives may be palmitic acid.

[0043] In a third aspect of the disclosure, there is provided a composition prepared according to the method of the second aspect of the disclosure.

Definitions

[0044] The following are some definitions that may be helpful in understanding the description of the present disclosure. These are intended as general definitions and should in no way limit the scope of the present disclosure to those terms alone, but are put forth for a better understanding of the following description.

[0045] Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0046] The terms "a" and "an" are used herein to refer to one or to more than one (i.e. to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0047] In the context of this specification the term "about" is understood to refer to ±10% of the recited value.

[0048] Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of 1 .0 to 5.0 is intended to include all sub-ranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 5.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 5.0, such as 2.1 to 4.5. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited herein is intended to include all higher numerical limitations subsumed therein.

[0049] Any description of prior art documents herein, or statements herein derived from or based on those documents, is not an admission that the documents or derived statements are part of the common general knowledge of the relevant art.

[0050] For the purposes of description, all documents referred to herein are hereby incorporated by reference in their entirety unless otherwise stated

Brief Description of the Drawings

[0051 ] Figure 1. Compression moulded blocks formed from compositions according to the disclosure.

Detailed Description

[0052] The inventors have surprisingly found that a blend of algal material, a non-algal polymer, and optionally an additive can provide a bioplastic composition having good strength and elongation properties.

[0053] Algae are an ideal source of material for bioplastics as they have a high growth yield per area, ability to be grown in non-arable or arid regions, and ability to grow in non-freshwater environments.

Algal bioplastic composition

[0054] In a first aspect of the disclosure, there is provided a composition comprising or consisting of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives, wherein the algal biomass or algae-derived material are obtained from an algae selected from Kappaphycus alvarezii and Euchema denticulatum.

[0055] The reference to w/w refers to mass percentage relative to the total mass of the composition. [0056] In some embodiments, the composition may comprise about 20-80% w/w of a non- algal polymer, or about 20-30, 20-40, 20-50, 20-60, 20-70, 30-40, 30-50, 30-60, 30-70, 30- 80, 40-50, 40-60, 40-70, 40-80, 50-60, 50-70, 50-80, 60-70, 60-80, or about 70-80% w/w of a non-algal polymer. The composition may comprise about 40-60% w/w of a non-algal polymer. The composition may comprise about 30-70% w/w of a non-algal polymer. The composition may comprise about 60-70% w/w of a non-algal polymer. In some embodiments, the composition may comprise about 20% w/w of a non-algal polymer, or about 30, 40, 50, 60, 70, or about 80% w/w of a non-algal polymer. The composition may comprise about 40% w/w of a non-algal polymer. The composition may comprise about 50% w/w of a non-algal polymer. The composition may comprise about 60% w/w of a non-algal polymer. The composition may comprise about 70% w/w of a non-algal polymer.

[0057] In some embodiments, the composition may comprise about 20-80% w/w of algal biomass or an algae-derived material, or about 20-30, 20-40, 20-50, 20-60, 20-70, 30-40, 30- 50, 30-60, 30-70, 30-80, 40-50, 40-60, 40-70, 40-80, 50-60, 50-70, 50-80, 60-70, 60-80, or about 70-80% w/w of algal biomass or an algae-derived material. The composition may comprise about 40-60% w/w of algal biomass or an algae-derived material. The composition may comprise about 30-70% w/w of algal biomass or an algae-derived material. The composition may comprise about 30-40% w/w of algal biomass or an algae-derived material. In some embodiments, the composition may comprise about 20% w/w of algal biomass or an algae-derived material, or about 30, 40, 50, 60, 70, or about 80% w/w of algal biomass or an algae-derived material. The composition may comprise about 30% w/w of algal biomass or an algae-derived material. The composition may comprise about 35% w/w of algal biomass or an algae-derived material. The composition may comprise about 40% w/w of algal biomass or an algae-derived material. The composition may comprise about 50% w/w of algal biomass or an algae-derived material. The composition may comprise about 60% w/w of algal biomass or an algae-derived material.

[0058] In some embodiments, the composition may comprise about 0-20% w/w of one or more additives. That is, the total amount of all of the additives included in the composition is between 0 and 20% w/w. The composition may comprise about 0-2, 0-5, 0-10, 0-15, 2-5, 2-10, 2-15, 2- 20, 5-10, 5-15, 5-20, 10-15, 10-20 or about 15-20% w/w of one or more additives. The composition may comprise about 2-10% w/w of one or more additives. The composition may comprise about 0% of one or more additives, or about 2, 5, 10, 15, or about 20% w/w of one or more additives. The composition may comprise about 5% w/w of one or more additives.

[0059] The algal biomass or algae-derived material are obtained from an algae selected from Kappaphycus alvarezii and Euchema denticulatum. The algal biomass or algae-derived material may be obtained from Kappaphycus alvarezii. The algal biomass or algae-derived material may be obtained from Euchema denticulatum.

[0060] Algal biomass refers to material obtained from as-harvested algae with minimal processing, for example limited to only drying and grinding to powder. Algal biomass also refers to algal mass remaining after extraction of high value products such as polysaccharides, proteins, pigments and/or hormones. For example, algal biomass includes the algal mass remaining after the extraction of sulfated polysaccharides or alginate as described below. An algae-derived material refers to a component of algae which has been isolated from as- harvested algae. For example, sulfated polysaccharides and alginate are algae-derived materials that can be isolated from as-harvested algae. Methods of isolating these materials from algae have been described previously, for example in Carbohydrate Polymers, 136 (2016), p. 930-935, and J. Phycol. 45 (2009), p. 962-973. Sulfated polysaccharides found in algae which may be included in the composite of the first aspect of the disclosure include carrageenan, ulvan, and fucoidan.

[0061 ] The non-algal polymer may be any conventional polymer known to the skilled person which is suitable for forming plastics. The non-algal polymer may be a hydrocarbon-based polymer. The non-algal polymer may be a polyester. The non-algal polymer may be selected from the group consisting of polycaprolactone (PCL), low density polyethylene (LDPE), poly(lactic acid) (PLA), polypropylene (PP) and poly(hydroxybutyrate) (PHB). PCL, PHB and PLA are polyesters. When the non-algal polymer is PCL, the PCL may have a number average molecular weight of between about 50,000-100,000, or about 80,000.

[0062] The one or more additives, when present, may serve to improve the elongation properties of the composition without reducing its tensile strength. Without wishing to be bound by theory, the inventors believe that the additives may form ester or amide bonds with the caprolactone and/or or the algal biomass or algae-derived material which alter the strength and elongation properties of the resulting composition, for example by cross-linking. Alternatively or additionally, the inventors believe that the additives may function as plasticisers. The one or more additives may be selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid. The composition may comprise combinations of additives such as polyethylene glycol and citric acid, urea and choline chloride, or urea and glycerol. Where the one or more additives are a combination of polyethylene glycol and citric acid or urea and glycerol, each components may be included in equal amounts. Where the one or more additives are a combination of urea and choline chloride, the urea and choline chloride may be included in a molar ratio of 2:1. In some embodiments, the one or more additives may be palmitic acid. In some embodiments, the one or more additives may be a beeswax product. The beeswax product may be, for example, a mixture of fatty acid triglycerides, limonene and beeswax, in particular a mixture of about 70-80% w/w fatty acid triglycerides, about 15-20% w/w limonene and about 5% w/w beeswax.

[0063] The composition may not be in the form of a film, a microbead, a nanoparticle or a fiber. A microbead refers to a bead having a diameter between 1 pm and 1 mm. A nanoparticle refers to a particle having a diameter less than 1 pm. The composition may be provided in the form a block or a pellet, or a plurality of blocks or pellets. Blocks or pellets can then be subject to further processing such as moulding or 3D printing.

[0064] The composition may have a tensile strength of at least about 3 MPa, as measured by ASTM D638. The composition may have a tensile strength of at least about 4, 5, 6, 7, 8, 9, or about 10 MPa. The composition may have tensile strength of about 5-20 MPa, or about 5-10, 5-15, 10-15, 10-20, or about 15-20 MPa. The composition may have tensile strength of about 5-15 MPa. The composition may have a tensile strength of about 5 MPa, or about 6, 7, 8, 9, 10, 11 , 12 ,13, 14, 15, 16, 17, 18, 19, or about 20 MPa.

[0065] The composition may have an elongation at break of at least about 2%, as measured by ASTM D638. The composition may have an elongation at break of at least about 5, 10, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750 or at least about 800%. The composition may have an elongation at break of about 100-800%, or about 2-100, 2-200, 2-300, 2-400, 2-500, 2-600, 2-700, 2-800, 100-200, 100-300, 100-400, 100-500, 100-600, 100-700, 200-300, 200-400, 200-500, 200-600, 200-700, 200-800, 300-400, 300-500, 300- 600, 300-700, 300-800, 400-500, 400-600, 400-700, 400-800, 500-600, 500-700, 500-800, 600-700, 600-800, or about 700-800%. The composition may have an elongation at break of about 100-500%. The composition may have an elongation at break of about 2,% or about 5, 10, 50, 100, 200, 300, 400, 500, 600, 700, or about 800%.

[0066] In an alternative aspect there is provided a composition comprising or consisting of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives.

[0067] In this alternative aspect, the algal biomass or algae-derived material may be obtained from any suitable algae, such as a microalgae or a macroalgae (i.e. seaweed). Examples of suitable algae include algae of the genus Ulva, such as Ulva ohnoi or Ulva lactuca, algae of the genus Kappaphycus, such as Kappaphycus alverizii, algae of the genus Chlorella, such as Chlorella vulgaris, algae of the genus Scenedesmus, algae of the genus Phaeodactylum, such as Phaeodactylum tricornutum.

A method of preparing an algal bioplastic composition

[0068] In a second aspect of the disclosure, there is provided a method of preparing a composition comprising a non-algal polymer, algal biomass or an algae-derived material, and optionally one or more additives, the method comprising:

[0069] The mixing of step (i) of the second aspect of the disclosure may be carried out using any suitable means of achieving comprehensive mixing of the components of the composition. In some embodiments, step (i) may be carried out in a twin-screw extruder, internal mixer, two roll mill, or single screw extruder. In some embodiments, step (i) may be carried out in a twin- screw extruder. In this case, step (i) may be repeated once to ensure sufficient mixing. That is, the composition formed in the twin-screw extruder may be fed back in to the hopper of the twin-screw extruder and mixed a second time. When step (i) is carried out in a single- or twin- screw extruder, the screw L/D ratio, screw design, and nozzle design can be varied to improve mixing efficiency.

[0070] The mixing step of step (i) of the second aspect of the disclosure may be carried out at elevated temperature. The elevated temperature may be below 180 °C. The elevated temperature may be about 80-150 °C, or about 80-90, 80-100, 80-110, 80-120, 80-130, 80- 140, 90-100, 90-1 10, 90-120, 90-130, 90-140, 90-150, 100-1 10, 100-120, 100-130, 100-140, 100-150, 110-120, 110-130, 110-140, 110-150, 120-130, 120-140, 120-150, 130-140, 130- 150, or about 140-150 °C. The elevated temperature may be between about 90-130 °C. Where the mixing step of step (i) is carried out in a twin screw extruder, the non-algal polymer, algal biomass or algae-derived material, and optionally one or more additives may be passed through different zones of the twin screw extruder having different temperatures. The zones may have increasing temperatures in the range of 80-150 °C. The zones may have increasing temperatures in the range of 90-130 °C. In some embodiments, the non-algal polymer, algal biomass or algae-derived material, and optionally one or more additives are passed through a first zone at 90 °C, followed by a second zone at 100 °C, followed by a third zone at 1 10 °C, followed by a fourth zone at 120 °C, followed by a fifth zone at 130 °C. [0071 ] Where the mixing step of step (i) is carried out in a twin screw extruder, the rotation speed of the twin screw extruder may be about 20-120 rpm, or about 20-40, 20-60, 20-80, 20- 100, 40-60, 40-80, 40-100, 40-120, 60-80, 60-100, 60-120, 80-100, 80-120, or about 100-120 rpm. The rotation speed of the twin screw extruder may be about 40-60 rpm. The rotation speed of the twin screw extruder may be about 100-120 rpm. The rotation speed of the twin screw extruder may be about 100-1 10 rpm. The rotation speed of the twin screw extruder may be about 20 rpm, or about 30, 40, 50, 60, 70, 80, 90, 100, 110 or about 120 rpm. The rotation speed of the twin screw extruder may be about 50 rpm. The rotation speed of the twin screw extruder may be about 100 rpm. The rotation speed of the twin screw extruder may be about 110 rpm. Where step (i) is repeated once to ensure sufficient mixing in the twin screw extruder, the rotation speed on the first pass of the components of the composition through the twin screw extruder may be higher than the rotation speed on the second pass of the composition through the twin screw extruder. For example, the components of the composition may be passed through the twin screw extruder at 1 10 pm, followed by passing the composition through the twins screw extruder a second time at 100 rpm. Where the composition contains one or more additives, the rotation speed of the extruder may be reduced to ensure enhanced reactive extrusion or mixing and incorporation of the additive into the composition. In this case, the rotation speed of the twin screw extruder may be about 40-60 rpm, or about 50 rpm. Where the composition does not contain one or more additives, the rotation speed of the twin screw extruder may be about 100-120 rpm, or about 100-1 10 rpm.

[0072] Following step (i) of the second aspect of the disclosure, the composition may be extruded and then formed into pellets. For example, where step (i) takes place in a twin screw extruder, the composition may be, in a step (ii), extruded through a die to form a strand of the composition. Then, in a step (iii), the strand is formed into pellets, for example by cutting the strand into pellets. Pellets form a convenient substrate for further processing. The method of the second aspect of the disclosure may thus further comprise a step (iv.a.) of compression moulding, injection moulding, thermoforming, blow moulding, calendaring, or extruding the composition in a desired shape, or alternatively, the method may further comprise a step (iv.b.) of 3D printing the composition in a desired shape.

[0073] In the method of the second aspect of the disclosure, the nature of the non-algal polymer, algal biomass or an algae-derived material, and one or more additives, and the amounts thereof in the composition, are as described above in relation to the first aspect of the disclosure. [0074] In an alternative aspect of the disclosure, there is provided a method of preparing a composition comprising a non-algal polymer, algal biomass or an algae-derived material, and optionally one or more additives, the method comprising:

(i) mixing the non-algal polymer, algal biomass or algae-derived material, and optionally one or more additives, at elevated temperature to form the composition.

[0075] In this alternative aspect, the algal biomass or algae-derived material may be obtained from any suitable algae, such as a microalgae or a macroalgae (i.e. seaweed). Examples of suitable algae include algae of the genus Ulva, such as Ulva ohnoi or Ulva lactuca, algae of the genus Kappaphycus, such as Kappaphycus alverizii, algae of the genus Chlorella, such as Chlorella vulgaris, algae of the genus Scenedesmus, algae of the genus Phaeodactylum, such as Phaeodactylum tricornutum.

[0076] In a third aspect of the disclosure, there is provided a composition prepared according to the method of the second aspect of the disclosure.

[0077] The present disclosure may be described by reference to the following numbered forms:

1 . A composition comprising or consisting of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives, wherein the algal biomass or algae-derived material are obtained from an algae selected from Kappaphycus alvarezii and Euchema denticulatum.

2. The composition of form 1 consisting of: about 40-60% w/w of a non-algal polymer; and about 40-60% w/w of algal biomass or an algae-derived material.

3. The composition of form 1 or form 2, consisting of: about 40% w/w of a non-algal polymer; and about 60% w/w of algal biomass or an algae-derived material.

4. The composition of form 1 or form 2, consisting of: about 50% w/w of a non-algal polymer; and about 50% w/w of algal biomass or an algae-derived material.

5. The composition of form 1 or form 2, consisting of: about 60% w/w of a non-algal polymer; and about 40% w/w of algal biomass or an algae-derived material.

6. The composition of form 1 , consisting of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

7. The composition of form 1 or form 6, consisting of: about 30-70% w/w of a non-algal polymer; about 30-70% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

8. The composition of any one of forms 1 , 6, and 7, consisting of: about 30-70% w/w of a non-algal polymer; about 30-70% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

9. The composition of any one of forms 1 , and 6 to 8, consisting of: about 60-70% w/w of a non-algal polymer; about 30-40% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

10. The composition of any one of forms 1 , and 6 to 9, consisting of: about 60% w/w of a non-algal polymer; about 35% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

11 . The composition of any one of forms 1 to 10, wherein the algae-derived material is a sulfated polysaccharide. 12. The composition of form 11 , wherein the sulfated polysaccharide is selected from the group consisting of carrageenan, ulvan, and fucoidan.

13. The composition of form 11 or form 12, wherein the sulfated polysaccharide is ulvan.

14. The composition of form 11 or form 12, wherein the sulfated polysaccharide is carrageenan.

15. The composition of any one of forms 1 to 14, wherein the non-algal polymer is selected from the group consisting of polycaprolactone (PCL), poly(lactic acid) (PLA), low density polyethelene (LDPE), polypropylene (PP) and poly(hydroxybutyrate) (PHB).

16. The composition of any one of forms 1 to 15, wherein the non-algal polymer is PCL.

17. The composition of form 16, wherein the PCL has a number average molecular weight of between about 50,000 and 100,000.

18. The composition of form 16 or form 17, wherein the PCL has a number average molecular weight of about 80,000.

19. The composition of any one of forms 1 to 18, wherein the one or more additives are selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid.

20. The composition of any one of forms 1 to 19, wherein the one or more additives is a beeswax product.

21 . The composition of any one of forms 1 to 19, wherein the one or more additives is palmitic acid.

22. The composition of any one of forms 1 to 21 , wherein the composition is not in the form of a film, a microbead, a nanoparticle or a fiber.

23. The composition of any one of forms 1 to 22, wherein the composition is in the form of a block or a pellet.

24. The composition of any one of forms 1 to 23, wherein the composition has a tensile strength of at least 3 MPa measured according to ASTM D638.

25. The composition of any one of forms 1 to 24, wherein the composition has an elongation at break of at least 2% measured according to ASTM D638. 26. A method of preparing a composition comprising a non-algal polymer, algal biomass or an algae-derived material, and optionally one or more additives, the method comprising:

27. The method of form 26, wherein step (i) is carried out in a twin screw extruder.

28. The method of form 26 or form 27, wherein the elevated temperature is between about 80 °C and about 150 °C.

29. The method of any one of forms 26 to 28, wherein the method further comprises:

(ii) extruding the composition; and

(iii) forming the composition into pellets.

30. The method of any one of forms 26 to 29, wherein the method further comprises:

(iv.a.) compression moulding, injection moulding, thermoforming, blow moulding, calendaring, or extruding the composition in a desired shape.

31 . The method of any one of forms 26 to 29, wherein the method further comprises:

(iv.b.) 3D printing the composition in a desired shape.

32. The method of any one of forms 26 to 31 , wherein the composition comprises or consists of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives.

33. The method of any one of forms 26 to 32, wherein the composition consists of: about 40-60% w/w of a non-algal polymer; and about 40-60% w/w of algal biomass or an algae-derived material.

34. The method of any one of forms 26 to 33, wherein the composition consists of: about 40% w/w of a non-algal polymer; and about 60% w/w of algal biomass or an algae-derived material.

35. The method of any one of forms 26 to 34, wherein the composition consists of: about 50% w/w of a non-algal polymer; and about 50% w/w of algal biomass or algae-derived material.

36. The method of any one of forms 26 to 35, wherein the composition consists of: about 60% w/w of a non-algal polymer; and about 40% w/w of algal biomass or an algae-derived material.

37. The method of any one of forms 26 to 32, wherein the composition consists of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

38. The method of any one of forms 26 to 32 and 37, wherein the composition consists of: about 30-70% w/w of a non-algal polymer; about 30-70% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

39. The method of any one of forms 26 to 32, 37 and 38, wherein the composition consists of: about 30-70% w/w of a non-algal polymer; about 30-70% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

40. The method of any one of forms 26 to 32, and 37 to 39, wherein the composition consists of: about 60-70% w/w of a non-algal polymer; about 30-40% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives. 41 . The method of any one of forms 26 to 32, and 37 to 40, wherein the composition consists of: about 60% w/w of a non-algal polymer; about 35% w/w of algal biomass or an algae-derived material; and about 5% w/w of one or more additives.

42. The method of any one of forms 26 to 41 , wherein the algae-derived material is a sulfated polysaccharide.

43. The method of form 42, wherein the sulfated polysaccharide is selected from the group consisting of carrageenan, ulvan, and fucoidan.

44. The method of form 42 or form 43, wherein the sulfated polysaccharide is ulvan.

45. The method of form 42 or form 43, wherein the sulfated polysaccharide is carrageenan.

46. The method of any one of forms 26 to 45, wherein the non-algal polymer is selected from the group consisting of polycaprolactone (PCL), poly(lactic acid) (PLA), low density polyethelene (LDPE), polypropylene (PP), and poly(hydroxybutyrate) (PHB).

47. The method of any one of forms 26 to 46, wherein the non-algal polymer is PCL.

48. The method of form 47, wherein the PCL has a number average molecular weight of between about 50,000 and 100,000.

49. The method of form 47 or form 48, wherein the PCL has a number average molecular weight of about 80,000.

50. The method of any one of forms 26 to 49, wherein the one or more additives are selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid.

51 . The method of any one of forms 26 to 50, wherein the one or more additives is a beeswax product.

52. The method of any one of forms 26 to 51 , wherein the one or more additives is palmitic acid.

53. A composition prepared according to the method of any one of forms 26 to 52. Examples

Preparation of algal biomass or algae-derived material

[0078] Carrageenan was extracted from Kappaphycus alverizii according to the procedure of Carbohydrate Polymers, 136 (2016), p. 930-935. Briefly, the algae was treated with a deep eutectic solution (ethylene glycol: choline chloride in 2:1 molar ratio) in an autoclave at 120 °C and 1 psi pressure for 20 minutes. The solids were then washed thoroughly with water and dried in oven till no further weight loss is noted. This dried mass was powdered in a grain grinder and sieved through 2-micron sieve.

[0079] Ulvan was extracted from Ulva lactuca according to the procedure of J. Phycol. 45 (2009), p. 962-973. Briefly, the algae was refluxed in sodium oxalate (0.5 M) at 85 °C for 2 hours. The solids were then filtered and washed.

[0080] Algal biomass was prepared by washing harvested algae and drying. The dried algae was powdered and sieved, for example with a 2 pm sieve. Algal biomass may also be obtained following extraction of harvested algae using the methods described above, or following extraction with acetone or ethanol.

Preparation of algal bioplastic compositions

[0081 ] Blends were prepared according to Table 1 below and passed twice through a Collin ZK 12X 24D twin screw extruder. The initial pass was carried out at 110 rpm with zone temperature of 90/100/110/120/130 °C. The extruded strand was cooled and pelletised. The pellets were fed back into the hopper and a second pass was carried out at 100 rpm with zone temperature of 90/100/110/120/130 °C. The extruded strand following the second pass was again cooled and pelletised. The pellets were used for compression moulding or 3D printing as described below.

[0082] Where additives were included the composition were prepared as above, except that mixing speed was reduced to 50 rpm.

Compression moulding

[0083] Compression moulding was carried out in a 30-ton machine with heated platens. The pellets obtained above were preheated to 1 10 °C and the mould closed. Pressure (100 bar) was applied for five minutes. The mould was cooled to 35 °C and parts were ejected. Compression moulded blocks are depicted in Figure 1. 3D Printing

[0084] The pellets obtained above were fed into a UR10 robot 3D printer operated at 160 °C to make a cylindrical shape of diameter 5 cm.

Testing

[0085] Testing was carried out in accordance with ASTM D638. Dumbbell specimens of ASTM Type IV dimensions were compression moulded as described above. The test specimens were loaded in a Shimadzu AGS-X universal testing machine. Testing was carried out at a speed of 10 mm/s with a 10 kN load cell. The tensile strength and elongation at break were calculated from the raw data obtained from the machine. Tensile strength at break measures the maximum stress a plastic specimen can withstand while being stretched before breaking and is measured as the force per unit cross sectional area (MPa or psi). The elongation at break or ultimate elongation is the percentage increase in length that occurs before it breaks under tension and is expressed in % with respect to the initial length.

Results

[0087] Those skilled in the art will appreciate that the disclosure described herein is susceptible to variations and modifications other than those specifically described. It is to be understood that the disclosure includes all such variations and modifications. The disclosure also includes all of the steps, features, compositions and compounds referred to or indicated in this specification, individually or collectively, and any and all combinations of two or more of said steps, features, compositions and compounds.

Claims

CLAIMS:

2. The composition of claim 1 consisting of: about 40-60% w/w of a non-algal polymer; and about 40-60% w/w of algal biomass or an algae-derived material.

3. The composition of claim 1 , consisting of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

4. The composition of any one of claims 1 to 3, wherein the algae-derived material is a sulfated polysaccharide.

5. The composition of any one of claims 1 to 4, wherein the non-algal polymer is selected from the group consisting of polycaprolactone (PCL), poly(lactic acid) (PLA), low density polyethelene (LDPE), polypropylene (PP) and poly(hydroxybutyrate) (PHB).

6. The composition of any one of claims 1 to 5, wherein the one or more additives are selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid.

7. The composition of any one of claims 1 to 6, wherein the composition is not in the form of a film, a microbead, a nanoparticle or a fiber.

8. The composition of any one of claims 1 to 7, wherein the composition is in the form of a block or a pellet.

9. The composition of any one of claims 1 to 8, wherein the composition has a tensile strength of at least 3 MPa measured according to ASTM D638.

10. The composition of any one of claims 1 to 9, wherein the composition has an elongation at break of at least 2% measured according to ASTM D638.

11. A method of preparing a composition comprising a non-algal polymer, algal biomass or an algae-derived material, and optionally one or more additives, the method comprising:

12. The method of claim 11 , wherein the elevated temperature is between about 80 °C and about 150 °C.

13. The method of claim 11 or claim 12, wherein the method further comprises:

(ii) extruding the composition; and

(iii) forming the composition into pellets.

14. The method of any one of claims 11 to 13, wherein the composition comprises or consists of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 0-20% w/w of one or more additives.

15. The method of any one of claims 11 to 14, wherein the composition consists of: about 40-60% w/w of a non-algal polymer; and about 40-60% w/w of algal biomass or an algae-derived material.

16. The method of any one of claims 11 to 14, wherein the composition consists of: about 20-80% w/w of a non-algal polymer; about 20-80% w/w of algal biomass or an algae-derived material; and about 2-10% w/w of one or more additives.

17. The method of any one of claims 11 to 16, wherein the algae-derived material is a sulfated polysaccharide.

18. The method of any one of claims 11 to 17, wherein the non-algal polymer is selected from the group consisting of polycaprolactone (PCL), poly(lactic acid) (PLA), low density polyethelene (LDPE), polypropylene (PP), and poly(hydroxybutyrate) (PHB).

19. The method of any one of claims 11 to 18, wherein the one or more additives are selected from the group consisting of polyethylene glycol, citric acid, polyethylene glycol dimethacrylate, urea, glycerol, choline chloride, a beeswax product, and palmitic acid.