Biodegradable composite materials and methods of making same

Abstract

Disclosed is a composite biodegradable polymeric-based material comprising: at least 50% wt. of a polyester; a nucleator, a polymeric softener and at least 5 wt.% biodegradable plasticizer. The composite material is characterized by a significantly increased Tc, compared to a similar material devoid of the nucleator. Further, solid foam composite comprising crosslinked polyester and method of making thereof are also provided.

Description

BIODEGRADABLE COMPOSITE MATERIALS AND METHODS OF MAKING SAMECROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of Israeli Patent Application No. 316902, filed November 07, 2024, the content of which is incorporated herein by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates generally to biodegradable polymeric based materials. More specifically, the present invention relates to a composite material, comprising one or more nucleating agent.BACKGROUND OF THE INVENTION

[0003] The fashion industry accounts for about 8% of the world's total greenhouse gas emissions. Furthermore, due to the frequent changes in “fashion”, most of the products of this industry are being replaced constantly with very low level of recycling. Making the fashion industry one of the largest pollutant in the world. While natural fabrics such as, cotton and silk may degrade into harmless material, in time, all the synthetic fibers / materials are expected to last several hundreds of years.

[0004] The development of biodegradable polymeric materials is one of the greatest promises in reducing pollution from synthetic polymers. Biodegradable polymers are polymers configured to disintegrate by bacterial decomposition process to result in natural byproducts such as gases (CO2, N2), water, biomass, and inorganic salts.

[0005] Known biodegradable polymers include both natural polymers, such as, polysaccharides (e.g., starch) and synthetic polymers, such as polyester and combination of both synthetic and natural polymers. A promising synthetic polymer is polybutylene adipate terephthalate (PBAT). However, both polyester based biodegradable polymers and PBAT based biodegradable polymers are unsuitable for the use in the fashion industry due to their mechanical properties. Polyester based biodegradable polymers are too week and / or are highly hygroscopic and PBAT is too stiff and rigid for fashion articles.

[0006] Accordingly, there is a need for a biodegradable based polymer that will have both sufficient strength and flexibility for the use in fashion articles while beingwaterproof at least until a deliberate biodegradation processes is initiated (for example, in a compost er).SUMMARY OF THE INVENTION

[0007] In one aspect of the invention, there is provided a composite material comprising: at least 50% polyester; at least 10 wt.% plasticizer; at least 5 wt.% polymeric softener; and a nucleator; wherein: said plasticizer is in a liquid state at a temperature between -20 and 50°C, said nucleator comprises a mineral particle.

[0008] In one embodiment, the nucleator further comprises a fatty acid salt; wherein a wt. concentration of said fatty acid salt within said composite is at least about 0.05%.

[0009] In one embodiment, the wt. concentration of said fatty acid salt within said composite is between about 0.05% and about 5%.

[0010] In one embodiment, a wt. concentration of said mineral particle within said composite is at least about 0.1%.

[0011] In one embodiment, the wt. concentration of said mineral particle within said composite is between about 0.1 and 10%.ranging between XX and YY, n and m are each independently between 2 and 10 (e.g. polybutylene adipate-co-terephthalate (PBAT), Polybutylene sebacate-co-terephthalate (PBST).

[0013] In one embodiment, the polyester comprises: any one of Polyhydroxy alkanoate (PHA), Polylactic acid (PLA), polyglycolic acid (PGA), PLGA, caprolactone, including any blend and any copolymer thereof.

[0014] In one embodiment, the fatty acid salt comprises alkali metal salt, alkali earth metal salt or both; and wherein the fatty acid comprises a C5-C20 fatty acid.

[0015] In one embodiment, the plasticizer is a small molecule plasticizer, characterized by MW between 100 and 1000 Da.

[0016] In one embodiment, the small molecule plasticizer comprises any one of: alkyl citrate, acetylated alkyl citrate, epoxidized oil, isosorbide diester oil, alkoxylated carboxylic acid (e.g. Bis(2-(2-butoxyethoxy)ethyl) adipate), citrate oils, and polyol.

[0017] In one embodiment, the mineral particle comprises talc, mica, bentonite, sepiolite, illite, zeolite, palygorskite, attapulgite, smectite, montmorillonite, hectorite, kaolinite, halloysite, or vermiculite, including any combination thereof.

[0018] In one embodiment, the composite material further comprises a biodegradable filler.

[0019] In one embodiment, the biodegradable filler comprises any of: starch, food waste, plant material, waste material, spices, cellulose, and seaweeds.

[0020] In one embodiment, a wt. concentration of said biodegradable filler within said composite is between 0.5 and 10%, and wherein said biodegradable filler comprises starch.

[0021] In one embodiment, a wt. concentration of said plasticizer within said composite is between 10 and 20% and wherein said plasticizer comprises the alkyl citrate.

[0022] In one embodiment, a wt. concentration of said polymeric softener within said composite is between 10 and 30%, and wherein said polymeric softener comprises a polyvinyl ester or a co-polymer thereof.

[0023] In one embodiment, the polyvinyl ester or the co-polymer thereof comprises polyvinyl acetate (PVA), PEVA, or both.

[0024] In one embodiment, a wt. concentration of said nucleator within said composite is between 1 and 10%.

[0025] In one embodiment, a weight ratio between the fatty acid salt and said mineral particle is between 1:2 and 1:8.

[0026] In one embodiment, the mineral particle comprises talc, and said fatty acid salt comprises a stearate salt.

[0027] In one embodiment, a wt. concentration of said fatty acid within said composite is between about 0.5 and about 1.5%.

[0028] In one embodiment, a wt. concentration of said mineral particle within said composite is between about 1 and about 5%.

[0029] In one embodiment, the composite material is characterized by a crystallization temperature (Tc) being at least 5% greater than a Tc of a similar composition devoid of said nucleator.

[0030] In one embodiment, a Tc of said composite is between 68 and 85C.

[0031] In another a[sect, there is a solid foam composition comprising: at least 50% polyester; wherein said polyester is a crosslinked polyester; at least 10 wt.% plasticizer; at least 5 wt.% polymeric softener; and a nucleator; wherein: said plasticizer is in a liquid state at a temperature between -20 and 50°C, said nucleator comprises a mineral particle; and said solid foam composition is characterized by a porosity between 20 and 98%.

[0032] In one embodiment, the nucleator further comprises a fatty acid salt; and wherein a wt. concentration of said fatty acid salt within said solid foam composition is at least about 0.05% and wherein a wt. concentration of said mineral particle within said solid foam composition is at least about 0.3%.

[0033] In one embodiment, the crosslinked polyester is characterized by a crosslinking degree between 0.01 and 80%.

[0034] In one embodiment, the solid foam composition further comprises a biodegradable filler.

[0035] In one embodiment, the solid foam composition is characterized by a density of between 1.2 and 0.02gr / cm3.

[0036] In one embodiment, the solid foam composition is in a form of a molded article, a sponge or a foamed sheet.

[0037] In another aspect, there is a method of making the solid foam composition of the invention, comprising generating a mixture comprising an organic peroxide, said polyester, said plasticizer, said polymeric softener, said nucleator and a foaming agent; shaping said mixture via a thermoplastic polymer processing to obtain a shaped mixture, and inducing (i) foaming of said shaped mixture and (ii) crosslinking of said polyester within said shaped mixture, thereby obtaining said solid foam composition.

[0038] In one embodiment, generating is by compounding said mixture by extrusion; and wherein said shaping and inducing are performed simultaneously or subsequently.

[0039] In one embodiment, crosslinking is performed by providing said shaped mixture to a temperature between 160 and 250C.

[0040] In one embodiment, the steps (i) and (ii) are performed simultaneously or subsequently; and wherein said shaping is performed at a temperature between about 120 and about 180C.

[0041] In one embodiment, a w / w concentration of the organic peroxide in said mixture is between 0.001 and 5%.

[0042] In one embodiment, a w / w concentration of the foaming agent in said mixture is between 0.5 and 20% or between 1 and 20%.

[0043] In one embodiment, a method of making the solid foam composition of the invention, comprising generating a mixture comprising a cross-linking agent, a foaming agent, said polyester, said plasticizer, said polymeric softener, and said nucleator; shaping said mixture via a thermoplastic polymer processing to obtain a shaped mixture, and inducing (i) foaming of said shaped mixture and (ii) crosslinking of said polyester within said shaped mixture, thereby obtaining said solid foam composition.DETAILED DESCRIPTION

[0044] One skilled in the art will realize the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0045] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated.Composite

[0046] In one aspect of the invention, there is provided a composite material comprising at least 50% polyester; at least 8 or at least 10 wt.% plasticizer; at least 5 wt.%polymeric softener; and a nucleator; wherein the plasticizer is in a liquid state at a temperature between -20 (or less) and 50°C.

[0047] As used herein, the term “nucleator” refers to a material that facilitates the formation of nuclei during the crystallization process of the molten composite material. Nucleators significantly enhance the crystallization temperature of the molten composite material. This enhancement in crystallization temperature facilitates faster solidification of the molten material and is highly significant during the manufacturing process of the articles disclosed herein. The article of the invention, in some embodiments thereof is manufactured by hot melt processing. Accordingly, faster solidification rate of the molten composite material reduces the cycle time in manufacturing processes such as hot melt processing, injection molding, 3-D printing and extrusion and foaming. This allows for more units to be produced in a given timeframe, increasing overall production capacity and potentially results in lower production costs. Moreover, articles produced from the compositions containing the nucleators have more uniform and controlled dimensions due to shrinkage and or fine cell structure of foams. Additionally, the inventors have surprisingly observed that the presence of nucleators is essential in particular for 3D printing applications.

[0048] In some embodiments, the crystallization temperature (Tc) of the composite material is at least about 65C, at least about 70C, about 72C, about 75C, about 80C, between about 65 and about 90C, between about 65 and about 85C, or between about 70 and about 90C, between about 70 and about 85C, between about 70 and about 80C, including any range between, wherein the Tc is determined by DSC.

[0049] In some embodiments, the Tc of the composite material of the invention is by at least 10%, at least 20% at least 30%, or between 5 and 50%, between 5 and 40% between 5 and 30%, between 5 and 20%, between 5 and 10%, between 10 and 20%, between 10 and 40%, between 10 and 30% greater than the Tc of a similar material devoid of the nucleator. In some embodiments, the w / w concentration of the nucleator in the composite material is sufficient for increasing the Tc thereof by at least 10%, at least 20%, at least 30%, or between 5 and 50%, between 5 and 40%, between 5 and 30%, between 5 and 20%, between 5 and 10%, between 10 and 20%, between 10 and 40%, between 10 and 30% including any range between, as compared to a similar material devoid of the nucleator.

[0050] In some embodiments, the nucleator is present in the composite material at a concentration of at least 0.05%, at least 0.1%, at least 0.5%, at least 1%, at least 2%, at least 1.5%, or between 0.5 and 10%, between 1 and 10%, between 0.5 and 2%, between 0.2 and 2%, between 0.3 and 2%, between 0.4 and 5%, between 0.4 and 3%, between 0.4 and 2%, between 0.3 and 5%, between 0.3 and 3%, between 0.5 and 5%, between 0.5 and 3%, between 1 and 5%, between 1 and 3%w / w, including any range between.

[0051] In some embodiments, the nucleator comprises one or more materials. In some embodiments, the nucleator comprises at least 2 materials. In some embodiments, the nucleator comprises a mineral particle. In some embodiments, the nucleator comprises a fatty acid salt. In some embodiments, the nucleator comprises the mineral particle and the fatty acid salt. In some embodiments, a weight ratio between the mineral particle and the fatty acid salt within the composite material is between 8:1 and 1: 1, between 8:1 and 2:1, between 6:1 and 1:1, between 6:1 and 2:1, between 5:1 and 2:1, between 6:1 and 3:1, including any range between.

[0052] In some embodiments, the nucleator comprises the fatty acid salt, wherein a wt. concentration of the fatty acid salt within the composite material is at least about 0.05%, at least about 0.1%, at least about 0.2%, at least about 0.5%, at least about 1%, or between about 0.3% and about 5%, between about 0.5% and about 5%, between about 0.3% and about 3%, between about 0.3% and about 2%, between about 0.5% and about 2%, including any range between.

[0053] In some embodiments, the nucleator is or comprises the mineral particle, wherein a wt. concentration of the mineral particle within the composite material is at least about 0.1%, at least about 0.3%, at least about 0.5%, at least about 0.8%, at least about 1%, at least about 1.5%, at least about 2%, or between 0.5 and 10%, between 0.5 and 8%, between 0.5 and 5%, between 1 and 10%, between 1 and 5%, between 0.5 and 3%, between 0.8 and 2%, between 0.8 and 5%, between 0.8 and 3%, including any range between.

[0054] In some embodiments, the nucleator is or comprises the mineral particle and the fatty acid salt, wherein a wt. concentration of the mineral particle within the composite material is between 1 and 10%, between 1 and 5%, between 0.5 and 3%, between 0.8 and 2%, between 0.8 and 5%, between 0.8 and 3%, including any range between; and wherein a wt. concentration of the fatty acid salt within the composite material is betweenabout 0.3% and about 5%, between about 0.5% and about 5%, between about 0.3% and about 3%, between about 0.3% and about 2%, between about 0.5% and about 2%, including any range between. In some embodiments, the nucleator is or comprises the mineral particle and the fatty acid salt, wherein a wt. concentration of the mineral particle within the composite material is between about 1 and about 4%, and wherein a wt. concentration of the fatty acid salt within the composite material is between about 0.5 and about 1.5%. In some embodiments, the nucleator is or comprises the mineral particle and the fatty acid salt, wherein a wt. concentration of the mineral particle within the composite material is between about 1 and about 3%, and wherein a wt. concentration of the fatty acid salt within the composite material is between about 0.5 and about 1%.

[0055] In some embodiments, the mineral particle is characterized by an average particle size between lOOnm and lOOum, between 1 and lOOum, between 10 and 100 um, including any range between.

[0056] In some embodiments, the mineral particle comprises one or more clay particles, such as but not limited to talc, mica, bentonite, sepiolite, illite, zeolite, palygorskite, attapulgite, smectite, montmorillonite, hectorite, kaolinite, halloysite, or vermiculite, including any combination thereof. In some embodiments, the mineral particle consist essentially of talc. In some embodiments, the nucleator consists essentially of talc particles and optionally of fatty acid, wherein a w / w ratio between the talc particle and the fatty acid within the nucleator is between 6:1 and 1:1, between 6:1 and 2:1, between 5:1 and 2:1, between 6:1 and 3:1, including any range between.

[0057] In some embodiments, the fatty acid salt is a solid at a processing temperature of the composite material. In some embodiments, the processing temperature comprises a temperature of hot melt processing, such as injection molding, pelletizing, extrusion and / or 3D-printing. In some embodiments, the fatty acid salt is a solid at a temperature of about 200C.

[0058] In some embodiments, the fatty acid salt is or comprises alkali metal salt, alkali earth metal salt or both. In some embodiments, the fatty acid salt comprises alkali metal or alkali earth metal as a counter cation (e.g. Na, Ca, Rb, Cs, Be, Mg, K, Li, Sr or Ba- cation) or any combination of thereof.

[0059] In some embodiments, the fatty acid salt comprises a C5-C30, C10-C30, C15- C30, C15-C20, C10-C20 fatty acid anion, including any range between. In some embodiments, the fatty acid salt comprises a saturated or unsaturated fatty acid.

[0060] In some embodiments, the fatty acid salt is or comprises a stearate salt. In some embodiments, the stearate salt comprises Na-stearate, Ca-stearate or both.

[0061] In some embodiments, the nucleator comprises the mineral particle and the fatty acid salt as disclosed above, wherein a w / w concentration of the nucleator in the composite material is between 2 and 10%, between 2.5 and 10%, between 3 and 10%, between 2 and 8%, between 2 and 6%, including any range between.

[0062] In some embodiments, the nucleator comprises talc and the fatty acid salt as disclosed above, wherein a w / w concentration of the nucleator in the composite material is between 2 and 10%, between 2.5 and 10%, between 3 and 10%, between 2 and 8%, between 2 and 6%, including any range between.

[0063] In another aspect of the invention, the composite material is biodegradable. In some embodiments, each of the constituents of the composite material is biodegradable. In some embodiments, at least 90%, or between 90 and 100, between 90 and 99, between 95and 99%w / w of the composite material is biodegradable. In some embodiments, the polyester is a biodegradable polymer. In some embodiments, the plasticizer is biodegradable. In some embodiments, the polymeric softener is biodegradable.

[0064] The composite biodegradable polymeric-based material may further include at least lwt.% biodegradable filler configured to stabilize the biodegradable plasticizer inside the polymeric matrix. In some embodiments, the composite material further comprises a biodegradable filler. The biodegradable filler is optionally present within the composite in an amount sufficient for retaining the biodegradable plasticizer inside the polymeric matrix.

[0065] In another aspect, there is provided herein a composite material comprising a biodegradable polymer in a form of a polymeric matrix, the nucleator, optionally at least 1 wt.% biodegradable filler, at least 5 wt.% of the polymeric softener, and at least 8 or at least 10 wt.% plasticizer, wherein the biodegradable filler, the polymeric softener and / or plasticizer are distributed within the polymeric matrix. In some embodiments, the polymeric matrix is a non-crosslinked matrix. In some embodiments, the polymeric matrix is or comprises the polyester disclosed herein. In some embodiments, the polyesteris devoid of cross-linking. In some embodiments, at least 90%, at least 95%, at least 99% by weight of the polyester is a non-crosslinked polyester.

[0066] In some embodiments, the biodegradable filler the polymeric softener and / or plasticizer are homogeneously distributed within the polymeric matrix. In some embodiments, the composite material of the invention is biodegradable. In some embodiments, the composite material of the invention consists essentially of the biodegradable polymer, the biodegradable filler, one or more nucleator, polymeric softener and the biodegradable plasticizer. In some embodiments, the composite material of the invention is a solid at a temperature ranging between -50 and 60°C, between -50 and 40°C, between 40 and 60°C, including any range between.

[0067] In some embodiments, the term “composite material” and the term “biodegradable polymeric based material” are used herein interchangeably.

[0068] In some embodiments, the plasticizer is located within the inner portion of the polymeric matrix. In some embodiments, the outer portion of the polymeric matrix is substantially devoid of the plasticizer and / or of the biodegradable filler. In some embodiments, the plasticizer modifies the mechanical properties of the composite material of the invention. In some embodiments, the composite material of the invention comprises an amount of the plasticizer sufficient to provide elasticity thereto. In some embodiments, the composite material of the invention is elastic material. In some embodiments, the composite material of the invention is an elastic material or is a viscoelastic material. In some embodiments, the weight per weight (w / w) concentration of the biodegradable plasticizer is sufficient to provide elastic or viscoelastic properties to the composite material of the invention.

[0069] In some embodiments, the composite material comprises a single polyester specie, or a plurality of chemically distinct polymers (e.g., a polymer blend). In some embodiments, the polymer of the invention is a thermoplastic polymer. In some embodiments, the polymer of the invention is or comprises a polyester, such as PCL, PLA, PGA, PLGA, PBAT, a polyhydroxyalkanoate (PHA) and its copolymers (e.g., PHB, PHBV, PHHx, etc.), a polyol (e.g. polyvinylalcohol), a polyalkoxylate (e.g. PEG, PPG, etc.), Polybutylene succinate PBS and its copolymers, Polylactic acid PLA and its copolymers or alike, poly vinyl acetate and its copolymers, a starch-based polymer, a polydioxanone, a polyhydroxybutyrate, a polyhydroxyvalerate, a polyphosphoester, apolyamide (e.g. nylon, a polyamino acid) including any copolymer thereof, thermoplastic polyurethane TPU and its copolymers including any copolymer and any combination thereof. In some embodiments, the polyester of the invention is a solid at a temperature ranging between -50 and 60°C, between -50 and 40°C, between 40 and 60°C, including any range between.

[0070] In some embodiments, the polyester is or comprises a poly-terephthalate copolymer. In some embodiments, the polyester is represented by Formula I: A-co-B, wherein A is a polyester and B is a poly-terephthalate. In some embodiments, A is a polyester obtained via a polycondensation of a diol and a di-carboxylic acid.

[0071] In some embodiments, the poly-terephthalate co-polymer is represented by Formula 1:, wherein PT is a poly-terephthalate, x is an integer ranging between 10 and 100, between 10 and 1000, between 50 and 100, between 50 and 500, between 100 and 1000, between 100 and 200, between 200 and 500, between 500 and 1000, between 700 and 1000, n and m are each independently between 2 and 10.

[0072] In some embodiments, the poly-terephthalate co-polymer is or comprises any of: polybutylene adipate-co-terephthalate (PBAT), Polybutylene sebacate-co- terephthalate (PBST), Polyethylene adipate-co-terephthalate (PEAT), Polypropylene adipate-co-terephthalate (PPAT), Polybutylene succinate-co-terephthalate (PBST), and Polyethylene succinate-co-terephthalate (PEST), including any blend thereof.

[0073] In some embodiments, the polyester (e.g. poly-terephthalate co-polymer) is characterized by a Mn between 10000 and 200000Da, between 10000 and lOOOOODa, between 10000 and 60000Da, between 20000 and 80000Da, between 30000 and lOOOOODa, including any range between.

[0074] In some embodiments, the w / w concentration of the polyester (e.g. polyterephthalate co-polymer) within the composite material is at least 50 wt.%, 55 wt.%, 60 w.%, 65 wt.%, 75 wt.% and more, including any range between. In some embodiments, the w / w concentration of the polyester within the composite material is between 50 and80%, between 50 and 75%, between 50 and 60%, between 60 and 75%, between 60 and 80%, between 50 and 70%, including any range between.

[0075] In some embodiments, the plasticizer is non-compatible (e.g. immiscible) with the polyester of the invention. In some embodiments, the plasticizer of the invention is a liquid at a temperature ranging between -80 °C and 80°C, between -40 °C and 60°C, between -30 °C and 60°C, between -20 °C and 60°C, between -40 °C and 50°C, between - 30 °C and 50°C, between -20 °C and 50°C, between -40 °C and 0°C, between -30 °C and 0°C, between 0°C and 60°C, between 0°C and 50°C, between 10 °C and 50°C, including any range between.

[0076] In some embodiments, the plasticizer is a small molecule. In some embodiments, the plasticizer is a small organic molecule having a MW of less than 1,000 Daltons (Da). In some embodiments, the plasticizer has a MW of between 100 and 1,000 Da, between 100 and 300 Da, between 100 and 200 Da, between 200 and 500 Da, between 200 and 1000 Da, between 200 and 300 Da, between 100 and 500 Da, between 100 and 800 Da, between 300 and 500 Da, between 100 and 1,000 Da, between 500 and 800 Da, between 500 and 1,000 Da, between 800 and 1,000 Da, including any range between. Each possibility represents a separate embodiment.

[0077] In some embodiments, the plasticizer is or comprises a single species or a plurality of chemically distinct species. In some embodiments, the plasticizer is or comprises alkyl citrate (e.g. trialkyl citrate, such as Acetyl tributyl citrate (ATBC), triethyl citrate), acetylated alkyl citrate, isosorbide diester (e.g. isosorbide fatty acid ester, such as isosorbide dioctanoate), oil, epoxidized oil (e.g. isopentyl epoxy soyate), alkoxylated carboxylic acid (e.g. Bis(2-(2-butoxyethoxy)ethyl) adipate), citrate oil, oil, a fatty acid, or a fatty acid ester, a mono- or diglyceride, including any ester thereof, and polyol (e.g. glycerol, an oligosaccharide), or any combination thereof.

[0078] In some embodiments, the plasticizer is or comprises any one of: acetyl tributyl citrate (ATBC), triethyl citrate, isopentyl epoxy soyate, bis(2-(2-butoxyethoxy)ethyl) adipate, citrate oils, glycerol, or any combination thereof. Additional biodegradable plasticizers are well known in the art.

[0079] In some embodiments, a w / w concentration of the plasticizer within the composite material of the invention is between 5 and 30%, between 8 and 30%, between 10 and 30%, between 15 and 20%, between 10 and 20%, between 15 and 30%, between5 and 15%, between 5 and 7%, between 5 and 8%, between 8 and 10%, between about 10 and about 30%, between about 10 and about 20%, between about 20 and about 30%, between 5 and 13%, between 13 and 20%, including any range between.

[0080] In some embodiments, the polymeric softener comprises polyvinyl ester and its copolymers. Such polymeric softeners may be used to bond and hold the plasticizer within the polymeric matrix. In some embodiments, the polymeric softener may cause softening of the composite material to the required degree, for example, the degree required by the fashion industry. The term “polyvinyl ester” encompasses a polymer having a linear carbohydrate backbone derived from a vinyl group and pending ester groups (which are not participating in the linkage between the repeating units, contrary to polyesters). The term “polyvinyl ester” may encompass a polymer of Formula:, wherein n represents an integer (such as ranging between 10 and 50.000), and R is H, C1-C30 alkyl (such as methyl) aryl or C1-C30 alkyl-aryl. The term “polyvinyl ester” as used herein may encompass polyvinyl acetate.

[0081] In some embodiments, the polymeric softener (e.g. polyvinyl ester) comprises polyvinyl acetate (PVA), PEVA, polyvinyl laurate, polyvinyl propionate, polyvinyl butyrate, polyvinyl benzoate, and polyvinyl stearate or any combination thereof including any copolymer thereof. In some embodiments, the polymeric softener is characterized by an average molecular weight between 10000 and 500000Da, including any range between.

[0082] In some embodiments, a wt. concentration of the polymeric softener within the composite material is between 10 and 30%, between 10 and 20%, between 15 and 30%, between 10 and 15%, including any range between.

[0083] As known in the art polyvinyl acetate is not considered “biodegradable polymer”. However, the inventors have surprisingly found that adding 10-20 wt.% polyvinyl acetate to the polymeric matrix, when the other polymers are biodegradablepolymers, may result in a biodegradable polymeric composition. Such a composition may fully decompose due to biological processes.

[0084] In some embodiments, the biodegradable polymeric matrix may include polyvinyl ester or any copolymer thereof in a wt.% of 5-35, 5-20, 10-30 of the total weight of the composite material. In some embodiments, the addition of the 20-35 wt.% polyvinyl acetate may cause softening of the biodegradable material to the required degree, for example, the degree required by the fashion industry. In some embodiments, the composite material comprises PBST as the polyester, and talc and stearic acid as the nucleator. In some embodiments, the composite material comprises PBAT as the polyester, and talc and stearic acid as the nucleator. In some embodiments, the composite material comprises PBST or PBAT as the polyester, talc and stearic acid as the nucleator, polyvinyl ester (such as PVA or PEVA) as the polymeric softener and alkyl citrate (e.g. trialkyl citrate, such as Acetyl tributyl citrate (ATBC), triethyl citrate), acetylated alkyl citrate or isosorbide diester as the small molecule plasticizer.

[0085] In some embodiments, the composite material may further include at least 0.5wt.%, at least lwt.%, at least 2wt.% or between 0.5 and 10%, between 0.5 and 5%, between 0.5 and 3%, between 1 and 10%, between 2 and 10%, between 2 and 8%wt. of the biodegradable filler, for example, 3 wt.%, 5 wt.%, and more. In some embodiments, a w / w concentration of the biodegradable filler within the composite material of the invention is between 1 and 10%, between 2 and 10%, between 2 and 7%, between 2 and 5%, between 1 and 6%, between 3 and 6%, between 4 and 8%, between 4 and 6%, between 5 and 10%, including any range between. The biodegradable filler is advantageous for stabilization of relatively large amounts of the liquid plasticizer inside the polymeric matrix,

[0086] In some embodiments, a w / w concentration of the biodegradable filler within the composite of the invention is sufficient to substantially retain the biodegradable plasticizer within the polymer matrix. In some embodiments, a w / w concentration of the biodegradable filler within the composite of the invention is sufficient so as to retain at least 85%, at least 90%, at least 95%, at least 97%, at least 99%, at least 99.5%, at least 99.9% of the initial weight content of the biodegradable plasticizer, including any range between. In some embodiments, a w / w concentration of the biodegradable filler withinthe composite of the invention is sufficient for retaining the biodegradable plasticizer inside the polymeric matrix.

[0087] In some embodiments, a w / w concentration of the biodegradable filler within the composite of the invention is sufficient to substantially prevent leakage of the biodegradable plasticizer from the inner portion of the polymeric matrix.

[0088] In some embodiments, the biodegradable filler may be of natural origin. For example, the biodegradable filler may be selected from, food waste, spices, scent, starch- based products (e.g., cereals), cellulose (e.g., wood flicks), a waste particulate material (e.g. compost and / or wood waste material such as wood chips, sawdust, etc.), a plant material (e.g. flour, buckwheat flour, semolina flour, cornflour, corn starch, corn sledge, rice flour, tapioca flour, potato flour, soy flour, ground flax meal, flax flour, hemp flour), seaweeds and the like. The filler may provide, in addition to stabilizing the plasticizer, also colors (e.g., pigment), smell, and texture to the composite material.

[0089] In some embodiments, additional biodegradable materials may be added to the composite material, for example, natural pigment(s).

[0090] As used herein a “biodegradable material” may be any material configured to substantially (e.g. about 50%, about 70%, about 80%, about 90%, about 95%, 99% or more degradation by weight of the composite material, including any range between) disintegrate by enzymatic (e.g. microbial) decomposition process. In some embodiments, the biodegradable material undergoes degradation so as to result in natural byproducts. In some embodiments, the term "biodegradable" as used herein, also encompasses the term "bioerodible", which describes a composition / article which decomposes under environmental conditions into smaller fractions, thus substantially losing its structure and / or mechanical properties. In some embodiments, the term “bioerosion” refers to erosion of the composition / article initiated by microorganisms, and resulting in at least partial degradation of the composition / article.

[0091] The biodegradable material may be from synthetic and / or natural source. In some embodiments, the bacterial decomposition of the biodegradable material may be a source for naturally hydrocarbon gas.

[0092] In some embodiments, the composite material substantially retains at least 90%, at least 95%, at least 97%, at least 99%, at least 99.5%, at least 99.9% by weightof the plasticizer inside the polymeric matrix, when exposed to a pressure of up to 200 Kg / m2.

[0093] In some embodiments, the composite material or article of the invention is characterized by shore A hardness of at least 70, at least 73, at least 75, at least 80, or between about 75 and about 90, including any range between.

[0094] Shore hardness is measured according to ASTM D2240 for measuring the hardness of polymers, elastomers, and rubbers.

[0095] In some embodiments, the composite material or article of the invention (i.e. non-porous composite, having a porosity below 10%, or below 5%) is characterized by a density of between 1.2 and lgr / cm3, between 1.1 and 1.2gr / cm3, between 1.2 and 0.9gr / cm3, including any range between. In some embodiments, the composite material or article of the invention (i.e. non-porous composite, having a porosity below 10%, or below 5%) is characterized by a density of between 1.2 and lgr / cm3, between 1.1 and 1.2gr / cm3, , including any range between.

[0096] In some embodiments, the composite material is a porous material. In some embodiments, the composite material is a non-porous material. In some embodiments, the composite material is characterized by a porosity between 5 and 98 vol. %, between 5 and 20 vol.%, between 20 and 50 vol.%, between 20 and 95 vol.%, between 30 and 95 vol.%, between 50 and 70 vol.%, between 50 and 98 vol.%, between 70 and 80 vol.%, between 80 and 90 vol.%, between 90 and 99 vol.%, including any range between. In a nonlimiting example, the porosity is between 70 to 85 vol.%. In some embodiments, the porous composite material is characterized by an average pore size between 1 micron to 1 mm, 1 micron to 2 mm, and 0.5 microns to 3 mm, and any value in between.

[0097] In some embodiments, the composite material is substantially water-free. In some embodiments, the composite material comprises a residual amount of water which is naturally included in biodegradable fillers. In some embodiments, the total amount of water in the composite material may not exceed 1.5 wt.%, 1.3 wt.%, 1.2 wt.%, 1 wt.%, 0.8 wt.%, 0.7 w.t%, 0.6 wt.% or less.

[0098] In some embodiments, the composite material is in a form of pellets, granules, or a filament. In some embodiments, the composite material is a masterbatch. In some embodiments, the composite material / masterbatch is a moldable composition. In some embodiments, the moldable composition is suitable for shaping or molding via any ofmethods suitable for thermoplastic polymer processing. In some embodiments, the thermoplastic polymer processing comprises any one of: injection molding, 3D printing and extrusion, including any combination thereof.

[0099] In some embodiments, the composite material may be used to fabricate an article, such as, a final product, semi-finished product or raw material for the fabrication of other products, as discussed hereinbelow. In some embodiments, a semi-finished product may be an extruded flat strand to be used for making belts and raw material may include extruded strips / strands filaments to be fed into a 3D printer for printing the product.

[0100] In some embodiments, the method of making the moldable composition comprises mixing all the constituents of the composite material except the nucleator to obtain a mixture, compounding the mixture, thereby obtaining a first compounded mixture, and subsequently compounding the first compounded mixture and the nucleator, thereby obtaining the moldable composition. In some embodiments, the second compounding is performed at least 12, at least 15, at least 20h after the completion of the first compounding step. The mixture may include the polyester (e.g., terephthalatecopolymer such as PBAT or PBST), the plasticizer, the polymeric softener and optionally the biodegradable filler, as disclosed hereinabove.

[0101] In some embodiments, the method of making the moldable composition comprises a single compounding step, comprising mixing all the constituents of the composite material except the nucleator to obtain a mixture; and compounding the mixture while adding the nucleator, thereby obtaining the moldable composition.

[0102] In some embodiments, any of the compounding steps is performed in an extruder. For example, all the components of the mixture (and optionally the nucleator, in case of the single compounding step) may be inserted into a twin-screw extruder, heated, above the melting or softening point of the polyester to be mixed together to form the moldable composition. In some embodiments, other mixing equipment and techniques may be used for mixing and compounding of the mixture.

[0103] In some embodiments, the moldable composition may be further shaped or molded to form a product. In some embodiments, the shaping or molding step is performed by a thermoplastic polymer processing.

[0104] For example, the moldable composition may be extruded to form elongated (e.g., spools) of trips or strands to be used as final products or raw material for additional products. Alternatively, the moldable composition can be injection molded into a final shape (e.g., footwear). In a nonlimiting example, an injection molding machine can be used for forming final products, such as, flip-flops, smartphone covers, and the like. Additionally or alternatively, the moldable composition in a form of filaments (e.g., strands) can be loaded into a 3D printing machine to be remelted and printed using any known method. In some embodiments, the moldable composition may be extruded into a die to form a film (e.g., a sheet).

[0105] As used herein a “product” may include any article that can be manufactured from polymers, for example, final products (e.g., fashion articles, toys, packages, kitchen tools, disposable dishes, and the like), semifinal products (e.g., threads) and raw materials to be provided for further processing (e.g., filaments for 3D printing). The product can be made using any known production method, such as, extrusion, injection molding, three- dimensional (3D) printing and the like.

[0106] As used herein, a fashion article, may be, a footwear, wallets, belts, bags, smartphone covers, bracelets, and the like.

[0107] In some embodiments, the method may further include foaming the moldable composition, or the product. In some embodiments, foaming is performed after generating the moldable composition, or after the shaping step.

[0108] In some embodiments, the foaming step is performed by introducing a controlled amount of porosity to the moldable composition or to the product / article, wherein the moldable composition or the product / article is in a molten state. For example, a gas such as CO2 may be added into the moldable composition in the molten state (e.g., during the shaping step). In yet another example, any type of foaming agent, such as sodium bicarbonate, and or Azodicarbonamide based compositions, may be added to the moldable composition in any one of the compounding step(s), and then foaming can be induced by inducing gas release from the foaming agent (e.g. via thermal decomposition thereof). In some embodiments, the foaming step comprises heating or providing the moldable composition or the product to a temperature sufficient for gas release from the foaming agent.

[0109] In some embodiments, the amount of porosity of the product depends on the amount of added gas or amount of added foaming agent, for example, between 20 vol.% to 99 vol.%, between 10 vol.% to 99 vol.%, between 30 vol.% to 99 vol.%, between 50 vol.% to 99 vol.%, between 60 vol.% to 80 vol.%, between 40 vol.% to 80 vol.%, between 40 vol.% to 90 vol.%, between 40 vol.% to 95 vol.%, or any range between. In some embodiments, the size of the pores is between 1 micron to 1 mm, 1 micron to 2 mm, and 1 micron to 3 mm, and any value in between.Solid foam

[0110] In another aspect, there is provided a solid foam composition comprising at least 50% polyester; wherein the polyester is a crosslinked polyester; at least 10 wt.% plasticizer; at least 5 wt.% polymeric softener; and a nucleator; wherein the plasticizer, the polymeric softener and the nucleator are as disclosed hereinabove; and wherein the solid foam composition is characterized by a porosity between 20 and 98%. In some embodiments, the w / w concentration and the chemical nature of the entire constituents of the solid foam composition is as described above for the composite material.

[0111] In some embodiments, each of the polymeric chains of the crosslinked polyester is or comprises the polyester as disclosed above, such as terephthalate copolymer. In some embodiments, at least 5%, at least 10%, at least 20%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or between 50 and 99%, between 10 and 99%, between 30 and 99%, between 50 and 95% by weight or by number of the polymeric chains in the solid foam composition are crosslinked, including any range between. In some embodiments, the crosslinked polyester comprises a plurality of polymeric chains crosslinked via C-C bond crosslinks. In some embodiments, the crosslinked polyester is a terephthalate-co-polymer crosslinked via a plurality of C-C bond crosslinks.

[0112] In some embodiments, the crosslinked polyester is characterized by a crosslinking degree between 0.01 and 80%, between 0.01 and 10%, between 10 and 30%, between 0.01 and 5%, between 0.01 and 4%, between 0.01 and 3%, between 0.01 and 2%, between 0.01 and 1%, between 1 and 10%, between 10 and 20%, between 20 and 30%, between 30 and 50%, between 50 and 80%, between 30 and 60%, between 50 and 70%, between 50 and 60%, including any range between. In some embodiments, the termcrosslinking degree encompasses a weight portion of the crosslinked monomers (i.e. monomers of the polymeric chain bound to each other via a CC-bond) relative to the total number of monomers in the sample. Alternatively, term crosslinking degree can be determined based on weight portion remaining insoluble after Soxhlet extraction from an appropriate solvent, such as xylene, toluene, DMSO, DMF, THF, etc.

[0113] In some embodiments, the nucleator comprises the mineral particle and the fatty acid salt as disclosed above, wherein a w / w concentration of the nucleator in the solid foam composition is between 0.5 and 10%, between 0.5 and 1%, between 0.5 and 2%, between 0.5 and 2.5%, between 2.5 and 10%, between 3 and 10%, between 2 and 8%, between 2 and 6%, including any range between.

[0114] In some embodiments, any one of the solid foam composition and the composite material further comprises an additional constituent, selected from the biodegradable filler, a scent, coloring agent, UV-blocking agent, anti-oxidant, etc., including any combination thereof. In some embodiments, a w / w concentration of the one or more additional constituent(s) in the solid foam composition / the composite material is between 0.01 and 10%, between 0.1 and 10%, between 0.5 and 10%, between O.Oland 1%, between 0.1 and 5%, including any range between.

[0115] In some embodiments, the additional constituent comprises lavender oil as a scent; a carotenoid as a coloring agent; titanium dioxide as a UV-blocking agent and / or Vitamin E as an anti-oxidant.

[0116] In some embodiments, the solid foam composition further comprises trace amounts any one of the foaming agent and / or an organic peroxide, or a decomposition product thereof (e.g. decomposition product dicumyl-peroxide is cumene). A foaming agent is usually a solid that creates gas bubbles for foam formation, usually induced by heating. Non-limiting examples of foaming agent include sodium bicarbonate, citric acid, hydrogen peroxide precursor (such as percarbonate), and azodicarbonamide.

[0117] In some embodiments, the solid foam composition is characterized by a density of between 1.2 and 0.02gr / cm3, between 1.1 and 0.02gr / cm3, between 1.2 and 0.8gr / cm3, between 1.2 and 0.5gr / cm3, between 0.1 and 0.02gr / cm3, between 0.2 and 0.02gr / cm3, between 0.3 and 0.02gr / cm3, between 0.5 and 0.02gr / cm3, including any range between.

[0118] In some embodiments, the solid foam composition is shaped in a form of a product, as described hereinabove. In some embodiments, the solid foam composition is shaped in a form of molded article / product, a sponge or a sheet.

[0119] In some embodiments, the method of making the solid foam composition comprises mixing all the constituents of the solid foam composition (i.e. the polyester, the plasticizer, the polymeric softener, the nucleator, and optionally any of the additional constituents) and optionally further the foaming agent and / or the cross-linking agent to obtain a mixture; shaping the mixture to obtain a shaped mixture, and inducing (i) foaming and (ii) polyester crosslinking within the shaped mixture, thereby obtaining the solid foam composition; or wherein the solid foam composition is devoid of the foaming agent and / or the crosslinking agent and wherein the step (i) and / or step (ii) further comprises adding the foaming agent and / or the cross-linking agent to the mixture and / or to the shaped mixture.

[0120] In some embodiments, a w / w concentration of the polyester (such as PBAT and / or PBST) in the mixture is between 50 and 80%, a w / w concentration of the plasticizer (such as alkyl citrate; or the isosorbide diester) in the mixture is between about 5 and about 30% or between about 10 and 30%, a w / w concentration of the polymeric softener (such as PVA and / or PEVA) in the mixture is between 5 and 30% or between 10 and 20%, including any range between as disclosed above.

[0121] In some embodiments, a w / w concentration of the nucleator in the mixture is between 0.5 and 10%, including any range between as disclosed above.

[0122] In some embodiments, the crosslinking agent is or comprises an organic peroxide. In some embodiments, the cross linking agent comprises a bifunctional crosslinking moiety, such as Isocyanate, a Glycidyl, an Ionomer or any combination of thereof. In some embodiments, the crosslinking agent may a liquid or a solid. In some embodiments, the crosslinking agent may comprise the organic peroxide absorbed on a carrier (such as silica, talc, etc.).

[0123] In some embodiments, a w / w concentration of the organic peroxide in the mixture is between 0.001 and 5%, between 0.002 and 5%, between 0.005 and 5%, between 0.01 and 5%, between 0.1 and 5%, between 0.3 and 5%, between 0.5 and 5%, between 0.5 and 3%, between 0.5 and 2%, between 0.1 and 2%, including any range between.

[0124] In some embodiments, a w / w concentration of the foaming agent in the mixture is between 1 and 20%, between 1 and 10%, between 0.5 and 5%, between 0.5 and 10%, between 3 and 5%, between 1 and 3%, between 1 and 5%, including any range between.

[0125] In some embodiments, generating the mixture is performed by compounding. In some embodiments, generating comprises compounding said polyester, said plasticizer, said polymeric softener, said nucleator and optionally any of the additional constituent to obtain a masterbatch. In some embodiments, generating comprises compounding said polyester, said plasticizer, said polymeric softener, said nucleator and one of the crosslinking agent and the foaming agent and optionally any of the additional constituent to obtain a masterbatch. In some embodiments, generating the mixture comprises an additional step of mixing the masterbatch with the organic peroxide and / or the foaming agent.

[0126] In some embodiments, shaping the mixture is performed via a thermoplastic polymer processing. In some embodiments, shaping comprises extrusion or injection molding.

[0127] In some embodiments, the step (ii) is performed by activating the organic peroxide. In some embodiments, the step (ii) is performed by heating the shaped mixture to a temperature suitable for activation of the organic peroxide. In some embodiments, the temperature suitable for activation of the organic peroxide (also referred to herein as “a first temperature) is between 100 and 200°C, between 120 and 200°C, between 110 and 180°C, between 140 and 160°C, including any range between. In some embodiments, the activation encompasses decomposition of the organic peroxide to generate radicals and to initiate polyester crosslinking.

[0128] In some embodiments, the step (i) is performed by heating the shaped mixture to a temperature suitable for initiating gas formation from the foaming agent (also referred to herein as “a second temperature”). In some embodiments, the second temperature is between 120 and 280°C, between 120 and 200°C, between 120 and 180°C, between 120 and 160°C, between 120 and 140°C, between 140 and 200°C, including any range between. In some embodiments, the first temperature and the second temperature are substantially the same.

[0129] In some embodiments, the foaming agent is a gas or a supercritical fluid (e.g. CO2 or N2) step (i) is performed by directing gas flow into the shaped mixture, or by supercritical fluid foaming via introducing the supercritical fluid into the shaped mixture.

[0130] In some embodiments, the steps (i) and (ii) are performed subsequently. In some embodiments, the steps (i) and (ii) are performed simultaneously.

[0131] In some embodiments, the steps (i) and / or (ii) are performed during the shaping step. In some embodiments, the steps (i) and / or (ii) are performed while shaping the mixture. In some embodiments, the steps (i) and / or (ii) are performed subsequently to the shaping step.

[0132] In some embodiments, the organic peroxide is a polymer crosslinking initiator. In some embodiments, the organic peroxide is substantially stable under compounding conditions (i.e. at least 50%, at least 70% or at least 90% of the initial amount of the organic peroxide remains within the mixture after compounding).

[0133] In some embodiments, compounding conditions comprise application of pressure and heating sufficient for compounding of the mixture by extrusion. In some embodiments, compounding is performed by extrusion at a temperature between 110 and 170°C. In some embodiments, the organic peroxide and / or foaming agent is / are added to the mixture after the compounding step (e.g. during the shaping step).

[0134] In some embodiments, at a temperature suitable for shaping the mixture, the organic peroxide is characterized by a half-life greater than the time period required for the completion of the shaping step. In some embodiments, at a temperature between 120 and 170°C the organic peroxide is characterized by half-life between 2 and lOmins.

[0135] In some embodiments, the organic peroxide is activated at a temperature between 100 and 250°C, between 100 and 200°C, between 110 and 250°C, between 120 and 200°C, between 100 and 180°C, between 110 and 190°C, including any range between. In some embodiments, activation of the organic peroxide comprises substantial decomposition into radicals to induce polyester crosslinking, wherein substantial decomposition comprises (i) at least 30%, at least 50%, at least 70%, at least 90%, at least 95% decomposition relative to the initial peroxide amount, and (ii) a crosslinking (or scorching time, i.e. Mooney scorch) of the polyester below 20, below 15, or below 10 min.

[0136] Examples of suitable organic peroxides compatible with the shaping step performed at 100-180°C include but are not limited to Luperox (2,5-dimethyl-2,5-di-(tert- butylperoxy)hexane; 1,3-1 ,4-bis(tertbutylperoxyisopropyl)benzene; n-butyl-4,4-di(tert- butylperoxy) valerate ; 1,1 -di(tert-butylperoxy)- 3 ,3,5 -trimethylcyclohexane ; tert- butylcumylperoxide; Dicumyl peroxide), Benzoyl peroxide, and Di-tert-butyl peroxide.General

[0137] In the discussion unless otherwise stated, adjectives such as “substantially” and “about” modifying a condition or relationship characteristic of a feature or features of an embodiment of the invention, are understood to mean that the condition or characteristic is defined to within tolerances that are acceptable for operation of the embodiment for an application for which it is intended. Unless otherwise indicated, the word “or” in the specification and claims is considered to be the inclusive “or” rather than the exclusive or, and indicates at least one of, or any combination of items it conjoins.

[0138] It should be understood that the terms “a” and “an” as used above and elsewhere herein refer to “one or more” of the enumerated components. It will be clear to one of ordinary skill in the art that the use of the singular includes the plural unless specifically stated otherwise. Therefore, the terms “a”, “an” and “at least one” are used interchangeably in this application.

[0139] As used herein the term “about” refers to ± 10 %.

[0140] The terms “comprises”, “comprising”, “includes”, “including”, “having” and their conjugates mean “including but not limited to”.

[0141] For purposes of better understanding the present teachings and in no way limiting the scope of the teachings, unless otherwise indicated, all numbers expressing quantities, percentages or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0142] In the description and claims of the present application, each of the verbs, “comprise”, “include”, and “have” and conjugates thereof, are used to indicate that theobject or objects of the verb are not necessarily a complete listing of components, elements or parts of the subject or subjects of the verb.

[0143] Other terms as used herein are meant to be defined by their well-known meanings in the art.

[0144] Unless specifically stated or obvious from context, as used herein, the term "or" is understood to be inclusive.

[0145] Throughout this specification and claims, the word “comprise” or variations such as “comprises” or “comprising” indicate the inclusion of any recited integer or group of integers but not the exclusion of any other integer or group of integers.

[0146] As used herein, the term “consists essentially of’ or variations such as “consist essentially of’ or “consisting essentially of’ as used throughout the specification and claims, indicate the inclusion of any recited integer or group of integers, and the optional inclusion of any recited integer or group of integers that do not materially change the basic or novel properties of the specified method, structure, or composition.

[0147] As used herein, the terms "comprises", "comprising", "containing", "having" and the like can mean "includes", "including", and the like; "consisting essentially of or "consists essentially" likewise has the meaning ascribed in U.S. patent law and the term is open-ended, allowing for the presence of more than that which is recited so long as basic or novel characteristics of that which is recited is not changed by the presence of more than that which is recited, but excludes prior art embodiments. In one embodiment, the terms "comprises" "comprising", and "having" are / is interchangeable with "consisting".

[0148] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0149] All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation, or identification of any reference in this application shall not be construed as an admissionthat such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting.EXAMPLE 1Composite material compositions and properties

[0150] The inventors successfully manufactured composite biodegradable polymeric- based formulations according to some embodiments of the invention including the following nucleator(s): 0.5-5%w / w of talc and / or 0.3-2% Na- / Ca-stearate. 3 different formulations have been prepared, including PBAT (BASF), or PBST (BASF) as the polyester, and including various amounts of the nucleator. Table 1 summarizes the formulations.

[0151] Table 1:00152] The formulations (from Table 1) have been manufactured by compounding of the mixture components either in two steps (the nucleator was added in the second compounding step), or in a single compounding step in an extruder.

[0153] The compounded formulations were shaped into samples (e.g. dog bone tensile test samples) by injection molding. The samples were subsequently tested for hardness and Tc. Table 2 summarizes the impact of the addition of nucleators on the physicalproperties of the samples. DSC (Differential Scanning Calorimetry) was performed according to ISO 11357. Shore hardness was measured according to ASTM D2240 for measuring the hardness of polymers, elastomers, and rubbers.

[0154] Table 2:

[0155] As can be seen from Table 2, addition of the nucleator(s) significantly increased the Tc of the samples, compared to a similar (control) sample without the nucleator. Further, it is apparent that a combination of both talc and stearate salt results in a more pronounced Tc increase, as compared to a single nucleator specie (e.g. talc).

[0156] Furthermore, the inventors observed that a combination of talc and stearate salt (1.5-3% talc and 0.5-1% Na-stearate, with a total nucleator concentration of at least 2.5%w / w) was superior for stabilizing composite material-based filament, and for further use thereof for 3D printing. The inventors observed that the addition of nucleators resulted in composite material-based filaments with a uniform cross-section, and further improvedthe filament recovery. Moreover, combined talc and stearate salt based filaments required shorter cooling times, which is advantageous for 3D-pringting process.

[0157] From the other hand, addition of more than 10%w / w nucleators negatively affected the recovery of the filaments. To this end, the inventors postulate that a w / w concentration of between about 2 and 10% is optimal at least for the composite material based filaments disclosed herein.

[0158] Additionally, the inventors induced foaming (physical or chemical) of the abovementioned samples to evaluate the impact of nucleators on the physical stability of the foamed products. The inventors observed that the addition of nucleators combining talc and stearate salt at a w / w concentration of between about 1 and 10% significantly improved physical stability of the foamed samples. Foaming was induced by incorporating a foaming agent into the formulation (either during the compounding step, or during the shaping step).EXAMPLE 2Crosslinked solid foams

[0159] Generally solid foams can be manufactured in a form of foamed sheets or injected molded foamed articles.Foamed Sheets:

[0160] This process is taking place in 2 steps:

[0161] Step 1 - the material is shaped into a form of a sheet using a relevant process, such as cast extrusion. In step 1 , the crosslinking agent and foaming agent are added but not activated or only partially activated. Crosslinking agent can be added as received or as a master-batch (MB). In case of adding the crosslinking agent as MB, the crosslinking agent can be processed with the bio-polymer (2-8% of crosslinking agent in MB). Part of the crosslinking agent or all of it can also be added to the formulation during the compounding process. Crosslinking agent concentration in the foamed sheet is between 0.002 - 2.5% (w / w of the total composite).

[0162] Foaming agent can be added as received or as a MB. In case of adding the foaming agent as a MB, the foaming agent can be processed with the bio-polymer and (20-50% of foaming agent in MB). Foaming agent concentration in the foamed sheet is between 1.5 - 10% (w / w of the total composite). The process temperature of step 1 is 120 - 190 C.

[0163] The result of step 1 is a sheet which is substantially non-crosslinked and not foamed.

[0164] Step 2 - the sheet is processed to activate the crosslinking and foaming agents. In step 2 the sheet formed in step 1 is heated in an oven (170-230 C) for 1-10 min. Step 2 can take place as a continuous step to step 1 to form 1 production line, but can also take place as a separate process.Injected molded foamed products:

[0165] In this process, the composite is mixed with crosslinking agent and foaming agent and injected into a mold.

[0166] Crosslinking agent can be added as received or as a master-batch (MB). In case of adding the crosslinking agent as MB, the crosslinking agent can be processed with the bio-polymer (2-8% of crosslinking agent in MB). Part of the crosslinking agent or all of it can also be added to the formulation during the compounding process. Crosslinking agent concentration in the injection molded article is between 0.002 - 2.5% (w / w of the total composite).

[0167] Foaming agent can be added as received or as MB. In case of adding the foaming agent as MB, the foaming agent can be processed with the bio-polymer and (20- 50% of foaming agent in MB). Foaming agent concentration in the injection molded article is between 1- 10% (w / w of the total composite).

[0168] The inventors successfully manufactured foamed shaped products using both processes disclosed above. Exemplary constituents used for manufacture of such foams are disclosed in Table 3 below.Table 3

[0169] Furthermore, Table 4 summarizes selected properties of the exemplary crosslinked vers, non-crosslinked foams.Table 4

[0170] Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Furthermore, all formulas described herein are intended as examples only and other or different formulas may be used. Additionally, some of the described method embodiments or elements thereof may occur or be performed at the same point in time.

[0171] While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.

[0172] Various embodiments have been presented. Each of these embodiments may of course include features from other embodiments presented, and embodiments not specifically described may include various features described herein.

Claims

CLAIMS1. A composite material comprising: at least about 50%wt. polyester; at least 8 wt.% or at least 10 wt.% plasticizer; at least 5 wt.% polymeric softener; and a nucleator; wherein: said plasticizer is in a liquid state at a temperature between -20 and 50°C, said nucleator comprises a mineral particle.

2. The composite material of claim 1, wherein said nucleator further comprises a fatty acid salt.

3. The composite material of claim 1 or 2, wherein a wt. concentration of the nucleator within said composite is between about 0.5% and about 10%.

4. The composite material any one of claims 1 to 3, wherein a wt. concentration of the polyester within the composite material is between 50 and 80%; and wherein the polyester comprises:wherein PT is poly- terephthalate, x is an integer ranging between 10 and 1000, n and m are each independently between 2 and 10 (e.g. polybutylene adipate-co-terephthalate (PBAT), Polybutylene sebacate-co-terephthalate (PBST).

5. The composite material any one of claims 1 to 3, wherein a wt. concentration of the polyester within the composite material is between 50 and 80%; and wherein the polyester comprises: any one of Polyhydroxy alkanoate (PH A), Polylactic acid (PLA), polyglycolic acid (PGA), PLGA, caprolactone, including any blend and any copolymer thereof.

6. The composite material according to any one of claims 1 to 5, wherein the plasticizer is a small molecule plasticizer, characterized by MW between 100 and 1000 Da; and wherein a wt. concentration of said plasticizer within said composite is between 8 and 30%.

7. The composite material of claim 6, wherein the small molecule plasticizer is or comprises any one of: alkyl citrate, acetylated alkyl citrate, epoxidized oil, isosorbide diester , alkoxylated carboxylic acid, citrate oils, and polyol.

8. The composite material according to any one of claims 1 to 7, wherein the polyester is selected from polybutylene adipate-co-terephthalate (PBAT) and Polybutylene sebacate-co-terephthalate (PBST) and wherein a wt. concentration of the polyester in the composite material is between about 50 and about 70%.

9. The composite material according to any one of claims 1 to 8, wherein a wt. concentration of said polymeric softener within said composite is between 5 and 30%, and wherein said polymeric softener comprises a polyvinyl ester or a copolymer thereof.

10. The composite material of claim 9, wherein said polyvinyl ester or the co-polymer thereof is selected from polyvinyl acetate (PVA), PEVA and a combination thereof.

11. The composite material of claim 10, wherein said polymeric softener is the polyvinyl ester and wherein a wt. concentration of said polymeric softener within said composite is between 5 and about 20%.

12. The composite material according to any one of claims 1 to 11, wherein a wt. concentration of said plasticizer within said composite is between about 10 and about 30% and wherein said plasticizer comprises alkyl citrate; or the isosorbide diester; said polymeric softener is selected from polyvinyl acetate (PVA), PEVA and a combination thereof and a wt. concentration of said polymeric softener within said composite is between 5 and about 20%; wherein the polyester is selected from polybutylene adipate-co-terephthalate (PBAT) and Polybutylene sebacate-co-terephthalate (PBST) and wherein a wt. concentration of the polyester in the composite material is between about 50 and about 70%.

13. The composite material of any one of claims 2 to 12, wherein the fatty acid salt is or comprises alkali metal salt, alkali earth metal salt or both; and wherein the fatty acid is a C5-C20 fatty acid.

14. The composite material according to any one of claims 1 to 13, wherein the mineral particle is or comprises talc, mica, bentonite, sepiolite, illite, zeolite,palygorskite, attapulgite, smectite, montmorillonite, hectorite, kaolinite, halloysite, or vermiculite, including any combination thereof.

15. The composite material according to any one of claims 2 to 14, wherein a weight ratio between the fatty acid salt and said mineral particle is between 1:2 and 1:8.

16. The composite material according to any one of claims 2 to 15, wherein said mineral particle is talc, and said fatty acid salt is a stearate salt.

17. The composite material according to any one of claims 2 to 16, wherein a wt. concentration of said fatty acid within said composite is between about 0.5 and about 2%; and wherein a wt. concentration of said mineral particle within said composite is between about 0.5 and about 5% or between about 1 and about 5%.

18. The composite material according to any one of claims 1 to 17, further comprising a biodegradable filler selected from starch, food waste, plant material, waste material, spices, cellulose, and seaweeds.

19. The composite material according to claim 18, wherein a wt. concentration of said biodegradable filler within said composite is between 0.5 and 10%.

20. The composite material according to claim 18 or 19, wherein said biodegradable filler is or comprises starch.

21. The composite material according to any one of claims 1 to 20, characterized by a crystallization temperature (Tc) being at least 5% or at least 10% greater than a Tc of a similar composition devoid of said nucleator.

22. The composite material according to any one of claims 1 to 21, wherein a Tc of said composite is between 68 and 85C.

23. The composite material according to any one of claims 1 to 22, characterized by a shore A hardness 50-shore D50.

24. The composite material according to any one of claims 1 to 23, characterized by a porosity between 5 and 99%.

25. The composite material according to any one of claims 1 to 24, being in a form of a moldable composition selected from granules, pellets and a filament, wherein said moldable composition is suitable for shaping via a thermoplastic polymer processing.

26. The composite material of claim 25, wherein the moldable composition is manufactured by compounding said polyester, said plasticizer, said polymericsoftener and optionally said biodegradable filler, to obtain a mixture; and compounding said mixture while adding said nucleator, thereby obtaining said moldable composition.

27. The composite material of claim 25, wherein the moldable composition is manufactured by one step compounding of (i) said nucleator and (ii) said polyester, said plasticizer, said polymeric softener and optionally said biodegradable filler.

28. The composite material of any one of claims 25 to 27, wherein said thermoplastic polymer processing comprises any one of: injection molding, 3D printing and extrusion, including any combination thereof.

29. A solid foam composition comprising: at least 50% polyester; wherein said polyester is a crosslinked polyester; at least 10 wt.% plasticizer; at least 5 wt.% polymeric softener; and a nucleator; wherein: said plasticizer is in a liquid state at a temperature between -20 and 50°C, said nucleator comprises a mineral particle; and said solid foam composition is characterized by a porosity between 20 and 98%.

30. The solid foam composition of claim 29, wherein said nucleator further comprises a fatty acid salt; and wherein a wt. concentration of said fatty acid salt within said solid foam composition is at least about 0.05% and wherein a wt. concentration of said mineral particle within said solid foam composition is at least about 0.3%.

31. The solid foam composition of claim 29 or 30, wherein a wt. concentration of the nucleator within said composite is between about 0.5% and about 10%; and wherein said crosslinked polyester is characterized by a crosslinking degree between 0.01 and 80%.

32. The solid foam composition of any one of claims 29 to 31 wherein a wt. concentration of the polyester within the composite material is between 50 and 80%; and wherein the polyester comprises:wherein PT is poly-terephthalate, x is an integer ranging between 10 and 1000, n and m are each independently between2 and 10; or(ii) wherein the polyester comprises: any one of Polyhydroxy alkanoate (PH A), Polylactic acid (PLA), polyglycolic acid (PGA), PLGA, caprolactone, including any blend and any copolymer thereof.

33. The solid foam composition of any one of claims 29 to 32, wherein the plasticizer is a small molecule plasticizer, characterized by MW between 100 and 1000 Da; and wherein a wt. concentration of said plasticizer within said composite is between 8 and 30%; wherein said polymeric softener comprises a polyvinyl ester or a co-polymer thereof; and wherein a wt. concentration of said polymeric softener within said composite is between 5 and 30%.

34. The solid foam composition of claim 33, wherein the small molecule plasticizer is or comprises any one of: alkyl citrate, acetylated alkyl citrate, epoxidized oil, isosorbide diester , alkoxylated carboxylic acid, citrate oils, and polyol.

35. The solid foam composition of claim 33, wherein said polyvinyl ester or the copolymer thereof is selected from polyvinyl acetate (PVA), PEVA and a combination thereof and wherein a wt. concentration of said polymeric softener within said composite is between 5 and about 20%.

36. The solid foam composition of any one of claims 29 to 35, wherein the mineral particle is or comprises talc, mica, bentonite, sepiolite, illite, zeolite, palygorskite, attapulgite, smectite, montmorillonite, hectorite, kaolinite, halloysite, or vermiculite, including any combination thereof.

37. The solid foam composition of any one of claims 30 to 36, wherein the fatty acid salt is or comprises alkali metal salt, alkali earth metal salt or both; and wherein the fatty acid is a C5-C20 fatty acid.

38. The solid foam composition of any one of claims 29 to 37, wherein a wt. concentration of said plasticizer within said composite is between about 10 and about 30% and wherein said plasticizer comprises the alkyl citrate; or theisosorbide diester; said polymeric softener is selected from polyvinyl acetate (PVA), PEVA and a combination thereof and a wt. concentration of said polymeric softener within said composite is between 5 and about 20%; wherein the polyester is selected from polybutylene adipate-co-terephthalate (PBAT) and Polybutylene sebacate-co-terephthalate (PBST) and wherein a wt. concentration of the polyester in the composite material is between about 50 and about 70%.

39. The solid foam composition of any one of claims 29 to 38, optionally further comprising a biodegradable filler; wherein the solid foam composition is in a form of a molded article, a sponge or a foamed sheet and is characterized by a density of is between 1.2 and 0.02gr / cm3.

40. A method of making the solid foam composition of any one of claims 29 to 39, comprising generating a mixture comprising said polyester, said plasticizer, said polymeric softener and said nucleator; shaping said mixture via a thermoplastic polymer processing to obtain a shaped mixture, and inducing (i) foaming of said shaped mixture and (ii) crosslinking of said polyester within said shaped mixture, thereby obtaining said solid foam composition; wherein (a) said mixture and / or said shaped mixture further comprises nucleator and an organic peroxide, a foaming agent.

41. The method of claim 40, wherein said generating is by compounding said mixture by extrusion; and wherein said shaping and inducing are performed simultaneously or subsequently.

42. The method of claim 40 or 41, wherein said crosslinking is performed by providing said shaped mixture to a temperature between 100 and 250C.

43. The method of any one of claims 40 to 42, wherein the steps (i) and (ii) are performed simultaneously or subsequently; and wherein said shaping is performed at a temperature between about 120 and about 180C.

44. The method of any one of claims 40 to 43, wherein a w / w concentration of the organic peroxide in said mixture is between 0.001 and 5%.

45. The method of any one of claims 40 to 44, wherein a w / w concentration of the foaming agent in said mixture is between 1 and 20%.

46. The composite material according to any one of claims 1 to 28, wherein the mineral particle is talc, and optionally wherein fatty acid salt is stearate salt.

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