Compositions, systems and mixtures for manufacturing flexible polyflavonoid based foams, method for manufacturing said foams, and flexible foams obtained thereof

Abstract

The present invention refers to a composition for manufacturing a flexible polyflavonoid based foam comprising at least one vegetable extract comprising polyflavonoids, at least one condensation agent selected from furfuryl alcohol, hexamine and a combination thereof, a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant, optionally at least one oil, at least one dispersing agent comprising at least two hydroxy groups and water. System and mixture comprising said composition, at least one blowing agent and at least one catalyst. A method for manufacturing a flexible polyflavonoid based foam from said composition, system or mixture, and the flexible foam obtained thereof.

Description

[0001] COMPOSITIONS, SYSTEMS AND MIXTURES FOR MANUFACTURING FLEXIBLE POLYFLAVONOID BASED FOAMS, METHOD FOR MANUFACTURING SAID FOAMS, AND FLEXIBLE FOAMS OBTAINED THEREOF

[0002] FIELD OF THE INVENTION

[0003] The present invention refers to a novel aqueous composition comprising at least one vegetable extract comprising polyflavonoids, at least one condensation agent, at least one surfactant, at least one dispersing agent, optionally at least one oil, and water, wherein these ingredients are as defined in this document. This composition is particularly useful for manufacturing flexible polyflavonoid based foams, when used in combination with at least one blowing agent and at least one acid catalyst.

[0004] Thus, the present invention also provides a system for manufacturing flexible polyflavonoid based foams, wherein said system comprises, isolated one to each other, the aqueous composition (component A) according to the invention, at least one blowing agent (component B) and at least one acid catalyst (component C), as well as a mixture comprising said composition in combination with the at least one blowing agent and the at least one acid catalyst, wherein the blowing agent and the acid catalyst are as described in this document.

[0005] The present invention also provides a method for manufacturing a flexible polyflavonoid based foam from the composition, system and / or mixture as described herein, and a flexible polyflavonoid based foam obtained from said composition, system and / or mixture, preferably by the method of the invention.

[0006] Flexible foams according to the invention may be used in a great variety of different industrial applications such as, for example, in packaging, floral foams or thermal insulation of buildings, polymeric devices, pipes or furniture comprising sandwich type panels such as plywood panels, Medium Density Fibreboards (MDF) or the like. Additionally, flexible foams according to the invention can be used in automotive and vehicle's industry in general, as well as in the manufacture of cushion materials such as vehicles seats and wheelchairs, clothing, sport / leisure products or medical materials.

[0007] BACKGROUND OF THE INVENTION

[0008] Polyurethanes (PU) are a broad class of materials such as, for example, foams, fibres, elastomers, coatings, and adhesives commonly used in a broad range of applications. Pll foams (also referred to as PLIFs) are the most commonly used polyurethanes. They are materials of low density and low thermal conductivity and, therefore, are suitable for thermal insulating applications. Pll foams can exhibit a wide range of stiffness, hardness, and density. Among those, flexible Pll foams are especially useful for providing cushioning, support and comfort for furniture, packaging, and components used in transportation, dairy commodities, vehicle materials, clothing, sport / leisure products, medical materials, civil engineering, building materials, and the like. Among these fields of application, particularly in applications of cushion materials such as vehicle seats and wheelchairs, it is required to reduce the hardness felt during initial compression when sitting, and the feeling of shakiness caused by lateral tilting of the occupant's waist, buttocks and the like when traveling on a curve.

[0009] Improvements in passenger compartment comfort continue to be one of the key needs of the global transportation industry. Flexible molded polyurethane foams have successfully contributed to the comfort provided by all forms of transportation seating. However, comfort experience is a combination of many different factors, including the trend towards a density reduction in foams to give the passenger the experience of a softer foam and, at the same time, maintaining the technical performance specifications such as giving sufficient support, which implies having a much harder foam at the bottom.

[0010] Most of the synthesis of PLIFs are still based on the petrochemical industry. However, there are some important issues associated with the oil industry, such as environmental pollution, sustainability, and market instability. Other disadvantages of PLIFs are their low decomposition and flammability temperature (Pll decomposes at about 230 °C and starts to burn between 315°C and 370°C, whereas the fire curve in standardised fire resistance test reaches the order of 1000°C, exceeding the 600°C in just 4 minutes), and the fact that Pll is a flame-spreading compound. With the aim to avoid these problems, the development and use of alternatives based on renewable resources for the manufacture of more environmentally friendly foams is receiving an increasing attention nowadays.

[0011] One of the most promising alternatives to Pll foams are those based on phenolic compound such as polyflavonoids (also referred to as condensed tannins). These polyphenolic based compounds may be obtained from renewable feedstock, in particular, from vegetable biomass. Thus, condensed tannins and their flavonoid precursors are known for their wide distribution in nature and particularly for their substantial concentration in the wood and bark of various trees. These include various Acacia (wattle or mimosa), Schinopsis (quebracho), Tsuga (hemlock), Rhus (sumach), Pinus (pine), Carva illinoinensis (pecan) and Pseudotsuga mesiesii (Douglas fir) species.

[0012] Patent application ITTO201304445 A1 discloses a composition for manufacturing a tannin-based foam material comprising: 35-50 wt. % of tannin, 1-40 wt.% of a condensation agent, 2-8 wt.% of an expanding agent and 4-15 wt.% of a catalyst, wherein the composition is totally formaldehyde-free. According to the disclosure of this patent application, the condensation agent may be, among others, furfural or hexamine, but preferably comprises glutaraldehyde; the expanding agent may be a solvent with a boiling point comprised between 30°C and 70°C; and the catalyst may be an acid catalyst or, preferably, a basic catalyst. Expanded materials obtained from compositions described therein are substantially rigid structures and, therefore, they are not suitable for those application that require some degree of flexibility in the foam.

[0013] According to patent application EP2734560 A1 , prior known formulations used to obtain foam materials containing tannin potentially contain relatively meaningful amounts of formaldehyde, a polluting, toxic and carcinogenic compound. The objective of this patent application is to provide formaldehyde free flavonoid tannin-based foam materials. In order to achieve this goal, formaldehyde present in previous formulations is replaced by a significantly high amount of furfuryl alcohol, thus, EP2734560 A1 discloses a formulation for manufacturing a foam material based on flavonoids tannins comprising an amount of furfuryl alcohol greater than 20 % by weight of the totally formaldehyde- free composition. Furfuryl alcohol is typically characterised by a bad odour and still have some hazard concerns and, therefore, there is still a need to improve the formulation and foams disclosed in this prior art document.

[0014] More specifically, there is still a need to develop flexible polyflavonoid based foams, in particular foams complying with the Indentation Force Deflection test (test B1) of ASTM D3574, a standard test method commonly used in the field of the invention to characterise flexible cellular materials.

[0015] DESCRIPTION OF THE INVENTION

[0016] The inventors surprisingly found that flexible polyflavonoid based foams, i.e., cellular organic polymeric materials complying with the Indentation Force Deflection test (test B1) of ASTM D3574, can be manufactured from the compositions, systems and mixtures described in this document. Thus, the current invention provides some important advantages in the manufacture of foam materials to be used as an alternative to Pll foams, since they can be obtained from renewable resources such as polyflavonoid based polymers, are formaldehyde free, the amount of hazard compounds such as furfuryl alcohol can be reduced or even avoided, are no flammable, and, last but not least, they show the required flexibility to be used in a wide range of different industrial application wherein this parameter is important to avoid the development of cracks in the foam material which may negatively affect its performance.

[0017] Therefore, a first aspect of the invention refers to a composition for manufacturing a flexible polyflavonoid based foam, characterised in that said composition comprises:

[0018] - about 41 wt.% to about 83 wt.% of at least one vegetable extract comprising polyflavonoids;

[0019] - not more than 18 wt.% of a condensation agent selected from furfuryl alcohol, hexamine and a combination thereof;

[0020] - about 0.2 wt.% to about 10 wt.% of at least one surfactant, wherein said surfactant is a non-ionic surfactant or a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant;

[0021] - 0 to about 14 wt.% of at least one oil, preferably a vegetable oil;

[0022] - about 0.1 wt.% to about 28 wt.% of at least one dispersing agent comprising at least two hydroxyl groups; and

[0023] - about 5 wt.% to about 30 wt.% of water; wherein these amounts are expressed by weight with respect to the total amount of the composition, so that the sum of said ingredients is lower to or equal to 100 %.

[0024] In the manufacture of flexible polyflavonoid based foams according to the invention, this composition is used in combination with at least one blowing agent and at least one acid catalyst. In particular, the composition of the invention corresponds to component A of the system and mixture also disclosed in this document.

[0025] The amount of water in the composition of the invention can be adjusted so that the total amount of water in the mixture of the invention, i.e., a mixture comprising said composition (component A), at least one blowing agent (component B) and at least one acid catalyst (component C) will be of about 10 wt.% to about 35 wt.%, preferably of about 15 wt.% to about 30 wt.%. “Flexible” in the frame of the present invention is meant to refer to the ability of the polyflavonoid based foam to bend or to be bent easily without breaking. In particular, it should be understood that a flexible foam in the context of this invention does not show any rupture during the Indentation Forse Deflection (IFD) test according to the method specified in Test B1 of ASTM D3574. More specifically, a flexible foam is a cellular organic polymeric material that does not rupture with a specimen 200 x 25 x 25 mm is bent around a 25 mm diameter mandrel at a uniform rate of one lap in 5 seconds at a temperature between 18 and 29 °C. Moreover, the flexible polyflavonoid based foam according to the invention is capable to recover equal to or higher than 94% of its initial thickness after having been subjected to said method.

[0026] In the frame of this invention, it should be understood that polyflavonoids (also referred to as polyflavonoid based polymers in this document) are polymers which main polyphenolic pattern is formed by flavonoid monomers.

[0027] In particular, polyflavonoid based polymers according to the invention are free from formaldehyde or monomers derived from formaldehyde and, therefore, they are free from phenol formaldehyde resins.

[0028] According to the invention described herein, the composition for manufacturing a flexible polyflavonoid based foam comprises at least one vegetable extract comprising polymers with a polyphenolic pattern mainly formed by flavonoids units with different condensation degree (flavan-3-ol and flavan-2,4-diol) as well as other flavonoids analogs. [Roux DG, Ferreira D, Botha J J. Forest. Products. Journal 26, 27 (1980); Roux DG, Ferreira D, Botha J J. Journal of Agricultural and Food Chemistry 28, 216 (1980); Roux DG, Ferreira D, Hundt HKL, Malan E. Applied Polymer Symposium 28, 335 (1975)]. These biosubstances are known in the art as condensed tannins, as well as polyflavonoids or proanthocyanins polymers.

[0029] The vegetable extract comprising polyflavonoids polymers is preferably selected from mimosa bark extract, quebracho wood extract, hemlock bark extract, sumach bark extract, pine bark extract, pecan nut pith extract, Douglas fir bark extract, oak wood extract and a combination thereof. More preferably, the vegetable extract comprised in the composition of the invention is selected from mimosa bark extract, quebracho wood extract, pecan nut pith extract, pine bark extract and a mixture thereof.

[0030] Compositions according to particular embodiments of the invention comprise at least one vegetable extract comprising polyflavonoids preferably having a Stiasny number of 25% to 100%, more preferably of 40% to 100%. The Stiasny number is a well-known parameter commonly used in the art to determine the polyphenol content, more specifically the formaldehyde-condensable polyphenol content, of vegetable extracts comprising polyflavonoids. This parameter is measured according to the procedure proposed by Yazaki and Hillis (see Yazaki, Y., Hillis, W.E., 1980. Molecular size distribution of radiata pine bark extracts and its effects on properties. Holzforschung 34, 125-130). According to this method, 0.25 g of extract were taken and dissolved in water to a final volume of 25 mL. Next, 2.5 mL of 10 M HCI and 5 mL of 37% formaldehyde solution were added and the mixture was kept at reflux for 30 minutes. Afterwards, the precipitate obtained was separated by vacuum filtration on a filter plate. The precipitate was washed with distilled water until complete removal of formaldehyde and dried in an oven at 105°C until constant weight. The Stiasny number was calculated as the percentage of precipitate obtained from the initial extract.

[0031] Vegetable extracts comprising polyflavonoids used to prepare the composition as described herein may be in solid form or an aqueous solution. In any case, the amount of vegetable extract in the composition of the invention, expressed by weight of solid content of the vegetable extract with respect to the total weight of said composition (component A), is of about 41 wt.% to about 83 wt.%, preferably of about 48 wt.% to about 72 wt.%.

[0032] In addition to the at least one vegetable extract comprising polyflavonoids, the composition of the invention also comprises not more than about 18 wt. %, preferably not more than about 14 % wt.% of a condensation agent selected from furfuryl alcohol, hexamine and a combination thereof, wherein these amounts are expressed by weight of the condensation agent with respect to the total weight amount of the composition (component A). Said condensation agents are capable of inducing the condensation of the polyflavonoids and / or copolymerizing with them.

[0033] Furfuryl alcohol, also known as 2-(hydroxymethyl) furan, 2-furylmethanol or 2- furancarbinol, is a naturally occurring product deriving from catalytic reduction of furfural, that can be obtained as a residual from hydrolysis of sugars of agricultural harvests. Furfuryl alcohol used to prepare the composition as described herein may be in liquid form.

[0034] In any case, the amount of furfuryl alcohol in the composition of the invention, expressed by weight of furfuryl alcohol with respect to the total weight of said composition (component A), is not higher than 18 wt.%, preferably not higher than 14 wt.%, more preferably of about 3 wt.% to about 12 wt.%. In some particularly preferred embodiments, the amount of furfuryl alcohol is of about 7 wt.% to about 12 wt.%, if the composition is oil free, or of about 3 wt.% to about 6 wt.% if an oil as defined in this document is also comprised in the composition of the invention (component A).

[0035] Different to some previously known compositions for manufacturing foams comprising furfuryl alcohol, the composition of the invention provides an important advantage since the amount of this hazardous compound can significantly be reduced (preferably not higher than 10 wt.% in the mixture with the foaming agent and the acid catalyst) or even avoided when hexamine is used instead of furfuryl alcohol. The amount of furfuryl alcohol can also be reduced by adding an oil as defined herein to the composition. In such a case, the amount of furfuryl alcohol may preferably range of about 3 wt.% to about 6 wt.% in the composition for manufacturing flexible polyflavonoid based foams of the invention, i.e., preferably of about 3 wt.% to about 5 wt.% in the mixture of said composition with at least one foaming agent and at least one acid catalyst.

[0036] Inventors surprisingly found that flexible polyflavonoid based foams having compression resistance (measured at 10% strain, EN-826) higher than 70 KPa, preferably of 80 KPa to 250 KPa can be obtained from a composition according to the invention comprising furfuryl alcohol in an amount of about 2 wt.% to about 18 wt.%, preferably about 3 wt.% to about 12 wt.%, more preferably of about 7 wt.% to about 12 wt.%; a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant in an amount of about 0.2 wt.% to about 10 wt.%, preferably of about 1.5 wt.% to about 3.2 wt.%, wherein these amounts are expressed as weight of furfuryl alcohol or surfactant mixture, respectively, with respect to the total weight of the composition (component A); and being said composition free from oils as described in this document.

[0037] These foams have two important qualities that make them particularly suitable to be used as an alternative of commercial XPS foams in the manufacture of sandwich type panels such as plywood panels, Medium Density Fibreboards (MDF) or the like. In the one hand, they have a suitable flexibility (i.e., they have not ruptured during the ASTM D3575 method, test B1 IFD test) and, therefore, cracks can be avoided. On the other hand, these flexible foams possess the required high compression resistance to withstand press conditions required in manufacturing the panels.

[0038] Hexamine, also known as hexamethylenetetramine or methenamine, is a suitable alternative for replacing or reducing the amount of furfuryl alcohol as condensation agent in the manufacture of foam materials according to the invention. Hexamine used to prepare the composition according to the invention may be either in solid form or, preferably, an aqueous solution comprising about 30 wt.% to about 40 wt.% of hexamine.

[0039] In any case, the amount of hexamine in the composition of the invention, expressed by weight of hexamine (on dry basis) with respect to the total weight of said composition, is not higher than 18 wt.%, preferably not higher than 14 wt.%, more preferably of about 1 wt.% to about 6 wt.%. In some particularly preferred embodiments, the amount of hexamine is of about 2 wt.% to about 6 wt.%, if the composition is oil free, or of about 1 wt.% to about 4 wt.% if an oil as defined in this document is also comprised in the composition of the invention (component A).

[0040] Compositions comprising hexamine as condensation agent give rise to more flexible foams than those where furfuryl alcohol is used (i.e. , they typically have a lower IFD at 25 %). Both stability and flexibility of foams obtained using hexamine as a condensation agent can be significantly increased in adding an oil, preferably a vegetable oil, as described in this document. Thus, the composition for manufacturing flexible foams of the invention preferably comprises of about 1 wt.% to about 4 wt.% of hexamine and not higher than about 14 wt. % of an oil, preferably of about 2 wt% to about 4 wt.% of an oil, amounts expressed by weight in relation to the total weight of the composition.

[0041] The condensation agent comprised in the composition of the invention may also be a mixture of furfuryl alcohol and hexamine. In those embodiments, flexibility of the polyflavonoid based foam obtained from that composition can be increased by increasing the amount of hexamine; whereas compression resistance can be increased by increasing the amount of furfuryl alcohol. Therefore, the weight ratio of furfuryl alcohol and hexamine can be adjusted depending on the required properties of the polyflavonoid-based foam to be obtained.

[0042] The surfactant comprised in the composition according to the invention may be at least one no-ionic surfactant or, preferably, a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant. Thus, although flexible foam materials can be obtained from a composition comprising a non-ionic surfactant instead of the surfactant mixture as described herein, using said surfactant mixture is preferred because foam materials with a greater flexibility and consistency can be obtained.

[0043] Furthermore, foam materials with a significantly higher compression resistance (measured at 10% strain, EN-826), in particular higher than 70 KPa, preferably of 80 to 250 KPa, can be obtained from a composition according to the invention comprising of about 2 wt.% to about 18 wt.%, preferably of about 3 wt.% to about 12 wt.%, more preferably of about 7 wt.% to about 12 wt.%, of furfuryl alcohol; and of about 0.2 wt.% to about 10 wt.%, preferably of about 1 .5 wt.% to about 3.2 wt.%, of the surfactant mixture as described herein, wherein these amounts are expressed as weight of furfuryl alcohol or surfactant mixture, respectively, with respect to the total weight of the composition; and being said composition free from oils as described in this document.

[0044] “Non-ionic surfactants” are surfactants that do not bear an electrical charge. Although they do not contain an ionic group as their hydrophilic component, hydrophilic properties are conferred on them by the presence of a number of oxygen atoms in one part of the molecule which are capable of forming hydrogen bonds with molecules of water. For example, many long chain alcohols exhibit some surfactant properties, such as fatty alcohols, cetyl alcohol, stearyl alcohol, and cetostearyl alcohol, and oleyl alcohol. Other non-ionic surfactants are alcohol ethoxylates (in particular primary or secondary alcohol ethoxylates), polyglycol ethers having an average molecular weight higher than 1000 g / mol, polyoxyethylene alkyl ethers, polyalkyl glycol alkyl ethers (e.g., polyethylene and polypropylene glycol alkyl ethers), glucoside alkyl ethers, polyethylene glycol alkylphenyl ethers, glycerol alkyl esters or silicon polyether compounds.

[0045] In some embodiments of the invention, the non-ionic surfactant may be selected from secondary alcohol ethoxylate, ethoxylated fatty alcohol, polyoxyethylene alkyl ester, silicon polyether compound and a combination thereof. Preferably, the non-ionic surfactant comprises a silicon polyether compound which is a blend of dimethicone and polyethylene glycol such as PEG-12 dimethicone, and / or a polysorbate such as polysorbate 80.

[0046] “Anionic surfactants” are surfactants that contain anionic functional groups at their head, such as sulfate, sulfonate, sulfosuccinate, phosphate, and carboxylates. Prominent alkyl sulfates include ammonium lauryl sulfate, sodium lauryl sulfate (sodium dodecyl sulfate, SLS, or SDS), and the related alkyl-ether sulfates sodium laureth sulfate (sodium lauryl ether sulfate or SLES), and sodium myreth sulfate. Also, docusate (dioctyl sodium sulfosuccinate), perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate, sodium naphthalen-2-sulfonate, alkyl-aryl ether phosphates and alkyl ether phosphates are anionic surfactants. Suitable alkyl carboxylates include C12-C22 alkyl carboxylates, such as carboxylates of lauric acid (C12), myristic acid (C14), palmitic acid (C16), stearic acid (C18), oleic acid (C18: 1 ), C20+C22 fatty acids, or a combination thereof.

[0047] In the composition for manufacturing a polyflavonoid based foam according to the invention, the anionic surfactant may be selected from sulfosuccinates, in particular alkyl sulfosuccinates such as dioctyl sodium sulfosuccinate; sulfonates, in particular alkyl aryl sulfonates or aryl sulfonates (more specifically, sodium napthtalene-2-sulfonate); fatty acid salts, in particular alkaline or ethanolamine salts of fatty acids; and a combination thereof. Preferably, the anionic surfactant comprises an alkyl sulfosuccinate such as dioctyl sodium sulfosuccinate; an aryl sulfonate such as sodium napthtalene-2-sulfonate, or a combination thereof.

[0048] The amount of surfactant in the composition of the invention, expressed by weight of surfactant with respect to the total weight of said composition, is of about 0.2 wt.% to about 10 wt.%, preferably of about 1 wt.% to about 6 %wt., more preferably of about 1.3 wt.% to about 3.2 wt.%.

[0049] In those embodiments of the invention wherein the composition for manufacturing a flexible polyflavonoid based foam comprises a surfactant mixture, said mixture preferably comprises of about 1.3 wt.% to about 2.8 wt.% of at least one non-ionic surfactant and about 0.2 wt.% to about 0.5 wt.% of at least one anionic surfactant, amounts expressed as weight of the corresponding surfactant with respect to the total weight of the composition.

[0050] In the composition of the invention, anionic surfactants such as, in particular, fatty acid salts may either be added or obtained in situ by a saponification reaction. The weight percentages indicated refer to the final concentration of surfactants within the composition, independently of whether they were added as such or generated in situ for example by reaction of fatty acids with a base.

[0051] Typical bases which can be added to the composition of the invention to generate the surfactant in situ are those which may be used in a saponification. Such bases may include but are not limited to alkali metal hydroxides such as sodium or potassium hydroxide, preferably sodium hydroxide, or other alkaline compounds such as alkali metal carbonates, alkaline earth hydroxides, ammonia, or organic amines such as an ethanolamine. In particular, the base may be selected from ammonia and an ethanolamine such as monoethanolamine, diethanolamine, triethanolamine or a combination. Preferably, the ethanolamine is diethanolamine.

[0052] The amount of base comprised in the composition of the invention may depend on the amount of surfactant and the base used.

[0053] The composition for manufacturing flexible foams of the invention may comprise at least one oil, preferably a vegetable oil, in an amount equal to or lower than 14 wt.%, preferably in an amount of about 2 wt.% to about 4 wt.%, wherein this amount is expressed as weight of oil with respect to the amount of the composition (component A of the system and mixture according to the invention). The addition of an oil as described in this document to the composition of the invention, either as such or in the form of an aqueous formulation comprising a kinetically stable O / W emulsion or suspension, significantly increase the softness of the foam material, so that foam materials obtained from said composition in combination with at least one blowing agent and at least one acid catalyst as described herein can be considered as super-soft foam material, so that the 25 % IFD may be equal to or lower than 40 N, (measured according to Test B1 of ASTM-D3574-17).

[0054] In more preferred embodiments, said compositions according to the invention can provide foams having a deep down support since the support factor of the foams according to the invention may be higher than 6.

[0055] Another important advantage of adding an oil to compositions according to the invention comprising furfuryl alcohol as condensation agent is that the amount of this agent can be reduced to an amount of about 3 wt.% to about 6 wt.% of furfuryl alcohol with respect to that weight of the composition.

[0056] Said oil may be a vegetable oil such as, for example, but not limited to, soybean oil, palm oil, rapeseed oil, corn oil, sunflower oil, linseed oil, cardanol oil or a mixture thereof. These vegetable oils may be refined, hydrogenated or partially hydrogenated. Besides, recycled oils such as those obtained from cooking and mineral oils such as Bright stock can also be used. Bright stock refers to lube base oils of high viscosity produced by atmospheric distillation and vacuum distillation, then extracting and dewaxing solvents from residual oils, and finally hydro finishing.

[0057] In some embodiments of the invention, the oil is at least one vegetable oil and, more specifically at least one refined vegetable oil with a flash point higher than 260°C, measured according to ASTM D92-18. Said oil may be added to the composition of the invention as a kinetically stable vegetable oil-based formulation, that is also referred to as Vegetable Oil Formulation 1 (VOF1) in this document, and may be an oil in water (O / W) emulsion comprising:

[0058] - about 30 wt.% to about 60 wt.% of at least one refined vegetable oil with a flash point higher than 260°C, preferably higher than 280°C, more preferably of 300°C to 350°C, measured according to ASTM D92-18;

[0059] - about 1 wt.% to about 5 wt.% of at least one anionic surfactant, at least one nonionic surfactant or a combination thereof, wherein

[0060] - the anionic surfactant is selected from aryl sulfonate, (higher than C12) alkyl sulfate, (equal to or higher than C12) alkyl carboxylate, alkaline salt of C10-C15 alkyl-aryl-sulfonic acid and a combination thereof, and - the non-ionic surfactant is selected from primary alcohol ethoxylate, secondary alcohol ethoxylate and a combination thereof, wherein said non-ionic surfactant has a HLB higher than 8;

[0061] - about 0.2 wt.% to about 4 wt.% of at least one rheological additive which is an ionic polysaccharide, preferably selected from the group consisting of gum ghatti, xanthan gum and a combination thereof; and

[0062] - water; wherein the formulation has an active matter content of about 31 wt% and about 69 wt% and the rest of the formulation, until reaching 100 wt.%, is water, the active matter content comprising all the components which are different from water; and wherein the viscosity of the formulation is of about 100 cP to about 1500 cP, preferably about 150 cP to about 1200 cP (25°C, Viscosimeter Brookfield HV, spindle 02).

[0063] Viscosity ranges and values specified in this document are expressed in cP, a well- known viscosity unit commonly used in the technical field of the invention. These viscosity ranges and values can be unambiguously converted to the corresponding ranges and values according to SI Units (Pa s), since that 1 cP is equal to 10'3Pa s. For instance, the emulsion of the invention has a preferred viscosity of 150 cP to 1200 cP, i.e. , of 0.15 Pa s to 1.2 Pa s. The viscosity of the VOF1 can be measured at 25°C using a Brookfield HV Viscometer, in particular DV-1 , preferably spindle 02, at 20 rpm.

[0064] In the frame of the present invention, it should be understood that the expression “refined vegetable oils” refers to crude oils obtained by mechanical or solvent extraction of vegetables, which has been chemically or physically refined to get a better quality, a more acceptable aspect (limpidity), a lighter odour and colour, longer stability and good safety through the elimination of pollutants. Refined vegetable oils may be obtained by conventional processes as those described, for example, in Said Gharbi, The Scientific World Journal, Vol. 2022, Article ID 6627013 (2022). Those refined vegetable oils has not been submitted to any kind of hydrogenation and, therefore, they can also be referred to as non-hydrogenated oils or non-hydrogenated vegetable oils.

[0065] Vegetable oils comprised in the VOF1 described herein are non-hydrogenated oils (i.e., they comprise a high proportion of unsaturated fatty acids), which are liquid in normal conditions (20 °C and 1 atm (101 MPa)). Thus, the refined vegetable oil comprised in the vegetable oil formulation 1 described herein preferably has an iodine value higher of about 50 g iodine per 100 g of oil. The iodine value may be determined following the standard UNE-EN ISO 3961 :2018 Animal and vegetable fats and oils. Determination of iodine value. The refined vegetable oil comprised in the VOF1 preferably is refined soybean oil having a flash point, determined according to ASTM D92-18, higher than 260°C, preferably of about 300°C to about 350°C, and an iodine value, determined according to LINE-EN ISO 3961 :2018, of about 120 g to about 155 g iodine per 100 g of soybean oil.

[0066] In some particular embodiments, the anionic surfactant comprised in the Vegetable Oil Formulation 1 (VOF1) is an aryl sulfonate surfactant, preferably a naphthalene sulfonate surfactant, and more preferably sodium naphthalene sulfonate.

[0067] In some preferred embodiments, the Vegetable Oil Formulation 1 is also characterised in that the oil particles in the emulsion have a gaussian distribution with a Sauter mean diameter (D(3,2)) of about 0.5 pm to about 1.5 pm, preferably of about 0.5 pm to about 1.0 pm, measured by laser diffraction in a Mastersizer 300 equipment.

[0068] “Sauter mean diameter”, also designated as D(3,2), D32 or D(32) is the mean diameter with the same ratio of volume to surface area as the entire ensemble. It was originally developed by German scientist Josef Sauter in the late 1920s. The size of drops is determined based on the absorption / scattering of light. The technique depends on the fact that absorption / scattering is proportional to the surface area of the drops.

[0069] In some other embodiments of the invention, the vegetable oil comprised in the composition for manufacturing a flexible polyflavonoid based foam is a combination of hydrogenated or partially hydrogenated palm oil, soy oil and, optionally paraffin, which can be added to the composition of the invention as a kinetically stable vegetable oilbased formulation defined in patent EP3519505 B1. This formulation is also referred to as Vegetable Oil Formulation 2 (VOF2) in this document and may comprise an O / W emulsion or suspension, which further comprises:

[0070] - from 1 wt.% to 5 wt.% of surfactant, preferably from 2 wt.% to 3 wt.%, the surfactant being one or more selected from anionic and non-ionic surfactants, the surfactant being added as such or obtained in situ by addition of between 1 wt.% and 3 wt.% of an ethanolamine, preferably between 1 wt.% and 2 wt.%;

[0071] - 15 wt.% to 50 wt.% of hydrogenated or partially hydrogenated palm oil, preferably from 33 wt.% to 39 wt.%;

[0072] - from 0 to 25 wt.% of paraffin;

[0073] - from 2 to 8 wt.% of soy oil, preferably from 4 wt.% to 8 wt.%; wherein the total amount of oil, being the sum of palm oil, paraffin and soy oil in the O / W suspension does not exceed 55 wt.%; wherein, within the total amount of oils, from 2 wt.% to about 10 wt.% is nonhydrogenated oil, preferably from 3 wt.% to 6 wt.%, and the rest is hydrogenated and / or partially hydrogenated oil; and wherein the O / W suspension has a solids content of between 30 wt.% and 55 wt.%, preferably between 45 wt.% and 55 wt.%, and the rest of the suspension, until reaching 100 wt.%, is water, the solids content comprising all the components of the O / W suspension which are different than water.

[0074] As noted above, the terms “suspension” and “emulsion” in the context of the VOF2 are used indistinctly, as the oily particles in the aqueous phase of said formulation, at normal temperature and pressure conditions, are often in the solid state.

[0075] The ethanolamine may be selected for example, but not limited to, from monoethanolamine, diethanolamine, triethanolamine or a combination thereof. Preferably, the ethanolamine is diethanolamine.

[0076] The iodine value of the total amount of oils in this vegetable oil-based formulation (VOF2) is preferably above 10 g of iodine per 100 g of the total amount of oils, since the suspensions and thus the formulations therewith obtained are kinetically much more stable than if the iodine value is below 10.

[0077] In some embodiments, the soy oil in the formulation according to these embodiments (VOF2) is non-hydrogenated soy oil, having an iodine value ranging from 120 to 155 gr iodine per 100 gr of soy oil.

[0078] Preferably, the VOF2 does not comprise paraffin.

[0079] The surfactant of the VOF2 may be a mixture of at least one non-ionic surfactant and at least one anionic surfactant. In some embodiments of the invention, the non-ionic surfactants preferably are alcohol ethoxylates, whereas the anionic surfactants preferably are C12-C22 alkyl carboxylates such as the carboxylates of lauric acid (C12), myristic acid (C14), palmitic acid (C16), stearic acid (C18), oleic acid (C18:1), or C20+C22 fatty acids. Preferably, the anionic surfactant is a mixture of diethyl ammonium carboxylate of palmitic acid, stearic acid and C20-C22 fatty acids.

[0080] In the VOF2 as defined herein, preferably at least about 50 wt.% of the fatty acids in the total amount of oil are fatty acids have from 20 to 22 carbon atoms. In the case not sufficient fatty acids of said length are contained in the oils used as raw materials, fatty acids having 20 to 22 carbon atoms may be added to the formulation, until the indicated percentage is reached. In the composition according to the invention, the O / W suspension comprised in the VOF2 preferably has a solids content of between 30 wt.% and 55 wt.%, preferably 50 wt.%, and the rest of the suspension, until reaching 100 wt.% of the O / W suspension, is water, the solids content comprising all the components which are different than water.

[0081] In particular embodiments of the invention, the VOF2 comprised in the composition (component A) according to the invention may be a product manufactured by the Spanish company FORESA, S.A. (http: / / www.foresa.com / en), offered under the denomination BIOWAX.

[0082] The composition for manufacturing flexible polyflavonoid based foams of the invention comprise of about 0.1 wt.% to about 28 wt.%, preferably of about 12 wt.% to about 22 wt.%, of at least one dispersing agent having at least two hydroxyl groups (i.e., said agent can be also identified as a polyol o polyhydric alcohol having dispersing function), wherein these percentages are expressed as weight of said agent with respect to the amount of the composition.

[0083] Suitable dispersing agent having at least two hydroxyl groups may be, for example, but not limited to, polyhydric alcohols such as those selected from the group consisting of ethylene glycol, propylene glycol, 1 ,3-propanediol, 1 ,2-butylene glycol, 1 ,3-butylene glycol, 1 ,4-butanediol, 2-methyl-1 ,3-propanediol, 1 ,6-hexanediol, pentaerythritol, sorbitol, neopentyl glycol, glycerol, trimethylolpropane, 2,2,4,4-tetramethyl-1 ,3- cyclobutanediol, 3-methyl-1 ,5-pentanediol, 1 ,4-cyclohexanedimethanol, 1 ,3- cyclohexanedimethanol, bisphenol A ethoxylates, diethylene glycol, tetraethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, pentaerythritol, glycerol, trimethylolpropane, polyethylene glycols having an average molecular weight up to 1000 g / mol, block or random copolymers of ethylene oxide and propylene oxide having at least two hydroxyl groups and an average molecular weight up to 1000 g / mol, and mixtures thereof. Preferably, the dispersing agent is glycerol, diethylene glycol or a combination thereof; more preferably said dispersing agent is diethylene glycol.

[0084] Addition of this essential ingredient to the composition of the invention helps to solubilize the polyflavonoids in the liquid medium, which is important due to the fact a reduced amount of water is required in the mixture of the invention in order to the foaming process takes place properly. Furthermore, a polyol as described in this document, preferably if selected from glycerol, diethylene glycol and a combination thereof, is also essential to impart the required flexibility to the foams and, therefore, avoid the formation of cracks.

[0085] Diethylene glycol provides the additional advantages that more flexible, soft and homogeneous foam materials can be obtained from a composition comprising of about 0.1 wt.% to about 28 wt.% of this compound, preferably of about 12 wt.% to about 22 wt.%, even if manufactured at a large scale.

[0086] The composition of the current invention may optionally include other ingredients such as odour scavenger, fragrances, biocides, thickeners and / or bases. One or more of these additives may be added to the composition of the invention just before its use or they may be added previously, for example during the manufacturing of the composition, provided that none of these further additives negatively affect the stability of the composition of the invention during storage.

[0087] In particular embodiments, the composition of the invention may comprise of about 17 wt.% to about 30 wt.%, of water, wherein this amount is expressed as weight with respect to the amount of the composition. As previously mentioned, the amount of water in the composition as described herein is preferably adjusted so that the water content of the mixture comprising said composition (component A), at least one blowing agent (component B) and at least one acid catalyst will be of about 10 wt.% to about 35 wt.%.

[0088] A further object of the present invention refers to a system for manufacturing a flexible polyflavonoid based foam comprising, isolated one of each other:

[0089] - Component A: the composition as defined in this document,

[0090] - Component B: at least one blowing agent, and

[0091] - Component C: at least one acid catalyst.

[0092] In particular embodiments, the system for manufacturing a flexible polyflavonoid based foam of the invention comprises, isolated one of each other:

[0093] - Component A: about 72 wt.% to about 98.5 wt.% of the composition as defined in this document,

[0094] - Component B: about 0.5 wt. % to about 5 wt.% of at least one blowing agent, and

[0095] - Component C: about 1 wt.% to about 23 wt.% of at least one catalyst acid, wherein these amounts are expressed as weight of the composition, the blowing agent or the acid catalyst, respectively, with respect to the total amount of the system, so that the sum of components A, B and C is lower to or equal to 100 %.

[0096] “Blowing agent” in the frame of the present invention refers to a solvent or substance that can generate gas in situ. In particular, a solvent or substance having a boiling point of about 35°C to about 120°C, preferably of about 30°C to about 70°C. Suitable blowing agents may be, for example, but not limited to, n-pentane, isopentane, cyclopentene, cyclohexane, hexane, isohexane, heptane, diethyl ether or combinations thereof. Preferably, the blowing agent is isohexane because of its high-efficiency as foaming agent / blowing agent and its boiling point (about 60°C), which enables the manufacture of the flexible foams according to the invention in a controller manner, in particular at industrial scale.

[0097] Thus, the system of the invention may comprise, as component B, about 0.5 wt. % to about 5 wt.% of at least one blowing agent which preferably is a solvent or substance having a boiling point of about 35°C to about 120°C, preferably of about 30°C to about 70°C, wherein said blowing agent preferably is isohexane. In some particular embodiments, component B is at least one blowing agent as defined herein, in an amount of about 1 .8 wt.% to about 3.8 wt.%, wherein these amounts are expressed with respect of the total amount of the system, i.e., with respect to the sum of components A, B and C.

[0098] “Acid catalyst” in the frame of the present invention refers to any acid substance capable to favour the polymerization of the polyflavonoids and the condensation agent thus producing the polymeric matrix of the flexible polyflavonoid based foam materials of the invention. Suitable acid catalyst may be, for example, but not limited to, phenol sulfonic acid, p-toluensulfonic acid, xylenesulfonic acid, phenolsulfonic acid, benzenesulfonic acid, trichloroacetic acid, boric acid, phosphoric acid, sulfuric acid and mixtures thereof. Preferably, the acid catalyst is phenol sulfonic acid.

[0099] Thus, the system of the invention may comprise, as component C, about 1 wt. % to about 23 wt.% of at least one acid catalyst, preferably phenol sulfonic acid. In some particular embodiments, component C is at least one acid catalyst as defined herein, in an amount of about 8 wt.% to about 14 wt.%, wherein these amounts are expressed with respect of the total amount of the system, i.e., with respect to the sum of components A, B and C.

[0100] In a further aspect, the invention refers to a mixture for manufacturing a flexible polyflavonoid based foam, wherein said mixture comprises components A, B and C as described in this document.

[0101] In particular embodiments, the mixture for manufacturing a flexible polyflavonoid based foam of the invention comprises:

[0102] - about 40 wt.% to about 60 wt.% of at least one vegetable extract comprising polyflavonoids;

[0103] - not more than 13 wt.%, preferably not more than 10 wt.%, of a condensation agent selected from furfuryl alcohol, hexamine and a combination thereof;

[0104] - about 0.2 wt.% to about 7 wt.% of at least one surfactant, wherein said surfactant is a non-ionic surfactant or a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant; - 0 to about 10 wt.% of at least one oil, preferably a vegetable oil;

[0105] - about 0.1 wt.% to about 20 wt.% of at least one dispersing agent having at least two hydroxyl groups, preferably diethylene glycol, glycerol or a combination thereof;

[0106] - about 0.5 wt.% to about 5 wt.% of at least one blowing agent, which preferably is isohexane;

[0107] - about 1 wt.% to about 23 wt.% at least one acid catalyst, which preferably is phenol sulfonic acid; and

[0108] - about 10 wt.% to about 35 wt.% of water; wherein these amounts are expressed by weight with respect to the total weight amount of the mixture, so that the sum of said ingredients is lower to or equal to 100 %.

[0109] In more particular embodiments, the mixture for manufacturing a flexible polyflavonoid based foam of the invention comprises:

[0110] - about 43 wt.% to about 53 wt.% of at least one vegetable extract comprising polyflavonoids;

[0111] - a condensation agent selected from: about 3 wt.% to about 10 wt.% of furfuryl alcohol, and about 1 wt.% to about 5 wt.% hexamine;

[0112] - at least one surfactant, wherein said surfactant is: about 1.2 wt.% to about 2.3 wt.% of a non-ionic surfactant, or about 1 .4 wt.% to about 2.7 wt.% of a surfactant mixture comprising about 0.2 wt.% to about 0.45 wt.% at least one anionic surfactant and about 1.2 wt.% to about 2.3 wt.% of at least one non-ionic surfactant;

[0113] - 0 or about 1.5 wt.% to about 3 wt.% of at least one oil, preferably a vegetable oil which may be added as such or as an aqueous formulation, in particular VOF1 or VOF2 as defined herein;

[0114] - about 11 wt.% to about 18 wt.% of at least one dispersing agent having at least two hydroxyl groups, preferably diethylene glycol, glycerol or a combination thereof;

[0115] - about 1.8 wt.% to about 3.8 wt.% of at least one blowing agent, which preferably is isohexane; - about 8 wt.% to about 14 wt.% at least one acid catalyst, which preferably is phenol sulfonic acid; and

[0116] - about 15 wt.% to about 30 wt.% of water; wherein these amounts are expressed by weight with respect to the total weight amount of the mixture, so that the sum of said ingredients is lower to or equal to 100 %.

[0117] A further object of the present invention is a method for manufacturing a flexible polyflavonoid based foam from the composition, system and / or mixture as described in this document. More specifically, the present invention provides a method for manufacturing said flexible foam material from a composition as described herein in combination with at least one blowing agent and at least one acid catalyst, wherein the method comprises the following steps: i) preparing a composition (component A) as described in this document by: i-1) mixing the required amounts of the following ingredients: a. a condensation agent selected from furfuryl alcohol, hexamine and a combination thereof, b. at least one surfactant, wherein said surfactant is a non-ionic surfactant or a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant; c. optionally, an oil, preferably a vegetable oil; d. at least one dispersing agent having at least two hydroxyl groups; and e. water; and stirring until a first homogeneous intermediate mixture is obtained; i-2) adding the required amount of at least one vegetable extract comprising polyflavonoids and stirring until homogenisation, thus obtaining the composition according to the invention as described herein (component A); ii) adding the required amount of the at least one blowing agent (component B) and stirring until a second homogeneous intermediate mixture (components A + B) is obtained; iii) adding the required amount of at least one acid catalyst (component C) and stirring until a homogeneous mixture is obtained and the temperature of said mixture reach about 35 °C to about 120 °C, with the proviso that the temperature is not higher than the boiling point of the blowing agent; for instance, if the blowing agent is isohexane, the temperature of the composition can be adjusted to about 40 °C to 60°C; the mixture thereby obtained corresponds to the mixture of components A, B and C as described in this document; and iv) maintaining the mixture of step iii) at a temperature of about 35°C to about 120°C for at least 30 min, with the proviso that the temperature is not lower than 10°C below the boiling point of the blowing agent, thus obtaining a flexible polyflavonoid based foam as defined in this document; for instance, if the blowing agent is isohexane, the temperature of the mixture in step iv) can be adjusted to preferably about 50°C to about 90°C.

[0118] “Required amounts” as specified in the method for manufacturing a foam materials according to the invention should be understood as the amount of each of the ingredients this expression refers to which is needed to obtain a flexible foam from the composition, system or mixture as described in this document. From the disclosure of the invention a skilled person could directly an easily determine these amounts.

[0119] In the frame of this invention it should be understood that “homogenisation” can be visually determined. Thus, it is considered that homogenisation is achieved in steps i-2), ii) or iii) when neither different phases nor suspended particles can be visually observed in a sample of the composition of step i-2), the second intermediate mixture of step ii) (components A + B) or the mixture of step iii) (components A+B+C), respectively.

[0120] The flexible foams of the invention may be manufactured sequentially adding each of the ingredients comprised in the composition of the invention (component A) except for the vegetable extract comprising polyflavonoids to water, under stirring or equivalent means of mixing, so that homogenisation of the ingredient added is achieved before starting the addition of the next. Optionally, further additives such as odour scavenger, fragrances, biocides, thickeners and / or bases may also be added at this step of the method. First homogeneous intermediate mixture obtained in step i-1) can be stored at least 15 days at a temperature of about 20 °C to about 30 °C before continuing with the method of the invention without jeopardizing properties of the flexible foam obtained.

[0121] The at least one vegetable extract comprising polyflavonoids may be added to the first homogeneous intermediate mixture in solid form or as an aqueous solution. In those embodiments wherein an aqueous solution of vegetable extract is used, it may be a commercially available solution or, alternatively, it may be prepared in house from a solid vegetable extract or from an aqueous solution of vegetable extract with a different solid content. In any case, said extract may be added all at once or gradually, provided that the stirring rate is enough to achieve homogenisation before continuing with the method. Then, the composition according to the invention may be mixed with at least one blowing agent and at least one acid catalyst as described in this document. In particular, the composition obtained in step i-2) may be adjusted at a temperature of about 30°C to about 10°C lower than the boiling point of the at least one blowing agent, which may be a solvent or substance having a boiling point of about 35°C to about 120°C, preferably of about 30°C to about 70°C, more preferably said blowing agent is isohexane.

[0122] After that, the required amount of the at least one blowing agent (component B), preferably isohexane, may be added to the composition and the second intermediate mixture comprising the composition (component A) and the blowing agent (component B) is stirred until homogenisation of the blowing agent in said intermediate mixture is achieved. Then, the required amount of at least one acid catalyst as defined herein (component C) may be added and the mixture according to the invention (components A, B and C) is stirred until homogenisation.

[0123] Said mixture may be adjusted at a temperature of about 35 °C to about 120 °C, with the proviso that said temperature is not higher than the boiling point of the blowing agent, to initiate the expansion process. The mixture may then be poured in a container adapted to be heated at the required temperature and introduced into an oven to be heated at a temperature of about 35 °C to about 120 °C, with the proviso that the temperature is not lower than 10°C below the boiling point of the blowing agent, for a period of at least 30 min, preferably of 25 min to 2 h, to finish the expansion process and begin the curing process.

[0124] In those particular embodiments wherein the blowing agent is isohexane, the temperature in step iii) is preferably adjusted of about 40 °C to about 60 °C and, once a homogeneous mixture is obtained, said mixture can be introduced and left at a temperature of about 75°C for a period of at least 30 min, preferable from 25 min to 2 h, to finish the expansion process and begin the curing process.

[0125] The flexible polyflavonoid based foam material of the invention thus obtained is finally dried at a room temperature (i.e., a temperature of 20 °C to 30°C).

[0126] A further object of the present invention refers to the use of the composition, the system or the mixture disclosed in this document for manufacturing flexible polyflavonoid based foams, preferably according to the method as also described in this document.

[0127] The present invention also refers to the flexible polyflavonoid based foams obtained or obtainable from the composition, the system or the mixtures as disclosed in this document, preferably when they are obtained or obtainable by the method of the invention as also described in this document.

[0128] Advantageously, flexible polyflavonoid based foams according to the invention do not show any rupture during the Indentation Forse Deflection (IFD) test according to the method specified in Test B1 of ASTM D3574. More specifically, a flexible foam is a cellular organic polymeric material that does not rupture with a specimen 200 x 25 x 25 mm is bent around a 25 mm diameter mandrel at a uniform rate of one lap in 5 seconds at a temperature between 18 and 29 °C. Moreover, the flexible polyflavonoid based foam according to the invention is capable to recover equal to or higher than 94% of its initial thickness after having been subjected to said method.

[0129] In particular embodiments, the flexible polyflavonoid based foam obtained from the composition, system and / or mixture described herein, preferably when they are manufacture according to the method of the invention as also described herein, may be a super-soft foam, i.e., a foam having a 25% IFD less than 40 N. determined according to test B1 of ASTM D3574. High values of the Indentation Force Deflection (IFD) test imply higher hardness, whereas low IFD results indicate soft foam materials.

[0130] Inventors found that the addition of an oil, preferably a vegetable oil, to the composition of the invention (component A) significantly increases flexibility of the foam material obtained, so that the 25% IDF (determined according to test B1 of ASTM D3574) of said foam can be reduced to 30 N or less. Even more surprisingly, the inventors found that the composition, system and / or mixture of the invention comprising the combination of a surfactant mixture further comprising at least one non-ionic surfactant and at least one anionic surfactant as described herein, and a vegetable oil, preferably wherein said oil is added as a kinetically stable formulation such as VOF1 or VOF2, can be used in the manufacturing of polyflavonoid based foams having a 25% IDF (determined according to test B1 of ASTM D3574) equal to or lower than 22 N, more preferably equal to or lower than 15. Thus, the addition of a vegetable oil to said composition, system and / or mixture is able to reduce IDF of the foam obtained in more than a about 40 %, more preferably more than about 70 %.

[0131] A second parameter that can be used to characterise foam materials according to the invention is the IFD at 65 % of its original height. This second IFD measurement can be used to help determine the ability of the foam to provide deep down support. Typically, the more difference between the 25 % IFD and the 65 % IFD, the more ability the foam has to support weight. The ratio of the 65 % IFD divided by the 25 % IFD is known as foam’s support factor. It is possible to specify a low 25% IFD on a foam with a high support factor to create extra surface softness without causing the foam to “bottom out” when weight is applied. *[(PFA) Polyurethane foam association 2016]

[0132] Thermal conductivity is directly linked to energy efficiency. The lower the thermal conductivity of a product such as foam material, the better its property in preventing heat flow and the more efficient it will be in preventing heat loss. Flexible polyflavonoid based foams according to the invention preferably have a thermal conductivity of about 40 mW / mK to about 45 mW / mK (measured according to UNE-EN-12667). Said thermal conductivity is suitable enough for the foam materials of the invention to be efficiently used in thermal insulation products.

[0133] Compression resistance of a foam material can be measured by the compressive stress at 10% strain test (measured according to EN-826). As previously mentioned in this document, inventors surprisingly found that flexible foams having compression resistance (measured at 10% strain, EN-826) higher than 70 KPa, preferably of 80 KPa to 250 KPa can be obtained from a composition according to the invention comprising furfuryl alcohol in an amount of about 2 wt.% to about 18 wt.%, preferably of about 3 wt.% to about 12 wt.%, more preferably of about 7 wt.% to about 12 wt.%; and a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant in an amount of about 0.2 wt.% to about 10 wt.%, preferably of about 1.5 wt.% to about 3.2 wt.%, wherein these amounts are expressed as weight of furfuryl alcohol or surfactant mixture, respectively, with respect to the total weight of the composition (component A); and being said composition free from oils as described in this document.

[0134] These foams have several important qualities that make them particularly suitable to be used as an alternative of commercial XPS foams in the manufacture of sandwich type panels. More specifically, they have a suitable flexibility ( / .e., they have not ruptured during the ASTM D3575 method, test B1 IFD test) and, therefore, cracks can be avoided. Additionally, these flexible foams possess the required high compression resistance to withstand press conditions required in sandwich type panels manufacturing. And, last but not least, they are not flammable.

[0135] Further object of the invention refers to the use of the flexible polyflavonoid based foam materials described in this document, preferably when obtained or obtainable by the method also described herein, in packaging, floral foams or as thermal insulator, for example, but not limited to, in thermal insulation of buildings, polymeric devices or pipes. Flexible foams according to the invention, in particular those having a low IDF 25 % value and a higher support factor, can be used in automotive and vehicle's industry in general, as well as in the manufacture of cushion materials such as vehicles seats and wheelchairs, clothing, sport / leisure products or medical materials.

[0136] Additionally, those foams obtained from a free-oil composition, system and / or mixture comprising furfuryl alcohol in combination with a surfactant mixture may be used in the manufacture of furniture comprising sandwich type panels such as plywood panels, Medium Density Fibreboards (MDF) or the like; and foams obtained from a composition, system and / or mixture comprising hexamine may be used as floral foams.

[0137] The term “about” when used in the context of the present invention preceding a number and referring to it, is to be understood as designating any value lying within the range defined by the number ±5%, more preferably a range defined by the number ±2%. For example, the expression “about 10” should be construed as “within the range of 9.5 to 10.5”, preferably “within the range of 9.8 to 10.2”.

[0138] Through the description and the claims, the word “comprises” and variations thereof are not intended to exclude other technical features, ingredients or steps. Additional advantages and features of the invention will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the invention without undue burden.

[0139] BRIEF DESCRIPTION OF THE FIGURES

[0140] Figure 1 shows different images of foam samples. Figure 1a shows a sample according to the invention during the IFD process; figure 1b shows different samples of foams according to the invention after the I FD process; figures 1 c and 1 d show no flexible foams (no part of the invention) after the IFD process, and figure 1e shows an image of the XPS foam after the IFD process.

[0141] Figure 2 shows a graph with the thermal conductivity of foams E1 and E4 according to the invention.

[0142] Figure 3 shows a graph with the Indentation Force Deflection (IFD) of foams E1 and E4 according to the invention.

[0143] Figure 4 shows the compression strength of foams E1 and E2 according to the invention.

[0144] EXAMPLES In the following, the invention will be further illustrated by means of examples and comparative examples. The examples should in no case be interpreted as limiting the scope of the invention, but only as an illustration of the invention.

[0145] Mimosa extract used in these examples was a solid powder with a Stiasny number of40% to 100%.

[0146] VOF1 was a vegetable oil formulation manufactured by the Spanish company FORESA, S.A. (http: / / www.foresa.com / en). This formulation comprised refined soybean oil and had a density of about 950 Kg / m3to about 980 Kg / m3; a viscosity of about 1000 mPa.s to about 1200 mPa.s and a pH of about 8.0 to about 10.0.

[0147] VOF2 was a vegetable oil formulation identified as (VOF1) manufactured by the Spanish company FORESA, S.A. (http: / / www.foresa.com / en), and offered under the denomination BIOWAX. This formulation comprised a combination of hydrogenated or partially hydrogenated palm oil, soy oil and, optionally paraffin, and had a density of about 850 Kg / m3to about 950 Kg / m3, a viscosity of about 50 mPa.s to about 150 mPa.s and a pH of about 9.0 to about 10.0.

[0148] Recycled oil was a mixture of olive oil and sunflower oil.

[0149] Non-ionic surfactant such as PEG-12 Dimethicone or Polysorbate 80.

[0150] Anionic surfactants such as a dioctyl sodium sulfosuccinate or sodium naphthalene-2- sulfonate.

[0151] All amounts included in the examples description here below are expressed as weight of the compound, extract or oil(s) this amount is referring to.

[0152] EXAMPLE 1 (E1): Flexible foam obtained from a composition comprising furfuryl alcohol and a combination of non-ionic and anionic surfactant, but without oil

[0153] 20 g of furfuryl alcohol, 0.5 g of dioctyl sodium sulfosuccinate and 5.5 g of PEG-12 Dimethicone, 43 g of DEG and water were stirred together until homogenisation. Then, a 111 g of vegetable extract comprising polyflavonoids was added to that intermediate liquid mixture and strongly stirred until homogeneous composition (component A, with a solid content of 92 %) was obtained. Afterward, 4 g isohexane (component B) and 28 g of phenol sulfonic acid (component C) were added, by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 20%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After 30 minutes, the flexible polyflavonoid based foam obtained were dried at a temperature of about 20 °C to about 30 °C.

[0154] Blocks of foam with dimensions of 50 x 50 x 50 mm or 100 x 100 x 50 mm were weighed to obtain the bulk density and the mechanical resistance to compression. Thermal conductivity was measured from the foam samples with dimensions of 300 x 300 mm. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity.

[0155] The mechanical properties results showed a foam with a compressive stress at 10% strain of 230 KPa, value that can be compared to the values of a commercial XPS foam (i.e. , 270 KPa). Moreover, this foam presented flexibility since it is able to recover > 94 % of its initial structure after being subjected to Indentation Force Deflection method test (ASTM-D3574-17-B1). On the other hand, the thermal conductivity gave outstanding value of 44 mW / mK, being the thermal conductivity value between 30-40 mW / mK for XPS / EPS.

[0156] EXAMPLE 2 (E2): Flexible foam obtained from a composition comprising hexamine and a combination of non-ionic and anionic surfactant, but without oil

[0157] A liquid mixture was composed of 10 g of hexamine, 1 g of dioctyl sodium sulfosuccinate and 4 g of PEG-12 Dimethicone, 42 g of DEG and water. 114 g vegetable extract comprising polyflavonoids in powder form was then added to the liquid mixture and strongly stirred until homogeneous composition (component A, with a solids content of 84 %) was obtained. Afterward, 7 g of isohexane (component B) and 24 g of phenol sulfonic acid (component C) were added, by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 22%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After 30 minutes, the flexible polyflavonoid based foam obtained were dried at a temperature of about 20 °C to about 30 °C.

[0158] Blocks of foam with dimensions of 50x 50 x 50 mm or 100 x 100 x 50 mm were weighed to obtain the bulk density and the mechanical resistance to compression. Thermal conductivity was measured from the foam samples with dimensions of 300 x 300 mm. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity.

[0159] The mechanical properties results showed a foam with a compressive stress at 10% strain of 90 KPa. The IFD data showed higher flexibility of the foam regarding example 1 (E1). The thermal conductivity gave outstanding value of 41 mW / mK, being the thermal conductivity value between 30-40 mW / mK for XPS / EPS. Despite having some good properties, the stability of the foam formed is low, since some cracks were observed after a few days.

[0160] EXAMPLE 3 (E3): Flexible foam obtained from a composition comprising furfuryl alcohol, a combination of non-ionic and anionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0161] A liquid mixture composed of 11 g of furfuryl alcohol, 0.5 g of dioctyl sodium sulfosuccinate and 4.5 g of PEG-12 Dimethicone, 32 g of DEG, 5 g of refined soybean oil comprised in Vegetable Oil Formulation 1 (VOF1) and water was stirred together. Then, 112 g of vegetable extract comprising polyflavonoids were added and strongly mixed with that liquid mixture until homogeneous composition (component A, with a solids content of 85 %) was obtained. After this operation, 8 g of isohexane (component B) and 28 g the phenol sulfonic acid (component C) were added, by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 24%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After 30 minutes, the flexible polyflavonoid based foam obtained were dried at a temperature of about 20 °C to about 30 °C.

[0162] Blocks of foam with dimensions of 50* 50 x 50 mm or 100 x 100 x 50 mm were weighed to obtain the bulk density and the mechanical resistance to compression. Thermal conductivity was measured from the foam samples with dimensions of 300 x 300 mm. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity.

[0163] The mechanical properties results showed a foam with a compressive stress at 10% strain of 11 KPa. The addition of VOF1 increased the flexibility of the foam regarding example 1 (E1). The thermal conductivity gave upstanding value of 45 mW / mK, being the thermal conductivity value between 30-40 mW / mK for XPS / EPS.

[0164] EXAMPLE 4 (E4): Flexible foam obtained from a composition comprising hexamine, a combination of non-ionic and anionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0165] A liquid mixture composed of 5 g of hexamine, 1 g of dioctyl sodium sulfosuccinate and 4 g of PEG-12 Dimethicone, 32 g of DEG, 6 g of refined soybean oil comprised in Vegetable Oil Formulation 1 (VOF1) and water was stirred together. Then, 112 g of vegetable extract comprising polyflavonoids were added and strongly mixed with that liquid mixture until homogeneous composition (component A, with a solids content of 76 %) was obtained. Afterward, 8 g of isohexane (component B) and 28 g of phenol sulfonic acid (component C) were added, by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 28%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After 30 minutes, the flexible polyflavonoid based foam obtained were dried at a temperature of about 20 °C to about 30 °C.

[0166] Blocks of foam with dimensions of 50* 50 x 50 mm or 100 x 100 x 50 mm were weighed to obtain the bulk density and the mechanical resistance to compression. Thermal conductivity was measured from the foam samples with dimensions of 300 x 300 mm. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity.

[0167] The mechanical properties results showed a foam with a compressive stress at 10 % strain of 11 KPa. IFD test gave an 8.7 support factor number. This value was the higher value obtained in all foams tested indicating the firmness of the flexible foam. The thermal conductivity gave upstanding value of 43 mW / mK, being the thermal conductivity value between 30-40 mW / mK for XPS / EPS.

[0168] EXAMPLE 5 (E5): Flexible foam obtained from a composition comprising furfuryl alcohol and a non-ionic surfactant, but without oil

[0169] A liquid mixture composed of 19 g of furfuryl alcohol, 4 of PEG-12 Dimethicone, 33 g of DEG and water was stirred together. A 112 g of vegetable extract comprising polyflavonoids were added and mixed into said liquid mixture until homogeneous composition (component A, with a solids content of 89 %) was obtained. Afterward, 6 g of isohexane (component B) and 30 g of phenol sulfonic acid (component C) were added, by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 20%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After 30 minutes, the flexible polyflavonoid based foam obtained were dried at a temperature of about 20 °C to about 30 °C.

[0170] Blocks of foam with dimensions of 50x 50 x 50 mm or 100 x 100 x 50 mm were weighed to obtain the bulk density and the mechanical resistance to compression. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity.

[0171] Results determined that the compressive stress at 10% strain was quite lower than considering the foam of Example 1 (E1) with similar density. The IFD results were like the foam of reference (E1). EXAMPLE 6 (E6): Flexible foam obtained from a composition comprising hexamine, a non-ionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0172] A liquid mixture composed of 5 g of hexamine, 4 g of PEG-12 Dimethicone, 32 g of DEG, 5 g of refined soybean oil comprised in Vegetable Oil Formulation 1 (VOF1) and water was stirred together. Then, 113 g of vegetable extract comprising polyflavonoids were added and strongly mixed into that liquid mixture until homogeneous composition (component A, with a solids content of 77 %) was obtained. Afterward, 9 g of isohexane and 32 g of phenol sulfonic acid were added by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 28%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After 30 minutes, the flexible polyflavonoid based foam obtained were dried at a temperature of about 20 °C to about 30 °C.

[0173] Blocks of foam with dimensions of 50 x 50 x 50 mm or 100 x 100 x 50 mm were weighed to obtain the bulk density and the mechanical resistance to compression. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity.

[0174] A flexible foam was obtained with similar results as the example 4 (E4). Nevertheless, the use of a single non-ionic surfactant produces that the foam's flexibility was lost over time.

[0175] EXAMPLE 7 (E7): Flexible foam obtained from a composition comprising hexamine, a combination of non-ionic and anionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0176] This foam was obtained following the same procedure described above for example 4 (E4) with the proviso that 1 g of sodium naphthalene-2-sulfonate was used as anionic surfactant instead of the sulfosuccinate (component A, with a solids content of 76 %).

[0177] No significantly differences in the final data were obtained in comparison with the foam of example 4 (E4).

[0178] EXAMPLE 8 (E8): Flexible foam obtained from a composition comprising hexamine, a combination of non-ionic and anionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0179] This foam was obtained following the same procedure described above for example 4 (E4) with the proviso that 4 g of Polysorbate 80 was used as non-ionic surfactant instead of PEG-12 dimethicone (component A, with a solids content of 76 %). No significantly differences in the final data were obtained in comparison with the foam of example 4 (E4).

[0180] EXAMPLE 9 (E9): Flexible foam obtained from a composition comprising hexamine, a combination of non-ionic and anionic surfactant, and a recycled oil

[0181] This foam was obtained following the same procedure described above for example 4 (E4) with the proviso that 5 g of recycled oil was used instead of VOF1 (component A, with a solids content of 88 %).

[0182] The exchange of VOF1 for recycled oil increased the density. Moreover, foams were obtained with higher flexibility (IFD 25 % 11 N) and less firmness (support factor 3.91) in comparison with that of example 4 (E4).

[0183] EXAMPLE 10 (E10): Flexible foam obtained from a composition comprising hexamine, a combination of non-ionic and anionic surfactant, and a mineral oil

[0184] This foam was obtained following the same procedure described above for example 4 (E4) with the proviso that 5 g of mineral oil was used instead of VOF1 (component A, with a solids content of 88 %).

[0185] The exchange VOF1 for mineral oil increased the density. Moreover, compressive stress at 10% showed similar results than example 4 (E4), but the flexibility and firmness of the foam obtained from mineral oil is quite lower in comparison with E4.

[0186] EXAMPLE 11 (E11): Flexible foam obtained from a composition comprising furfuryl alcohol and a combination of non-ionic and anionic surfactant, and a vegetable oil O / W formulation (VOF2)

[0187] This foam was obtained following the same procedure described above for example 3 (E3) with the proviso that 5 g of a combination of hydrogenated or partially hydrogenated palm oil and soy oil comprised in VOF2 was used instead of vegetable oil VOF1 (component A, with a solids content of 76 %). The exchange VOF1 for VOF2 makes no significant differences in the final data obtained.

[0188] EXAMPLE 12 (E12): Flexible foam obtained from a composition comprising hexamine, a combination of non-ionic and anionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0189] This foam was obtained following the same procedure described above for example 4 (E4) with the proviso that 32 g of lipoxol 400 was used instead of DEG, with a solids content of 76 %). The exchange DEG for lipoxol 400 makes no significant differences in the final data obtained.

[0190] EXAMPLE 13 (E13): Flexible foam obtained from a composition comprising furfuryl alcohol, a combination of non-ionic and anionic surfactant, but without oil.

[0191] This foam was obtained following the same procedure described above for example 1 (E1) with the proviso that 43 g D-Sorbitol was used as dispersing agent instead of DEG (component A, with a solids content of 76 %).

[0192] No significantly differences in the final data were obtained in comparison with the foam of example 1 (E1).

[0193] EXAMPLE 14 (E14): Flexible foam obtained from a composition comprising furfuryl alcohol, a combination of non-ionic and anionic surfactant, but without oil.

[0194] This foam was obtained following the same procedure described above for example 1 (E1) with the proviso that 43 g 1 ,4-cyclohexanedimethanol was used as dispersing agent instead of DEG (component A, with a solids content of 76 %).

[0195] No significantly differences in the final data were obtained in comparison with the foam of example 1 (E1).

[0196] COMPARATIVE EXAMPLE 1 (CE1): Foam obtained from a composition comprising furfuryl alcohol, an anionic surfactant, but without oil

[0197] A liquid mixture composed of 19 g of furfuryl alcohol, 1 g of dioctyl sodium sulfosuccinate, 33 g of DEG and water was stirred together. Then, 112 g of vegetable extract comprising polyflavonoids were added and strongly mixed with that liquid mixture until homogeneous composition (component A, with a solids content of 88 %) was obtained. Afterward, 6 g of isohexane (component B) and 30 g of phenol sulfonic acid (component C) were added by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 20%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After overnight, the results were not satisfactory due to a polyflavonoid based rigid block was obtained and foaming did not take place, only 20-30 mm was the thickness of the block. Hence, mechanical properties of the comparative example 1 were not accurate or could not be carried out.

[0198] Blocks of foam with dimensions of 50 x 50 x 50 mm were weighed to obtain the bulk density. Before analysis the samples were stored at least 6 h at 20 °C and 50 % relative humidity. COMPARATIVE EXAMPLE 2 (CE2): Foam obtained from a composition comprising hexamine, an anionic surfactant, and a vegetable oil O / W formulation (VOF1)

[0199] A liquid mixture was composed of 5 g of hexamine, 1 g of dioctyl sodium sulfosuccinate, 32 g of DEG, 5 g of refined soybean oil comprised in Vegetable Oil Formulation 1 (VOF1) and water was stirred together. Then, 113 g of vegetable extract comprising polyflavonoids were added and strongly mixed to that liquid mixture until homogeneous composition (component A, with a solids content of 76 %) was obtained. Afterward, 9 g of isohexane (component B) and 29 g of phenol sulfonic acid (component C) were added by stirring for 90 s after the addition of each reagent to ensure homogenisation (the total amount of water in the final mixture was 28%). Finally, the mixture was poured into a mold and placed it in a ventilated oven preheated at 75 °C where foaming and hardening were carried out. After overnight the results were not satisfactory due to a polyflavonoid based rigid block was obtained instead of flexible foam. Hence, mechanical properties of comparative example 2 (CE2) could not be carried out.

[0200] Table 1. Characterization of polyflavonoid based foams

Claims

CLAIMS1. A composition for manufacturing a flexible polyflavonoid based foam, characterised in that said composition comprises:- about 41 wt.% to about 83 wt.% of at least one vegetable extract comprising polyflavonoids;- a condensation agent selected from about 3 wt.% to about 18 wt.% of furfuryl alcohol, about 1 wt.% to about 18 wt.% of hexamine and a combination thereof;- about 0.2 wt.% to about 10 wt.% of a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant;- 0 to about 14 wt.% of at least one oil, preferably a vegetable oil;- about 0.1 wt.% to about 28 wt.% of at least one dispersing agent comprising at least two hydroxyl groups which is selected from the group consisting of ethylene glycol, propylene glycol, 1 ,3-propanediol, 1 ,2-butylene glycol, 1 ,3-butylene glycol, 1 ,4-butanediol, 2-methyl-1 ,3-propanediol, 1 ,6-hexanediol, pentaerythritol, sorbitol, neopentyl glycol, glycerol, trimethylolpropane, 2,2,4,4-tetramethyl-1 ,3- cyclobutanediol, 3-methyl-1 ,5-pentanediol, 1 ,4-cyclohexanedimethanol, 1 ,3- cyclohexanedimethanol, bisphenol A ethoxylates, diethylene glycol, tetraethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, pentaerythritol, glycerol, trimethylolpropane and mixtures thereof;- about 5 wt.% to about 30 wt.% of water; wherein these amounts are expressed by weight with respect to the total amount of the composition, so that the sum of said ingredients is lower to or equal to 100 %.

2. The composition of claim 1 , wherein the vegetable extract is selected from mimosa bark extract, quebracho wood extract, hemlock bark extract, sumach bark extract, pine bark extract, pecan nut pith extract, Douglas fir bark extract, oak wood extract and a combination thereof; preferably it is selected from mimosa bark extract, quebracho wood extract, pecan nut pith extract, pine bark extract and a combination thereof.

3. The composition of any one of claims 1 to 2, wherein the Stiasny number is of 25% to 100%, preferably of 40% to 100%.

4. The composition of any one of claims 1 to 3, wherein- the condensation agent is furfuryl alcohol in an amount of about 3 wt.% to about 18 wt.%, preferably of about 3 wt.% to about 12 wt.%, more preferably of about 7 wt.% to about 12 wt.%;- the surfactant mixture comprises at least one anionic surfactant and at least one non-ionic surfactant in an amount of about 0.2 wt.% to about 10 wt.%, preferably of about 1.5 wt.% to about 3.2 wt.%, wherein these amounts are expressed as weight of furfuryl alcohol or surfactant mixture, respectively, with respect to the total weight of the composition; with the proviso that the composition is free from oil.

5. The composition of any one of claims 1 to 4, wherein the non-ionic surfactant comprises a silicon polyether compound, which preferably is a blend of dimethicone and polyethylene glycol, more preferably PEG-12 dimethicone; a polysorbate or a combination thereof.

6. The composition of any one of claims 1 to 5, wherein the anionic surfactant is selected from a sulfosuccinate, an aryl sulfonate and a combination thereof; preferably the anionic surfactant is selected from dioctyl sodium sulfosuccinate, sodium naphthalen-2-sulfonate and a combination thereof.

7. The composition of any one of claims 1 to 6, wherein the surfactant mixture comprises of about 1.3 wt.% to about 2.8 wt.% of at least one non-ionic surfactant and about 0.2 wt.% to about 0.5 wt.% of at least one anionic surfactant, wherein these amounts are expressed as weight of non-ionic surfactant or anionic surfactant, respectively, with respect to the total weight amount of the composition.

8. The composition of any one of claims 1 to 3 or 5 to 7, wherein said composition comprises of about 2 wt.% to about 4 wt.% of at least one oil, amount expressed as weight of oil with respect to the total weight of the composition, preferably the oil is a vegetable oil.

9. The composition of any one of claims 1 to 8, wherein the at least one dispersing agent is selected from diethylene glycol, glycerol and a combination thereof, preferably diethylene glycol.

10. A system for manufacturing a flexible polyflavonoid based foam, characterised by comprising, isolated one of each other:- Component A: the composition as defined in any one of claims 1 to 9,- Component B: at least one blowing agent, and- Component C: at least one acid catalyst.

11. The system according to claim 10, wherein:- the at least one blowing agent is a solvent or substance having a boiling point of about 35°C to about 120°C, preferably of about 30°C to about 70°C, more preferably the blowing agent is isohexane;- the at least one blowing agent is present in an amount of about 0.5 wt. % to about 5 wt.%, preferably of about 1.8 wt.% to about 3.8 wt.%, wherein these amounts are expressed with respect of the total amount of the system; or- a combination of the above.

12. The system of any one of claims 10 or 11 , wherein the at least one acid catalyst, preferably phenol sulfonic acid, is present in an amount of about 1 wt. % to about 23 wt.%, preferably of about 8 wt.% to about 14 wt.%, wherein these amounts are expressed with respect of the total amount of the system.

13. A mixture for the manufacturing of a flexible polyflavonoid based foam, characterized by comprising:- Component A: the composition as defined in any one of claims 1 to 9,- Component B: the at least one blowing agent as defined in claims 10 or 11 , and- Component C: the at least one acid catalyst as defined in claims 10 or 12.

14. A method for manufacturing a flexible polyflavonoid based foam, wherein the method comprises the following steps:i) preparing a composition as defined in any one of claims 1 to 9 by: i-1) mixing the required amounts of the following ingredients: a. a condensation agent selected from furfuryl alcohol, hexamine and a combination thereof, b. a surfactant mixture comprising at least one anionic surfactant and at least one non-ionic surfactant; c. optionally, an oil, preferably a vegetable oil; d. at least one dispersing agent having at least two hydroxyl groups; and e. water; and stirring until a first homogeneous intermediate mixture is obtained; i-2) adding the required amount of at least one vegetable extract comprising polyflavonoids and stirring until homogenisation, thus obtaining the composition as defined in any one of claims 1 to 9; ii) adding the required amount of the at least one blowing agent as defined in claims 10 or 11 and stirring until a second homogeneous intermediate mixture is obtained; iii) adding the required amount of at least one acid catalyst as defined in claims 10 or 12 and stirring until a homogeneous mixture is obtained and the temperature of said mixture reach about 35 °C to about 120 °C, with the proviso that the temperature is not higher than the boiling point of the blowing agent; and iv) maintaining the mixture of step iii) at a temperature of about 35°C to about 120°C for at least 30 min, with the proviso that the temperature is not lower than 10°C below the boiling point of the blowing agent, thus obtaining a flexible polyflavonoid based foam.

15. A flexible polyflavonoid based foam obtained or obtainable from the composition as defined in any one of claims 1 to 9, the system as defined in any one of claims 10 to 12, or the mixture as defined in claim 13, preferably by the method as defined in claim 14.

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