WO2021148938A1

WO2021148938A1 - Ceramic-based composites materials methods and uses thereof

Info

Publication number: WO2021148938A1
Application number: PCT/IB2021/050378
Authority: WO
Inventors: Sandra Cristina DE ALMEIDA PINA; Emanuel MOUTA FERNANDES; Rita REBELO; Flávia Cristina MARQUES LOBO; Tiago José QUINTEIROS LOPES HENRIQUES DA SILVA; Vitor Manuel Correlo Da Silva; Joaquim Miguel Antunes Correia De Oliveira; Rui Luís GONÇALVES DOS REIS
Original assignee: Association For The Advancement Of Tissue Engineering And Cell Based Technologies & Therapies (A4Tec) - Associação
Priority date: 2020-01-20
Filing date: 2021-01-19
Publication date: 2021-07-29

Abstract

The present disclosure relates to a mouldable material/raw material comprising calcium phosphate particles, ionic-doped calcium phosphate particles, calcium carbonate, or mixtures thereof; and/or chitosan, a thermoplastic polymer and cork particles. The disclosure also relates to a composition comprising the mouldable material/raw and articles comprising the described material/raw material wherein the article is a habitat product, furniture material/raw material, construction material/raw material, automotive material, an aeronautics piece/part, upholstery, flooring material/raw material, automotive component, packaging component and aeroplane component. A method to obtain the mouldable material/raw material is also disclosed.

Description

D E S C R I P T I O N

CERAMIC-BASED COMPOSITES MATERIALS METHODS AND USES

THEREOF

Technical field

[0001] The present disclosure concerns the production of ceramic-based composites incorporating thermoplastic polymers, cork and calcium-based particles, functionalized with different elements that improve electrical conductivity, mechanical resistance, and antibacterial properties, and its use in habitat industry, transports industry, and aeronautics.

Background

[0002] Ceramics are a class of inorganic materials used in engineering and biomedical applications due to their properties, such as hardness, strength, electrical conductivity, brittleness, and resistance to chemical corrosion.

[0003] Calcium phosphates (CaPs) are a class of inorganic non-metallic ceramics possessing appropriate biological properties, such as bioactivity, bioresorbability, and osteoconductivity. These ceramic materials are also characterized by their hardness, strength, electrical conductivity, and brittleness.

[0004] The incorporation of metallic ions (e.g., Li, Sr and Ga) in the CaPs present beneficial effects on the mechanical and acoustic performance, electrical conductivity and antimicrobial properties.

[0005] The addition of chitosan, a linear polysaccharide composed of randomly distributed b-(l 4)linked D-glucosamine (deacetylated unit) and N-acetyl-D- glucosamine (acetylated unit), is obtained by chitin via de-acetylation and can be used to improve the antimicrobial potential of different materials. [0006] Cork presents a closed cell wall and an anisotropic structure, low density, good thermal and acoustic insulation properties and impermeability to liquids, among others, that make it a material of choice for several applications.

[0007] The combination of cork with polymeric matrices by using melt-based technologies is a field with high potential to be explored. In a recent document WO2017164757 (Al) it is described a method for preparing panels made of a composite of cork and polyethylene, comprising the mixing of 10-64% granulated cork and 36-90% granulated polyethylene for the building sector in particular as the core of a lining, however these cork composites applied in the construction sector lacks in some features such as wear or surface resistance, thermal conductivity or improved stiffness as compared with the composite materials that use natural fibres were the main chemical component it is cellulose.

[0008] In achieving a commercially viable product it is generally desirable that a material applied in the construction sector that will be in contact with a person shall present several features such as scratch resistance or appropriated mechanical resistance for the function. Furthermore, other relevant characteristics such as good aesthetics, chemical resistance or antibacterial properties may be required or desirable for the required application.

[0009] Hybrid thermal protection systems have been developed based on cork-ceramics composites. These composites are based in cork and C/C-SiC ceramic matrix composites (CMC) and can be obtained by in situ polymerization of the cork on the top of CMC, or through a high temperature commercial inorganic adhesive.

[0010] Document EP2683676A2 discloses a method for the preparation process of ceramic and/or composite materials that comprise bonding elements in order to improve mechanical and other properties associated with the ceramic and/or composite materials.

[0011] Document WO2011115514 (A2) discloses a method to obtain ceramic laminated panel with cork and fibres in different material layers. In comparison with traditional flooring made of ceramic floor tiles, this document claims significant weight reduction, improved mechanical and insulation properties for application in the construction industry.

General Description

[0012] The present disclosure concerns the production of functionalized ceramic-based composites incorporating polymer (e.g. polyolefin such as polyethylene, polypropylene, and bio-based polymers, or others), cork and calcium-based particles, wherein calcium- based particles are selected from a list consisting of CaP particles and calcium carbonate particles, or mixtures thereof. The disclosure also relates to the use of the composite in habitat industry, automotive industry, and aerospace.

[0013] The present disclosure also relates to a method for producing the composite structures of polymer, cork and CaPs wherein the CaPs are doped with different ions (e.g. Zn, Sr, Li, Mg, and Ga).

[0014] In addition, in the solution of the present disclosure the constituents of the composite are well distributed in the polymer matrix and infer in the final properties of the material.

[0015] In an embodiment, the polymer is a thermoplastic material from petrochemical or natural based origin.

[0016] The present disclosure provides a method of extruding/moulding/or injection moulding a cork-polymer composition reinforced by a ceramic material. More particularly, the disclosure relates to the extrusion/injection moulding of such mixtures to produce a material orto be applied in a subsequent melt process such as compression moulding, thermoforming, injection moulding or additive manufacturing.

[0017] In an embodiment, the CaPs particles, particularly nanopowders, can form a tight interface with the polymeric matrices, resulting in enhanced mechanical properties of the material of the present disclosure.

[0018] In an embodiment, the ionic incorporation into the structure of CaPs can improve the physico-chemical and biological processes of CaPs.

B [0019] In an embodiment, the ionic-doped CaPs particles are obtained via wet chemical precipitation method using precursors of Ca, P, and nitrates of ionic dopants, in a medium of controlled temperature and pH, followed by calcination.

[0020] The present disclosure relates to a mouldable material/raw material comprising calcium-based particles, with a size up to 5 pm, wherein calcium-based particles are selected from a list consisting of CaP particles and calcium carbonate particles, or mixtures thereof; and/or chitosan; a thermoplastic polymer; and cork particles, wherein the granulometry of the cork particles are up to 5 mm.

[0021] In an embodiment, the CaP particles may be selected from a list consisting of: a, b-tricalcium phosphate, hydroxyapatite, or mixtures thereof.

[0022] In an embodiment, the CaP particles are ionic-doped CaP particles.

[0023] In an embodiment, the composition may comprise 5-30 wt.% (wt_particies/wt_totai) of calcium-based particles, preferably 5-20 wt.% (wt_particies/wttotai) of calcium-based particles.

[0024] In an embodiment, the composition may comprise 40-90 wt.% (wt_poiymer/wt_totai) of a thermoplastic polymer, preferably 50-70 wt.% (wt_poiymer/wt_totai).

[0025] In an embodiment, the composition may comprise 5-35 wt.% (wt_COrk _P a rticl es/ W t tota I ) Of COrk particles, preferably 10-25 Wt.% (wtcork _Particles/wttotal).

[0026] In an embodiment, the composition comprises 5-30 wt.% (wt_partides/wt_totai) of a plurality of calcium-based particles; 40-90 wt.% (wt_poiymer/wt_totai) of a thermoplastic polymer; and 5-35 wt.% (wt_Cork _Particies/wt_totai) of cork particles.

[0027] In an embodiment, the composition may comprise a weight ratio of chitosan of 1 wt.% up to 20 wt.%, preferably 5 wt.% up to 15 wt.%.

[0028] In an embodiment, the calcium-based particles are a powder, preferably a nanopowder, and their size may be up to 5 pm, preferably 0-3 pm.

[0029] In an embodiment, the cork particles granulometry varies between 100 pm to 5 mm, preferably ranging from 250 pm to 4 mm. [0030] In an embodiment, the ions of the ionic-doped CaPs may be selected from a list consisting of: lithium, strontium, zinc, magnesium, gallium, or mixtures thereof.

[0031] In an embodiment, the ions of the ionic-doped CaPs may be selected from a list comprising zinc, strontium, lithium or mixtures thereof.

[0032] In an aspect of the present disclosure, the mouldable material/raw material of the present disclosure comprises a coupling agent, preferably maleic anhydride.

[0033] In an embodiment, the thermoplastic is selected from a list consisting of: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyamide (PA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyhydroxyalkanoate (PHA) and polylactic acid (PLA), or mixtures thereof.

[0034] In an aspect of the present disclosure, the polymer of the mouldable material/raw material is a thermoplastic, and the polymer to cork ratio is 60/40-90/10 wt.%, preferably 80/20 wt.%.

[0035] An aspect of the present disclosure relates to a composition comprising the mouldable material/raw material, wherein the composition further comprises a low- density polyethylene, preferably between 700-980 Kg/m³, more preferably 850 - 925 Kg/m³.

[0036] In an embodiment, the composition comprises doped calcium phosphate particles wherein the amount of the ions is up to 10 mol.%, preferably between 5-10 mol. %.

[0037] An aspect of the present disclosure relates to an article comprising the mouldable material/raw material, wherein the material is applied as a coating material with acid resistance and electrical conductivity.

[0038] In an embodiment, the article related to the present subject matter promotes antibacterial resistance, preferably acting as antifouling agent by preventing the biofilm formation. The article may be a habitat product, furniture material/raw material, construction material/raw material, automotive material, an aeronautics piece/part, upholstery, flooring material/raw material, automotive component, packaging component and aeroplane component.

[00B9] In an embodiment, the present disclosure also comprises a method to obtain the mouldable material/raw material comprising: (i) mixing the components of the material; (ii) co-rotating the mixture in a twin-screw extruder (TSE); (iii) cooling part of the extrudate in a water bath; (iv) drying the obtained pellets in a vacuum oven at 50°C until stabilization; (v) grounding the dried pellets by a pelletizer to produce composite pellets; (vi) compression moulding, thermoforming, injection moulding or additive manufacturing process; and (vii) discontinuing heating to obtain the ceramic-based material.

[0040] In an embodiment, the preparation method of the mouldable material/raw material further comprise the following steps: adding polymer and cork in a ratio ranging from 60/40 to 90/10 wt.%, preferable 80/20 wt.%; adding 5-20 wt.% of ionic-doped CaPs particles to the previous mixture; mixing composites in a mechanical agitator; placing in the hopper of the extruder machine to obtain the final product or to be further used in a subsequent melt process such as compression moulding, thermoforming, injection moulding or additive manufacturing process.

[0041] In an embodiment, crystalline CaPs phases may be determined by XRD and FTIR techniques, to assess their crystallinity and the presence of functional groups.

[0042] In an embodiment, the incorporation of ionic doping elements into the CaPs particles may be calculated on the basis of XRD patterns through Rietveld analysis.

[0043] In an embodiment, the crystallinity of the composites may be determined by X- ray diffraction.

[0044] In an embodiment, the mechanical properties of the composites may be determined by compressive strength in dry state. [0045] In an embodiment, the static contact angles of the composites may be determined in a goniometer using deionized water and diiodomethane as test liquids.

[0046] In an embodiment, the surface energy of the composites may be calculated from the contact angles data.

[0047] In an embodiment, the adherence and biofilm formation of Escherichia coli (E. coli, Gram negative bacteria) and Staphylococcus aureus (S. aureus, Gram positive bacteria) may be evaluated on the composites surface.

[0048] The presence of different ions in the composites is a way to improve electrical conductivity, mechanical resistance and antibacterial properties. The incorporation of Sr, Zn, and Li present beneficial effects on the mechanical and antibacterial properties.

[0049] The material of the present disclosure is functionalized with ions incorporated in the structure (e.g. Li, Sr, Zn, Mg, and Ga). Therefore, materials with conductive and/or antibacterial properties are within the scope of the present invention.

[0050] The material of the present disclosure comprises a very well distribution of the different constituents of the composite in the polymeric matrix and this distribution infers in the final properties of the material.

Brief Description of the Drawings

[0051] The following figures provide preferred embodiments for illustrating the description and should not be seen as limiting the scope of invention.

[0052] Figure 1. Appearance of the produced pellets by extrusion process that can be used in a subsequent melt-based process as shown in the present disclosure, compression moulding for obtaining the composite materials.

[0053] Figure 2. XRD patterns of PP/cork and 10 wt. % of ionic-doped CaPs.

[0054] Figure 3. SEM/EDS analysis of the composites: A) PP/Cork, B) PP/Cork/20 ZnTCP, and C) respective EDS elemental analysis of PP/Cork (left) and PP/Cork/20 ZnTCP (right). [0055] Figure 4. SEM analysis of E. Coli and S. aureus adhesion and biofilm formation on the polypropylene (PP) based composites, after seeding for 24 hours. For each bacterium, magnification of X200 and X5000, respectively.

[0056] Figure 5. SEM analysis of E. Coli and S. aureus adhesion and biofilm formation on the low-density polyethylene (LDPE) based composites, after seeding for 24 hours. For each bacterium, magnification of X200 and X5000, respectively.

Detailed Description

[0057] The present disclosure is also further described, in particular, using embodiments of the disclosure. Therefore, the disclosure is not limited to the descriptions and illustrations provided. These are used so that the disclosure is sufficiently detailed and comprehensive. Moreover, the intention of the drawings is for illustrative purposes and not for the purpose of limitation.

[0058] The present disclosure concerns the production of composites incorporating a thermoplastic polymer, cork and calcium-based particles, and its use in habitat industry, automotive industry, and aerospace.

[0059] The present disclosure also relates to a method for producing the composites of polymer, cork and calcium-based particles, preferably CaPs particles (e.g., b-tricalcium phosphate, hydroxyapatite), more preferably CaPs particles doped with different ions (e.g. Zn, Sr, Li, Mg, and Ga).

[0060] The present disclosure also relates to a method of extruding a mouldable material/raw material composition reinforced by the calcium-based particles, such as ionic-doped calcium phosphate particles, wherein the size of the ionic-doped calcium phosphate particles is up to 5 pm. More particularly the disclosure relates to the extrusion of such mixtures to produce a material or to be applied in a subsequent melt process such as compression moulding, thermoforming, injection moulding or additive manufacturing. [0061] In an embodiment, the compositions are prepared using at least a polymeric thermoplastic, cork particles and calcium-based particles. The polymer is a thermoplastic material from petrochemical or natural based origin. The cork particles comprise a particle size ranging from 100 pm up to 6 mm, preferably ranging from 250 pm up to 4 mm. The calcium-based particles may include or be selected from ceramics as calcium carbonate, calcium sulfate, tricalcium phosphate, tetracalcium phosphate, or the incorporation of metallic ions on the ceramics. The ceramic may also be a mixture of several different ceramics. The ceramic material can be added in the powder form or in microparticles.

[0062] In an embodiment, the materials of the present disclosure may be formed by using extrusion, injection moulding, pultruding, compression moulding, combinations of the previous melt technologies or any appropriate moulding or forming process may be used.

[0063] In an embodiment for several formulations, the thermoplastic polymer/cork ratio used was 80/20 wt.% followed by the addition of different percentages of calcium- based particles and optionally further comprising chitosan.

Example 1:

[0064] In an embodiment, the compositions of the material were prepared using a polymeric thermoplastic, cork particles with a particle size of 0.5 up to 1 mm and the ceramic powder. The polymer used was a polypropylene with melting temperature of 153 °C. For all the prepared formulations, the polymer/cork ratio used was 80/20 wt.% followed by the addition of different percentages of ceramic. In this example, it was used different amounts of strontium tricalcium phosphate (SrTCP) in the powder form and the properties were compared with the formulation without ceramic PP/Cork (80/20) wt.% as presented in Table 1. Prior to the compounding process, each composition was placed into a mechanical agitator, for mixing and homogenization of the composition. Each composition was placed independently into a SCF TSE 16 mm co-rotating twin screw extruder with a screw length to diameter ratio (L/D) of 25 and die of circular geometry, allowing the composition and posterior production of a continuous fibre or profile. Part of the extrudate was cooled in water bath and subsequently, ground by a pelletizer to produce composite pellets suitable for compression moulding. The temperature profile used in the extruder from the die to the hopper was set as 175; 175; 160; 140 °C respectively with the motor speed at 50 rpm.

[0065] Table 1. Compositions based on polymer/Cork (80/20) wt.% and with different percentages of ceramic produced by extrusion process followed by compression moulding.

PC 80 20 0 0 0 0

[0066] Afterward, a certain amount of pellets from each composition was subjected to compression moulding process by collect and disperse the pellets into a mould with a rectangular geometry (around 200 x 230 mm²) and 2 mm of thickness, containing on the top and on the bottom two removals covers. Between the pellets and the top and bottom mould walls it was used two Teflon sheets to promote the unmoulding process. This system was placed in a hydraulic press at a temperature of 175 °C, pressure 4 ton and time 10 min, followed by a cooling stage consisting on maintaining the pressure and using water to decrease the temperature aiming to decrease the temperature of the material inside the mould near to the room temperature. Finally, the pressure is removed and the small contraction that occurs on the board allows the unmoulding of composite material. Subsequently from those materials, were cut specimens with a thickness of 2 mm according ASTM 638 to evaluate the mechanical properties under tensile load using an Instron 5543 machine model, a load cell of 1 KN and a crosshead speed of 2 mm/min.

[0067] In an embodiment, the composite mouldable materials/raw materials of the present disclosure produced by this method are characterized by possessing a thickness of 2±0.1 mm (Figure 1) and by exhibiting a brownish colour. The ionic presence into the composite materials is confirmed by XRD and EDS analysis shown in Figure 2 and Figure 3C, respectively. The mechanical properties of the composite materials are shown in Table 2.

[0068] Table 1: Mechanical properties under tensile load of PP/Cork (80/20) wt.% and loaded with different percentages of different calcium-based particles (ionic-doped calcium phosphate particles, doped as defined in column 1, and CaC0₃) and comparative data (PC).

PC 21.21 ± 1.49 578.23 ± 31.50 6.32 ± 0.60

[0069] The mechanical properties under tensile load of the composites obtained by extrusion process followed by compression moulding reveals some increase on the stiffness of composite materials of the present disclosure as compared with the PP/Cork (80/20) wt.% solution. Moreover, the addition of SrTCP ceramic up to 10 wt.% does not present any negative effect on the maximum tensile strength or tensile strain properties. [0070] In terms of composite materials morphology, scanning electron microscopy (SEM) analysis showed a homogeneous distribution of the constituents in the polymer matrix (Figure BA and B).

Example 2:

[0071] In an embodiment, the same composition based on PP/Cork (80/20) wt.% of the example 1 was mixed with other ceramic material, namely with 10 wt.% of Zinc- tricalcium phosphate (ZnTCP). The composites were mixed according to the methodology described on example 1. The produced compositions are reported in Table 1.

[0072] A material from different formulation of the mouldable material of the present disclosure was obtained showing a surface appearance similar to the composites of the previous example however with mechanical properties slightly different, as shown in Table 1, due to the use of different functionalized TCP ceramic. The presence of ZnTCP in the composite increases clearly the stiffness of the materials. Comparing with the control condition PP/Cork (80/20) wt.% that presents a tensile modulus of 578.23±31.50 MPa, the ceramic mouldable material of the present disclosure containing 10 wt.% of ZnTCP shows 614.09±39.46MPa and for 20 wt.% of ZnTCP the stiffness increases for 671.56±27.33 MPa. This represents increases of 6.2 and 16.1 % respectively, with the maintenance of the tensile strength or strain properties.

Example 3:

[0073] In an embodiment, the same composition based on PP/Cork (80/20) wt.% of the example 1 was mixed with other ceramic material, namely with 10 wt.% of Calcium Carbonate (CaCC>3). The composites were mixed according to the methodology described on example 1.

[0074] It was measured the mechanical properties under tensile load of the composite materials. Moreover, the thermal conductivity was performed in samples of 50 x 50 x 6 mm³ at temperature of 23 °C and according to the standard UNE - EN 22007-2, and the results are shown in Table 3. [0075] The addition of CaCC>3 does not increase the mechanical properties under tensile load, and the obtained mouldable material of the present disclosure presented higher thermal conductivity properties.

Example 4:

[0076] In an embodiment, the same composition based on PP/Cork (80/20) wt.% of the example 1 was compound with other ceramic material, namely with 10 wt.% of Lithium Tricalcium Phosphate (LiTCP). The composites were compound according with the methodology described in the example 1. The new material was tested according to the described in the example 1 and example 3. In comparison with the PP/Cork (80/20) wt.%, the compound of this example improved tensile strength and tensile modulus in 18.6% and 19.2% respectively. The compound of this example reveals higher mechanical performance under tensile mode that was not expected. The thermal conductivity also increased as compared with the composition PP/Cork (80/20) wt.%.

[0077] Table 3 compares the PP/Cork (80/20) wt.% composition of the present disclosure using 10 wt.% of ceramic agent. The results confirm the high potential of the LiTCP to promote the mechanical properties and surprising the effect of ZnTCP that presents a decrease in the thermal conductivity as compared with all formulations.

[0078] Table 2: Tensile and thermal conductivity of the composite materials with 10 wt.% of ceramic content in comparison with the PP/Cork (80/20) wt.% composition.

PC — 21.21 ± 1.49 578.23 ± 31.50 +

Example 5:

[0079] In an embodiment, a different composition based on a bio-based low-density polyethylene (LDPE) with a density of 925 Kg/m³, was tested under similar methodology. The composition LDPE/Cork (80/20) wt. % was compounded alone or in the presence of chitosan with medium molecular weight from Sigma, with and without coupling agent based on high density polyethylene graft maleic anhydride (HDPE-g-MA), and the formulations are listed in Table 4. The composites were compound by extrusion followed by compression moulding according to the methodology described on example 1.

[0080] Table 4: Composition of the developed composites based on LDPE (925 Kg/m³).

[0081] The different developed materials were characterized in terms of density, mechanical properties under tensile mode and water uptake tests.

[0082] The results presented in Table 5 revealed a small increase in the composite density preferably in the presence of the coupling agent based on HDPE-g-MA. The stiffness and the maximum strength of the composite materials increase with the addition of chitosan, preferably in the presence of coupling agent. Moreover, by using this strategy it was possible to maintain the maximum strain at break. [0083] Table 5: Density, tensile properties and water uptake values of the composites based on LDPE.

[0084] In terms of water uptake, the composites present low values of absorption for 48 h being the composition PE/CK CHT10 presenting the highest value of 2.45%. By using the coupling agent, it was possible to reduce for 1.34%, being a good indication for materials applied on the habitat or other sectors of application.

Example 6:

[0085] The adhesion and biofilm formation of the bacteria E. Coli and S. aureus on the surface of polypropylene (PP) and low density polyethylene (LDPE) based composites were evaluated by direct contact assay, during 24 h of culturing, and the results were observed by SEM, as presented in Figure 4 for PP matrix, and in Figure 5 for LDPE matrix, respectively.

[0086] After 24 hours of culturing, both bacteria adhered to the composites, with no biofilm formation detected. E. coli and S. aureus morphology showed cells with regular and smooth shapes.

[0087] The PP based composites containing Zn showed less S. aureus adhesion on its surface, while the presence of Sr presented an increase of the bacteria with the increase of SrTCP concentration. In the case of the LDPE based composites (Figure 5), the incorporation of chitosan in the polymer-cork system decreases the number of E. Coli. The LDPE composites containing chitosan, in the presence of coupling agent based on maleic anhydride, showed higher number of bacteria. Moreover, the addition of 20 wt.% of cork decreased the number of bacteria revealing to be a promising solution for the purposed applications.

Ionic-doped calcium phosphates preparation

[0088] In an embodiment, the ionic-doped nanopowders are obtained by aqueous precipitation from calcium nitrate tetrahydrate (Ca(NC>₃)₂.4H₂0) and diammonium hydrogen phosphate ((NH^HPC^) in a medium of controlled pH with the addition of NH4OH. Ionic-doped nanopowders (0-10 mol. %) are synthesized by adding suitable amounts of the precursor nitrates of the doping elements. The precipitated suspensions are kept for 4 h under constant stirring conditions at 90 °C. The resulting precipitates are vacuum filtered, dried at 100 °C, and heat treated for 2 h at 1100 °C. The powders are ground under dry conditions in a planetary mill, followed by sieving.

Preparation of polymer/cork/ionic-doped composites

[0089] In an embodiment, the raw materials were pre-mixed and further compounded in co-rotating twin-screw extruder (TSE). The mixture was placed in the hopper and feed at a constant rate using a temperature profile from 140 °C up to 175 °C at 50 rpm. Part of the extrudate was cooled in water bath and subsequently ground by a pelletizer to produce composite pellets suitable for compression moulding. Prior to this step, the produced pellets were dried in a vacuum oven at 50 °C until stabilize. Afterthe extrusion step, compression moulding was conducted using manual hydraulic, preheated to 175 °C under 4 ton pressure for 10 min, and then heating was discontinued and the plates cooled using cold water to room temperature, while still under pressure.

[0090] All references recited in this document are incorporated herein in their entirety by reference, as if each and every reference had been incorporated by reference individually.

Preparation of polymer/cork/chitosan/ionic-doped composites

[0091] In an embodiment, the polymer/cork/chitosan/ionic-doped composites are prepared according to the previous example, where the main difference was the addition of chitosan in the pre-mixing step. The obtained materials present good dimensional stability and improved antibacterial properties.

[0092] Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. The scope of the present invention is not intended to be limited to the above description, but rather is as set forth in the appended claims.

[0093] Furthermore, it is to be understood that the invention encompasses all variations, combinations, and permutations in which one or more limitations, elements, clauses, descriptive terms, etc., from one or more of the claims or from relevant portions of the description is introduced into another claim. For example, any claim that is dependent on another claim can be modified to include one or more limitations found in any other claim that is dependent on the same base claim.

[0094] Furthermore, where the claims recite a composition, it is to be understood that methods of using the composition for any of the purposes disclosed herein are included, and methods of making the composition according to any of the methods of making disclosed herein or other methods known in the art are included, unless otherwise indicated or unless it would be evident to one of ordinary skill in the art that a contradiction or inconsistency would arise.

[0095] Where ranges are given, endpoints are included. Furthermore, it is to be understood that unless otherwise indicated or otherwise evident from the context and/or the understanding of one of ordinary skill in the art, values that are expressed as ranges can assume any specific value within the stated ranges in different embodiments of the invention, to the tenth of the unit of the lower limit of the range, unless the context clearly dictates otherwise. It is also to be understood that unless otherwise indicated or otherwise evident from the context and/or the understanding of one of ordinary skill in the art, values expressed as ranges can assume any subrange within the given range, wherein the endpoints of the subrange are expressed to the same degree of accuracy as the tenth of the unit of the lower limit of the range. [0096] In addition, it is to be understood that any particular embodiment of the present invention may be explicitly excluded from any one or more of the claims. Where ranges are given, any value within the range may explicitly be excluded from any one or more of the claims. Any embodiment, element, feature, application, or aspect of the compositions and/or methods of the invention can be excluded from any one or more claims. For purposes of brevity, all of the embodiments in which one or more elements, features, purposes, or aspects is excluded are not set forth explicitly herein.

[0097] The aforementioned embodiments are combinable.

[0098] The following claims further set out particular embodiments of the disclosure.

[0099] The following references, should be considered herewith incorporated in their entirety:

1. Triantou K., Perez B., Marinou A., Florez S., Mergia K., Vekinis G., de Montbrun A. Performance of cork and ceramic matrix composite joints for re-entry thermal protection structures. Composites Part B: Engineering, 108, 270-278, 2017.

2. S.Kannan, S.l. Vieira, S.M. Olhero, P.M.C. Torres, S. Pina, O.A.B. da Cruz e Silva, J.M.F. Ferreira. Synthesis, Mechanical and Biological Characterization of Ionic Doped Carbonated Hydroxyapatite / beta-Tricalcium phosphate mixtures. Acta Biomaterialia, 7, 1835-1843, 2011.

Claims

C L A I M S

1. A mouldable material/raw material comprising:

5-30 wt.% (wtparticies/wttotai) of calcium-based particles with a size up to 5 pm, wherein calcium-based particles are selected from a list consisting of: a, b- tricalcium phosphate, hydroxyapatite, and calcium carbonate particles, or mixtures thereof and/or 1-20 wt.% (wtchitosan/w ai) chitosan;

40-90 wt.% (wtpoiymer/wttotai) of a thermoplastic polymer; and

5-35 wt.% (wtcor particies/wttotai) of cork particles wherein the granulometry of the cork particles are up to 5 mm.

2. The material according to any of the previous claims, wherein calcium phosphate particles are ionic-doped calcium phosphate particles.

3. The material according to any of the previous claims comprising 5-20 wt.% of calcium-based particles (wtparticies/wttotai).

4. The material according to any of the previous claims comprising 50-70 wt.% (wtpoiymer/wttotai) of thermoplastic polymer.

5. The material according to any of the previous claims comprising 10-25 wt.% (wt_COr_k particies/wttotai) of cork particles.

6. The material according to any of the previous claims comprising:

5-30 wt.% (wtparticies/wttotai) of a plurality of calcium-based particles;

40-90 wt.% (wtpoiymer/wttotai) of a thermoplastic polymer; and

5-35 wt.% (wtcork particies/wttotai) of cork particles.

7. The material according to any of the previous claims comprising a weight ratio of chitosan from 5 to 15 wt.%. (wtchitosan/wWai)

8. The material according to any of the previous claims, wherein the calcium-based particles are a powder, preferably a nanopowder.

9. The material according to any of the previous claims wherein the ions of the ionic- doped calcium phosphate particles are selected from a list consisting of zinc, strontium, lithium, magnesium, gallium, or mixtures thereof.

10. The material according to any of the previous claim wherein the ions of the ionic- doped calcium phosphate particles are selected from a list consisting of zinc, strontium, lithium or mixtures thereof.

11. The material according to the previous claims wherein the granulometry of the cork particles varies between 100 pm - 6 mm, preferably 250 pm - 4 mm.

12. The material according to the previous claims wherein the granulometry of the ionic doped calcium phosphate particles varies between 0 - 5 pm, preferably 0- 3 pm.

13. The material according to any of the previous claims further comprising a coupling agent, preferably wherein the coupling agent is maleic anhydride.

14. The material according to any of the previous claims wherein the thermoplastic is selected from a list consisting of: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyamide (PA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), polyvinyl alcohol (PVA), polyhydroxyalkanoate (PHA) and polylactic acid (PLA), or mixtures thereof.

15. The material according to the previous claims, wherein the polymer is a thermoplastic and the polymer to cork ratio is 60/40 - 90/10 wt.%, preferably 80/20 wt.%.

16. A composition comprising the mouldable material/raw material described in any of the previous claims.

17. The composition according to any of previous claims according the previous claim wherein the composition further comprises a low-density polyethylene, preferably between 700-980 Kg/m³, more preferably 850 - 925 Kg/m³.

18. The composition according to any of previous claims wherein the amount of the ions in the doped calcium phosphate particles is up to 10 mol.%, preferably between 5- 10 mol. %.

19. An article comprising the mouldable material/raw material described in any of the previous claims.

20. The article described in any of the previous claims wherein the material of the present disclosure is applied as a coating material with acid resistance and electrical conductivity.

21. The article described in any of the previous claims wherein the material promotes antibacterial resistance, preferably acting as antifouling agent by preventing the biofilm formation.

22. The article of the previous claim wherein the article is a habitat product, furniture material/raw material, construction material/raw material, automotive material, an aeronautics piece/part, upholstery, flooring material/raw material, automotive component, packaging component and aeroplane component.

23. A method to obtain the mouldable material/raw material described in any of the previous claims comprising the following steps: mixing the components of the material; co-rotating the mixture in a twin-screw extruder (TSE); cooling part of the extrudate in a water bath; drying the obtained pellets in a vacuum oven at 50°C until stabilization; grounding the dried pellets by a pelletizer to produce composite pellets; compression moulding, thermoforming, injection moulding or additive manufacturing process; discontinuing heating; to obtain the ceramic-based material.

24. The method according to any of the previous claims comprising the steps of: adding polymer and cork, according to the ratios indicated in the previous claims; adding 5-20 wt.% of ionic-doped calcium phosphate particles to the previous mixture; mixing composites in a mechanical agitator; placing the mixture in the hopper of the extruder machine to obtain the final product or to be further used in a subsequent melt process such as compression moulding, thermoforming, injection moulding or additive manufacturing process.