Method of cross-linking polysaccharides from macroalgae to form polymeric materials

Abstract

The invention relates to a method (1) for producing a polymeric material, the method (1) comprising the following steps (11, 12, 13): providing macroalgae (7) containing carrageenan; adjusting the weight-average molecular weight of carrageenan to less than 800000 g / mol; feeding macroalgae (7) into the processing chamber (4); and processing the macroalgae (7) in the processing chamber (4) to form a polymeric material. The invention also relates to a method (2) for producing a bioplastic product in a device (3) comprising a processing chamber (4) and a molding device (10), the method (2) comprising the following steps (11, 12, 13, 14, 15, 16): producing a polymeric material from carrageenan-containing macroalgae (7) in the processing chamber (4); and shaping the polymeric material in a shaping apparatus (10) to form the bioplastic product. The invention also relates to a bioplastic product obtained according to the method (2).

Description

Technical Field

[0001] The present invention relates to a method for producing a polymer material from carrageenan-containing macroalgae. Furthermore, the present invention relates to a method for producing a bioplastic product from such a polymer material in an apparatus comprising a processing chamber and at least one forming device. The present invention also relates to a corresponding bioplastic product. Background Art

[0002] Methods for producing polymer materials from polysaccharides from macroalgae and methods for producing bioplastic products therefrom are already known in the prior art, in particular as molding processes or extrusion processes. For example, an extrusion process for encapsulating liquids is known from WO 2018 / 172781 A1 and WO 2020 / 065270 A1, and a compression molding process is also known from US 2017 / 0266847 A1.

[0003] Bioplastic products have great advantages over plastic products made from fossil raw materials, in particular they do not release fossil carbon dioxide and they are biodegradable. However, a problem with known methods for producing bioplastic products based on macroalgae is that the properties of the macroalgae from which the polysaccharides are obtained are subject to natural fluctuations. Therefore, continuous production of such bioplastic products with consistent processing parameters and consistent product quality cannot be achieved in a satisfactory manner, so that the industrial production of bioplastic products based on macroalgae has not yet been successful. Summary of the invention

[0004] Based on this situation, the object of the present invention is to propose a method that can continuously and simply produce bioplastic products based on macroalgae.

[0005] The objects of the invention are achieved by the features of the independent claims. Advantageous embodiments are provided in the dependent claims. If technically feasible, the teachings of the dependent claims can be combined with the teachings of the independent and dependent claims as required.

[0006] The advantages of the claimed aspects of the invention are explained below and preferred modified embodiments of aspects of the invention are further described. The explanations, especially the explanations about the definitions of advantages and features, are basically descriptive and preferred embodiments, rather than restrictive embodiments. If the explanations are restrictive, they will be explicitly mentioned.

[0007] According to a first aspect of the present invention, this object is achieved by a method for producing a polymer material, the method comprising the steps of providing macroalgae containing carrageenan, adjusting the weight average molecular weight of the carrageenan to less than 800,000 g / mol, supplying the macroalgae to a processing chamber and processing the macroalgae in the processing chamber to form a polymer material.

[0008] When elements are named by numbers, such as "first element", "second element" and "third element", the numbers are used only to distinguish the names and do not indicate a dependency of the elements on each other or a mandatory order of the elements. This means in particular that, for example, a device or process does not have to include a "first element" to include a "second element". Furthermore, the device may also include a "first element" as well as a "third element" without necessarily including a "second element". It is also possible to provide a single number for multiple units of an element, such as multiple "first elements".

[0009] A polymer material is understood to mean a material which is formed at least partially from macromolecules, in particular crosslinked macromolecules, and which is suitable for further processing into a plastic product. A plastic product is understood to mean a polymer material which is brought into a specific product form. In particular, the plastic product is subsequently provided with the desired material properties after shaping (for example by drying and cooling the plastic product). As long as a plastic product carries the prefix "bio", it is a plastic product made exclusively of biodegradable materials. In particular, a bioplastic product is made exclusively of polymer materials based on polysaccharides from macroalgae and is completely biodegradable overall.

[0010] The processing chamber is formed by a cavity which can be filled, for example, via an inlet and can be emptied, for example, via an outlet, wherein the inlet and outlet can also coincide. In particular, the processing chamber is, for example, a closed cavity into which the macroalgae and optionally other raw materials are initially introduced and which is then closed. However, the processing chamber is preferably a processing chamber with one or more inlets and one or more outlets, in which the processing can be carried out continuously. The inlet and outlet are then sealed, for example by the inflow of raw materials or the outflow of polymer material, so that the interior of the processing chamber can be pressurized to a level above the ambient pressure. In or at the processing chamber, a device for controlling the temperature and pressure in the processing chamber is particularly provided.

[0011] The macroalgae have a certain natural proportion of carrageenan, which forms the polymer structure of the polymer material or bioplastic and for this purpose forms compounds and / or crosslinks during the production process. Preferably, the macroalgae are dried and comminuted for processing, wherein the macroalgae particles thus obtained are mechanically, chemically and / or thermally bonded and / or crosslinked during processing to form the polymer material or bioplastic product. For example, red algae such as Kappaphycus Alvarezii or Euchema Denticulatum are used as macroalgae.

[0012] The molecular weight of a macromolecule, also called molecular mass, is the sum of the molar masses of the repeating structural units. The molar mass of a structural unit consists of the sum of the masses of the atoms that make up that structural unit. Polymers do not have an exact molecular weight, but have a molecular weight distribution that allows for various average values, such as the number average molecular weight. or weight average molecular weight Weight average molecular weight Given by the following formula

[0013]

[0014] where w i is the weight fraction of polymer molecules composed of i monomer units, so w i Describes the weight of the polymer molecule N i M i The total mass of all polymer molecules ∑N i M i Ratio.

[0015]

[0016] Therefore, the measured molar masses of macromolecules always represent average values.

[0017] The weight average molecular weight of carrageenan is determined in particular by gel permeation chromatography, in particular after the carrageenan is extracted from macroalgae. The determination specifically comprises the following steps: (a) providing a 1% acetic acid / sodium acetate buffer having a pH of 7.5 to 8.0, (b) adding about 1.5% of a carrageenan-containing material, (c) extracting the carrageenan at 95° C. for 1 to 2 hours using a low speed stirrer, (d) filtering through a filter cloth and a filter aid layer on top using a suction filter, (e) cooling to below 50° C. after filtering, (f) coagulating the carrageenan with 2 to 3 parts of isopropanol, and (g) drying the carrageenan at or below 60° C.

[0018] The first aspect of the present invention now includes the teaching that molecular weight is used as a factor for the qualification of macroalgae for the production of polymer materials. This is based on the surprising discovery that by keeping the weight-average molecular weight of the contained carrageenan less than 800,000 g / mol while keeping the processing parameters constant, a polymer material with consistent properties is obtained, which enables the production of bioplastic products in a continuous process with consistent properties and consistent product quality, wherein the macroalgae as a whole are used as raw materials. Thus, although the properties of the natural raw materials used are correspondingly subject to natural fluctuations, it is still possible to achieve consistent material properties of the polymer material. Thus, in a continuously performed process, the macroalgae can continuously and consistently supply carrageenan with a regulated weight-average molecular weight of less than 800,000 g / mol. The method according to the first aspect of the present invention enables the continuous industrial production of polymer materials or bioplastic products based on macroalgae in a particularly advantageous manner. In particular, the polymer material produced by the method according to the first aspect of the present invention can be molded by various remolding processes as required, thereby establishing a wide range of applications.

[0019] The conventional weight average molecular weight of polysaccharides naturally occurring in macroalgae varies greatly from one macroalgae to another and is, for example, in the range of 200,000 g / mol to 1,300,000 g / mol. It is also known from the literature that certain polysaccharides or certain macroalgae have values ​​of up to 2,000,000 g / mol. In particular, the molecular weight of polysaccharides present in a certain macroalgae may vary greatly. The method according to the first aspect of the invention includes the teaching of adjusting the weight average molecular weight in the macroalgae in this regard.

[0020] In the processing chamber, the macroalgae are preferably mixed with a liquid, especially water, with a ratio of liquid to solid of 3:1 to 1:9 for processing, wherein in the processing chamber, the vapor pressure of water at least at a first temperature greater than or equal to 100 degrees Celsius acts on the mixture and adjusts the mixture to the first temperature.

[0021] The method preferably comprises an additional step of determining the weight average molecular weight, in particular by gel permeation chromatography, such as by the above-mentioned gel permeation chromatography step or by an indirect method, before the macroalgae is supplied to the processing chamber. This additional step is preferably carried out after or during the adjustment of the weight average molecular weight. In this way, the weight average molecular weight of the carrageenan after adjustment is verified and ensured. In one embodiment, the verification and assurance can be carried out by an indirect method, so that the determination can be carried out in a sufficiently short time to process a large amount of macroalgae during the continuous operation of the method.

[0022] Preferably, macroalgae is processed in a processing chamber to form a polymer material by the physical crosslinking of carrageenan. Physical crosslinking can be caused by various parameters (particularly the formation of hydrogel). The entanglement or interlocking of macromolecules that can be affected by the concentration and molecular weight of polymers in solution is just a method of gelation. Other physical crosslinking methods are based on, for example, hydrogen bridge bonds, hydrophobic, hydrophilic, ionic interactions (Coulomb force), complex formation or the formation of crystal structure. This form of gel formation is reversible. K-carrageenan or l-carrageenan and other polysaccharides form hydrogels in aqueous solution by forming intramolecular bonds and intermolecular bonds, wherein the hemiacetal oxygen group, hydroxyl or methyl of the polysaccharide residue promotes hydrogen bridge bonds or van der Waals bonds. The sulfate group and carboxyl group of the sugar residue of some acidic polysaccharides (for example, k-carrageenan, l-carrageenan or alginate) also participate in intramolecular binding and / or intermolecular binding by monovalent or divalent cations, which show as ionic bonds or electrostatic attraction.

[0023] Depending on the molecular weight, the polysaccharides can be processed, in particular physically crosslinked, to carry out the method, with different degrees of processing in certain processing parameters and in certain equipment, wherein in particular the resulting polymer material has different properties depending on the molecular weight of the polysaccharide. The properties of the polymer material should be such that the polymer material can be easily processed in given equipment with given processing parameters and can be processed into a bioplastic product with advantageous properties for a specific application. Therefore, the weight-average molecular weight of the macroalgae carrageenan is preferably determined according to the processing parameters, the equipment and the desired properties of the resulting bioplastic product and adjusted accordingly. Relevant properties of the polymer material are, for example, its rheological properties and chemical properties. Relevant properties of the bioplastic product are in particular mechanical properties, such as toughness and strength, and for example chemical resistance. For example, the weight average molecular weight of the carrageenan used to provide the macroalgae is adjusted to less than 800,000 g / mol, less than 790,000 g / mol, less than 780,000 g / mol, less than 770,000 g / mol, less than 760,000 g / mol, less than 750,000 g / mol, less than 740,000 g / mol, less than 730,000 g / mol, less than 720,000 g / mol, less than 710,000 g / mol, less than 700 ,000g / mol, less than 690,000g / mol, less than 680,000g / mol, less than 670,000g / mol, less than 660,000g / mol, less than 650,000g / mol, less than 640,000g / mol, less than 630,000g / mol, less than 620,000g / mol, less than 610,000g / mol, less than 600,000g / mol, less than 590,000g / mol, less than 580 ,000g / mol, less than 570,000g / mol, less than 560,000g / mol, less than 550,000g / mol, less than 540,000g / mol, less than 530,000g / mol, less than 520,000g / mol, less than 510,000g / mol, less than 500,000g / mol, less than 490,000g / mol, less than 480,000g / mol, less than 470,000g / mol, less than 460 ,000g / mol, less than 450,000g / mol, less than 440,000g / mol, less than 430,000g / mol, less than 420,000g / mol, less than 410,000g / mol, less than 400,000g / mol, less than 390,000g / mol, less than 380,000g / mol, less than 370,000g / mol, less than 360,000g / mol, less than 350,000g / mol, less than 340,000g / mol, less than 330,000g / mol, less than 320,000g / mol, less than 310,000g / mol, less than 300,000g / mol, less than 290,000g / mol, less than 280,000g / mol, less than 270,000g / mol, less than 260,000g / mol, less than 250,000g / mol, less than 240,000g / mol, less than 230,000g / mol, less than 220,000g / mol, less than 210,000g / mol, less than 200,000g / mol, less than 190,000 g / mol, less than 180,000 g / mol, less than 170,000 g / mol, less than 160,000 g / mol, less than 150,000 g / mol, less than 140,000 g / mol, less than 130,000 g / mol, less than 120,000 g / mol, less than 110,000 g / mol, less than 100,000 g / mol, less than 90,000 g / mol, less than 80,000 g / mol, less than 70,000 g / mol, less than 60,000 g / mol or less than 50,000 g / mol. ,

[0024] In addition, the weight average molecular weight of carrageenan used to provide macroalgae is preferably adjusted to greater than 1,000 g / mol, greater than 10,000 g / mol, greater than 20,000 g / mol, greater than 30,000 g / mol, greater than 40,000 g / mol, greater than 50,000 g / mol, greater than 60,000 g / mol, greater than 70,000 g / mol, greater than 80,000 g / mol, greater than 90,000 g / mol or greater than 100,000 g / mol.

[0025] In the case of macroalgae, the weight average molecular weight of the carrageenan is determined, for example, by mechanical, thermal, chemical, enzymatic, aerobic and / or anaerobic biological methods, radiation and / or ultrasound. Preferably, the macroalgae is enzymatically treated to adjust the weight average molecular weight of the carrageenan, and subjected to tempering and / or storage.

[0026] Macroalgae containing carrageenan are particularly suitable for the present method because, in addition to processing (especially physical crosslinking), they also have favorable properties for being transported into the processing chamber (for example to the molding equipment) and also have favorable material properties for bioplastic products. In addition to carrageenan, macroalgae can also contain other substances.

[0027] In a preferred embodiment, in addition to the macroalgae, at least one second raw material, in particular an aqueous liquid, is supplied to the processing chamber. For example, the liquid is essentially formed by water and may also contain other substances. In particular, the liquid may also contain a solid, which is or becomes a liquid, for example, at the temperature and pressure in the processing chamber. It is also within the scope of the present invention if the macroalgae and other raw materials (e.g. the second raw material) are added at different times in the method. The second raw material can be designed for various processing-related functions, such as improving the rheological properties or solubility of the carrageenan, or achieving certain properties of the polymer material or the bioplastic product made therefrom, such as certain mechanical properties. Particularly preferably, the second raw material comprises water and at least one additive, such as a solvent and / or a plasticizer, to achieve good solubility of the carrageenan and good mechanical properties of the bioplastic product made from the polymer material.

[0028] The additive in solvent form preferably has a high polarity so that good overall solubility of the polar carrageenan can be achieved.

[0029] It is further preferred that the additive is non-volatile. In particular, the additive in the form of a plasticizer is non-volatile. Thus, during and after the drying and cooling of the bioplastic product, the additive remains in the bioplastic product and does not evaporate. This applies in particular to the expected use or transport conditions, in particular the expected use or transport temperature of the bioplastic product, for example at ambient temperatures of up to 80 degrees Celsius. Such temperatures can be reached, for example, in a transport container under solar radiation.

[0030] In a preferred embodiment, at least one additive includes glycerol and / or sorbitol. In other embodiments, at least one additive is formed by pentaerythritol, polyols, sugar alcohols, poly(ethylene oxide), poly(propylene oxide), nonionic surfactants and / or anionic surfactants, which respectively act as plasticizers in bioplastic products. Other preferred additives that act as solvents in particular are glycols (e.g., ethylene glycol or diethylene glycol), methanol, ethanol, maltodextrin and / or urea. The following substances may also be used as additives: 1,3-butanediol, acetate and fatty acid esters of glycerol, acetone, acetylated distarch adipate, acetylated monoglyceride, acid-treated starch, alkali-treated starch, ascorbic acid, palmitic acid ascorbyl ester, ascorbyl stearate, azodicarbonamide, beeswax, bleached starch, bone phosphate, brominated vegetable oil, calcium acetate, calcium aluminum silicate, vegetable oil, calcium ascorbate, calcium benzoate, calcium bromate, calcium carbonate, calcium chloride, calcium citrate, calcium dihydrogen phosphate, calcium ferrocyanide, gluconic acid Calcium, calcium bisulfite, calcium hydroxide, calcium iodate, calcium lactate, calcium lactate gluconate, calcium lactobionate, sucrose, calcium peroxide, calcium phosphate, calcium polyphosphate, calcium salts of fatty acids, calcium silicate, calcium sorbate, calcium stearate, calcium stearoyl lactylate, calcium sulfate, calcium tartrate, soy protein, calcium iodate, candelilla wax, carnauba wax, locust bean gum, castor oil, citric acid, pea protein, citric acid and fatty acid esters of glycerol, crosslinked sodium carboxymethylcellulose, carboxymethylcellulose, copper sulfate of mono- and di-glycerides of fatty acids sulfate of monound diglycerides of fatty acids), diammonium sulfate, dicalcium pyrophosphate, diethyl pyrocarbonate, ethanol, ethyl cellulose, ethyl hydroxyethyl cellulose, esters of glycerol and thermally oxidized soy fatty acids, zein, ethoxylated mono- and diglycerides, ethyl hydroxyethyl cellulose, formic acid, gelatin, glycerine, guar gum, gum arabic, peroxide derivatives, hydrogen peroxide, hydroxylated lecithin, hydroxypropyl cellulose, hydroxypropyl distarch, cellulose derivatives.

[0031] According to a second aspect of the invention, the object is achieved by a method for producing a bioplastic product in an apparatus comprising a processing chamber and at least one molding device, the method comprising the following steps: producing a polymer material from carrageenan-containing macroalgae in a processing chamber according to a prescribed method, and molding the polymer material in at least one molding device to form a bioplastic product. In this case, molding can be carried out, for example, in a processing chamber designed as a mold in the case of a molding process, simultaneously with or before crosslinking, or, for example, in an extrusion process, after crosslinking. Using the method according to the second aspect of the invention, the advantages already described for the first aspect of the invention are correspondingly achieved. In particular, the method is suitable for producing bioplastic products with consistent properties or consistent product quality in a continuous process.

[0032] The method according to the second aspect of the present invention may also optionally include the step of drying the bioplastic product and / or cooling the bioplastic product. Here, drying and / or cooling the bioplastic product is optional, because it is only performed or must be performed when there is a corresponding residual moisture and / or temperature in the bioplastic product after molding (i.e. when the residual moisture and / or temperature is higher than the desired one).

[0033] The processing chamber in the method according to the second aspect of the invention can, for example, be formed by a simple cavity, wherein the method is carried out in batches. In a preferred embodiment, the processing chamber is formed by a screw extruder. Particularly preferably, the screw extruder is formed as a twin-screw extruder. In the screw extruder, one or more parallel screws extend through a channel, suck in the macroalgae or raw material on the inlet side, and push them into or through a forming device on the outlet side. Preferably, several raw materials are mixed in the screw extruder. Here, the geometry of the screws and the operating parameters of the screw extruder can be used to determine the conveying capacity of the screw extruder and the pressure in the processing chamber. Preferably, the pressure cannot escape from the inlet side or the outlet side of the processing chamber because the inlet and outlet are sealed by the macroalgae / raw material and the polymer material.

[0034] Particularly preferably, at least one shaping device is formed by an extrusion nozzle. By using an extrusion nozzle, the polymer material coming out of the processing chamber can be continuously shaped into endless forms, such as films, film semi-finished products or profiles. An optional drying and cooling process can be carried out after the shaping step, for example under ambient conditions, wherein the waste heat of the bioplastic product can be used to dry the bioplastic product. In another embodiment, at least one shaping device is formed by an injection molding device. Then, the polymer material can be used to produce bioplastic products with relatively complex geometries by injection molding.

[0035] According to a third aspect of the present invention, the object is achieved by a bioplastic product obtained by the method according to the second aspect of the present invention. The bioplastic product accordingly has the advantages of the first and second aspects of the present invention. In particular, the bioplastic product has consistent properties and consistent product quality, is fully biodegradable, and can be produced into relatively complex geometric shapes.

[0036] In particular, the bioplastic product is characterized in that, like macroalgae, it has a weight average molecular weight of polymer molecules. In one embodiment, the molecular weight of the bioplastic product is less than 700,000 g / mol, less than 690,000 g / mol, less than 680,000 g / mol, less than 670,000 g / mol, less than 660,000 g / mol, less than 650,000 g / mol, less than 640,000 g / mol, less than 630,000 g / mol, less than 620,000 g / mol, less than 610,000 g / mol, less than 600,000 g / mol, less than 590,000 g / mol, less than 580,000 g / mol, less than 570,000 g / mol, less than 560,000 g / mol, less than 58 ... g / mol, less than 550,000 g / mol, less than 540,000 g / mol, less than 530,000 g / mol, less than 520,000 g / mol, less than 510,000 g / mol, less than 500,000 g / mol, less than 490,000 g / mol, less than 480,000 g / mol, less than 470,000 g / mol, less than 460,000 g / mol, less than 450,000 g / mol, less than 440,000 g / mol, less than 430,000 g / mol, less than 420,000 g / mol, less than 410,000 g / mol, less than 400,0 00g / mol, less than 390,000g / mol, less than 380,000g / mol, less than 370,000g / mol, less than 360,000g / mol, less than 350,000g / mol, less than 340,000g / mol, less than 330,000g / mol, less than 320,000g / mol, less than 310,000g / mol, less than 300,000g / mol, less than 290,000g / mol, less than 280,000g / mol, less than 270,000g / mol, less than 260,000g / mol, less than 250,000g / mol, less than 240 ,000g / mol, less than 230,000g / mol, less than 220,000g / mol, less than 210,000g / mol, less than 200,000g / mol, less than 190,000g / mol, less than 180,000g / mol, less than 170,000g / mol, less than 160,000g / mol, less than 150,000g / mol, less than 140,000g / mol, less than 130,000g / mol, less than 120,000g / mol, less than 110,000g / mol, less than 100,000g / mol, less than 90,000g / mol, less than 80,000 g / mol, less than 70,000 g / mol, less than 60,000 g / mol, less than 50,000 g / mol, less than 40,000 g / mol, less than 30,000 g / mol, less than 20,000 g / mol or less than 10,000 g / mol. ,

[0037] It is further preferred that the bioplastic product is formed into a film, a film semi-finished product or a profile. With such a bioplastic product, the advantages of the method according to the second aspect of the invention are particularly achieved. In particular, such a bioplastic product requires product properties to be adjusted within narrow limits and to have a consistent quality. For example, in the case of a film, a local deviation in product quality at a certain point of the film will lead to an increased risk of cracking at that point. Furthermore, it is particularly preferred that the bioplastic product is extruded. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The present invention will be described in more detail below based on preferred embodiments in conjunction with the accompanying drawings. In the accompanying drawings, the term "drawing" is abbreviated as "figure".

[0039] In the attached picture:

[0040] Figure 1 A schematic flow chart of a method according to a first aspect of the present invention is shown;

[0041] Figure 2 A schematic flow chart showing a method according to a second aspect of the present invention; and

[0042] Figure 3 A schematic cross-sectional view of an apparatus for performing the method according to the first aspect and / or the second aspect of the present invention is shown. DETAILED DESCRIPTION

[0043] The exemplary embodiments described are merely examples and may be modified and / or supplemented in various ways within the scope of the claims. Each feature described for a specific exemplary embodiment may be used independently or in combination with other features in any other exemplary embodiment. Each feature described for an exemplary embodiment of a specific claim category may also be used in a corresponding manner in exemplary embodiments of different claim categories.

[0044] Figure 1A method 1 according to a first aspect of the invention is shown, which is used to produce a polymer material from carrageenan-containing macroalgae in a processing chamber. In a first step 11, macroalgae containing carrageenan are provided. In a second step 12, the weight-average molecular weight of the carrageenan of the macroalgae is adjusted to less than 800,000 g / mol to achieve that the macroalgae can be processed with consistent properties and consistent product quality in subsequent steps. In a third step 13, the macroalgae is supplied to the processing chamber. In particular, other raw materials (such as liquids containing water and additives) for improving the processing conditions in the processing chamber and / or the properties of the first raw material and / or its (intermediate) product are supplied to the processing chamber. In a fourth step 14, the macroalgae in the processing chamber is processed, in particular by physical crosslinking of the carrageenan, to form a polymer material. The third step 13 and the fourth step 14 can be performed sequentially or simultaneously, or can be smoothly merged with each other.

[0045] Figure 2 A method 2 according to a second aspect of the invention is shown for producing a bioplastic product in an apparatus comprising a processing chamber and a molding device. Method 2 first comprises method 1, wherein a polymer material is produced in a processing chamber, in particular by physical crosslinking of carrageenan. This is followed by a fifth step 15, wherein the polymer material is molded in a molding device to form the bioplastic product. The molding device can be, for example, an extrusion nozzle or an injection molding device. In an optional sixth step 16, the bioplastic product is dried, and in a also optional seventh step 17, the bioplastic product is cooled. The sixth step 16 and the seventh step 17 can be performed simultaneously, wherein the waste heat dissipated by the cooling can also be used to dry the bioplastic product.

[0046] Figure 3 An apparatus 3 for carrying out the method 1 according to the first aspect of the invention and / or the method 2 according to the second aspect of the invention is shown. The apparatus 3 is designed as a twin-screw extruder and comprises a processing chamber 4, wherein two screws 5.1, 5.2 are arranged on parallel rotation axes. The screws 5.1, 5.2 are shown in a greatly simplified form, but comprise windings (not shown) whose geometry matches one another, so that the screws 5.1, 5.2 exert pressure on the medium arranged in the processing chamber 4 during rotation and also cause the medium to mix and be conveyed in the axial direction A.

[0047] The carrageenan-containing macroalgae 7 is introduced into the processing chamber 4 via a funnel 6, and a second raw material 8 is introduced via a hose, the second raw material 8 being in particular in liquid form and containing at least one additive in addition to water. The second raw material 8 is particularly used to ensure that the carrageenan can be at least partially dissolved therein. The macroalgae 7 and the second raw material 8 are mixed in the processing chamber 4 by screws 5.1, 5.2. The resulting mixture is conveyed along the processing chamber 4 in the axial direction A while being further mixed and pressurized. In addition, the mixture is temperature-controlled to the processing temperature by using a temperature control device 9. In addition, the mechanical work done by the screws 5.1, 5.2 on the mixture also introduces thermal energy. In general, during the passage through the processing chamber 4, the carrageenan in the mixture is physically cross-linked, so that the macroalgae 7 is processed to form a polymer material.

[0048] A molding device 10 is arranged at the end-side outlet of the processing chamber 4 in the axial direction A, through which the polymer material is pushed. The molding device 10 is configured, for example, as an extrusion nozzle, wherein, at the extrusion nozzle, molding extrusion into a desired geometry (e.g., the geometry of a profile, a film or a film semi-finished product) is performed. Downstream of the extrusion nozzle, for example, a cooling and drying section not shown in detail is provided, through which the bioplastic product formed at the extrusion nozzle can be cooled and / or dried. The molding device 10 can also be designed as an injection nozzle for injecting the polymer material into an injection mold. The bioplastic product formed by injection molding (e.g., after molding) is then removed from the injection mold and cooled and / or dried in ambient air.

[0049] Reference numerals list

[0050] 1 Method

[0051] 2 Methods

[0052] 3 Equipment

[0053] 4 Processing room

[0054] 5.1 Screw

[0055] 5.2 Screw

[0056] 6 Funnel

[0057] 7. Macroalgae containing carrageenan

[0058] 8 Second raw material

[0059] 9 Temperature control device

[0060] 10 Molding equipment

[0061] 11First processing step – providing macroalgae

[0062] 12 Second processing step - adjusting the weight average molecular weight of carrageenan

[0063] 13 Third Processing Step - Supplying Macroalgae to the Processing Chamber

[0064] 14 Fourth processing step - processing of macroalgae to form polymer material

[0065] 15Fifth processing step - shaping the polymer material

[0066] 16Sixth processing step - drying the bioplastic product

[0067] 17 Seventh processing step - cooling the bioplastic product

[0068] A Axial direction

Claims

1. A method (1) for producing a polymer material, the method (1) comprising the steps (11, 12, 13): Providing macroalgae containing carrageenan (7); Adjusting the weight average molecular weight of the carrageenan to less than 800,000 g / mol; supplying the macroalgae (7) to a processing chamber (4); and The macroalgae (7) is processed in the processing chamber (4) to form a polymer material.

2. The method (1) according to claim 1, wherein: The processing of the macroalgae (7) in the processing chamber (4) to form a polymer material is performed by physical cross-linking of the carrageenan.

3. The method (1) according to claim 1 or 2, wherein: Before supplying the macroalgae (7) to the processing chamber (4), the weight average molecular weight of the carrageenan is determined, in particular by gel permeation chromatography after extraction of the carrageenan from the macroalgae (7) or by an indirect method.

4. A method according to any one of the preceding claims, wherein: The macroalgae (7) is adjusted to a weight average molecular weight of the carrageenan of less than 600,000 g / mol, in particular less than 400,000 g / mol.

5. The method (1) according to any one of the preceding claims, wherein: The macroalgae (7) is enzymatically treated, temperature-adjusted, mixed and / or stored to adjust the weight average molecular weight of the carrageenan.

6. The method (1) according to any one of the preceding claims, wherein: In addition to the macroalgae (7), at least a second raw material (8), in particular an aqueous liquid, is fed into the processing chamber (4).

7. The method (1) according to claim 6, wherein: The second raw material (8) contains water and at least one additive, in particular a solvent and / or a plasticizer.

8. A method (2) for producing a bioplastic product in a device (3) comprising a processing chamber (4) and at least one molding device (10), the method (2) comprising the following steps (11, 12, 13, 14, 15, 16): The method (1) according to any one of the preceding claims, producing a polymer material from carrageenan-containing macroalgae (7) in the processing chamber (4); shaping the polymer material in the shaping device (10) to form a bioplastic product; optionally drying the bioplastic product; as well as The bioplastic product is optionally cooled.

9. The method (2) according to claim 8, wherein: The processing chamber (4) is formed by a screw extruder, in particular a twin-screw extruder.

10. The method (2) according to claim 8 or 9, wherein: The at least one shaping device (10) is formed by an extrusion nozzle or an injection molding device.

11. The method (2) according to any one of claims 8 to 10, wherein: The method (2) is carried out continuously.

12. Bioplastic product obtained by the method (2) according to any one of claims 8 to 11.

13. The bioplastic product of claim 12, comprising a molecular weight of less than 700,000 g / mol.

14. The bioplastic product according to claim 12 or 13, which is formed into a film, a film semi-finished product or a profile.

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