A method for producing starch polymer liquid mixture

Abstract

The invention is related to a method for producing a starch polymer liquid mixture, especially a solution or a suspension, and a starch polymer liquid mixture which obtained by said method.

Description

[0001]DESCRIPTION A METHOD FOR PRODUCING STARCH POLYMER LIQUID MIXTURE Technical Field The present invention is an advanced method for producing starch liquid polymer mixtures, especially solutions and suspensions, by incorporating polymer powder through the process of dry annealing. This method enables the creation of versatile starch polymer forms, including both homogeneous solutions and stable suspensions. The starch polymer solutions and suspensions obtained through this groundbreaking technique exhibit enhanced properties and offer a wide range of applications. Prior Art (Acid) Hydrolysis of a starch suspension or starch slurry is an important chemical modification that can significantly change the structural and functional properties of starch without disrupting its granular morphology. This process requires processing times between two and three hours to complete the hydrolysis. Using the newly developed dry-ANNealing process and understanding the effect of hydrolysis on starch structure and functionality is of great importance during the physicochemical treatment of the starch. During this hydrolysis process, amorphous regions are preferentially hydrolyzed, which enhances the crystallinity and double helical content of acid hydrolyzed starch. The effects of hydrolysis on amylose content, chain length distribution of amylopectin molecules, molecular and crystalline organization (including lamellar structure) and granular morphology are the main instruments for the desired starch modification. By physicochemical treatment, obtained modified starch application’s individual functional properties include swelling power, gelatinization, retrogradation, pasting and gel texture which also includes the forming of so- called starch nanocrystals. There are typically two routes for manufacturing a starch-based biopolymer: a disperse polymer matrix or as a co-continuous phase matrix. The synthesis of polymer blends or copolymers is carried out to develop polymers with improved properties, e. g. mechanical properties, or properties that are generally not attainable in either single pure component. In 1    the synthesis of polymer blends of polar and nonpolar components there often arise miscibility problems. To increase the miscibility of hardly miscible or immiscible blends binding agents or compatibilizers, respectively, are used. Compatibilizers are substances which increase the stability and / or morphology of a hardly miscible or an immiscible blend of polymers by creating interactions between the two previously immiscible polymers. Copolymers are formed when the proper functional groups in each component of the immiscible blend interact with the binding agents or compatibilizer. These interactions include hydrogen, ionic or covalent bonds. Commonly, block or graft copolymers are used as compatibilizers, wherein the copolymer is made of the two components in the immiscible blend. The respective portions of the copolymer are able to interact with the two components of the immiscible blend to make the phase morphology more stable. The increased stability is caused by reducing the size of the phase-separated particles in the blend. The size reduction results from the lower interfacial tension, due to accumulating block copolymers at the interfaces between the two polymers. Thus, the immiscible blend breaks up into smaller particles in the melt phase. In turn, these phase separating particles do not consolidate and grow because the interfacial tension is much lower, wherein the polymer blend is stabilized. EP3632937A1 describes that the need for a further reactive extrusion process that is activated by the cross-linked starch / HBA polymer which gets hydra bonded with any other polymer. In this particular patent application, mentioned polymers are a PBAT ( Basf Ecoflex) a PBST ( Mitsubishi GS-Pla, a L(L)DPE ( INEOS, SABIC) a PVOH ( Aquapack) a PCL ( Perstorp) a PLA (Ingeo) PHB / PHA (Kaneka), into a new but typical for this process. Twisted Bundled Pair co-continuous phase where both polar and non-polar polymers form an integer part of the new almost transparent polymer with, sometimes enhanced properties of both single polymers. Instead of using a nano sized continuous layer of a compatibilizer as described in one of the older studies, an HBA (Hydro Binding Agent for Polymers) is binding the polar and non-polar polymers via HO and other carbolic molecules intertwined together as almost one polymer backbone. In this method, the composition of HBA must be mixed in twin screws extrude for molecular treatment and only after that the composition is blown. 2    As a result, all of the problems mentioned above has made it necessary to provide a novelty in the related field. Objects of the Invention The main object of the present invention is to establish a method for producing biopolymers liquid mixture, especially solution and suspension based upon starch. Especially, the aim is to provide a method for producing biopolymers liquid mixture, especially solution and suspension based upon native starch. As a result, all of the problems mentioned above have made it necessary to provide a novelty in the related field. Objects of the Invention The main object of the present invention is to establish a method for producing liquid biopolymer mixtures, especially solutions and suspensions based on starch. Specifically, the aim is to provide a method for producing liquid biopolymer mixtures, particularly solutions and suspensions based on native starch. Another objective of the present invention is to establish a method comprising steps of the physicochemical treatment of starch with the hydro-binding agent (HBA) in a continuous manner. Another objective of the present invention is to establish a cheaper method for producing starch-based polymer liquid mixture, especially solution and suspension. Another objective of the present invention is to eliminate the requirement of the compatibilizers without immiscibility problem. Another objective of the present invention is to provide starch polymer solutions with molecular-level homogeneity. Another objective of the present invention is to provide stable suspensions with well- dispersed polymer particles. Thus,  starch polymer solutions and suspensions gain improved characteristics and offer flexibility and applicability in various industries. 3    Another objective of the present invention is to achieve a prominent level of hydra binding a starch with any type of other polar or non-polar polymer typically having a melting temperature in the range of 65°C to max.140°C. Another objective of the present invention is replacing molecular treatment with physicochemical treatment and obtaining Starch Polymer Powder (SPP) liquid mixture which can be produced by a single screw extruder or together with a co-polymer without compounding, directly being blown, casted or injected into a wide range of polymer applications. Another objective of the present invention is obtaining SPP liquid mixture especially suitable as a Starch co-polymer in a cold XNBR “dipping” process and natural rubber applications. Another objective of the present invention is eliminating extrusion step requirement in couple of the application. However, this invention is also applicable in extrusion process, too. Brief Description of the Invention The invention describes a dry annealing method for producing starch-based polymer. The annealing (ANN) process already has important industrial applications, imparting different characteristics to products due to an increase in starch granule size, thermal stability, Tgeland the availability of starch to digestion by enzymes such as α-amylase. In ANN, the parameters of moisture, temperature and heating time determine the results. The ANN process requires normally an excess of water (76% w / w) or an intermediate containing water (40% w / w). The objective of this treatment is to improve molecular mobility. ANN is associated with a physical reorganization of the starch granule in the presence of water. Water is a suitable plasticizer for starch. Starch granule hydration causes a transition from a glassy to a static state, increasing the mobility of the amorphous regions to a crystalline state. These changes generate tangential and radial movements in the crystalline and amorphous regions, and physicochemical modifications increase chain interaction in the crystallinity region. The ANN process is associated with partial gelatinization of starch state that the ANN term can only be used when the temperature of the process does not reach Tgeland therefore gelatinization does not occur. In ANN starch, the Tgelafter modification is not less than the Tgelof the native starch. 4    However, there is ANN process, or dry ANN process, that is introduced for making a biopolymer. The term “dry” doesn’t refer the method doesn’t use any of water. It only means the water content is very low for a normal ANN process. The method of the present invention is still water / liquid at a very low rate. Furthermore, post drying of components is not necessary for the dry ANN process, in contrast to normal ANN processes. Moreover, product can be in powder form with certain residual moisture (RM). For example, RM for corn starches between 12% and 20% and is 19% and 27% for potato starches. To achieve such a goal, the dry annealing process was introduced for process of starch-based biopolymers. In this process, a starch is “opened and activated” by dry annealing process friction and friction induce on the starch granule structure in the presence of an Acid and crosslinker and hydro binding agent. In this process, the amylose and amylopectin molecules are being rearranged, cross-linked, and preferably mixed with one or more emulsifiers an anti- stalling agent and other processing aid. To make this dry-annealing process possible, a preliminary acid hydrolysis process is undertaken. Where the pre hydrolized starch now does not get distrought by the rigerous drying process. The resulting modified starch has a better molecular structure in which the ANN process can work better on. Detailed description of the present invention   The invention is related to a method for producing a starch polymer, especially bio(degradable) polymer, preferably in powder form, and a starch polymer powder which obtained by said method. The main steps of this method are; At the end of the production of starch, during slurry phase, 0.5 to 2% (w / w) of at least 1 acid is added. To enable the dry-annealing process, a preliminary acid hydrolysis step is conducted. This ensures that the pre-hydrolyzed starch is not adversely affected by the rigorous drying process. The resulting modified starch has an improved molecular structure that is more compatible with ANN processes. 5    Detailed Description of the Present Invention The invention pertains to a method for producing a starch polymer, specifically a biodegradable polymer, preferably in powder form. The method also produces a starch polymer powder obtained through this process. The main steps of this method are as follows: At the end of starch production, during the slurry phase, 0.5 to 2% (w / w) of at least one type of acid is added to initiate pseudo-hydrolysis. Adding 0.2 to 2 % at least one acid by total weight of the liquid mixture and 1 to 6 w% initiator by total weight of the liquid mixture to the starch polymer powder, Cross-linking by addition of at least one cross-linker, Hydro binding by adding at least 2 to 20 % a hydro binding agent by total weight of the liquid mixture wherein. the temperature of suspension is kept between a gelatinization temperature (Tgel) of the starch polymer. Preferably, these steps are carried out according to the specific loading and temperature regime given in table 1. This process can be used for starch-based (bio)polymer solution and suspension. 6    Table 1. Load and Temperature Regime In a preferred embodiment the product of the starch ANNealing, Physicochemical Treatment according to the invention is a starch polymer that is produced by partial or full destructuration of the starch granule structure. In a further embodiment the starch granule structure is 70% to 90% de-structured, preferred 0.2 to 4w%, preferably 0.2 to 2w% acid. The acid as used herein, acetic acid, phosphoric, hydrochloric, citric, acetic, lactic, malic, tartaric, sulfuric, ascorbic, succinic, or stearic acid which is introduced by degree or the amount of hydrolysis. During test trials,  higher acid ratios worked better in combination with "cold" suspension polymers like (X)NBR. Higher acid ratios would work less better when the SPP would be processed under high temperatures and pressures typically used in extrusion compounding processes. The SPP would be more susceptible to degradation. In a further preferred embodiment, the provision of an acid according to step a) is carried out by suspension in an aqueous liquid mixture, mostly preferred in the initiator. Preferably, the initiator is starch plasticizer, especially in deionized water or solvent. In an embodiment the concentration of the acid suspension is 0.2% to 4% (w / w), preferred 1% (w / w). As used herein, “% (w / w)” refers to the mass of the acid relating to the mass of the acid suspension. In a further embodiment the suspension of an acid in an initiator, preferably solvent, is carried out under constant mixing. In a further embodiment the suspension of the initiator is carried out at a temperature between 15 and 65°C, preferably 20°C and 55°C. According to the invention, the provision of an acid, preferred the provision of a suspension of an acid in an initiator, is followed by the adjustment of the pH value to at least pH 2.1 at the start of the process. In a preferred embodiment the pH value is adjusted to pH 7.5 to 8.2. 7    from pH 2.1. This adjustment is carried out by use of pH adjuster, for example borax or sodium carbonate. In an embodiment the adjustment of the pH value to at least pH 7.3 according to step b) is carried out by addition of at least one crosslinker. In an embodiment the crosslinker is selected from, Phosphorous oxychloride, boric acid, sodium trimetaphosphate (STMP), sodium tripolyphosphate (STPP), epichlorohydrin, formaldehyde, Citric acid, preferred base is sodium hydroxide or bicarbonate. Advantageously, the addition of at least one carbonate produces a buffer solution. As used herein, the term “buffer” refers to mixture of a weak acid and its conjugate base or a mixture of a weak base and its conjugate acid, wherein the addition of an acid or a base does not change the pH value of the mixture. In a further embodiment the adjustment of the pH value to at least pH 7.3 according to step b) is carried out at a temperature between 25°C and 65°C, preferably at a temperature between 30°C and 55°C. In a further embodiment, the addition of at least one fatty acid and HBA according to step a) is carried out continuously and / or stepwise. In an embodiment the addition of HBA according to step a) is carried out between 1 to 20% w / w. In a preferred embodiment the addition of HBA according to step a) is carried out by addition 0.25 to 0.75% by total weight of the starch, preferably 2 to 7% total weight of the starch, preferably the addition of 0.25 to 1% (w / w) of at least one fatty acid. Advantageously, the addition of the HBA induces hydro binding and further crosslinking. In a further embodiment, residual moisture content of HBA is between 20% and 90%. In a further embodiment step a) is carried out at a temperature between 35°C and 65°C, preferably 40 to 45°C. Higher temperatures are not recommended as unwanted side effects due to the increased lumping can occur. In a further embodiment the method for production of a SPP according to the invention comprises the addition of an initiator before step a) or during step a) or before and during step a). In an embodiment the addition of an initiator is carried out before, during and after the addition of the crosslinker. In a preferred embodiment the addition of an initiator is carried out before the addition of the HBA, 8    In an embodiment the initiator is an inorganic compound preferred the initiator is selected from, water, sodium chloride, sodium bicarbonate, calcium carbonate, and muriatic acid or zinc oxide, mostly preferred the initiator is water. Advantageously, the initiator forms free radicals and thus initiates the reaction. In an embodiment step a) is continued for 3 min to 10 min after the initial addition of HBA, preferred after the addition of the initiator. In an embodiment step c) is continued until step b is finished. In one embodiment the pH value after the ANNealing ranges from 2.5 to 8.7, preferably 5.9 to 6.5. In a further embodiment the method for production of SPP according to the invention comprises the addition of a reducing agent after step a). In an embodiment the reducing agent is selected from Lithium hydroxide, sodium bisulphite, silicon dioxide, phosphoric acid, sodium tetraborate decahydrate and / or ionic cross-linkers, like graphene or silicates, nesosilicates or phyllosilicates, phosphoric acid. In a preferred embodiment the reducing agent is sodium hydroxide (NaOH). Advantageously, the reducing agent reduces the initiator and thus prevents side reactions. In a further embodiment the addition of a reducing agent is carried out at a temperature between 25 and 55°C, preferably 40°C and 45°C. In a further embodiment the method for production of SPP, the mixture of temperature is kept at or above 25°C. This temperature corresponds with the packaging temperature to prevent condensation to occur of the product and also the "flowability" will increase as a "Cakeking" of the powder will decrease. The basic feature of starch rheology is its viscosity. Other rheological characteristics involve texture, transparency or clarity, shear strength and the tendency for retrogradation. All of these features play important roles in the commercial applications of the SPP. Rheological SPP properties were studied through the behavior of viscosity curves, which are influenced by temperature and concentration. “Paste properties” is the term used to describe the changes that occur in starch after gelatinization in excess water. Rapid Visco Analyzer (RVA) Instrument was used to describe the viscosity parameter as functions of temperature and time. The RVA 9    describes paste behavior in three periods: (i) a controlled heating period, increasing the temperature of the liquid mixture from room temperature to a maximum that is generally determined at 95 °C; (ii) an isothermal period, maintaining the liquid mixture at the maximum temperature for analysis; and (iii) a cooling period, decreasing the temperature to approximately 50 °C. Throughout the analysis, the suspension is subjected to shear forces. Liquid mixture typically exhibits a peak in viscosity that starts after gelatinization and increases as the granules swell, followed by a decrease in viscosity due to granule disintegration and polymer realignment. A “Breakdown” is defined by a difference between the viscosity peak and the minimum viscosity at the maximum analysis temperature. During the cooling period, amylose leaching forms a gel or three-dimensional network. Gel formation further increases the viscosity, called the “cold paste viscosity”. The difference between the paste viscosity at the end of the cooling period and the minimum viscosity at 95 °C is termed the “setback”. Starch gels are composed of amylose chains and intermediate materials dispersed in a starch liquid mixture after granule disintegration in a three-dimensional network structure. The level and nature of the leached material and molecular interactions determine the viscoelastic properties. Methods used to describe the viscoelastic parameters of the paste include equipment such as a dynamic rheometer, an amylograph or a viscoamylograph. Several parameters describe the viscoelastic behavior of pastes: (G’), the measure of recovered or accumulated energy in each deformation cycle and an indicator of the elastic behavior of the paste; the dissipated energy (G’’), the loss of energy in each deformation cycle that describes the viscosity behavior of the material; and the modulus or tangent (G’’ / G’), describing the material’s behavior (high values (›1) indicate liquid-like behavior, and low values indicate solid-like (<1) behavior). Gel resistance is determined using a texture analyzer, in which parameters such as peak force [N] define the resistance of the three-dimensional network. The main factors affecting the rheological properties of starches are their source and the presence of other polymers. Many polymers coexist with starch in aqueous mixtures and interact in different ways to produce several attributes influencing the stability, texture and quality products. SPP paste viscosity is associated with lipids, mainly phospholipids, that complex with amylose and hinder or reduce the granule’s swelling capacity. Other effects associated with paste viscosity are decreased amylose solubility, increased formation time and limited gelling properties. Amylose-lipid complexes require high temperatures for 10    dissociation. Determining the thermal properties of the SPP involves terms such as the onset temperature (To), peak temperature (Tp), conclusion temperature (Tc), difference between Tc and To, and enthalpy of fusion, all of which can be measured using equipment like a differential scanning calorimeter (DSC) and depend on the starch concentration. During heating, To is the temperature at which the paste viscosity starts to increase; Tp is the maximum viscosity temperature; and Tc is the final temperature of the viscosity increment. (Tc-To) is a comparative measure, and an increase in this value indicates a high amount of granule modification in the amorphous and crystalline regions. Some researchers include retrogradation among the thermal properties of starch. This paste property typically begins 20 °C lower than its gelatinization temperature (Tgel), and retrogradation is proportional to the presence of amylopectin. Variations in a starch’s thermal properties after gelatinization and throughout refrigerated storage can be attributed to variations in the amylose / amylopectin ratio, the size and shape of the granule, and the presence or absence of lipids and proteins. Materials The materials used in the trial, their mean particle size and the supplier are listed in Table 2. In the first part of trials, excipients including, Loxiol EP55, and Loxiol G20 were used as the model materials to study the effect of material properties on the powder flow behavior. 11    Phosphorous oxychloride, Brenntag 10 boric acid, sodium trimetaphosphate (STMP), sodium tripolyphosphate (STPP), epichlorohydrin, formaldehyde, Citric acid Sorbitol, Glycerol, Mannitol, 0- Erythritol Table 2. Materials Chemical composition of the powder samples was analyzed using NIR spectroscopy. Chemometric calibration models were built for individual tracer-excipient combinations. The general protocol for building calibration models includes the following steps. Calibration samples with known concentrations of tracer are prepared by accurately massing the individual components. Calibration samples are then scanned multiple times to acquire representative spectra. The NIR analyzer used was an (Antaris system Thermo Fisher). The Ominc software package was used to acquire the calibration spectra, and the TQ Analyst was used to build the chemometric model. A PLS algorithm was used to build calibration curves. Each calibration model was validated using a cross-validation program (which leaves one spectra out at a time); in each case, after careful selection of spectral pre-treatments, a robust calibration model was built. Material flow properties were characterized using two methods, namely the Carr Index (C.I.) and the dilation. The Carr Index (C.I.) is an indicator of the compressibility of a powder. The higher the C.I. is, more compressible is the powder. The C.I. was calculated using Eq. 1 by measuring the bulk and tapped densities of a powder. [1] Dilation is a complementary measurement to the C.I. which is also an indicator of the 12    compressibility of the powder. Dilation was measured using a device called a GDR (Gravitational Displacement Rheometer). Dilation is calculated as the percent change in volume of the powder bed as function of time. Details on the experimental set-up of dilation measurement can be found in Faqih et al. [1] The procedure for dilation measurement can be briefly described as follows. Powder was filled up to 40% volume in a transparent acrylic cylinder, and then the cylinder was tapped on a tapping machine such that powder is compacted to its tapped density. The cylinder was then mounted on the GDR, which rotates the cylinder such that the powder tumbles inside the cylinder. The tumbling or avalanching motion of the powder is monitored in the cross-sectional direction using a camera. The images being captured using the camera are subsequently analyzed using an image analysis program to measure the change in the cross-sectional area of the powder. By assuming the uniform cross-sectional area across the length of the cylinder, powder dilation can be calculated. The dilation measurement, although complementary to the C.I., is more accurate, both because it is measured under the fully dilated state of the powder and because the common errors involved in bulk density measurements, such as powder compaction while filling the cylinder or inaccurate volume measurement due to an uneven powder surface, can be avoided in this measurement. Dilation is an indicator of the level of cohesion present in a powder; the greater the dilation, the more cohesive the powder. This fact has been proved for several materials through experimental as well as computational studies. In several experimental studies dilation is used as the material property that represents cohesion in the system. Bulk density was used as the second bulk material property. Bulk density measurements were performed by pouring powder in a graduated cylinder, and recording the mass and volume of the powder. 13    Table 3: Carr Index (C.I.) of Materials Dilation is a complementary measurement to the C.I., which is also an indicator of the compressibility of the powder. Dilation was measured using a device called a GDR (Gravitational Displacement Rheometer). Dilation is calculated as the percent change in volume of the powder bed as a function of time. Bulk density was used as the second bulk material property. Bulk density measurements were performed by pouring powder into a graduated cylinder and recording the mass and volume of the powder. Please note that the Carr Index values, bulk density, % Dilation, and d50 (μm) information in Table 3 are provided as general examples and may not be applicable to the specific materials. Furthermore, the starch-based biopolymer liquid mixture can be used to manufacture a biodegradable barrier film. The film's main component is a starch polymer matrix, derived from the specially developed SPP (starch polymer powder). This matrix forms the backbone of the film and provides mechanical strength and stability. 14    Furthermore, a biodegradable barrier film may comprise at least one of a reinforcement additive, a plasticizer, a processing aid, a filler, a functional additive, a coating layer and a laminating layer. Preferably, the biodegradable barrier film comprises more than of them, especially all of them. The reinforcement additives enhance specific properties of the film and may be incorporated into the starch polymer matrix. These additives can include fibers, nanoparticles, or other materials that improve tensile strength, flexibility, or barrier properties of the film. Plasticizers are often added to improve the film's flexibility and reduce brittleness. They facilitate the movement of polymer chains, allowing the film to adapt to different shapes and contours without breaking. During the extrusion process, certain additives may be used as processing aids to improve the film's processability. These aids help in achieving uniform dispersion of components and smooth extrusion. The fillers may be introduced to modify the film's properties. Fillers can contribute to factors like opacity, thermal conductivity, or flame resistance, depending on their nature and concentration. Functional additives are incorporated to imbue the film with specific characteristics, such as UV resistance, antimicrobial properties, or enhanced adhesion to other surfaces. Additional layers may be added to the film structure through coating or lamination processes. These layers can serve various purposes, such as improving barrier properties, enhancing printability, or adding decorative features. The biodegradable barrier production method represents an innovative approach to create high-quality films using co-rotating twin screw extruders, effectively eliminating the need for a separate compounding step. This method deviates from traditional processes that utilize single screw types and streamlines film production by directly processing the specially developed SPP (starch polymer powder) on the fusion line. 15    REFERENCES 1. A. Faqih, B. Chaudhuri, A.W. Alexander, C. Davies, F.J. Muzzio, M. Silvina Tomassone An experimental / computational approach for examining unconfined cohesive powder flow International Journal of Pharmaceutics, 324 (2006), pp.116-127 16

Claims

CLAIMS 1. A production method for starch-based (bio)polymer liquid mixture characterized by; Adding 0.2 to 2 % at least one acid by total weight of the liquid mixture and 1 to 6 w% initiator by total weight of the liquid mixture to the starch polymer powder, Cross-linking by addition of at least one cross-linker, Hydro binding by adding at least 2 to 20 % a hydro binding agent by total weight of the liquid mixture wherein the temperature of suspension is kept between a gelatinization temperature (Tgel) of the starch polymer.

2. Method of claim 1, wherein the starch granule structure is 70% to 99% de-structured by the acid.

3. Method of Claim 1 or 2, wherein the acid is selected from acetic acid, phosphoric, hydrochloric, citric, acetic, lactic, malic, tartaric, sulfuric, ascorbic, succinic or stearic acid which are introduced by degree or the amount of hydrolysis.

4. Method of any of preceding claims, wherein the acid and the initiator are added as a suspension to the starch.

5. Method of Claim 4, wherein concentration of the acid-the initiator suspension is between 0.2%- (w / w)-4% (w / w).

6. Method of claim 6, wherein the solvent is added at temperature between 15°C and 65°C.

7. Method of claim 1, wherein the adjusting pH of the mixture to pH 7.5- 8.2, after addition of the acid.

8. Method of claim 8, wherein the adjusting pH of the mixture is carried out by the cross- linker.

9. Method of claim 1 or 8, wherein the crosslinker is selected from phosphorous oxychloride, boric acid, sodium trimetaphosphate (STMP), sodium tripolyphosphate (STPP), epichlorohydrin, formaldehyde, Citric acid, preferred base is sodium hydroxide or bicarbonate.

10. Method of claim 1, wherein the initiator is a starch plasticizer.

11. Method of claim 1, wherein the initiator is a deionized water.

12. Method of claim 1, wherein the initiator is a solvent.

13. Method of claim 1, wherein  the initiator is selected from, water, sodium chloride, sodium bicarbonate, calcium carbonate, and muriatic acid or zinc oxide.

14. Method of claim 1, wherein further comprising step of adding a reducing agent.

15. Method of claim 1, wherein the reducing agent is selected from sodium hydroxide, lithium hydroxide, sodium bisulphite, silicon dioxide, phosphoric acid, sodium tetraborate decahydrate and / or ionic cross-linkers.

16. Method of claim 1, wherein further comprising step of adding  at least one sugar alcohol, polyols.

17. Method of claim 1, wherein the temperature of mixture is kept at or above 25°C.

18. Method of claim 1 and 17, wherein the acid is added at temperature between 25°C and 65°C .

19. Method of any of claim 1, 17, 18, wherein the initiator is added at temperature between 25°C and 65°C to the starch.

20. Method of any of claim 1, 17-19, wherein the cross-linker is added at temperature between 35°C and 65°C.

21. Method of any of claim 1, 17-20, wherein a hydro binding agent is added at temperature between 45°C and 65°.

22. A starch-based biopolymer liquid mixture is obtained by any of claims 1 to 21.

23. A starch-based biopolymer suspension is obtained by any of claims 1 to 21 24. A starch-based biopolymer solution is obtained by claims 1 to 21.

25. Use of starch-based biopolymer liquid mixture of Claim 22 to 24 in the dipping process of materials.

26. Use of starch-based biopolymer solution of Claim 22 to 24 in the dipping process of textile materials.

27. Use of starch-based biopolymer solution of Claim 22 in the extrusion process of materials.

28. A biodegradable barrier film comprising the starch-based biopolymer liquid mixture of claim 22 to 24.

29. A biodegradable barrier film further comprising at least one of a reinforcement additive, a plasticizer, a processing aid, a filler, a functional additive, a coating layer and a laminating layer.

30. A method for producing biodegradable barrier film of Claim 28 and 29 characterized by using co-rotating twin screw extruder.

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