Method of preparing flexible material from fabrics

Description

1 / 19 METHOD FOR PREPARING FLEXIBLE MATERIAL FROM FABRICS

[001] The present invention claims priority of the Chinese invention patent application submitted to the National Intellectual Property Administration of China on April 18, 2023, with application number 202310412795.6, entitled A Method for Preparing Flexible Material from Fabrics. TECHNICAL FIELD

[002] The present invention belongs to the technical field of reuse of discarded textiles, referring specifically to a method for preparing flexible and biodegradable material from fabrics. STATE OF THE ART

[003] With the increase in the population's consumption level, the rate of clothing replacement has accelerated, generating a large amount of discarded textiles, of which cotton fabrics represent a significant proportion. Currently, methods for recycling discarded fabrics or cellulosic materials mainly involve the complete dissolution of cellulose, followed by regeneration and reuse of the dissolved material. Although cellulose is the main component of discarded textiles, its complete dissolution and subsequent reuse present great difficulty. This occurs, firstly, because cellulose is a polyhydroxylated substance, which results in a high crystallinity of the cellulose fibers, hindering their complete dissolution. In the traditional viscose process, for example, there is an initial alkaline treatment, followed Petition 870250095175, dated 10 / 17 / 2025, page 11 / 57 2 / 19 by esterifying cellulose with carbon disulfide to form cellulose xanthate, which is then dissolved in a dilute alkaline solution to produce regenerated cellulose fiber. This process presents problems such as high energy consumption, serious pollution, and complex steps. On the other hand, the more recent dissolution method with NMMO (N-methylmorpholine-N-oxide) is technically complex and presents risks, since NMMO is highly explosive, requiring a recovery rate greater than 95% to make industrial production viable. The method with ionic liquids requires the use of pure and anhydrous ionic liquids to dissolve the cellulose, which implies high viscosity and high production costs. Secondly, due to the variety of colors of the fabrics, the process of bleaching mixed discarded textiles is extremely difficult, requiring multiple bleaching steps that intensify environmental pollution.Finally, the fabrics generally contain mixed fibers, the removal of which is highly challenging, further complicating the dissolution process. Thus, the strategy of complete cellulose dissolution for the reuse of cellulosic fabrics has proven unfeasible for industrial application. Existing complete dissolution technologies are more applicable to materials with a high cellulose content, such as wood pulp and cotton, and the resulting products are generally regenerated fibers and regenerated cellulose films. Furthermore, complete dissolution requires high temperatures and long processing times, which easily reduces the degree of cellulose polymerization, compromising the strength and toughness of the regenerated materials. Petition 870250095175, dated 10 / 17 / 2025, page 12 / 57 3 / 19

[004] On the other hand, the rapid growth of e-commerce has led to an increase in the consumption of packaging materials and in the volume of logistics waste. Currently, the films used in express delivery packaging are mainly manufactured from polyethylene, polypropylene, cellulose, nylon, and aluminum foil. Most plastics, such as polyethylene, polystyrene, and polyvinyl chloride (PVC), have long and stable polymer chains, requiring hundreds or even thousands of years to degrade. Therefore, if some of the discarded cellulose-based fabrics can be converted into flexible materials in the form of films, it will not only be possible to solve the problem of recycling discarded textiles, but it will also contribute to mitigating the difficulty of degradation of packaging materials, taking advantage of the high cellulose content present in the fabrics. SUMMARY OF THE INVENTION

[005] The present invention aims to utilize the cellulose present in fabrics containing cellulosic fibers, employing an aqueous solution of alkaline ionic liquid to activate the cellulose, followed by hot pressing and modification by polymer infiltration, with the objective of solving the problems of the existing technology, such as the complexity of the complete dissolution process of cellulose for recycling discarded fabrics and the low flexibility of the resulting cellulosic materials.

[006] To solve these problems, the present invention discloses a method for preparing flexible materials. Petition 870250095175, dated 10 / 17 / 2025, page 13 / 57 4 / 19 from fabrics, characterized by: performing a pretreatment to activate the fabric with an aqueous solution of ionic liquid, followed by hot pressing to bond the fibers and, finally, applying a polymer infiltration process to obtain the flexible material.

[007] The fabrics used in the present invention include woven fabrics, knitted fabrics, non-woven fabrics, braided fabrics, among others.

[008] In one embodiment, the aqueous solution of ionic liquid is prepared by adding deionized water to the ionic liquid, followed by adjusting the pH of the solution with an alkaline substance, resulting in an aqueous solution of alkaline ionic liquid.

[009] In one embodiment, the fabric may include discarded fabrics, defined as fabrics containing cellulosic fiber derived from used or discarded fabrics from households, businesses, or individuals, such as clothing, sheets, blankets, etc. The ionic liquid used comprises at least one of the following: 1-allyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium acetate, or 1-ethyl-3-methylimidazolium diethylphosphate.

[010] In one embodiment, the fabric is a pure or blended fabric with a cellulosic fiber content of 30 to 100%, the pure fabric being selected from cotton, linen, viscose, paper yarn or cupro, and the blended fabric containing at least two of the following fibers: cotton, linen, viscose, paper yarn or cupro. Petition 870250095175, dated 10 / 17 / 2025, page 14 / 57 5 / 19

[011] In one embodiment, the aqueous solution of ionic liquid contains a mass fraction of ionic liquid ranging from 70 to 95%, a mass fraction of alkaline substance ranging from 1 to 5%, the remainder being deionized water, and the alkaline substance includes at least one of imidazole, sodium hydroxide, or choline.

[012] The objective of the present invention is to prepare a flexible material in which partially dissolved cellulose acts as a binding element and undissolved fibers form the structural skeleton. For this purpose, the fabric is impregnated with an aqueous solution of ionic liquid, the degree of dissolution being controlled by water evaporation. If the humidity is too low, the fabric fibers dissolve excessively, reducing the proportion of structural fibers and compromising the mechanical properties and flexibility of the product. If the humidity is too high, the dissolution of the fibers is insufficient, resulting in poor connection between the fibers and hindering the formation of a uniform membrane material. The addition of alkaline substances promotes the swelling of the fibers in the fabric, allowing a more effective interaction between the ionic liquid and cellulose, increasing the homogeneity of the product.This homogeneity refers to the formation of a continuous film, without macroscopic defects such as pores or holes that could compromise its performance, but it does not imply absolute uniformity throughout the microstructure.

[013] In one embodiment, the activation pretreatment includes an impregnation step and a dissolution step. In impregnation, the tissue is immersed in an aqueous solution of ionic liquid; in Petition 870250095175, dated 10 / 17 / 2025, page 15 / 57 6 / 19 Dissolution: The impregnated tissue is subjected to heating for activation.

[014] Heating is carried out at temperatures of 45 to 200 °C, preferably 90 to 200 °C, more preferably 45 to 125 °C, for a time between 5 and 120 minutes.

[015] Optionally, between the impregnation and dissolution steps, there may be a pressing step to remove excess solution.

[016] In one embodiment of the present invention, the temperature during hot pressing is 80-200 °C, preferably 120-200 °C, the pressure is 0.05-15 MPa, preferably 0.05-1.5 MPa; and the pressing time is 0.5-300 seconds, preferably 0.5-60 seconds.

[017] The hot pressing process allows the ionic liquid present in the pre-treated activated tissue to reach the dissolution temperature, causing the tissue fibers to reach the desired degree of dissolution, forming a flexible material in which the partially dissolved cellulose acts as a binding element and the undissolved fibers form the structural skeleton. Therefore, the pressing temperature range must be adjusted to allow for adequate fiber dissolution. The pressing time should be neither excessively long nor too short. If it is too long, the resulting film will have many connections and little fibrous structure, impairing the mechanical properties and flexibility of the film; if it is too short, it will be difficult to form a uniform film material. Petition 870250095175, dated 10 / 17 / 2025, page 16 / 57 7 / 19

[018] In one embodiment of the present invention, the polymer impregnation process includes subjecting the fabric after hot pressing to an impregnation treatment in a liquid containing polymers, the polymers being at least one of polyethylene glycol, polyvinyl alcohol, citric acid ester-derived polymers, or sorbitol ester-derived polymers. The polymer concentration in the liquid varies from 1 to 50%, and the impregnation treatment time is from 0.1 to 24 hours.

[019] During impregnation treatment in liquid containing polymers, these polymers can penetrate the interior of the cellulose, reducing the interaction forces between the cellulose molecular chains and increasing the mobility of the molecular chains, which improves the plasticity and flexibility of the film material. Compared to impregnation treatment using only water or an aqueous solvent solution, this method significantly increases the flexibility of the film material produced.

[020] The present invention also describes a flexible material obtained by the method described above.

[021] In one embodiment of the present invention, the flexible material includes a cellulose-based film material.

[022] One of the objectives of the present invention is to provide uses for the flexible material described above in areas such as textiles, medicine, food packaging, adhesive tapes, cables, insulating substrates and flexible electronic devices.

[023] Beneficial Effects of the Invention: Petition 870250095175, dated 10 / 17 / 2025, page 17 / 57 8 / 19

[024] 1. The present invention utilizes an aqueous solution of alkaline ionic liquid to perform the activated dissolution of cellulose, followed by a hot pressing and polymer impregnation method to prepare the flexible material. Localized dissolution on the surface of the fibers generates a solution of cellulose macromolecules in an ionic liquid with adhesive properties, similar to a glue, which is then bonded to the undissolved fibers by hot pressing, obtaining a flexible material with partially dissolved cellulose as a bonding element and undissolved fibers as a structural framework. To achieve partial dissolution instead of complete dissolution, the invention uses an aqueous solution system of alkaline ionic liquid, controlling the degree of dissolution by evaporating the water.To improve the material's toughness, a polymer impregnation strategy is applied, using alcoholic polymers or esters, which also have the ability to form hydrogen bonds that penetrate between the cellulose chains, increasing the material's flexibility and resulting in a flexible, biodegradable, cellulose-based material.

[025] 2. The invention does not require the complete dissolution of the cellulose, preserving the natural strength of the fibers and significantly increasing the tensile strength of the flexible cellulose-based material, which can reach values ​​greater than 60 MPa.

[026] 3. The flexible cellulose-based material obtained by the method of the present invention exhibits a high elongation rate at break. After polymer impregnation treatment, the toughness of the material is significantly increased. Petition 870250095175, dated 10 / 17 / 2025, page 18 / 57 9 / 19 increased, with an elongation rate at break that can reach more than 50%.

[027] 4. Applying the method of the present invention to the reuse of discarded fabrics significantly reduces processing time, being highly efficient and energy-saving. Traditional cellulose film production processes require complete dissolution followed by film molding, with high temperatures and dissolution times that often last several hours. The present invention does not require complete dissolution of the cellulose; only a few minutes of surface dissolution are sufficient to generate the cellulose solution in ionic liquid, allowing hot pressing, saving processing time and reducing energy consumption. DETAILED DESCRIPTION OF THE INVENTION

[028] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, examples of embodiments of the invention will be described in detail and completely. Obviously, the examples described represent only some embodiments of the invention, and not all. Based on the embodiments described in this invention, all other embodiments that professionals in the field may obtain without performing inventive work are also within the scope of protection of the present invention.

[029] In Embodiment Examples 1-8 of the present invention and in Comparative Examples 1 and 2, the material used is hydroentangled cotton fiber nonwoven fabric, hereinafter referred to as nonwoven fabric; in Petition 870250095175, dated 10 / 17 / 2025, page 19 / 57 10 / 19 Example 9: The material used is recycled viscose, with a basis weight of 200 g / m2; in Example 10: The material is paper yarn, composed of 76% paper yarn and 24% polyester, with a basis weight of 20 g / m2.

[030] In Embodiment Examples 1-8 and Comparative Examples 1 and 2, the ionic liquid used is 1-butyl-3-methylimidazolium chloride; in Embodiment Example 9, the ionic liquid used is 1-ethyl-3-methylimidazolium chloride.

[031] Liquid absorption test: The tissues are weighed before and after impregnation, recording the weights as W0 and W1, respectively. The liquid absorption rate is calculated using the following formula:

[032] P=[(W1-W0) / W0]x100%

[033] The liquid absorption rate can be controlled by adjusting the pressing time and pressure on the roller.

[034] Tensile properties test: Performed in accordance with standard GB / T13022-1991 — “Tensile Performance Test Method for Plastic Films”.

[035] Biodegradability test method: Performed according to JISK6950-94 standard, using the natural biodegradation method. A certain quantity of the flexible film material is weighed and completely dried in an oven to obtain the weight M0. The sample is then buried 10 cm deep in natural soil. At regular intervals, the sample is retrieved and weighed again to determine the residual weight Mi. The degradation rate is calculated using the following formula: Petition 870250095175, dated 10 / 17 / 2025, page 20 / 57 11 / 19

[036] Br(%) = [(M0-M1) / M0]x100%

[037] Implementation Example 1

[038] A method for preparing flexible materials using discarded fabrics, including the following steps:

[039] (1) Preparation of an aqueous solution of alkaline ionic liquid: Weigh 70 g of 1-butyl-3-methylimidazolium ionic liquid, add 1 g of imidazole and 29 g of water, mix to form a homogeneous solvent.

[040] (2) Activation pretreatment: Place a cotton nonwoven in the alkaline aqueous solution of ionic liquid mentioned above, immerse at room temperature, pass through rollers to ensure a liquid retention rate of 100%, and then place the nonwoven fabric in an oven at 90°C for 180 minutes, obtaining a sample of pretreated and activated nonwoven fabric.

[041] (3) Hot press adhesion: Place the pre-treated nonwoven sample obtained in step (2) in a heat press, control the pressing temperature at 120°C and apply a pressure of 1.5 MPa for 60 seconds, obtaining a hot-pressed film material.

[042] (4) Impregnation treatment: Place the hot-pressed material obtained in step (3) in a 1% polyethylene glycol (Mn-20000) solution at room temperature for impregnation for 24 hours. Remove the prepared film material and air dry it to obtain a semi-translucent flexible film material.

[043] After testing, the resulting semi-translucent flexible film material exhibited a tensile strength of Petition 870250095175, dated 10 / 17 / 2025, page 21 / 57 12 / 19 tensile strength of 25.6 MPa, an elongation rate at break of 32.93% and a biodegradation rate of 93.43% in 90 days.

[044] Implementation Example 2

[045] The difference between Example 2 and Example 1 lies in the polymer used in the impregnation process. In Example 1, the polymer used was polyethylene glycol with a molecular weight of 20,000. In Example 2, polyvinyl alcohol (PVA1788) and sorbitol ester were used as impregnation polymers.

[046] Table 1: Effect of different impregnation polymers on the mechanical properties of the film Polymer Tensile Strength (MPa) Elongation at Break (%) Polyethylene glycol (Mn = 20000) 25.6 32.93 Polyvinyl alcohol (PVA1788) 16.2 24.21 Sorbitol ester 9.1 14.57

[047] As shown in Table 1, when aqueous solutions of the aforementioned polymers are used as a coagulation bath for impregnation treatment, the regenerated film materials obtained exhibit elongation at break significantly greater than 10%, demonstrating evident flexibility mechanical properties.

[048] Implementation Example 3

[049] The difference between Example 3 and Example 1 lies in the type of polymer used in the impregnation process. In Example 1, the selected impregnation polymer was polyethylene glycol with a molecular weight of 20,000. In Example 3, the impregnation polymer Petition 870250095175, dated 10 / 17 / 2025, page 22 / 57 Polyethylene glycol was also selected, but with molecular weights of 600 and 4,000.

[050] Table 2: Effect of PEG molecular weight on film mechanical properties Polymer tensile strength (MPa) Elongation at break (%) PEG 600 4.1 13.66 PEG 4000 7.03 14.07 PEG 20000 25.6 32.93

[051] As shown in Table 2, when polyethylene glycol solutions with different molecular weights are used as a coagulation bath for the Following impregnation treatment, the regenerated film materials obtained exhibit elongation at break significantly greater than 10%, demonstrating evident flexibility in their mechanical properties. Among other things, Among them, the PEG 20000 offers the best mechanical performance. general.

[052] Implementation Example 4

[053] The difference between Example 4 and Example 1 lies in the parameters of the hot pressing process. In Example 1, the pressing was carried out at 120 °C, under 1.5 MPa of pressure for 60 seconds. In Example 4, the parameters of the hot pressing process and the properties of the films obtained are presented in Table 3.

[054] Table 3: Effect of hot pressing process parameters on the mechanical properties of the film Petition 870250095175, dated 10 / 17 / 2025, page 23 / 57 14 / 19 Pressing temperature (°C) Pressure (MPa) Pressing time (s) Tensile strength (MPa) Elongation at break (%) 120 0.05 60 5.6 52.10 120 1.5 60 25.6 32.93 150 0.05 60 24.8 28.32 150 1.5 0.5 34.4 25.36 200 0.05 60 25.1 24.57 200 1.5 0.5 36.5 26.43

[055] As shown in Table 3, the materials Regenerated films obtained with different pressing parameters exhibit good tensile strength and elongation at break, demonstrating good mechanical flexibility performance.

[056] Implementation Example 5

[057] The difference between Example 5 and Example 1 lies in the temperature used in the activation pretreatment. In Example 1, pressing was performed at 120 °C, under 1.5 MPa pressure for 60 seconds. In Example 5, the activation pretreatment temperatures used and the properties of the films obtained are presented in Table 4.

[058] Table 4: Effect of activation pretreatment temperature on the mechanical properties of the film Temperature Tensile Strength at Rupture (°C) Elongation at Rupture (MPa) 25.6 32.93 Petition 870250095175, dated 10 / 17 / 2025, page 24 / 57 15 / 19 120 60.2 30.34 150 63.1 30.11 200 12.5 52.40

[059] As shown in Table 4, the regenerated film materials obtained at different activation temperatures exhibit good tensile strength and elongation at break, indicating good mechanical flexibility.

[060] Example of Implementation 6

[061] The difference between Example 6 and Example 1 lies in the concentration of the ionic liquid. In Example 1, the aqueous solution of ionic liquid had a concentration of 70%. In Example 6, the concentrations of ionic liquid used and the properties of the films obtained are presented in Table 5.

[062] Table 5: Effect of ionic liquid concentration on the mechanical properties of the film Concentration (%) Tensile strength (MPa) Elongation at break (%) 70 25.63 32.93 90 41.5 35.55 100 10.2 3.20

[063] As shown in Table 5, compared to the use of pure ionic liquid, the use of an aqueous solution of ionic liquid for the activation pretreatment resulted in regenerated films with better mechanical properties and flexibility.

[064] Example of Implementation 7 Petition 870250095175, dated 10 / 17 / 2025, page 25 / 57 16 / 19

[065] The difference between Example 7 and Example 1 lies in the alkaline base content of the ionic liquid solution. In Example 1, the alkali content was 1%. In Example 7, the alkali contents of the ionic liquid solution used and the properties of the films obtained are presented in Table 6.

[066] Table 6: Effect of alkaline base content on the mechanical properties of the film Basic content Elongation at break (%) (%) at break (MPa) 1 25.6 32.93 3 31.5 30.55 5 21.2 13.10

[067] As shown in Table 6, the regenerated film materials obtained with activation pretreatment in aqueous ionic liquid solutions with different base contents showed elongation at break greater than 10%, demonstrating evident mechanical flexibility.

[068] Example of Implementation 8

[069] The difference between Example 8 and Example 1 lies in the type of alkaline base added to the ionic liquid solution. In Example 1, the base used was imidazole. In Example 8, the different types of base used and the properties of the films obtained are presented in Table 7.

[070] Table 7: Effect of the type of alkaline base on the mechanical properties of the film Base type Tensile strength (MPa) Elongation at break (%) Petition 870250095175, dated 10 / 17 / 2025, page 26 / 57 17 / 19 Imidazole 25.6 32.93 Sodium hydroxide 35.5 28.55 Choline 23.2 15.70

[071] As shown in Table 7, the regenerated film materials obtained after activation pretreatment with aqueous ionic liquid solutions containing different types of base showed elongation at break greater than 10%, indicating evident mechanical flexibility.

[072] Comparative Example 1

[073] The difference between Example 1 and Comparative Example 1 is that the nonwoven fabric was not subjected to polymer impregnation treatment after hot pressing. The properties of the films obtained are presented in Table 8.

[074] Table 8: Effect of polymer impregnation treatment on the mechanical properties of the film Polymer impregnation treatment Tensile strength (MPa) Elongation at break (%) Untreated 36.2 8.70 Treated by impregnation 25.6 32.93

[075] As shown in Table 8, the regenerated film material subjected to polymer impregnation treatment exhibits a significant increase in elongation at break rate, with noticeably greater flexibility.

[076] Comparative Example 2 Petition 870250095175, dated 10 / 17 / 2025, page 27 / 57 18 / 19

[077] The difference between Comparative Example 2 and Example 1 lies in the order of polymer application. In Comparative Example 2, the PEG at the same concentration was added directly to the fabric before hot pressing, and no polymer impregnation treatment was performed after pressing. In Example 1, the impregnation treatment was performed after hot pressing. The properties of the resulting films are presented in Table 9.

[078] Table 9: Effect of polymer addition order on film mechanical properties Order of application of the polymer Tensile strength (MPa) Elongation at break (%) Added before pressing 10.5 5.70 Treated by impregnation 25.6 32.93

[079] As shown in Table 9, performing the impregnation treatment after hot pressing significantly improves the mechanical properties and flexibility of the resulting film, compared to adding the polymer before pressing.

[080] Example of Implementation 9

[081] The difference between Example 9 and Example 1 lies in the type of raw material used. In Example 1, the fabric used was cotton nonwoven, while in Example 9, viscose was used. After testing, the resulting flexible film material showed a tensile breaking strength of 33.4 MPa and an elongation at break of 34.27%.

[082] Example of Implementation 10 Petition 870250095175, dated 10 / 17 / 2025, p. 28 / 57 19 / 19

[083] The difference between Example 10 and Example 1 also lies in the type of raw material used. In Example 1, the fabric used was cotton nonwoven, while in Example 10, paper yarn was used. After testing, the resulting flexible film material showed a tensile breaking strength of 28 MPa and an elongation rate at break of 18%. Petition 870250095175, dated 10 / 17 / 2025, p. 29 / 57

Claims

1 / 3 CLAIMS 1. METHOD FOR PREPARING FLEXIBLE MATERIALS FROM FABRICS, characterized by comprising the steps of: performing a pre-treatment to activate the fabric with an aqueous solution of ionic liquid, followed by hot pressing to bond the fibers, and finally applying a polymer infiltration process to obtain the flexible material.

2. METHOD, according to claim 1, characterized in that the aqueous solution of ionic liquid is prepared by adding deionized water to the ionic liquid, followed by adjusting the pH of the solution with an alkaline substance, resulting in an aqueous solution of alkaline ionic liquid.

3. METHOD, according to claim 1 or 2, the ionic liquid being characterized by comprising at least one of the following: 1-allyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium acetate or 1-ethyl-3-methylimidazolium diethylphosphate.

4. METHOD, according to claim 1 or 2, characterized in that the fabric is a pure or blended fabric with a cellulosic fiber content of 30 to 100%, the pure fabric being selected from cotton, linen, viscose, paper yarn or cupro, and the blended fabric containing at least two of the following fibers: cotton, linen, viscose, paper yarn or cupro.

5. METHOD, according to claim 1 or 2, characterized in that, in the aqueous solution system of Petition 870250095175, of 10 / 17 / 2025, page 30 / 57 2 / 3 ionic liquid, the mass fraction of the ionic liquid varies from 70 to 95%, the mass fraction of the alkaline substance varies from 1 to 5%, the remainder being deionized water, and the alkaline substance includes at least one of imidazole, sodium hydroxide or choline.

6. METHOD, according to claim 1 or 2, characterized in that the activation pretreatment includes an impregnation step and a dissolution step, the impregnation step being the immersion of the fabric in an aqueous solution of ionic liquid, and the dissolution step being the thermal activation treatment of the fabric after removal of excess liquid, with a temperature between 90 and 200 °C and a processing time of 5 to 120 minutes.

7. METHOD, according to claim 1 or 2, characterized by the hot pressing being carried out at a temperature of 100 to 200 °C, under a pressure of 0.05 to 1.5 MPa, for a period of 0.5 to 60 seconds.

8. METHOD, according to claim 1 or 2, characterized in that the polymer infiltration process consists of subjecting the hot-pressed fabric to an infiltration treatment in a liquid containing polymers, the polymers being selected from at least one of the following: polyethylene glycol, polyvinyl alcohol, citrate polymers or sorbitol polymers, with the polymer concentration in the liquid ranging from 1 to 50% and the infiltration time ranging from 0.1 to 24 hours.

9. FLEXIBLE MATERIAL, characterized by being obtained by the method according to any one of claims 1 to 8. Petition 870250095175, dated 10 / 17 / 2025, page 31 / 57 3 / 3 10. USE OF THE FLEXIBLE MATERIAL, according to claim 9, characterized by being for the textile, pharmaceutical and food packaging, adhesive tapes, cables, insulating substrates and flexible electronic devices areas. Petition 870250095175, dated 10 / 17 / 2025, p. 32 / 57