Textile reinforced PVA based hydrogel composite material with high elastic properties and strength

Abstract

The invention relates to a textile-reinforced PVA-based hydrogel composite material with high elastic properties and strength that can be used in food, health, environment, textile sectors and wearable bioelectronic applications and its production method.

Description

[0001] TEXTILE REINFORCED PVA BASED HYDROGEL COMPOSITE MATERIAL WITH HIGH ELASTIC PROPERTIES AND STRENGTH

[0002] Technical Field

[0003] The invention relates to a textile-reinforced PVA-based hydrogel composite material with high elastic properties and strength that can be used in food, health, environment, textile sectors and wearable bioelectronic applications and its production method.

[0004] State of Art

[0005] Hydrogels are three-dimensional polymers that do not dissolve when they interact with water and swell by taking in the solvent. At their most basic, hydrogels are cross-linked polymer networks. Polyvinyl alcohol (PVA) is the building block of hydrogel materials because it is non-toxic, biocompatible and has high hydrophilic properties. PVA-based hydrogels are polymers widely used in many fields, especially in biomedicine by means of these advantageous properties. The low mechanical strength of pure PVA hydrogels is important in terms of creating new hydrogels with mixtures of PVA polymer and various polymers or different materials. Various approaches have been developed to increase the strength of the hydrogel. For example, it is aimed to increase the strength of the hydrogel structure by adding reinforcement elements such as particles, fibers, fabrics, etc. of various sizes to the hydrogel structure.

[0006] In the previous national patent application titled ‘A Method for Mass Production of Textile Reinforced Hydrogel Composites from Roll to Roll’, numbered TR2022 / 020603, made by the present inventors, a disadvantageous situation such as fragility emerged in the use of fabric reinforcements in the structure of the textile reinforced hydrogel composite material. There is a need for new textile-reinforced hydrogel structures that eliminate this disadvantage and offer additional stable properties such as high strength and high elasticity. As a result, due to the negativities described above and the inadequacy of existing solutions on the subject, it has become necessary to make a development in the relevant technical field.

[0007] Purpose of the Invention

[0008] The invention is inspired by the current situation and aims to solve the above- mentioned negativities.

[0009] The main purpose of the invention is to obtain a final composite structure that is both durable and elastic properties by creating a strong interface structure after the gelation process with the crosslinking agent containing TEOS, as the PVA yarn with gelation property will be in the reinforcement fabric structure.

[0010] The hydrogel composite material which is the subject of the invention is carried out in two stages, namely preparation of TEOS solution and production of fabric reinforced hydrogel composite. TEOS solutions are prepared in different ratios by volume, preferably at 50 rpm for 5 minutes in a magnetic stirrer. After the prepared TEOS solutions are impregnated into PVA reinforced fabrics, the samples prepared at each concentration are kept in a magnetic stirrer, preferably at 100'C, for 10 minutes. After the first washing, the samples are left to dry and subjected to a second washing process, preferably after 1 hour, and then the composite material is produced. The fabric structure may contain at least one fiber type selected from cotton, silk, linen, wool, regenerated cellulose, chitin, chitosan in different proportions, in addition to PVA.

[0011] The TEOS solution prepared with Tetraethyl orthosilicate (TEOS), ethanol, water and hydrochloric acid (HCI) chemicals included in the invention is used as a cross linker in textile reinforced composite hydrogel material and provides elasticity to the composite by contributing to the gelation of PVA yarns in the fabric structure. The fabric produced from cotton, silk, linen, wool, regenerated cellulose, chitin, chitosan yarn forms the reinforcement component in the composite hydrogel structure. It also provides the desired mechanical strength and stability to the composite material. Textile reinforced composite hydrogel structures formed by these two components emerge as an elastic and durable material.

[0012] The structural and characteristic features of the invention and all its advantages will be understood more clearly by means of the figures given below and the detailed description written by making references to these figures, and therefore the evaluation needs to be made by taking these figures and detailed description into consideration.

[0013] Figures to Help Understand the Invention

[0014] Figure 1 , Gelation process of fabrics (C: Cotton, P: PVA, a: Raw fabric, b: Elastic hydrogel)

[0015] FIGURE 2A is the tensile test results of the fabric reinforced hydrogel composite material in the warp direction. [ (a) TEOS 3, (b) TEOS 10, (c) TEOS 30, (d) TEOS 100]

[0016] FIGURE 2B is the tensile test results of the fabric reinforced hydrogel composite material in the weft direction. [ (a) TEOS 3, (b) TEOS 10, (c) TEOS 30, (d) TEOS 100]

[0017] Figure 2C is the tensile test results of Raw PVA / Cotton fabric, [(a) weft direction, (b) warp direction]

[0018] Detailed Description of the Invention

[0019] In this detailed description, preferred embodiments of the composite hydrogel which is the subject of the invention are described only for the purpose of better understanding the subject.

[0020] The invention is a polymer-based and textile-reinforced composite hydrogel material that can be used in food, health, environment, textile sectors and wearable bioelectronic applications, wherein; it comprises TEOS cross-linked PVA hydrogel matrix and fabric reinforcement.

[0021] In an embodiment of the invention, the said fabric is selected from the fabrics obtained by processing PVA yarn directly or through embroidery on woven, knitted and nonwoven surface fabrics.

[0022] In an embodiment of the invention, the said fabric comprises at least one fiber type selected from cotton, silk, linen, wool, regenerated cellulose, chitin, chitosan.

[0023] In an embodiment of the invention, the said fabric is knitted cotton fabric reinforced with PVA in the weft and / or warp or woven cotton fabric reinforced with PVA in the weft and / or warp. In an embodiment of the invention, woven cotton fabric containing PVA fiber in the weft and / or warp is used.

[0024] The composite hydrogel production method mentioned above, in its most basic form, comprises the following process steps: i. Preparation of TEOS solution ii. Applying TEOS solution to fabric containing PVA iii. Obtaining the elastic composite hydrogel material by applying the washing process.

[0025] In the preferred example of the invention, a fabric woven from PVA and cotton yarns is used, as seen in Figure 1. PVA yarn is the yarn found in the fabric structure and can hydrogelate in contact with the cross linker TEOS solution. Cotton yarn is the yarn found in the fabric structure that cannot hydrogelate in contact with the cross linker solution. The hydrogel part in the hydrogel matrix composite is formed after the PVA yarn in the weft and / or warp in the fabric structure comes into contact with the specific cross linker solution. The reinforcement part is cotton fabric with weft and warp made of cotton yarns. The fabric mentioned here consists of PVA and cotton yarns woven according to the desired weave structure (such as plain weave, twill, satin or its derivatives).

[0026] The fabric-reinforced hydrogel composite produced within the scope of the invention produced in the following two stages:

[0027] TEOS solution preparation process before gelation:

[0028] Within the scope of the invention, the gelation solution comprising 100, 30, 10, 3 parts TEOS by volume in 4 different ratios was prepared in a magnetic stirrer at 50 rpm for 5 minutes. Here, 100 parts TEOS was taken as 3.975 ml.

[0029] In the embodiments of the invention, solutions comprising 30.9-1.4% TEOS, 49-70% Ethanol, 19.5-27.8% water, 0.6-0.8% HCI by volume are used.

[0030] In the preferred embodiment of the invention, solutions comprising 30.9% TEOS, 49% Ethanol, 19.5% water, 0.6% HCI by volume are used. Table 1. TEOS solution (v.%) at different concentrations prepared in the studies carried out within the scope of the invention

[0031] Characteristics of the fabric to be gelled

[0032] In the invention, in the case that vertically oriented weft yarn is used, horizontally oriented warp yarn is used. At least one of the yarns used in vertical or horizontal directions must gel within the fabric structure when treated with cross linker. Alternatively, the warp and weft threads in the vertical and horizontal directions can be switched. The woven fabric structure used in the present invention is more stable after gelation compared to non-woven fabrics and knitted fabrics and has higher elasticity. PVA / Cotton ratios in the fabric structure may vary.

[0033] Production of composite hydrogel material from the prepared TEOS solution fabric

[0034] After the prepared TEOS solutions (100, 30, 10, 3) are impregnated into PVA / Cotton blended fabrics, the samples prepared at each concentration are kept in a magnetic stirrer at 1000 for 10 minutes to produce composit e materials. After the first washing, the samples are left to dry and subjected to a second washing process 1 hour later, after which the composite material production is carried out.

[0035] Break-Elongation Tests

[0036] The hydrogel composite material which is the subject of the invention was produced and subjected to break-elongation tests. As seen in Figure 2, the tests were performed for samples prepared in the weft and warp directions of TEOS solutions at different ratios (100, 30, 10, 3) prepared by volume and for raw fabric (40% PVA / 60% Cotton). According to the tensile test results of the raw fabric not treated with TEOS solution, the breaking load in the warp direction is 664.74 N and the breaking load in the weft direction is 683.35 N. Fabrics treated with TEOS solution showed an increase in percentage elongation (20%) in both weft and warp directions in direct proportion to the increase in TEOS amount. This situation also provides mechanistic insight as a result of the hydrogen bonding between the -Si-OH groups in the TEOS solution and the - OH groups in the PVA. In addition, the elongation amount of the produced material supports the tensile properties of the material as seen in Table 2.

[0037] Table 2. Tensile test results of raw PVA / Cotton fabric and fabric reinforced hydrogel composite material in warp and weft directions.

[0038] In the above descriptions, the hydrogel structure was obtained by using woven fabric construction. In addition, similar hydrogel structures can be obtained with PVA reinforced knitted fabric structures and textile structures obtained by processing PVA yarn directly or by embroidery on woven, knitted and non-woven surface fabrics. Likewise, these structures can be obtained by hydrogelation of PVA yarns processed by embroidery on non-fabric surfaces. In this hydrogelled structure, it includes the use of natural fibers such as cotton, silk, linen, wool as well as natural fibers such as regenerated cellulose, chitin and chitosan as reinforcement yarn.

[0039] The mixing ratio of the TEOS solution, the curing temperature and duration of the hydrogel composite material to be produced are the main points to be considered in the production of the composite material which is the subject of the invention. The temperatures, time and rates given under the relevant headings above are the results obtained from experimental studies conducted so far. Additional studies can be carried out to find the most optimum values for mixing ratios, temperature and times. The structure of the fabric preferably consists of PVA and cotton yarns. At least one of the vertical or horizontal yarns in the fabric (provided that it is PVA yarn) refers to the hydrogelable yarn. The pattern of the fabric can be changed by using different weave structures such as plain weave, twill, satin, etc.

[0040] In our invention, cross linkers with similar properties can be used in addition to the existing TEOS solution. Mixing ratios different from the ratios prepared by volume (100, 30, 10, 3) or similar mixing ratios in this range can be used. In addition, in this study, woven fabrics produced from cotton fiber were used as reinforcement material. Instead of prepared cotton fiber, natural fibers such as wool, linen, hemp can be used in the production of composite materials. Furthermore, in addition to woven fabric, knitted, non-woven and 3D woven fabrics can also be used, provided that at least one yarn component is gelatinous, and fabric structures obtained by attaching a gelatinous yarn component to these fabrics by embroidery and sewing methods.

Claims

CLAIMS1. A polymer-based and textile-reinforced composite hydrogel material that can be used in food, health, environment, textile sectors and wearable bioelectronic applications, characterized by comprising; TEOS cross-linked PVA hydrogel matrix and fabric reinforcement.

2. The material according to claim 1 , characterized in that; the said fabric is selected from fabrics obtained by directly or through embroidery of PVA yarn on woven, knitted and non-woven surface fabrics.

3. The material according to claim 1 , characterized in that; the said fabric comprises at least one fiber type selected from cotton, silk, linen, wool, regenerated cellulose, chitin and chitosan.

4. The material according to claim 1 , characterized in that; the said fabric is knitted cotton fabric with PVA reinforcement in the weft and / or warp or woven cotton fabric with PVA reinforcement in the weft and / or warp.

5. The material according to claim 1 , characterized by comprising; a fabric in plain weave, twill or satin weave structure.

6. A production method of the composite hydrogel according to any of the previous claims, characterized by comprising the following process steps: i. Preparation of TEOS solution ii. Application of TEOS solution to fabric containing PVA iii. Obtaining the elastic composite hydrogel material by applying the washing process.

7. The method according to claim 6, characterized in that; in the process step (i), solutions comprising TEOS, Ethanol, water, HCI are prepared by mixing at a speed of preferably 50 rpm for preferably 5 minutes.

8. The method according to claim 6, characterized in that; in the process step (i), the solution comprising 30.9-1.4% TEOS, 49-70% Ethanol, 19.5-27.8% water, 0.6-0.8% HCI by volume is prepared by mixing.

9. The method according to claim 6, characterized in that; in the process step (i), the solution comprising 30.9% TEOS, 49% Ethanol, 19.5% water and 0.6% HCI by volume is prepared by mixing.

10. The method according to claim 6, characterized in that; in the process step (ii), TEOS solution is applied at 100°C for 10 minutes.

11. The method according to claim 6, characterized in that; in the process step (ii), after the first washing, it is dried, then the second washing is done and dried.

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