Preparation method of polypeptide modified viscose spunlaced non-woven fabric

Abstract

The invention discloses a preparation method of polypeptide modified viscose spunlaced non-woven fabric, and belongs to the technical field of viscose fabric. The preparation method comprises the following steps: S1, putting a viscose spunlaced nonwoven fabric in a sodium periodate solution, and carrying out an oxidation reaction at room temperature in a dark place to prepare a dialdehyde cellulose fabric; s2, the dialdehyde cellulose fabric obtained in the step S1 and a sericin aqueous solution are subjected to a grafting reaction, and the polypeptide modified viscose spunlaced non-woven fabric is prepared. According to the method, the sericin can be effectively utilized, the hygroscopicity, the permeability and the water-retaining property of the viscose spunlaced non-woven fabric can be remarkably improved on the basis of ensuring the softness of the fabric, the additional value of the viscose spunlaced non-woven fabric is improved, and the application prospect of the viscose spunlaced non-woven fabric in the fields of medical treatment, sanitation, environmental protection and the like is widened.

Description

Technical Field

[0001] The present invention relates to the technical field of viscose fiber fabrics, and more particularly to a method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric. Background Art

[0002] In recent years, with rising demands for quality of life and growing environmental awareness, the textile industry is facing pressure to transition from traditional to green, high-performance fabrics. Viscose fiber, as a key textile raw material, has garnered widespread attention due to its excellent spinnability and hydrophilicity. However, spunlace nonwovens made from traditional viscose fibers still have shortcomings in terms of hygroscopicity, bioactivity, and functionality, making them unable to meet market demand for high-quality textiles.

[0003] Derived from the sericin byproduct of silk cocoon silk, peptides are compounds composed of multiple amino acids linked by peptide bonds, with a molecular weight intermediate between that of amino acids and proteins. As a class of substances with unique bioactivity, they have attracted widespread attention due to their excellent biocompatibility, bioactivity, and functionality. The development of methods to effectively improve the performance of viscose spunlace nonwovens by incorporating peptides into viscose fibers is crucial for improving product quality and meeting market demand. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and provide a method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric, which can not only ensure the softness of the fabric, but also significantly improve the hygroscopicity, permeability and water retention of the viscose fiber spunlace nonwoven fabric, thereby broadening the application prospects of the viscose fiber spunlace nonwoven fabric.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric comprises the following steps:

[0007] S1. placing a viscose spunlace nonwoven fabric in a sodium periodate solution and performing an oxidation reaction at room temperature in the dark to prepare a dialdehyde cellulose fabric;

[0008] S2. Grafting the dialdehyde cellulose fabric obtained in step S1 with the sericin aqueous solution to produce a polypeptide-modified viscose fiber spunlace nonwoven fabric.

[0009] The present invention is further configured such that, in step S1, the mass ratio of the viscose spunlace nonwoven fabric to the sodium periodate is 2:5-6.

[0010] The present invention is further configured such that, in step S1, the oxidation reaction time is 3-6 hours.

[0011] The present invention is further configured such that, in step S1, ethylene glycol is added to terminate the oxidation reaction.

[0012] The present invention is further configured such that after the oxidation reaction is terminated, the oxidized fabric is washed and dried to obtain the dialdehyde cellulose fabric.

[0013] The present invention is further configured such that, in step S2, the concentration of the sericin aqueous solution is 4-12 g / L; and the usage ratio of the sericin aqueous solution to the viscose spunlace nonwoven fabric in step S1 is 1500 mL:2 g.

[0014] The present invention is further configured such that, in step S2, the grafting reaction temperature is 40-45° C., and the reaction time is 1-5 hours.

[0015] The present invention is further configured such that, in step S2, the grafting reaction is carried out by heating in a water bath.

[0016] The present invention is further configured such that, in step S2, after the grafting reaction, the obtained fabric is first baked and then immersed in deionized water and then dried to obtain the polypeptide-modified viscose fiber spunlace nonwoven fabric.

[0017] The present invention is further configured as follows: the baking temperature is 125-135° C., the baking time is 85-100 seconds, and the soaking time is 7.5-9 hours.

[0018] In summary, the present invention has the following beneficial effects:

[0019] The present invention first uses sodium periodate as an oxidant to oxidize viscose spunlace nonwovens, effectively altering the surface structure of cellulose, increasing the aldehyde content and providing more reactive sites for peptide modification. The surface of the viscose spunlace nonwoven is then hydrophilically modified by grafting sericin onto it, producing a peptide-modified viscose spunlace nonwoven. This sodium periodate oxidation and peptide grafting modification effectively utilizes sericin, significantly improving the hygroscopicity, permeability, and water retention of the viscose spunlace nonwoven while maintaining fabric softness. This improves the added value of the nonwoven and broadens its application prospects in medical, sanitation, and environmental protection fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a graph showing the effect of different oxidation times on the aldehyde content of viscose spunlace nonwovens;

[0021] Figure 2 This is an appearance diagram showing the softness of the dialdehyde cellulose fabric prepared in step S1 of Example 1, Examples 2 to 4, and Comparative Examples 1 and 2; wherein, Figure 2(a)-(f) correspond to the dialdehyde cellulose fabrics prepared in Example 2, Example 1, Example 3, Example 4, Comparative Example 1, and Comparative Example 2, respectively;

[0022] Figure 3 Softness test results of the viscose spunlace nonwoven fabric and the polypeptide-modified viscose fiber spunlace nonwoven fabric prepared in Example 1;

[0023] Figure 4 FTIR infrared spectra of the viscose spunlace nonwoven fabric and the dialdehyde cellulose fabrics prepared in step S1 of Example 1, Examples 2-4, and Comparative Examples 1-2 (in the figure: DAC3, DAC4, DAC5, DAC6, DAC12, and DAC24 correspond to Example 2, step S1 of Example 1, Example 3, Example 4, Comparative Example 1, and Comparative Example 2, respectively);

[0024] Figure 5 The following are scanning electron microscope images of the raw material viscose spunlace nonwoven fabric at different magnifications;

[0025] Figure 6 These are scanning electron microscope images of the polypeptide-modified viscose fiber spunlace nonwoven fabric prepared in Example 1 at different magnifications. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] The polypeptide-modified viscose fiber spunlace nonwoven fabric of the present invention is prepared by the following method:

[0028] S1. Placing a viscose spunlace nonwoven fabric in a sodium periodate solution (mass ratio of viscose spunlace nonwoven fabric to sodium periodate is 2:5-6), and subjecting the fabric to oxidation reaction at room temperature in the dark for 3-6 hours (preferably 4 hours), then adding ethylene glycol to terminate the reaction, washing the oxidized fabric with deionized water several times, and drying the fabric at 40-50°C for 8-12 hours to obtain a dialdehyde cellulose fabric;

[0029] S2. The dialdehyde cellulose fabric obtained in step S1 is mixed with a sericin aqueous solution having a concentration of 4-12 g / L (the ratio of the sericin aqueous solution to the viscose spunlace nonwoven fabric in step S1 is 1500 mL:2 g), and a grafting reaction is carried out in a water bath heated at 40-45°C for 1-5 hours. After the reaction, the resulting fabric is baked at 125-135°C for 85-100 seconds, then immersed in deionized water for 7.5-9 hours, and then dried to obtain a polypeptide-modified viscose fiber spunlace nonwoven fabric.

[0030] In this step, with other conditions remaining the same (only the grafting time changes), the grafting rate gradually increases with the increase of grafting time. The main reason for this phenomenon is the reaction kinetic effect, that is, the grafting reaction can proceed more fully within a sufficient time, so that more sites on the fiber surface are occupied by polymer chains, thereby achieving a higher grafting rate.

[0031] In this step, with all other conditions remaining the same (only the concentration of the sericin solution was varied), the fabric grafting efficiency gradually increased as the sericin solution concentration increased from 4 g / L to 8 g / L, reaching its peak at 8 g / L. However, when the sericin solution concentration was further increased to above 10 g / L, the grafting efficiency actually decreased. This suggests that excessively high sericin solution concentrations lead to increased intermolecular competition in the reaction system, thereby reducing grafting efficiency.

[0032] The grafting rate also affects the softness of the fabric. With increasing grafting time, the softness of the fabric decreases; especially after grafting for more than 5 hours, the softness of the fabric decreases significantly, becoming stiff and failing to meet the softness requirements of nonwovens. The softness of the fabric also decreases with increasing sericin solution concentration. To achieve a balanced grafting rate and softness in viscose spunlace nonwovens, the preferred grafting reaction conditions are a sericin solution concentration of 8 g / L and a grafting time of 3 hours.

[0033] Example 1 Polypeptide-modified viscose fiber spunlace nonwoven fabric

[0034] S1. Preparation of dialdehyde cellulose fabric by sodium periodate oxidation method: 5.34 g of sodium periodate was dissolved in 200 mL of deionized water, 2 g of viscose spunlace nonwoven fabric (purchased from Hangzhou Hangfang Technology Co., Ltd.) was added, and the mixture was covered with aluminum foil and oxidized for 4 h at room temperature in the dark. Then, 3 g of ethylene glycol was added to terminate the reaction. The resulting fabric was washed three times with deionized water (30 min each time) and then dried in a vacuum oven at 40°C for 10 h to obtain dialdehyde cellulose fabric.

[0035] S2. Sericin grafting: The dialdehyde cellulose fabric obtained in step S1 was mixed with an 8 g / L sericin aqueous solution (the ratio of the sericin aqueous solution to the viscose spunlace nonwoven fabric in step S1 was 1500 mL:2 g). The grafting reaction was carried out by heating in a 40°C water bath for 3 h. After the reaction, the resulting fabric was baked at 130°C for 90 s, then soaked in deionized water for 8 h, removed, and dried to obtain a polypeptide-modified viscose fiber spunlace nonwoven fabric.

[0036] Example 2-Example 4 Preparation of dialdehyde cellulose fabric by sodium periodate oxidation method

[0037] Dialdehyde cellulose fabric was prepared according to step S1 of Example 1, except that the oxidation reaction time in Examples 2 to 4 was 3 h, 5 h, and 6 h, respectively.

[0038] Comparative Example 1-Comparative Example 2 Preparation of dialdehyde cellulose fabric by sodium periodate oxidation method

[0039] Dialdehyde cellulose fabric was prepared according to step S1 of Example 1, except that the oxidation reaction times of Comparative Examples 1 and 2 were 12 h and 14 h, respectively.

[0040] Results and Analysis

[0041] (1) The aldehyde content of the raw material viscose spunlace nonwoven fabric and the dialdehyde cellulose fabrics prepared in step S1 of Example 1, Examples 2 to 4, and Comparative Examples 1 and 2 were measured, and the effect of oxidation time on the aldehyde content was analyzed.

[0042] The aldehyde content was determined as follows: the fabric to be tested was cut into pieces and placed in a 100 mL beaker pre-filled with 50 mL of deionized water. The pH of the system was adjusted to 4.0 using a 0.1 mol / L aqueous hydrochloric acid solution. 5.0 mL of a 0.72 mol / L hydroxylamine hydrochloride solution with a pH of 4 was added to the beaker and stirred for 12 hours. During the reaction, the pH of the solution was maintained at 4, and 0.1 mol / L sodium hydroxide solution was continuously added dropwise. The volume of sodium hydroxide consumed was recorded, and the aldehyde content (mmol / g) was calculated according to formula (a):

[0043] (a);

[0044] Where C NaOH is the molar concentration of sodium hydroxide solution (mol / L); V NaOH is the volume of sodium hydroxide solution consumed (mL); m cellulose is the mass of dialdehyde cellulose fabric (g).

[0045] After testing, in the determination of aldehyde content, the amount of sodium hydroxide consumed by the dialdehyde cellulose fabrics and the raw material viscose spunlace nonwoven fabrics obtained in step S1 of Example 1, Examples 2-4, and Comparative Examples 1-2 is shown in Table 1. The influence of different oxidation times on the aldehyde content of the viscose spunlace nonwoven fabrics is shown in Table 1. Figure 1 shown.

[0046] Table 1

[0047]

[0048] Depend on Figure 1 It can be seen that as the oxidation reaction time increases, the aldehyde content in the cellulose fabric also gradually increases. The increase in aldehyde content is very significant during the oxidation time period of 3h to 6h, indicating that during this period, the oxidation reaction proceeds rapidly, and the hydroxyl groups at the C2 and C3 positions in the cellulose glucose unit dehydrogenate and form aldehyde groups at a relatively fast rate. From the oxidation time period of 12h to 24h, although the aldehyde content continues to increase, the growth rate slows significantly. This is because as the reaction time increases, more aldehyde groups are formed, and the number of remaining hydroxyl groups decreases, resulting in a decrease in the reaction rate.

[0049] (2) Softness analysis: The softness of the dialdehyde cellulose fabrics and the raw material viscose spunlace nonwoven fabrics prepared in step S1 of Example 1, Examples 2 to 4, Comparative Examples 1 and 2, and the polypeptide-modified viscose fiber spunlace nonwoven fabric prepared in Example 1 were tested using a hand-feel softness tester from Dataphysics Instruments Co., Ltd. (the test diameter was 10 cm, and the front and back sides of each sample were tested separately, and each side was tested 3 times, and the average value was taken).

[0050] The appearance of the dialdehyde cellulose fabric prepared in step S1 of Example 1, Examples 2-4, and Comparative Examples 1-2 shows the softness of the fabric. Figure 2 It was found that the longer the oxidation time, the harder the fabric and the lower the softness. When the oxidation time exceeded 6 hours, the hardness of the fabric was already very high. Considering that the feel and style of the fabric are also one of the important indicators of modification, the optimal oxidation time was determined to be 4 hours by comprehensively considering the aldehyde content and fabric softness.

[0051] Example 1 The softness test results of viscose spunlace nonwovens before and after oxidation and grafting modification are as follows: Figure 3 As shown. Figure 3 It can be seen that the oxidized and grafted viscose spunlace nonwoven fabric is less soft and has a harder feel than the original fabric. This is because the fiber flexibility, originally maintained by the hydrogen bond network, is destroyed during the oxidation process, making the fibers more rigid and brittle. In addition, the breakage and fragmentation of the fibers also reduces the mutual entanglement and support between the fibers, further increasing the stiffness of the fabric.

[0052] (3) FTIR infrared spectra of the raw material viscose spunlace nonwoven fabric and the dialdehyde cellulose fabric prepared in step S1 of Example 1, Example 2-Example 4, and Comparative Example 1-Comparative Example 2 are as follows: Figure 4 In the FTIR infrared spectrum, a series of significant vibration peaks can be observed, which remain stable before and after oxidation, including 3371cm -1 , 2900cm -1 、2322cm -1 、1648cm -1 and 1015cm -1 , which correspond to the OH stretching vibration, CH stretching vibration, OH bending vibration, CH deformation vibration and OH vibration deformation in the cellulose molecule, respectively.

[0053] It is particularly noteworthy that a new peak at 1734 cm-1 was added to the spectrum of the oxidized sample. -1 The vibration peak of 886cm in the spectrum is attributed to the stretching vibration of aldehyde C=O. As the sodium periodate oxidation time increases, the intensity of the vibration peak gradually increases, indicating that the aldehyde content has increased. -1 A significant enhancement of the hemiacetal vibration peak caused by the combination of aldehyde and hydroxyl groups was observed at the position. This significant enhancement not only reveals the progress of the oxidation reaction, but also indicates the increase of the aldehyde content. In addition, as the degree of oxidation gradually deepens, the peak at 1155cm -1 The intensity of the COC asymmetric stretching vibration peak at gradually decreased. This change is attributed to the cleavage of the ether bonds between the cellulose unit rings during the sodium periodate oxidation process, which leads to a significant decrease in the degree of polymerization of cellulose and, in turn, affects the vibration intensity of the COC bond. This finding further confirms the success of the oxidation reaction and its impact on the cellulose structure.

[0054] (4) The grafting rate of the polypeptide-modified viscose fiber spunlace nonwoven fabric prepared in Example 1 was calculated to be 40.49%.

[0055] The calculation formula is: ;

[0056] Where W is the mass of polypeptide-modified viscose fiber spunlace nonwoven fabric, and W0 is the mass of dialdehyde cellulose fabric before grafting.

[0057] (5) Scanning electron microscopy (SEM) analysis

[0058] Example 1 Scanning electron microscope images of viscose spunlace nonwoven fabric before and after oxidation and grafting modification are as follows Figure 5 and Figure 6 As shown. Figure 6It can be seen that after oxidation treatment, viscose fibers show signs of breakage and damage, primarily due to the oxidative action of sodium periodate, which breaks down the long-chain structure of cellulose. Electron microscopy images even reveal some fiber fragments, further confirming structural changes in the cellulose. Surface morphology images visually demonstrate these changes and reveal the reason for the decreased mechanical strength of oxidized cellulose. Analysis indicates that some hydroxyl groups at the C2 and C3 positions of the cellulose fibers are converted to aldehyde groups, disrupting the original hydrogen bond network and causing damage to the cellulose's internal structure, which in turn affects its mechanical properties.

[0059] (6) Capillary effect analysis

[0060] Follow the standard FZ / T01071-2008, "Test Method for Wicking of Textiles." Secure the fabric to a rack and pour water into a container on the base. Start timing. Measure and record the wicking height (in mm) at 1 minute, 5 minutes, 10 minutes, 20 minutes, and 30 minutes.

[0061] Table 2 shows the results of capillary effect analysis of the viscose spunlace nonwoven fabric before and after oxidation and grafting modification in Example 1. The mean wicking heights of both the original and modified fabrics increased with increasing testing time, demonstrating that both fabrics exhibited excellent capillary effect performance. However, the mean wicking heights of the modified fabric at each time point were slightly higher than those of the original fabric, indicating that the modified fabric exhibited superior capillary effect performance. This is due to the modification treatment enhancing the hygroscopicity and permeability of the modified fabric, thereby improving its capillary effect performance.

[0062] surface

[0063]

[0064] (7) Water retention rate (WRVs) analysis

[0065] The water retention rate test method is as follows: accurately weigh a certain mass of completely dried product, record the dry weight, add a certain amount of deionized water, stir thoroughly until the fabric is completely absorbed, then remove the fabric until the fabric stops dripping, weigh the fabric at this time and record the weight, and calculate the water retention rate according to the following formula:

[0066]

[0067] Table 3 shows the results of water retention analysis of the viscose spunlace nonwoven fabric before and after oxidation and grafting modification. As can be seen from Table 3, the water retention of the modified fabric increased from 152% of the original fabric to 197%, demonstrating a significant improvement in water retention. This indicates that oxidation and sericin modification effectively enhance the nonwoven fabric's water retention capacity.

[0068] surface

[0069]

[0070] (8) Liquid Water Management Test (MMT) Analysis

[0071] Test instrument: EY60MMT fully automatic liquid water management tester (EY Technology Testing Co., Ltd., Hong Kong, China).

[0072] Test Method: The experiment was conducted in accordance with the standard operating procedures of GB / T 21655.2-2019, "Evaluation of the Moisture Absorption and Quick-Drying Properties of Textiles - Part 2: Dynamic Moisture Transfer Method." To simulate the human perspiration process, a standard test solution was evenly applied to the surface of the knitted fabric in the liquid water management test. During the test, the surface and back layers of the specimen were each connected to two concentrically arranged sensors to record the moisture conductivity within annular regions (diameters of 5, 10, 15, 20, 25, and 30 mm, respectively) in real time. The specific experimental steps involved injecting water into the fabric surface using a pump for 20 seconds, followed by a 120-second test. After the test, several key data were obtained: fabric wetting time (surface and back layers), water absorption rate (surface and back layers), maximum wetting radius (surface and back layers), liquid water diffusion rate (surface and back layers), cumulative unidirectional transfer capacity, and overall liquid water management capacity (OMMC). Each sample was tested five times, and the average of the five results was recorded.

[0073] A fabric's liquid water management performance is largely dependent on the capillary action of the fiber or yarn, as well as the geometry and internal structure of the fiber, yarn, and fabric. To analyze the liquid water management capabilities of the samples, we graded them according to the index grading table in the rating standard GB / T21655.2-2019. The results are listed in Table 4 (the values ​​in parentheses represent the rating level; Grade 5 is the best and Grade 1 is the worst).

[0074] surface

[0075]

[0076] As can be seen from Table 4, in terms of grade, the maximum wetting radius and liquid water diffusion rate of the modified viscose spunlace nonwoven fabric are greatly improved compared with the original fabric, both of which are improved by 1-2 grades, and other values ​​such as wetting time and water absorption rate are also improved, indicating that the hygroscopicity of the modified viscose spunlace nonwoven fabric has been greatly improved.

[0077] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric, characterized in that: The following steps are involved: S1. placing a viscose spunlace nonwoven fabric in a sodium periodate solution and performing an oxidation reaction at room temperature in the dark to prepare a dialdehyde cellulose fabric; S2. Grafting the dialdehyde cellulose fabric obtained in step S1 with the sericin aqueous solution to produce a polypeptide-modified viscose fiber spunlace nonwoven fabric.

2. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S1, the mass ratio of the viscose spunlace nonwoven fabric to sodium periodate is 2:5-6.

3. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S1, the oxidation reaction time is 3-6 hours.

4. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S1, ethylene glycol is added to terminate the oxidation reaction.

5. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 4, characterized in that: After the oxidation reaction is terminated, the oxidized fabric is washed and dried to obtain dialdehyde cellulose fabric.

6. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S2, the concentration of the sericin aqueous solution is 4-12 g / L; the ratio of the sericin aqueous solution to the viscose spunlace nonwoven fabric in step S1 is 1500 mL:2 g.

7. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S2, the grafting reaction temperature is 40-45° C., and the reaction time is 1-5 hours.

8. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S2, the grafting reaction is carried out by heating in a water bath.

9. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 1, characterized in that: In step S2, after the grafting reaction, the obtained fabric is first baked and then soaked in deionized water and then dried to obtain a polypeptide-modified viscose fiber spunlace nonwoven fabric.

10. The method for preparing a polypeptide-modified viscose fiber spunlace nonwoven fabric according to claim 9, characterized in that: The baking temperature is 125-135°C, the baking time is 85-100s, and the soaking time is 7.5-9h.

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