Degradable composite non-woven fabric and preparation method thereof

Abstract

The invention discloses a degradable composite non-woven fabric and a preparation method of the degradable composite non-woven fabric, and relates to the technical field of non-woven fabrics. The composite material is prepared from the following components in parts by weight: 50 to 80 parts of polylactic acid, 20 to 50 parts of poly (butylene succinate), 6 to 15 parts of modified cotton fiber, 0.2 to 0.8 part of glyceryl monostearate, 1 to 3 parts of trimethylolpropane triacrylate and 0.4 to 1 part of distearyl thiodipropionate. The degradable composite non-woven fabric disclosed by the invention keeps excellent tensile strength, toughness and dimensional stability, and has a completely biodegradable characteristic; the composite material has good processability and usability, can be widely applied to the fields of medical treatment and public health, agricultural coverage, packaging materials and the like, conforms to the concept of green sustainable development, and has remarkable economic benefits and social values.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-woven fabrics, and particularly relates to a degradable composite non-woven fabric and a preparation method thereof. BACKGROUND

[0002] As an important textile material, non-woven fabric has the advantages of simple manufacturing process, high production efficiency, low cost, wide application, etc., and is widely used in medical and health, agricultural and horticultural, construction engineering, automobile industry, home decoration and other fields. Traditional non-woven fabric is mainly made of petroleum-based polymers such as polypropylene, polyester and polyethylene, and is prepared by melt blowing, spun-bonding, needling and other processes. However, with the increasingly serious global environmental problems, traditional petroleum-based non-woven fabric is difficult to naturally degrade after use, and accumulates in the environment for a long time, forming serious white pollution and causing persistent harm to the ecological environment.

[0003] In order to solve the above environmental problems, degradable non-woven fabric materials have received extensive attention in recent years. The degradable non-woven fabrics on the market at present mainly use biodegradable polymers such as polylactic acid (PLA), polybutylene adipate / terephthalate (PBAT), polybutylene succinate (PBS) and polyhydroxyalkanoate (PHA) as the base material. Among them, polylactic acid has become one of the main raw materials for preparing degradable non-woven fabric due to its good biocompatibility, complete degradability and relatively mature industrialization technology.

[0004] However, the existing degradable non-woven fabric technology still has many shortcomings: first, pure polylactic acid material has inherent defects such as brittleness, poor toughness and insufficient impact resistance, which limits its application in occasions with higher mechanical performance requirements; second, the thermal stability of single polymer base material is poor, the processing window is narrow, and the product is prone to thermal degradation and performance fluctuation; third, the existing degradable non-woven fabric generally lacks functionality, such as insufficient antibacterial performance, which is difficult to meet the requirements of special application fields such as medical and health; finally, the interface compatibility between natural fibers and polymer matrix is poor, the composite effect is not ideal, and it is difficult to fully exert the reinforcing effect of natural fibers.

[0005] For natural fiber reinforced degradable composites, the prior art mainly uses physical blending or simple surface treatment method. CN106032609A discloses a non-woven fabric and a manufacturing method thereof, the non-woven fabric is mixed by cotton fiber, bamboo fiber, pearl fiber and polylactic acid short fiber of epoxy compound, the weight fraction of cotton fiber in non-woven fabric is 20-30 parts, the weight fraction of bamboo fiber in non-woven fabric is 40-45 parts, the weight fraction of pearl fiber in non-woven fabric is 1-10 parts, and the weight fraction of polylactic acid short fiber of epoxy compound in non-woven fabric is 13-25 parts. However, due to the high density of hydroxyl group on the surface of natural fiber and strong polarity, the compatibility with the relatively hydrophobic polymer matrix is poor, which leads to insufficient interfacial bonding force and limited improvement of mechanical properties of the composite material. At the same time, the existing surface modification method of natural fiber mainly uses silane coupling agent treatment, which can improve the interfacial compatibility to a certain extent, but the treatment effect is not durable, and it is difficult to simultaneously endow the fiber with multiple functions such as antibacterial function.

[0006] Therefore, it is a technical problem to be solved in the field to develop a degradable composite non-woven fabric which has excellent mechanical properties and processing properties, and also has good biodegradability and functionality, and a corresponding efficient preparation method. SUMMARY

[0007] In order to solve the problems existing in the prior art, the purpose of the present application is to provide a degradable composite non-woven fabric and a preparation method thereof. The degradable composite non-woven fabric of the present application has excellent tensile strength, toughness and dimensional stability, and also has complete biodegradability, effectively solving the white pollution problem caused by traditional petroleum-based non-woven fabrics. The composite material has good processing performance and use performance, and can be widely used in medical health, agricultural covering, packaging materials and other fields, which meets the green and sustainable development concept, and has significant economic benefits and social value.

[0008] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0009] A degradable composite non-woven fabric is prepared from the following components in parts by weight: polylactic acid 50-80 parts, polybutylene succinate 20-50 parts, modified cotton fiber 6-15 parts, glycerol monostearate 0.2-0.8 parts, trimethylolpropane triacrylate 1-3 parts, and dioctadecyl thiodipropionate 0.4-1 part.

[0010] Preferably, the modified cotton fiber is prepared by the following method steps:

[0011] (1) dispersing cotton fibers into sodium hydroxide solution, stirring and treating, then washing to neutral, then dispersing the pretreated cotton fibers into a sodium periodate-containing phosphate buffer, slowly stirring and reacting in the dark, filtering, washing, and drying the product to obtain aldehyde-functionalized cotton fibers;

[0012] Alkaline treatment and oxidation to prepare aldehyde-functionalized cotton: the NaOH solution first swells the cellulose molecular chain, removing surface gum and impurities. Then, sodium periodate selectively oxidizes the ortho-hydroxyl groups on the cellulose molecular chain. During the oxidation process, IO4 - is reduced to IO3 - , while introducing active aldehyde groups on the cellulose chain to provide reaction sites for subsequent grafting reactions.

[0013] Preferably, in step (1), the diameter of the cotton fibers is 5-20 μm, and the length is 0.5-3 mm.

[0014] Preferably, in step (1), the amount ratio of cotton fibers, sodium hydroxide solution, sodium periodate, and phosphate buffer is 10 g: 200-300 mL: 0.5-2 g: 150-250 mL; the concentration of the sodium hydroxide solution is 2-5 mol / L, and the pH of the phosphate buffer is 6.0-7.0.

[0015] Preferably, in step (1), the stirring and treating conditions are 60-75 °C for 2-5 h, and the stirring and reacting conditions are 25-40 °C for 4-7 h.

[0016] (2) dispersing the aldehyde-functionalized cotton fibers into deionized water containing polyethyleneimine, adjusting the pH of the system, stirring and reacting, then adding sodium borohydride, and performing in-situ reduction under the same conditions, filtering, washing, and drying the product to obtain grafted cotton fibers;

[0017] PEI grafting reaction: the aldehyde groups on the surface of the aldehyde-functionalized fibers undergo nucleophilic addition reaction with the primary amino groups (-NH2) on the molecular chain of polyethyleneimine (PEI), and a Schiff base bond (-CH=N-) is formed through dehydration of the aminomethyl alcohol intermediate. Since the Schiff base is unstable in an aqueous environment, the added sodium borohydride acts as a reducing agent to reduce the unstable imine bond (-CH=N-) to a stable secondary amine bond (-CH2-NH-), realizing covalent grafting and fixation of PEI on the fiber surface.

[0018] Preferably, in step (2), the amount ratio of aldehyde-functionalized cotton fibers, polyethyleneimine, deionized water, and sodium borohydride is 10 g: 2-5 g: 100-200 mL: 0.4-1 g; the molecular weight of the polyethyleneimine is 10,000-25,000 Da.

[0019] Preferably, in step (2), the pH of the system is adjusted to 6.5-7.5; the stirring reaction condition is stirring reaction at 45-60℃ for 12-15h; and the in-situ reduction time is 2h.

[0020] (3) adding guanidyl propionic acid, EDC·HCl and NHS into deionized water, activating at room temperature, adjusting the pH of the system, then adding the grafted cotton fiber, stirring reaction, filtering, washing and drying the product to obtain the modified cotton fiber.

[0021] Guanidylization reaction: EDC·HCl first reacts with the carboxyl group of guanidyl propionic acid to form an active O-acylisourea intermediate, and then NHS further reacts with the intermediate to form a more stable NHS active ester. The primary amino group on the PEI chain on the grafted fiber surface performs nucleophilic attack on the NHS active ester to replace the NHS to form a stable amide bond (-CO-NH-), successfully covalently connecting the guanidyl-containing propionic acid segment to the fiber surface, and endowing the fiber surface with positive charge characteristics.

[0022] Preferably, in step (3), the amount ratio of guanidyl propionic acid, EDC·HCl, NHS, deionized water and grafted cotton fiber is 2-5g: 0.8-1.6g: 0.4-0.8g: 150-250mL: 10g.

[0023] Preferably, in step (3), the activation time is 20-40min; the pH of the system is adjusted to 7.0-8.0; and the stirring reaction condition is slow stirring reaction at 30-45℃ for 12-24h.

[0024] The application also claims a preparation method of the degradable composite non-woven fabric, comprising the following steps: mixing each component except trimethylolpropane triacrylate, feeding into a melting device, stirring uniformly after melting to obtain a melt; drawing a wire through a spinning box, laying a net, needling, then adding trimethylolpropane triacrylate to hot-press to obtain the degradable composite non-woven fabric.

[0025] Preferably, melting at 160-180℃, stirring at medium speed for 5-10min until uniformly dispersed to obtain a homogeneous melt; hot-pressing at 120-150℃ and 5-15MPa for 2-5min.

[0026] Compared with the prior art, the application has the following beneficial effects:

[0027] 1. The application provides a degradable composite non-woven fabric, polylactic acid as the main base material provides basic mechanical properties, but has problems such as greater brittleness and insufficient toughness, the introduction of polybutylene succinate significantly improves the flexibility and impact resistance of the material, effectively compensating for the brittleness of polylactic acid; modified cotton fiber has excellent rigidity, good toughness and dimensional stability, not only greatly improves the mechanical strength of the composite material as a reinforcing phase, but also acts as a heterogeneous nucleating agent to promote the crystallization of polylactic acid, thereby improving the thermal stability and use temperature range of the material; glycerol monostearate promotes the synergistic effect between components by improving the interfacial bonding; the crosslinking network constructed by trimethylolpropane triacrylate further strengthens the overall performance of the material; dilauryl thiodipropionate effectively inhibits thermal oxidation during processing, ensuring the stability of the material performance.

[0028] 2. The application provides a modified cotton fiber, alkali pretreatment effectively removes natural gum and impurities on the surface of the fiber, causes the fiber to swell moderately, and significantly improves the surface wetting characteristics; aldehyde group treatment introduces high-activity aldehyde group reaction sites on the surface of the fiber, not only provides a chemical bonding basis for subsequent grafting, but also enhances the affinity with the polymer matrix by increasing the surface polarity; the grafting of polyethyleneimine forms a functional surface layer rich in amino groups, and the polymer chain structure of the functional surface layer builds an effective molecular bridge between the fiber and the matrix, greatly improving the interfacial stress transfer efficiency and effectively improving the mechanical properties of the material, and the high-density amino functional groups provide sufficient reactivity for further functionalization; the final introduction of guanidino groups not only endows the fiber with antibacterial activity, but also avoids the migration and volatilization problems of traditional antibacterial agents through chemical bonding, ensuring the long-term effectiveness and stability of the antibacterial performance. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the application more clear, the application will be further described in detail below with examples. Of course, the specific examples described herein are only used to explain the application, and are not used to limit the application.

[0030] Unless otherwise specified, the chemical reagents and materials in the application are purchased through market channels or synthesized from raw materials purchased through market channels.

[0031] The polylactic acid is purchased from NatureWork, and the specification number is 2003D;

[0032] The polybutylene succinate is BioPBS from Mitsubishi Chemical.

[0033] A preparation method of a degradable composite non-woven fabric, comprising the following steps:

[0034] (1) dispersing 10 g of cotton fibers into 200-300 mL of 2-5 mol / L sodium hydroxide solution, stirring and treating at 60-75℃ for 2-5 h, then washing with deionized water until neutral, then dispersing the pretreated cotton fibers into 150-250 mL of a phosphate buffer (pH = 6.0-7.0) containing 0.5-2 g of sodium periodate, slowly stirring and reacting at 25-40℃ for 4-7 h in the dark, filtering, washing and drying the product to obtain aldehyde-functionalized cotton fibers;

[0035] (2) dispersing 10 g of aldehyde-functionalized cotton fibers into 100-200 mL of deionized water containing 2-5 g of polyethyleneimine, adjusting the pH of the system to 6.5-7.5, stirring and reacting at 45-60℃ for 12-15 h, then adding 0.4-1 g of sodium borohydride, and in-situ reducing under the same conditions for 2 h, filtering, washing and drying the product to obtain grafted cotton fibers;

[0036] (3) adding 2-5 g of guanidinopropionic acid, 0.8-1.6 g of EDC·HCl and 0.4-0.8 g of NHS into 150-250 mL of deionized water, activating at room temperature for 20-40 min, adjusting the pH of the system to 7.0-8.0, then adding 10 g of grafted cotton fibers, slowly stirring and reacting at 30-45℃ for 12-24 h, filtering the product, washing with deionized water and 0.1 mol / L sodium chloride solution in sequence, and drying to obtain modified cotton fibers;

[0037] (4) mixing polylactic acid 50-80 parts, polybutylene succinate 20-50 parts, modified cotton fibers 6-15 parts, glycerol monostearate 0.2-0.8 parts, and dioctadecyl thiodipropionate 0.4-1 part, feeding into a melting device, melting at 160-180℃, stirring at medium speed for 5-10 min until uniformly dispersed to obtain a homogeneous melt; spinning, laying and needling the melt through a spinning box, then adding 1-3 parts of trimethylolpropane triacrylate, hot pressing at 120-150℃ and 5-15 MPa for 2-5 min to form the degradable composite non-woven fabric.

[0038] The application will be further described below through specific examples.

[0039] Example 1

[0040] A preparation method of a degradable composite non-woven fabric, comprising the following steps:

[0041] (1) 10 g of cotton fibers were dispersed in 250 mL of 3 mol / L sodium hydroxide solution, stirred at 70°C for 3 h, then washed with deionized water to neutral, and then the pretreated cotton fibers were dispersed in 200 mL of a phosphate buffer (pH = 6.5) containing 2 g of sodium periodate, slowly stirred at 40°C for 4 h in the dark, and then the product was filtered, washed, and dried to obtain aldehyde-modified cotton fibers;

[0042] (2) 10 g of aldehyde-modified cotton fibers were dispersed in 150 mL of deionized water containing 5 g of polyethyleneimine, the pH of the system was adjusted to 7.0, and then stirred at 60°C for 15 h, then 1 g of sodium borohydride was added, and in-situ reduction was carried out under the same conditions for 2 h, and then the product was filtered, washed, and dried to obtain grafted cotton fibers;

[0043] (3) 5 g of guanidinopropionic acid, 1.6 g of EDC·HCl, and 0.8 g of NHS were added to 200 mL of deionized water, activated at room temperature for 30 min, the pH of the system was adjusted to 7.5, then 10 g of grafted cotton fibers were added, and slowly stirred at 45°C for 24 h, then the product was filtered, washed with deionized water and 0.1 mol / L sodium chloride solution in sequence, and dried to obtain modified cotton fibers;

[0044] (4) 8000 g of polylactic acid, 5000 g of polybutylene succinate, 1500 g of modified cotton fibers, 80 g of glyceryl monostearate, and 100 g of distearyl thiodipropionate were mixed and sent to a melting device, melted at 170°C, and stirred at medium speed for 8 min until uniformly dispersed to obtain a homogeneous melt; the melt was drawn into fibers through a spinning box, laid into a web, needled, then 300 g of trimethylolpropane triacrylate was added, and hot-pressed at 140°C and 10 MPa for 3 min to form the degradable composite non-woven fabric.

[0045] Example 2

[0046] A method for preparing a degradable composite non-woven fabric, comprising the following steps:

[0047] (1) 10 g of cotton fibers were dispersed in 250 mL of 3 mol / L sodium hydroxide solution, stirred at 70°C for 3 h, then washed with deionized water to neutral, and then the pretreated cotton fibers were dispersed in 200 mL of a phosphate buffer (pH = 6.5) containing 1.5 g of sodium periodate, slowly stirred at 35°C for 5 h in the dark, and then the product was filtered, washed, and dried to obtain aldehyde-modified cotton fibers;

[0048] (2) 10 g of aldehyde-modified cotton fibers were dispersed in 150 mL of deionized water containing 4 g of polyethyleneimine, the pH of the system was adjusted to 7.0, and then stirred at 55°C for 13 h, then 0.8 g of sodium borohydride was added, and in-situ reduction was carried out under the same conditions for 2 h, and then the product was filtered, washed, and dried to obtain grafted cotton fibers;

[0049] (3) 4 g guanidyl propionic acid, 1.2 g EDC-HCl, 0.6 g NHS were added into 200 mL deionized water, activated at room temperature for 30 min, the pH of the system was adjusted to 7.5, then 10 g grafted cotton fibers were added, slowly stirred at 40°C for 16 h, the product was filtered, washed with deionized water and 0.1 mol / L sodium chloride solution in turn, and dried to obtain modified cotton fibers;

[0050] (4) 7000 g polylactic acid, 4000 g polybutylene succinate, 1200 g modified cotton fibers, 60 g glyceryl monostearate, and 80 g dioctadecyl thiodipropionate were mixed and sent into a melting device, melted at 170°C, and stirred at medium speed for 8 min until uniformly dispersed to obtain a homogeneous melt; the melt was drawn into fibers by a spinning box, laid into a web, needled, then 200 g trimethylolpropane triacrylate was added, and hot-pressed at 140°C and 10 MPa for 3 min to form the degradable composite non-woven fabric.

[0051] Example 3

[0052] A method for preparing a degradable composite non-woven fabric, comprising the following steps:

[0053] (1) 10 g cotton fibers were dispersed into 250 mL 3 mol / L sodium hydroxide solution, stirred at 70°C for 3 h, then washed with deionized water until neutral, and then the pretreated cotton fibers were dispersed into 200 mL phosphate buffer solution (pH=6.5) containing 1 g sodium periodate, slowly stirred at 30°C for 6 h in the dark, and the product was filtered, washed, and dried to obtain aldehyde-modified cotton fibers;

[0054] (2) 10 g aldehyde-modified cotton fibers were dispersed into 150 mL deionized water containing 3 g polyethyleneimine, the pH of the system was adjusted to 7.0, and stirred at 50°C for 14 h, then 0.6 g sodium borohydride was added, and in-situ reduction was carried out under the same conditions for 2 h, and the product was filtered, washed, and dried to obtain grafted cotton fibers;

[0055] (3) 3 g guanidyl propionic acid, 1.0 g EDC-HCl, and 0.5 g NHS were added into 200 mL deionized water, activated at room temperature for 30 min, the pH of the system was adjusted to 7.5, then 10 g grafted cotton fibers were added, slowly stirred at 35°C for 20 h, the product was filtered, washed with deionized water and 0.1 mol / L sodium chloride solution in turn, and dried to obtain modified cotton fibers;

[0056] (4) 6000 g of polylactic acid, 3000 g of polybutylene succinate, 900 g of modified cotton fiber, 40 g of glycerol monostearate, and 60 g of dioctadecyl thiodipropionate were mixed and then fed into a melting device, melted at 170°C, and stirred at a medium speed for 8 min until uniformly dispersed to obtain a homogeneous melt; the melt was drawn through a spinning box, laid on a web, needled, and then 200 g of trimethylolpropane triacrylate was added and hot-pressed at 140°C and 10 MPa for 3 min to form the degradable composite non-woven fabric.

[0057] Example 4

[0058] A method for preparing a degradable composite non-woven fabric, comprising the following steps:

[0059] (1) 10 g of cotton fiber was dispersed in 250 mL of 3 mol / L sodium hydroxide solution, stirred at 70°C for 3 h, then washed with deionized water until neutral, and then the pretreated cotton fiber was dispersed in 200 mL of a phosphate buffer (pH = 6.5) containing 0.5 g of sodium periodate, slowly stirred at 25°C for 7 h in the dark, and then the product was filtered, washed, and dried to obtain aldehyde-modified cotton fiber;

[0060] (2) 10 g of aldehyde-modified cotton fiber was dispersed in 150 mL of deionized water containing 2 g of polyethyleneimine, the pH of the system was adjusted to 7.0, and the system was stirred at 45°C for 15 h, then 0.4 g of sodium borohydride was added, and in-situ reduction was carried out under the same conditions for 2 h, and then the product was filtered, washed, and dried to obtain grafted cotton fiber;

[0061] (3) 2 g of guanidyl propionic acid, 0.8 g of EDC·HCl, and 0.4 g of NHS were added to 200 mL of deionized water, activated at room temperature for 30 min, the pH of the system was adjusted to 7.5, then 10 g of grafted cotton fiber was added, and the system was slowly stirred at 30°C for 24 h, and then the product was filtered, washed with deionized water and 0.1 mol / L sodium chloride solution in sequence, and dried to obtain modified cotton fiber;

[0062] (4) 5000 g of polylactic acid, 2000 g of polybutylene succinate, 600 g of modified cotton fiber, 20 g of glycerol monostearate, and 40 g of dioctadecyl thiodipropionate were mixed and then fed into a melting device, melted at 170°C, and stirred at a medium speed for 8 min until uniformly dispersed to obtain a homogeneous melt; the melt was drawn through a spinning box, laid on a web, needled, and then 100 g of trimethylolpropane triacrylate was added and hot-pressed at 140°C and 10 MPa for 3 min to form the degradable composite non-woven fabric.

[0063] Comparative Example 1

[0064] A method for preparing a degradable composite non-woven fabric, comprising the following steps:

[0065] (1) 10 g of cotton fibers were dispersed in 250 mL of 3 mol / L sodium hydroxide solution, stirred at 70°C for 3 h, then washed with deionized water to neutral, and then the pretreated cotton fibers were dispersed in 200 mL of a phosphate buffer (pH = 6.5) containing 2 g of sodium periodate, slowly stirred at 40°C for 4 h in the dark, and then the product was filtered, washed, and dried to obtain aldehyde-modified cotton fibers;

[0066] (2) 10 g of the aldehyde-modified cotton fibers were dispersed in 150 mL of deionized water containing 5 g of polyethyleneimine, the pH of the system was adjusted to 7.0, and then stirred at 60°C for 15 h, then 1 g of sodium borohydride was added, and in-situ reduction was carried out under the same conditions for 2 h, and then the product was filtered, washed, and dried to obtain grafted cotton fibers;

[0067] (3) 8000 g of polylactic acid, 5000 g of polybutylene succinate, 1000 g of grafted cotton fibers, 500 g of guanidyl propionic acid, 80 g of glycerol monostearate, and 100 g of distearyl thiodipropionate were mixed and then fed into a melting device, melted at 170°C, and stirred at medium speed for 8 min until uniformly dispersed to obtain a homogeneous melt; the melt was drawn into fibers through a spinning box, laid into a web, needled, then 300 g of trimethylolpropane triacrylate was added, and hot-pressed at 140°C and 10 MPa for 3 min to form the degradable composite non-woven fabric.

[0068] Comparative Example 2

[0069] A method for preparing a degradable composite non-woven fabric, comprising the following steps:

[0070] (1) 10 g of cotton fibers were dispersed in 250 mL of 3 mol / L sodium hydroxide solution, stirred at 70°C for 3 h, then washed with deionized water to neutral, and then the pretreated cotton fibers were dispersed in 200 mL of a phosphate buffer (pH = 6.5) containing 2 g of sodium periodate, slowly stirred at 40°C for 4 h in the dark, and then the product was filtered, washed, and dried to obtain aldehyde-modified cotton fibers;

[0071] (2) 8000 g of polylactic acid, 5000 g of polybutylene succinate, 1000 g of aldehyde-modified cotton fibers, 500 g of polyethyleneimine, 80 g of glycerol monostearate, and 100 g of distearyl thiodipropionate were mixed and then fed into a melting device, melted at 170°C, and stirred at medium speed for 8 min until uniformly dispersed to obtain a homogeneous melt; the melt was drawn into fibers through a spinning box, laid into a web, needled, then 300 g of trimethylolpropane triacrylate was added, and hot-pressed at 140°C and 10 MPa for 3 min to form the degradable composite non-woven fabric.

[0072] The nonwoven fabrics prepared in Examples 1-4 and Comparative Examples 1-2 were subjected to performance tests. The grammage was tested according to GB / T 24218.1-2009 "Textiles - Nonwoven fabrics - Test methods - Part 1: Determination of the mass per unit area", the thickness was tested according to GB / T 24218.2-2009 "Textiles - Nonwoven fabrics - Test methods - Part 2: Determination of thickness", the mechanical properties were tested according to GB / T 24218.3-2010 "Textiles - Nonwoven fabrics - Test methods - Part 3: Determination of tensile strength and elongation at break (strip method)", and the initial and 50 washes antibacterial rates against E. coli ATCC 8099 and C. albicans ATCC 10231 were tested according to GB / T 20944.3-2008 "Textiles - Evaluation of antibacterial properties - Part 3: Shake flask method". The specific data are shown in Table 1.

[0073] Table 1 Performance test results of the composite nonwoven fabric

[0074]

[0075] The above description is merely preferred specific embodiments of the present application. The scope of the present application is not limited to the above specific embodiments, and any person skilled in the art can make equivalent substitutions or changes to the technical solutions and inventive concepts of the present application within the scope of the present application, which should be covered by the scope of protection of the present application.

Claims

1. A degradable composite nonwoven fabric, characterized by, The components are prepared by weight parts: polylactic acid 50-80 parts, polybutylene succinate 20-50 parts, modified cotton fiber 6-15 parts, glycerol monostearate 0.2-0.8 parts, trimethylolpropane triacrylate 1-3 parts, dioctadecyl thiodipropionate 0.4-1 part.

2. The degradable composite nonwoven fabric according to claim 1, characterized by, The modified cotton fiber is prepared by the following method steps: (1) dispersing the cotton fiber into a sodium hydroxide solution, stirring and treating, then washing to neutral, then dispersing the pretreated cotton fiber into a sodium periodate-containing phosphate buffer solution, slowly stirring and reacting in the dark, filtering, washing and drying the product to obtain aldehyde-based cotton fiber; (2) dispersing the aldehyde-based cotton fiber into deionized water containing polyethyleneimine, adjusting the pH of the system, stirring and reacting, then adding sodium borohydride, and in-situ reducing under the same conditions, filtering, washing and drying the product to obtain grafted cotton fiber; (3) adding guanidinopropionic acid, EDC·HCl and NHS into deionized water, activating at room temperature, adjusting the pH of the system, then adding grafted cotton fiber, stirring and reacting, filtering, washing and drying the product to obtain modified cotton fiber.

3. The degradable composite nonwoven fabric according to claim 2, characterized by, In step (1), the usage ratio of cotton fiber, sodium hydroxide solution, sodium periodate and phosphate buffer solution is 10g: 200-300mL: 0.5-2g: 150-250mL; the concentration of sodium hydroxide solution is 2-5mol / L, and the pH of phosphate buffer solution is 6.0-7.

0.

4. The degradable composite nonwoven fabric according to claim 2, wherein In step (1), the stirring and treating conditions are stirring and treating at 60-75℃ for 2-5h; the stirring and reacting conditions are stirring and reacting at 25-40℃ for 4-7h.

5. The degradable composite nonwoven fabric according to claim 2, wherein In step (2), the usage ratio of aldehyde-based cotton fiber, polyethyleneimine, deionized water and sodium borohydride is 10g: 2-5g: 100-200mL: 0.4-1g; the molecular weight of polyethyleneimine is 10000-25000Da.

6. The degradable composite nonwoven fabric according to claim 2, wherein In step (2), the pH of the system is adjusted to 6.5-7.5; the stirring and reacting conditions are stirring and reacting at 45-60℃ for 12-15h; the in-situ reduction time is 2h.

7. The degradable composite nonwoven fabric according to claim 2, wherein In step (3), the usage ratio of guanidinopropionic acid, EDC·HCl, NHS, deionized water and grafted cotton fiber is 2-5g: 0.8-1.6g: 0.4-0.8g: 150-250mL: 10g.

8. The degradable composite nonwoven fabric according to claim 2, wherein In step (3), the activation time is 20-40min; the pH of the system is adjusted to 7.0-8.0; the stirring and reacting conditions are slowly stirring and reacting at 30-45℃ for 12-24h.

9. A method for producing the degradable composite nonwoven fabric according to any one of claims 1 to 8, characterized by, The steps include: mixing all components except trimethylolpropane triacrylate, feeding into a melting device, stirring uniformly after melting to obtain a melt; drawing yarn, laying web, needling, then adding trimethylolpropane triacrylate and hot pressing to form the degradable composite non-woven fabric.

10. The method of claim 9, wherein, Melting at 160-180℃, stirring at medium speed for 5-10min until uniformly dispersed to obtain a homogeneous melt; hot pressing at 120-150℃ and 5-15MPa for 2-5min.

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