Completely biodegradable non-woven fabric composite material and preparation method thereof

Abstract

The invention belongs to the field of high polymer materials, and particularly relates to a completely biodegradable non-woven fabric composite material and a preparation method thereof. The non-woven fabric composite material provided by the invention comprises a non-woven fabric layer and a polymer film layer compounded on the surface of the non-woven fabric layer, the non-woven fabric layer is a bamboo fiber non-woven fabric; the polymer film layer comprises the following components: poly (butylene adipate terephthalate), polypropylene carbonate, glycidyl methacrylate and poly (diethylene glycol adipate). The non-woven fabric composite material provided by the invention can be completely biodegraded, has relatively high tensile strength and elongation at break, and has excellent water resistance and flexibility.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials, and particularly relates to a fully biodegradable nonwoven composite material and its preparation method. Background Technology

[0002] Non-woven fabric is a type of fabric formed without spinning or weaving; it is created by bonding or fusing fibers together using physical or chemical methods. The history of non-woven fabrics dates back to the early 20th century, initially primarily used as industrial filtration materials. With technological advancements, the applications of non-woven fabrics have gradually expanded to multiple industries, including healthcare, agriculture, construction, and packaging. Traditional non-woven fabrics are mainly made from petroleum-based synthetic fibers such as polypropylene (PP) and polyester (PET). While these materials possess good mechanical properties and durability, their non-degradability causes severe environmental pollution after use, especially in the field of disposable products such as masks, wet wipes, and shopping bags. The accumulation and incineration of large amounts of waste creates enormous environmental pressure.

[0003] The main problem with traditional petroleum-based nonwoven fabrics is their poor biodegradability. Taking polypropylene nonwoven fabric as an example, its degradation cycle in the natural environment can take hundreds, even thousands of years. These wastes not only consume vast amounts of land resources but also enter ecosystems through the food chain, posing potential threats to plant, animal, and human health. Furthermore, incineration releases large amounts of carbon dioxide and harmful gases, exacerbating the greenhouse effect and air pollution. With increasing global environmental awareness and increasingly stringent environmental regulations in various countries, developing biodegradable nonwoven materials has become crucial to solving this problem.

[0004] Biodegradable nonwoven fabrics are typically made from natural fibers (such as cotton, hemp, and bamboo pulp) or bio-based synthetic fibers (such as PLA, polylactic acid, PBAT, and PHA) through carding, air-forming, or melt-blowing processes. These fibers are biodegradable and can be broken down by microorganisms in specific environments (such as composting), thus addressing the environmental pollution problems of traditional petroleum-based nonwoven materials at their source. However, the mechanical properties of existing biodegradable nonwoven materials are generally low, which significantly limits their application scenarios. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a fully biodegradable nonwoven composite material and its preparation method. The nonwoven composite material provided by the present invention is fully biodegradable, has high tensile strength and elongation at break, and has excellent water-blocking properties and softness.

[0006] The present invention provides a fully biodegradable nonwoven composite material, comprising: a nonwoven layer and a polymer film layer composited on the surface of the nonwoven layer;

[0007] The non-woven fabric layer is bamboo fiber non-woven fabric;

[0008] The polymer film layer comprises polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate, and diethylene glycol adipate.

[0009] Preferably, the weight-average molecular weight of the polybutylene terephthalate (PET) is 7 × 10⁻⁶. 4 ~3×10 5 g / mol.

[0010] Preferably, the polypropylene carbonate has a weight-average molecular weight of 4 × 10⁻⁶. 4 ~3×10 5 g / mol.

[0011] Preferably, the weight-average molecular weight of the poly(ethylene adipate) is 3 × 10⁻⁶. 3 ~1.5×10 4 g / mol.

[0012] Preferably, the content of polybutylene terephthalate in the polymer film layer is 45~95wt%; the content of polypropylene carbonate in the polymer film layer is 4~50wt%; the content of glycidyl methacrylate in the polymer film layer is 0.1~1wt%; and the content of diethylene adipate in the polymer film layer is 0.1~5wt%.

[0013] Preferably, the bamboo fiber nonwoven fabric has a transverse tensile strength of 4~7MPa, a longitudinal tensile strength of 4~7MPa, a transverse elongation at break of 30~45%, and a longitudinal elongation at break of 40~55%.

[0014] This invention provides a method for preparing the fully biodegradable nonwoven composite material described in the above technical solution, comprising the following steps:

[0015] The polymer film masterbatch is hot-melted and cast using a coating machine, and then combined with the nonwoven fabric layer in the molten state to obtain a completely biodegradable nonwoven fabric composite material.

[0016] Preferably, the polymer film masterbatch is prepared according to the following steps:

[0017] Polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate and diethylene glycol adipate were melt-blended and then extruded and granulated to obtain polymer film masterbatch.

[0018] Preferably, the temperature of the hot melt casting is 170~210℃.

[0019] Preferably, the composite method is roll forming.

[0020] Compared with existing technologies, this invention provides a fully biodegradable nonwoven composite material and its preparation method. The nonwoven composite material provided by this invention comprises: a nonwoven layer and a polymer film layer laminated on the surface of the nonwoven layer; the nonwoven layer is bamboo fiber nonwoven fabric; the polymer film layer comprises polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate, and diethylene adipate. In this invention, polybutylene terephthalate (PBAT) is a flexible polymer that improves the flexibility of the film and has high viscosity, which enhances its adhesion to nonwoven fabrics. Polypropylene carbonate (PPC) is a flexible polymer at room temperature, which also improves the flexibility of the film and has high extensibility, thus improving the barrier properties of the film. Polyethylene adipate has the advantages of high boiling point, low volatility, no smoke during coating, and biodegradability, which can increase the melt flow rate of the coating resin, reduce the film thickness, and improve the coating production efficiency. Glycidyl methacrylate has epoxy functional groups on its molecular chain, which can chemically react with the terminal hydroxyl and carboxyl groups of PBAT, significantly increasing the viscosity of the blend. It can also chemically interact with multiple hydroxyl groups of nonwoven fibers, improving the adhesion to the nonwoven fabric and enhancing the peel strength of the nonwoven coating material. The nonwoven composite material provided by this invention has water-blocking properties and good mechanical properties, has a wide range of applications, is completely biodegradable, and is beneficial to environmental protection. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The present invention provides a fully biodegradable nonwoven composite material, comprising: a nonwoven layer and a polymer film layer composited on the surface of the nonwoven layer.

[0023] In the nonwoven composite material provided by this invention, the nonwoven layer is a bamboo fiber nonwoven fabric; the transverse tensile strength of the bamboo fiber nonwoven fabric is preferably 4~7 MPa, specifically 4 MPa, 4.2 MPa, 4.5 MPa, 4.7 MPa, 5 MPa, 5.2 MPa, 5.5 MPa, 5.7 MPa, 6 MPa, 6.2 MPa, 6.5 MPa, 6.7 MPa, or 7 MPa; the longitudinal tensile strength of the bamboo fiber nonwoven fabric is preferably 4~7 MPa, specifically 4 MPa, 4.2 MPa, 4.5 MPa, 4.7 MPa, 5 MPa, 5.2 MPa, 5.5 MPa, 5.7 MPa. a. 6MPa, 6.2MPa, 6.5MPa, 6.7MPa, or 7MPa; the transverse breaking elongation of the bamboo fiber nonwoven fabric is preferably 30-45%, specifically 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, or 45%; the longitudinal breaking elongation of the bamboo fiber nonwoven fabric is preferably 40-55%, specifically 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, or 55%.

[0024] In the nonwoven composite material provided by the present invention, the thickness of the nonwoven layer is preferably 15~50μm, specifically 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm or 50μm.

[0025] In the nonwoven composite material provided by the present invention, the polymer film layer comprises polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate and diethylene glycol adipate.

[0026] In the nonwoven composite material provided by the present invention, the weight-average molecular weight of the polybutylene terephthalate (PET) is preferably 7 × 10⁻⁶. 4 ~3×10 5 g / mol, specifically 7 × 10 4 g / mol, 8×10 4 g / mol, 9×10 4 g / mol, 1×10 5 g / mol, 1.1×10 5 g / mol, 1.2×10 5 g / mol, 1.5×10 5 g / mol, 1.7×10 5 g / mol, 2×10 5 g / mol, 2.3×10 5g / mol, 2.5×10 5 g / mol, 2.7×10 5 g / mol or 3×10 5 g / mol.

[0027] In the nonwoven composite material provided by the present invention, the weight-average molecular weight of the polypropylene carbonate is preferably 4 × 10⁻⁶. 4 ~3×10 5 g / mol, specifically 4 × 10 4 g / mol, 5×10 4 g / mol, 6×10 4 g / mol, 7×10 4 g / mol, 8×10 4 g / mol, 9×10 4 g / mol, 1×10 5 g / mol, 1.1×10 5 g / mol, 1.2×10 5 g / mol, 1.5×10 5 g / mol, 1.7×10 5 g / mol, 2×10 5 g / mol, 2.3×10 5 g / mol, 2.5×10 5 g / mol, 2.7×10 5 g / mol or 3×10 5 g / mol.

[0028] In the nonwoven composite material provided by the present invention, the weight-average molecular weight of the poly(ethylene adipate) is preferably 8 × 10⁻⁶. 3 ~1.2×10 4 g / mol, specifically 8 × 10 3 g / mol, 8.3×10 3 g / mol, 8.5×10 3 g / mol, 8.7×10 3 g / mol, 9×10 3 g / mol, 9.2×10 3 g / mol, 9.5×10 3 g / mol, 9.7×10 3 g / mol, 1×10 4 g / mol, 1.1×10 4 g / mol or 1.2×10 4 g / mol.

[0029] In the nonwoven composite material provided by the present invention, if the weight-average molecular weight of the polymer raw material is too high, its viscosity will be too high, which will reduce the melt index of the coating resin and make it unsuitable for coating machine to form a film; if the molecular weight is too low, it will be difficult to form a film, and the mechanical properties such as the tensile strength of the film will be greatly reduced.

[0030] In the nonwoven composite material provided by the present invention, the content of polybutylene terephthalate in the polymer film layer is preferably 45-95 wt%, specifically 45 wt%, 47 wt%, 50 wt%, 52 wt%, 55 wt%, 57 wt%, 60 wt%, 62 wt%, 65 wt%, 67 wt%, 70 wt%, 72 wt%, 75 wt%, 77 wt%, 80 wt%, 82 wt%, 85 wt%, 87 wt%, 90 wt%, 92 wt%, or 95 wt%.

[0031] In the nonwoven composite material provided by the present invention, the content of polypropylene carbonate in the polymer film layer is preferably 4 to 50 wt%, specifically 4 wt%, 5 wt%, 7 wt%, 8.9 wt%, 10 wt%, 12 wt%, 15 wt%, 17 wt%, 17.8 wt%, 20 wt%, 23 wt%, 25 wt%, 26.5 wt%, 27 wt%, 30 wt%, 32 wt%, 35 wt%, 36 wt%, 37 wt%, 40 wt%, 42 wt%, 45 wt%, 46 wt%, 47 wt%, or 50 wt%.

[0032] In the nonwoven composite material provided by the present invention, the content of glycidyl methacrylate in the polymer film layer is preferably 0.1~1wt%, specifically 0.1wt%, 0.15wt%, 0.2wt%, 0.25wt%, 0.3wt%, 0.35wt%, 0.4wt%, 0.45wt%, 0.5wt%, 0.55wt%, 0.6wt%, 0.65wt%, 0.7wt%, 0.75wt%, 0.8wt%, 0.85wt%, 0.9wt%, 0.95wt%, or 1wt%.

[0033] In the nonwoven composite material provided by the present invention, the content of polyethylene adipate in the polymer film layer is preferably 0.1~5wt%, specifically 0.1wt%, 0.3wt%, 0.5wt%, 0.7wt%, 1wt%, 1.2wt%, 1.5wt%, 1.7wt%, 2wt%, 2.3wt%, 2.5wt%, 2.7wt%, 3wt%, 3.2wt%, 3.5wt%, 3.7wt%, 4wt%, 4.2wt%, 4.5wt%, 4.7wt%, or 5wt%.

[0034] In the nonwoven composite material provided by the present invention, the thickness of the polymer film layer is preferably 5~30μm, specifically 5μm, 10μm, 15μm, 20μm, 25μm or 30μm.

[0035] This invention provides a method for preparing the fully biodegradable nonwoven composite material described in the above technical solution, comprising the following steps:

[0036] The polymer film masterbatch is hot-melted and cast using a coating machine, and then combined with the nonwoven fabric layer in the molten state to obtain a completely biodegradable nonwoven fabric composite material.

[0037] In the preparation method provided by this invention, the polymer film masterbatch is preferably prepared according to the following steps: polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate, and diethylene adipate are melt-blended and then extruded and granulated to obtain the polymer film masterbatch. The melt blending is preferably carried out in an extruder, more preferably in a twin-screw extruder; the operating temperature of the extruder is preferably 160~190℃; and the screw speed of the extruder is preferably 100~300 rpm.

[0038] In the preparation method provided by the present invention, the temperature of the hot melt casting is preferably 170~210℃; the operating speed of the coating machine is preferably 40~300 rpm.

[0039] In the preparation method provided by the present invention, the composite method is preferably roll pressing composite.

[0040] For clarity, the following examples will be used to provide a detailed description.

[0041] In the following embodiments provided by the present invention, polybutylene terephthalate (PBAT) was provided by Xinjiang Lanshan Tunhe Polyester Co., Ltd., model number TH801T; polypropylene carbonate (PPC) was provided by Zhejiang Huafeng Environmental Protection Materials Co., Ltd., model number HF901; and glycidyl methacrylate was provided by Sinopharm Group.

[0042] In the following embodiments provided by the present invention, the weight-average molecular weight of the polyethylene adipate used is 8.3 × 10⁻⁶. 3 g / mol; prepared by the following method: adipic acid and diethylene glycol undergo esterification reaction in the presence of tetrabutyl titanate catalyst, and poly(diethylene adipate) of the desired molecular weight is obtained by controlling the reaction temperature, reaction time and pressure.

[0043] In the following embodiments provided by the present invention, the extruder used is a SHJ-20 twin-screw extruder from Lantai Plastic Machinery Co., Ltd.; the coating machine used is a DL-1300 manufactured by Changzhou Kailwei Plastic Machinery Co., Ltd.

[0044] Example 1

[0045] PBAT, PPC, glycidyl methacrylate, and diethylene adipate were mixed in a mass ratio of 50:46:1.0:3.0 and then added to a twin-screw extruder. The extruder temperatures were set as follows: Zone 1: 160℃, Zone 2: 180℃, Zone 3: 190℃, Zone 4: 190℃, Zone 5: 190℃, Zone 6: 190℃, Zone 7: 190℃, Zone 8: 190℃, and Die Head: 185℃. The screw speed was set to 300 rpm. After extrusion, water cooling, stretching, and pelletizing, the coated modified resin was obtained.

[0046] The modified resin was processed using a coating machine. The temperatures of the main machine were set as follows: Zone 1: 160℃, Zone 2: 170℃, Zone 3: 180℃, Zone 4: 190℃, Zone 5: 200℃, and Zones 1, 2, 3, 4, and 5: 210℃. The machine speed was set to 300 rpm. The modified resin was hot-melted and cast into a film at the machine outlet and then rolled and laminated with bamboo fiber nonwoven fabric in a molten state. After winding, a nonwoven fabric coated composite material was obtained (nonwoven fabric thickness 30μm, film thickness 10~20μm).

[0047] Example 2

[0048] Referring to Example 1, the only difference is that the mass ratio of PBAT, PPC, glycidyl methacrylate, and diethylene adipate is adjusted to 60:36:1.0:3.0.

[0049] Example 3

[0050] Referring to Example 1, the only difference is that the mass ratio of PBAT, PPC, glycidyl methacrylate, and diethylene adipate is adjusted to 70:26.5:0.5:3.0.

[0051] Example 4

[0052] Referring to Example 1, the only difference is that the mass ratio of PBAT, PPC, glycidyl methacrylate, and diethylene adipate is adjusted to 80:17.8:0.2:2.0.

[0053] Example 5

[0054] Referring to Example 1, the only difference is that the mass ratio of PBAT, PPC, glycidyl methacrylate, and diethylene adipate is adjusted to 90:8.9:0.1:1.0.

[0055] Performance Evaluation

[0056] The tensile strength, tensile elongation at break, tensile modulus, water vapor transmission rate, and peel strength of the nonwoven fabric composite materials prepared in Examples 1-5 were tested, with pure bamboo fiber nonwoven fabric as a control. The test results are shown in Table 1.

[0057] Table 1. Tensile strength, tensile elongation at break, tensile modulus, water vapor transmission rate, and peel strength of nonwoven fabric coated composite materials.

[0058]

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A fully biodegradable nonwoven composite material, characterized in that, include: A nonwoven fabric layer and a polymer film layer laminated on the surface of the nonwoven fabric layer; The non-woven fabric layer is bamboo fiber non-woven fabric; The polymer film layer comprises polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate, and diethylene glycol adipate.

2. The nonwoven composite material according to claim 1, characterized in that, The weight-average molecular weight of the polybutylene terephthalate (PET) is 7 × 10⁻⁶. 4 ~3×10 5 g / mol.

3. The nonwoven composite material according to claim 1, characterized in that, The polypropylene carbonate has a weight-average molecular weight of 4 × 10⁻⁶. 4 ~3×10 5 g / mol.

4. The nonwoven composite material according to claim 1, characterized in that, The weight-average molecular weight of the poly(ethylene adipate) is 3 × 10⁻⁶. 3 ~1.5×10 4 g / mol.

5. The nonwoven composite material according to claim 1, characterized in that, The content of polybutylene terephthalate-adipate in the polymer film is 45~95wt%; the content of polypropylene carbonate in the polymer film is 4~50wt%; the content of glycidyl methacrylate in the polymer film is 0.1~1wt%; and the content of diethylene adipate in the polymer film is 0.1~5wt%.

6. The nonwoven composite material according to claim 1, characterized in that, The bamboo fiber nonwoven fabric has a transverse tensile strength of 4~7MPa, a longitudinal tensile strength of 4~7MPa, a transverse breaking elongation of 30~45%, and a longitudinal breaking elongation of 40~55%.

7. A method for preparing a fully biodegradable nonwoven composite material according to any one of claims 1 to 6, characterized in that, Includes the following steps: The polymer film masterbatch is hot-melted and cast using a coating machine, and then combined with the nonwoven fabric layer in the molten state to obtain a completely biodegradable nonwoven fabric composite material.

8. The preparation method according to claim 7, characterized in that, The polymer film masterbatch is prepared according to the following steps: Polybutylene terephthalate, polypropylene carbonate, glycidyl methacrylate and diethylene glycol adipate were melt-blended and then extruded and granulated to obtain polymer film masterbatch.

9. The preparation method according to claim 7, characterized in that, The temperature of the hot melt casting is 170~210℃.

10. The preparation method according to claim 7, characterized in that, The composite method is roll forming.

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