A biodegradable and environmentally friendly fiber tabletop and its preparation method

Abstract

This invention relates to the field of biodegradable tabletop manufacturing technology, specifically to a biodegradable and environmentally friendly fiber tabletop and its manufacturing method, comprising: a substrate layer, wherein the substrate layer is provided with a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer, and an outer reinforcement layer from bottom to top; a functional coating, wherein the functional coating is applied to the top of the substrate layer, wherein the functional coating is provided with a substrate surface treatment layer, an antistatic layer, and a surface sealing coating from bottom to top; and a coating layer, wherein the coating layer is bonded to the top of the functional coating, wherein the coating layer is provided with a functional coating and a peelable protective film from bottom to top. This invention uses biodegradable natural fibers and bio-based resin to construct the substrate layer, the moisture-proof sealing layer to block moisture erosion, the ionic liquid antistatic layer to achieve stable static dissipation without electromagnetic interference, and the biodegradable conductive layer on the surface coating to ensure high X-ray transmittance. The entire material system is completely biodegradable after disposal, making it widely applicable in electronic laboratories and medical environments.

Description

Technical Field

[0001] This invention relates to the field of biodegradable tabletop preparation technology, specifically to a biodegradable and environmentally friendly fiber tabletop and its preparation method. Background Technology

[0002] Fiber tabletops are flat panel components with fiber-reinforced composite materials as their core structure. They are made by bonding and curing high-strength fibers with a resin matrix, and combine lightweight, high rigidity, and functional designability. They are widely used in medical, laboratory, and industrial applications where there are special requirements for material performance.

[0003] Generally, traditional fiberboards are made of non-degradable synthetic fibers such as carbon fiber or glass fiber combined with petroleum-based resins such as epoxy resin and unsaturated polyester. The structure is mostly a single solid laminate or sandwich panel. Surface treatment relies on fluorine-containing coatings or metal coatings to achieve functions such as anti-fouling and anti-static properties. The overall material system is non-renewable and difficult to recycle.

[0004] However, in environments sensitive to static electricity, such as electronic laboratories, the antistatic layer of traditional fiber tabletops often relies on metal particles or carbon black filling, which is prone to failure due to wear and can interfere with electromagnetic equipment. In medical imaging scenarios, although carbon fiber tabletops have X-ray transmittance, they cannot be naturally degraded after disposal, resulting in permanent pollution. Their manufacturing process uses toxic solvents, releasing volatile organic compounds that endanger the health of operators, and the high cost of synthetic materials further restricts their widespread application.

[0005] Based on this, the present invention provides a biodegradable and environmentally friendly fiber tabletop and its preparation method to solve the above-mentioned technical problems. Summary of the Invention

[0006] The purpose of this invention is to provide a biodegradable and environmentally friendly fiber tabletop and its preparation method, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention proposes a biodegradable and environmentally friendly fiber tabletop, comprising:

[0009] The substrate layer is provided with a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer and an outer reinforcement layer from bottom to top.

[0010] The moisture-proof sealing layer is a modified polylactic acid film composed of a polylactic acid matrix with a thickness ≥0.3mm, 5-8wt% of grafted modified maleic anhydride compatibilizer, and 3-5wt% nano-montmorillonite with a particle size <50nm; the load-bearing reinforcement layer is a unidirectional flax fiber and a bio-based resin pre-impregnated material; the core layer is a honeycomb core material; and the outer reinforcement layer is a plain-weave hemp fiber and a bio-based resin pre-impregnated material.

[0011] A functional coating is applied to the top of the substrate layer, and the functional coating is provided with a substrate surface treatment layer, an antistatic layer and a surface sealing coating from bottom to top.

[0012] The substrate surface treatment layer is a bio-based epoxy primer composed of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent, and fumed silica. The mass ratio of cashew phenol glycidyl ether epoxy resin: polysaccharide anhydride curing agent: fumed silica is 40:10:1, and the fumed silica has a particle size of 12 nm. The antistatic layer is an ion-conductive waterborne coating composed of polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water. The mass ratio of imidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water is 15:5:3:77, and the diameter of the nanocellulose whiskers is 5-20 nm. The surface sealing coating is a bio-based polyurethane topcoat composed of castor oil-based polyester polyol, hexamethylene diisocyanate trimer, and nano-alumina, with a mass ratio of castor oil-based polyester polyol, hexamethylene diisocyanate trimer, and nano-alumina of 6:4:1. The OH value of the castor oil-based polyester polyol is 110 mg KOH / g, and the nano-alumina has a particle size of 50 nm.

[0013] A coating layer is bonded to the top of a functional coating layer, and the coating layer is provided with a functional coating and a peelable protective film from bottom to top.

[0014] The functional coating is poly(butylene adipate) / terephthalate, and its surface is grafted with a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate conductive layer through plasma activation, with a sheet resistance ≤10. 6 Ω / sq, thickness 50μm; the peelable protective film is a polyhydroxybutyrate film with a thickness of 25μm.

[0015] Preferably, in the unidirectional flax fiber and bio-based resin pre-impregnated material of the load-bearing reinforcement layer, the unidirectional flax fiber is a unidirectional layup of long flax fiber bundles with a fiber volume fraction ≥55% that has been treated with alkali and silane coupling agent KH550, and the bio-based resin is an epoxy soybean oil acrylate photocurable resin, which contains 0.5wt% phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide photoinitiator.

[0016] Preferably, the honeycomb core material of the core layer is a polybutylene succinate resin solution with a solid content of 40% impregnated with 100% recycled kraft paper as raw material, and a density ≥80kg / m³. 3 With a coating amount of 1.5 g / m 2Surface treatment with polyethyleneimine crosslinking agent.

[0017] Preferably, the outer reinforcing layer is a plain-weave hemp fiber and a bio-based resin pre-impregnated material, with a basis weight of 200 g / m² after acetylation treatment. 2 Plain-weave hemp fiber fabric prepreg material with thermoplastic resin of furanyl dicarboxylate copolymer.

[0018] This invention also proposes a method for preparing a biodegradable and environmentally friendly fiber tabletop, comprising the following steps:

[0019] S1. Prepare a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer and an outer reinforcement layer, and stack the four layers in sequence and hot press them to form a substrate layer;

[0020] S2. After cleaning the substrate layer obtained in S1, spray a mixture of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent and fumed silica to cure and form a substrate surface treatment layer. Then roll-coat a mixture of polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers and deionized water to form an antistatic layer. Spray a mixture of castor oil-based polyester polyol, hexamethylene diisocyanate trimer and nanoalumina to cure and form a surface sealing coating.

[0021] S3. A functional coating and a peelable protective film are sequentially laminated onto the substrate layer after the S2 coating is applied to form a coating layer. After roll pressing, a biodegradable and environmentally friendly fiber tabletop is obtained.

[0022] Preferably, the substrate layer fabrication process includes the following steps:

[0023] A1. Moisture-proof sealing layer forming: Polylactic acid granules are premixed with 5-8wt% maleic anhydride graft compatibilizer and 3-5wt% nano-montmorillonite with a particle size <50nm; then the mixture is fed into a twin-screw extruder for melt blending, and the extrusion temperature is controlled at 170-180℃; the melt is then cast through a T-die to a 40℃ mirror roller to form a film, and finally a film with a thickness ≥0.3mm is produced and wound up for later use;

[0024] A2. Preparation of prepreg for load-bearing reinforcement layer: Long flax fiber bundles were immersed in 5wt% NaOH solution for 60 min, washed with water, and then transferred to 1wt% KH550 silane coupling agent ethanol solution for impregnation; subsequently dried in an oven at 110℃; then the fiber bundles were unidirectionally laid up at a volume fraction ≥55%, and drawn through a 50℃ epoxy soybean oil acrylate resin bath for impregnation, the resin containing 0.5wt% TPO photoinitiator; finally, the mixture was subjected to a 365nm wavelength, 300mW / cm 2 Pre-curing with high-intensity ultraviolet light to produce semi-cured sheets;

[0025] A3. Core Layer Treatment: Hexagonal honeycomb core material is made from 100% recycled kraft paper, with each unit having a side length of 6mm; it is immersed in 40% PBS resin solution for 120s; then the solution is drained and dried in an 80℃ hot air oven for 30min; finally, PEI crosslinking agent is roller-coated, with the coating amount controlled at 1.5g / m². 2 ;

[0026] A4. Preparation of outer reinforcement layer prepreg: 200g / m 2 Plain hemp fibers are arranged in an acetylation environment with acetic anhydride vapor to control the weight gain rate of 8-10%; then the fiber cloth is introduced into a two-roller thermal laminator and double-sided laminated with PBF resin film with MFI=15g / 10min at a roller temperature of 150℃.

[0027] A5. Substrate lamination molding: The substrate is laminated in the following order: moisture-proof sealing layer, load-bearing reinforcement layer prepreg, core layer, and outer reinforcement layer prepreg; then it is fed into a hot press and pressed at 160℃ and 0.8MPa for 20 minutes; finally, it is cooled to 60℃ and demolded.

[0028] Preferably, the functional coating preparation process includes the following steps:

[0029] B1. Substrate surface treatment layer coating: Weigh cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent, and fumed silica at a mass ratio of 40:10:1; stir at 3000 rpm for 15 min using a high-speed disperser; then spray the coating onto the substrate surface, controlling the wet film thickness to 80 μm; finally, perform step curing: 80℃ / 30 min to 120℃ / 60 min;

[0030] B2. Antistatic layer coating: Polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water were then weighed according to a mass ratio of 15:5:3:77; ultrasonically dispersed at 500W for 30min; then rolled onto the upper surface of the substrate layer, controlling the wet film thickness to 50μm; finally dried with hot air at 60℃ for 20min.

[0031] B3. Surface sealing coating construction: Finally, mix castor oil polyester polyol with OH value of 110mgKOH / g, hexamethylene diisocyanate trimer, and nano alumina at a mass ratio of 6:4:1; spray it onto the upper surface of the substrate layer under high pressure and control the wet film thickness to 100μm; finally, perform two-stage curing from 25℃ / 24h to 80℃ / 2h.

[0032] Preferably, the coating layer preparation process includes the following steps:

[0033] C1. Functional Coating Process: A 50 μm PBAT film was placed in a plasma chamber and treated at 300 W and 20 Pa for 120 s; subsequently, EDOT monomer was vapor-deposited and simultaneously atomized into a PSS solution; FeCl3 vapor catalyst was introduced, and the reaction was carried out at 60 °C for 30 min, forming a sheet resistance ≤10 on the substrate after functional coating. 6 Ω / sq of PEDOT:PSS layer;

[0034] C2. Preparation of peelable protective film: Coat the surface of a 25μm PHB film with an acrylic-itaconic ester adhesive with a Tg=-45℃; control the adhesive layer thickness to 10μm; and then cure at 80℃ for 48h.

[0035] C3. Coating layer lamination: Finally, with the functional coated conductive layer facing down, it is laminated with the functional coating using a 100℃ hot roller press at a speed of 0.3MPa and 1m / min; then the protective film adhesive side is bonded to the PBAT substrate side and rolled at room temperature.

[0036] Compared with the prior art, the beneficial effects of the present invention are:

[0037] This invention constructs a substrate layer using biodegradable natural fibers and bio-based resin, with a moisture-proof sealing layer to block moisture erosion, an ionic liquid antistatic layer to achieve stable static dissipation without electromagnetic interference, and a biodegradable conductive layer on the surface to ensure high X-ray transmittance. The entire material system is completely biodegradable after disposal, avoiding environmental pollution. It can be widely used in electronic laboratories and medical environments, solving the solid waste problem caused by replacing petroleum-based composite materials with non-degradable traditional fiber tabletops. It innovates the ionic conductive antistatic mechanism, overcoming the equipment interference and insufficient wear resistance caused by traditional metal fillers. Furthermore, the low-temperature molding process eliminates the use of toxic solvents, achieving zero pollution in the manufacturing process, and providing a sustainable solution for precision laboratories and green healthcare. Detailed Implementation

[0038] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] I. Materials:

[0040] It should be noted that, unless otherwise stated, all biodegradable and environmentally friendly fiber tabletop materials used in this invention are commercially available.

[0041] This invention proposes a biodegradable and environmentally friendly fiber tabletop, comprising:

[0042] The substrate layer is provided with a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer and an outer reinforcement layer from bottom to top.

[0043] The moisture-proof sealing layer is a modified polylactic acid film composed of a polylactic acid matrix with a thickness of ≥0.3mm, 5-8wt% grafted modified maleic anhydride compatibilizer, and nano-montmorillonite with a particle size of <50nm and 3-5wt%; the load-bearing reinforcement layer is a unidirectional flax fiber and bio-based resin prepreg material; the core layer is a honeycomb core material; and the outer reinforcement layer is a plain-weave hemp fiber and bio-based resin prepreg material.

[0044] The functional coating is applied to the top of the substrate layer. The functional coating consists of a substrate surface treatment layer, an antistatic layer, and a surface sealing coating, arranged sequentially from bottom to top.

[0045] The substrate surface treatment layer is a bio-based epoxy primer composed of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent, and fumed silica. The mass ratio of cashew phenol glycidyl ether epoxy resin to polysaccharide anhydride curing agent to fumed silica is 40:10:1, and the fumed silica particle size is 12nm. The antistatic layer is an ion-conductive waterborne coating composed of polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water. The mass ratio of methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water is 15:5:3:77, and the diameter of the nanocellulose whiskers is 5-20 nm. The surface sealing coating is a bio-based polyurethane topcoat composed of castor oil-based polyester polyol, hexamethylene diisocyanate trimer, and nano-alumina. The mass ratio of castor oil-based polyester polyol, hexamethylene diisocyanate trimer, and nano-alumina is 6:4:1. The OH value of castor oil-based polyester polyol is 110 mg KOH / g, and the particle size of nano-alumina is 50 nm.

[0046] A coating layer is bonded to the top of the functional coating layer. The coating layer consists of a functional coating and a peelable protective film from bottom to top.

[0047] The functional coating is poly(butylene adipate) / terephthalate, and its surface is grafted with a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate conductive layer through plasma activation, with a sheet resistance ≤10. 6 Ω / sq, thickness 50μm; the peelable protective film is a polyhydroxybutyrate film, thickness 25μm.

[0048] It should also be noted that in the unidirectional flax fiber and bio-based resin prepreg material of the load-bearing reinforcement layer, the unidirectional flax fiber is a unidirectional layup of long flax fiber bundles with a fiber volume fraction ≥55% that has been treated with alkali and silane coupling agent KH550. The bio-based resin is an epoxy soybean oil acrylate photocurable resin, which contains 0.5wt% phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide photoinitiator.

[0049] It should also be noted that the honeycomb core material of the core layer is a polybutylene succinate resin solution with a solid content of 40% impregnated with 100% recycled kraft paper as the raw material, and a density ≥80kg / m³. 3 With a coating amount of 1.5 g / m 2 Surface treatment with polyethyleneimine crosslinking agent.

[0050] It should also be noted that the outer reinforcing layer is a plain-weave hemp fiber and bio-based resin pre-impregnated material with an acetylation treatment weight of 200 g / m². 2 Plain-weave hemp fiber fabric prepreg material with thermoplastic resin of furanyl dicarboxylate copolymer.

[0051] II. Process:

[0052] This invention also proposes a method for preparing a biodegradable and environmentally friendly fiber tabletop, comprising the following steps:

[0053] S1. Prepare a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer and an outer reinforcement layer, and stack the four layers in sequence and hot press them to form a substrate layer;

[0054] S2. After cleaning the substrate layer obtained in S1, spray a mixture of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent and fumed silica to cure and form a substrate surface treatment layer. Then roll-coat a mixture of polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers and deionized water to form an antistatic layer. Spray a mixture of castor oil-based polyester polyol, hexamethylene diisocyanate trimer and nanoalumina to cure and form a surface sealing coating.

[0055] S3. A functional coating and a peelable protective film are sequentially laminated onto the substrate layer after the S2 coating is applied to form a coating layer. After roll pressing, a biodegradable and environmentally friendly fiber tabletop is obtained.

[0056] It should also be noted that the substrate layer fabrication process includes the following steps:

[0057] A1. Moisture-proof sealing layer forming: Polylactic acid granules are premixed with 5-8wt% maleic anhydride graft compatibilizer and 3-5wt% nano-montmorillonite with a particle size <50nm; then the mixture is fed into a twin-screw extruder for melt blending, and the extrusion temperature is controlled at 170-180℃; the melt is then cast through a T-die to a 40℃ mirror roller to form a film, and finally a film with a thickness ≥0.3mm is produced and wound up for later use;

[0058] A2. Preparation of prepreg for load-bearing reinforcement layer: Long flax fiber bundles were immersed in 5wt% NaOH solution for 60 min, washed with water, and then transferred to 1wt% KH550 silane coupling agent ethanol solution for impregnation; subsequently dried in an oven at 110℃; then the fiber bundles were unidirectionally laid up at a volume fraction ≥55%, and drawn through a 50℃ epoxy soybean oil acrylate resin bath for impregnation, the resin containing 0.5wt% TPO photoinitiator; finally, the mixture was subjected to a 365nm wavelength, 300mW / cm 2 Pre-curing with high-intensity ultraviolet light to produce semi-cured sheets;

[0059] A3. Core Layer Treatment: Hexagonal honeycomb core material is made from 100% recycled kraft paper, with each unit having a side length of 6mm; it is immersed in 40% PBS resin solution for 120s; then the solution is drained and dried in an 80℃ hot air oven for 30min; finally, PEI crosslinking agent is roller-coated, with the coating amount controlled at 1.5g / m². 2 ;

[0060] A4. Preparation of outer reinforcement layer prepreg: 200g / m 2 Plain hemp fibers are arranged in an acetylation environment with acetic anhydride vapor to control the weight gain rate of 8-10%; then the fiber cloth is introduced into a two-roller thermal laminator and double-sided laminated with PBF resin film with MFI=15g / 10min at a roller temperature of 150℃.

[0061] A5. Substrate lamination molding: The substrate is laminated in the following order: moisture-proof sealing layer, load-bearing reinforcement layer prepreg, core layer, and outer reinforcement layer prepreg; then it is fed into a hot press and pressed at 160℃ and 0.8MPa for 20 minutes; finally, it is cooled to 60℃ and demolded.

[0062] It should also be noted that the functional coating preparation process includes the following steps:

[0063] B1. Substrate surface treatment layer coating: Weigh cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent, and fumed silica at a mass ratio of 40:10:1; stir at 3000 rpm for 15 min using a high-speed disperser; then spray the coating onto the substrate surface, controlling the wet film thickness to 80 μm; finally, perform step curing: 80℃ / 30 min to 120℃ / 60 min;

[0064] B2. Antistatic layer coating: Polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water were then weighed according to a mass ratio of 15:5:3:77; ultrasonically dispersed at 500W for 30min; then rolled onto the upper surface of the substrate layer, controlling the wet film thickness to 50μm; finally dried with hot air at 60℃ for 20min.

[0065] B3. Surface sealing coating construction: Finally, mix castor oil polyester polyol with OH value of 110mgKOH / g, hexamethylene diisocyanate trimer, and nano alumina at a mass ratio of 6:4:1; spray it onto the upper surface of the substrate layer under high pressure and control the wet film thickness to 100μm; finally, perform two-stage curing from 25℃ / 24h to 80℃ / 2h.

[0066] It should also be noted that the coating layer preparation process includes the following steps:

[0067] C1. Functional Coating Process: A 50 μm PBAT film was placed in a plasma chamber and treated at 300 W and 20 Pa for 120 s; subsequently, EDOT monomer was vapor-deposited and simultaneously atomized into a PSS solution; FeCl3 vapor catalyst was introduced, and the reaction was carried out at 60 °C for 30 min, forming a sheet resistance ≤10 on the substrate after functional coating. 6 Ω / sq of PEDOT:PSS layer;

[0068] C2. Preparation of peelable protective film: Coat the surface of a 25μm PHB film with an acrylic-itaconic ester adhesive with a Tg=-45℃; control the adhesive layer thickness to 10μm; and then cure at 80℃ for 48h.

[0069] C3. Coating layer lamination: Finally, with the functional coated conductive layer facing down, it is laminated with the functional coating using a 100℃ hot roller press at a speed of 0.3MPa and 1m / min; then the protective film adhesive side is bonded to the PBAT substrate side and rolled at room temperature.

[0070] Example 1: In this example, the preparation process of the biodegradable and environmentally friendly fiber tabletop, specifically, the key parameters for each step are as follows:

[0071] Step 1: Substrate layer fabrication:

[0072] A1. Moisture-proof sealing layer: Polylactic acid + 5wt% maleic anhydride + 5wt% nano montmorillonite → twin-screw extrusion (175℃) → casting film (thickness 0.3mm);

[0073] A2. Load-bearing reinforcement layer: Alkali treatment of flax fibers (5wt% NaOH, 60min) → KH550 coupling → Unidirectional layup (fiber volume fraction 55%) → Impregnation with epoxy soybean oil acrylate resin (containing 0.5wt% TPO) → UV pre-curing (365nm, 300mW / cm²) 2 );

[0074] A3. Core Layer: Recycled kraft paper honeycomb core impregnated with 40% PBS adhesive solution → dried at 80℃ → coated with PEI crosslinking agent (1.5g / m²). 2 );

[0075] A4. Outer reinforcing layer: acetylated hemp fiber cloth (8% weight gain) → hot-pressed composite PBF resin film (150℃);

[0076] A5. Lamination: Four layers stacked → hot pressing (160℃, 0.8MPa, 20min) → cooling and demolding;

[0077] Step 2: Functional coating application:

[0078] B1. Substrate surface treatment layer: Cashew phenol epoxy resin: polysaccharide anhydride: fumed silica = 40:10:1 → spraying (wet film 80μm) → step curing (80℃ / 30min → 120℃ / 60min).

[0079] B2. Antistatic layer: PVP: ionic liquid: nanocellulose: water = 15:5:3:77 → ultrasonic dispersion → roller coating (wet film 50μm) → drying at 60℃ for 20min;

[0080] B3. Surface sealing layer: Castor oil polyester: HDI trimer: nano alumina = 6:4:1 → spraying (wet film 100μm) → two-stage curing (25℃ / 24h → 80℃ / 2h);

[0081] Step 3: Coating layer lamination:

[0082] C1. Functional Coating: PBAT thin film plasma activation (300W, 20Pa, 120s) → vapor deposition of PEDOT:PSS (sheet resistance ≤10) 6 Ω / sq);

[0083] C2. Protective film: PHB film coated with acrylic adhesive (10μm) → cured at 80℃ for 48h;

[0084] C3. Lamination: Hot roll pressing (100℃, 0.3MPa) to bond the film layer;

[0085] Example 2: In this example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 1, and other processes and parameters were the same as in Example 1;

[0086] Example 3: In this example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 1, and other processes and parameters were the same as in Example 1;

[0087] Example 4: In this example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 1, and other processes and parameters were the same as in Example 1;

[0088] Example 5: In this example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 1, and other processes and parameters were the same as in Example 1;

[0089] The material composition variables for the examples are shown in Table 1:

[0090] Table 1: Parameter Table of Material Composition Variables in Examples

[0091] Group Moisture-proof layer nano-montmorillonite content Antistatic layer ionic liquid content substrate hot pressing temperature Example 1 5wt% 5wt% 160℃ Example 2 3wt% 5wt% 160℃ Example 3 8wt% 5wt% 160℃ Example 4 5wt% 3wt% 160℃ Example 5 5wt% 4wt% 140℃

[0092] Comparative Example 1: In this comparative example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 2, with other processes and parameters the same as in Example 1;

[0093] Comparative Example 2: In this comparative example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 2. Other processes and parameters were the same as in Example 1.

[0094] Comparative Example 3: In this comparative example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 2, and other processes and parameters were the same as in Example 1.

[0095] Comparative Example 4: In this comparative example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 2, with other processes and parameters the same as in Example 1;

[0096] Comparative Example 5: In this comparative example, a biodegradable and environmentally friendly fiber tabletop was prepared according to the variable parameters in Table 2, with other processes and parameters the same as in Example 1;

[0097] The comparative material composition variables are shown in Table 2:

[0098] Table 2: Comparative Example Material Composition Variable Parameter Table

[0099] Group Moisture-proof layer nano-montmorillonite content Antistatic layer ionic liquid content substrate hot pressing temperature Comparative Example 1 2wt% 5wt% 160℃ Comparative Example 2 10wt% 5wt% 160℃ Comparative Example 3 5wt% 2wt% 160℃ Comparative Example 4 5wt% 6wt% 160℃ Comparative Example 5 5wt% 5wt% 200℃

[0100] III. Performance Testing:

[0101] Biodegradable and environmentally friendly fiber tabletop samples were prepared according to the parameters of Examples 1-5 and Comparative Examples 1-5, and the following performance tests were performed on each group of samples, and the performance data were recorded:

[0102] a. Moisture resistance: Water absorption rate after immersion in water for 48 hours (ASTM D570);

[0103] b. Mechanical properties: Three-point bending strength (ISO178), interlaminar shear strength (ASTMD2344).

[0104] c. Antistatic properties: Surface resistance (GB / T1410);

[0105] d. Degradation rate: Weight loss rate in soil after 90 days of burial (ISO 20200);

[0106] Performance data from the recorded examples are shown in Table 3:

[0107] Table 3: Comparison of Performance Data of Examples

[0108] Group Water absorption rate (%) Bending strength (MPa) Interlaminar shear (MPa) Surface resistivity (Ω) 90-day degradation rate (%) Example 1 2.1 85.3 12.7 <![CDATA[3.2×10 7 ]]> 78.5 Example 2 3.8 76.2 10.9 <![CDATA[3.5×10 7 ]]> 75.2 Example 3 1.9 82.4 12.1 <![CDATA[3.0×10 7 ]]> 70.3 Example 4 2.3 84.1 12.5 <![CDATA[8.9×10 9 ]]> 77.1 Example 5 2.5 72.6 9.8 <![CDATA[3.4×10 7 ]]> 76.8

[0109] The comparative performance data is recorded in Table 4:

[0110] Table 4: Comparison of Performance Data for Comparative Scales

[0111] Group Water absorption rate (%) Bending strength (MPa) Interlaminar shear (MPa) Surface resistivity (Ω) 90-day degradation rate (%) Comparative Example 1 8.7 63.5 7.2 <![CDATA[3.3×10 7 ]]> 82.1 Comparative Example 2 2.0 68.4 8.5 <![CDATA[2.9×10 7 ]]> 52.6 Comparative Example 3 2.2 83.9 12.6 <![CDATA[>10 12 ]]> 76.9 Comparative Example 4 2.1 80.7 11.8 <![CDATA[1.5×10 6 ]]> 69.4 Comparative Example 5 3.9 58.3 6.4 <![CDATA[3.1×10 7 ]]> 81.5

[0112] IV. Results and Discussion

[0113] Please refer to Tables 1 to 4. It can be seen that the moisture-proof layer of the embodiment with nano-montmorillonite of 3-8 wt% is too low compared to the comparative example 1, 2 wt%, which leads to a 63% increase in water absorption. The comparative example 2, 10 wt% is too high, which causes agglomeration and a 16% decrease in mechanical strength. The 5 wt% in embodiment 1 balances moisture-proofness and mechanical properties.

[0114] Please refer to Tables 1 to 4. It can be seen that the ionic liquid in the antistatic layer of the examples (3-5 wt%) is too low compared to the comparative examples (3, 2 wt%), resulting in a surface resistivity >10. 12 Ω, loss of antistatic properties; in the comparative example, an excessively high concentration of 4.6 wt% triggered ion precipitation, resulting in an 11.5% decrease in degradation rate;

[0115] Please refer to Tables 1 to 4. It can be seen that, compared to Example 5 (140°C), the lower hot-pressing temperature of 140–180°C in the comparative example resulted in insufficient resin curing, leading to a 15% decrease in flexural strength. In the comparative example 5, the higher temperature of 200°C caused thermal degradation of the substrate, resulting in a 50% decrease in interlaminar shear strength.

[0116] Furthermore, Example 1, through the optimization of dispersibility and barrier properties with 5wt% nano-montmorillonite, the guarantee of antistatic properties with 5wt% ionic liquid, and complete curing at 160℃ without heat damage, has the lowest water absorption rate, the highest flexural strength, the standard surface resistance, and a degradation rate of >75%, avoiding the extreme risks of agglomeration and precipitation, and is suitable for industrial scale-up.

[0117] In summary, Embodiment 1 of this invention achieves the optimal solution within the component range due to the balance between components and processes, providing a reliable solution for the industrialization of biodegradable tabletops. This is the best embodiment of the invention. The fiber tabletop of this invention solves the solid waste problem caused by the non-degradability of petroleum-based composite materials when replacing traditional fiber tabletops with fully bio-based materials. It innovates an ion-conductive antistatic mechanism, overcomes the equipment interference and insufficient wear resistance caused by traditional metal fillers, and eliminates the use of toxic solvents through a low-temperature molding process, achieving zero pollution in the manufacturing process. This provides a sustainable solution for precision laboratories and green healthcare.

[0118] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0119] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A biodegradable and environmentally friendly fiber tabletop, characterized in that, include: The substrate layer is provided with a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer and an outer reinforcement layer from bottom to top. The moisture-proof sealing layer is a modified polylactic acid film composed of a polylactic acid matrix, 5-8 wt% grafted modified maleic anhydride compatibilizer, and 3-5 wt% nano-montmorillonite with a particle size <50 nm, and a thickness ≥0.3 mm; the load-bearing reinforcement layer is unidirectional flax fiber and bio-based resin pre-impregnated material; the core layer is a honeycomb core material; the outer reinforcement layer is plain-weave hemp fiber and bio-based resin pre-impregnated material. A functional coating is applied to the top of the substrate layer, and the functional coating is provided with a substrate surface treatment layer, an antistatic layer and a surface sealing coating from bottom to top. The substrate surface treatment layer is a bio-based epoxy primer composed of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent and fumed silica. The mass ratio of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent, and fumed silica is 40:10:1, and the fumed silica has a particle size of 12 nm. The antistatic layer is an ion-conductive waterborne coating composed of polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers and deionized water. The mass ratio of polyvinylpyrrolidone: ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt: nanocellulose whiskers: deionized water is 15:5:3:

77. The nanocellulose whiskers have a diameter of 5-20 nm; the surface sealing coating is a bio-based polyurethane topcoat composed of castor oil-based polyester polyol, hexamethylene diisocyanate trimer and nano alumina. The mass ratio of castor oil-based polyester polyol, hexamethylene diisocyanate trimer, and nano-alumina is 6:4:1, the OH value of the castor oil-based polyester polyol is 110 mg KOH / g, and the particle size of the nano-alumina is 50 nm. A coating layer is bonded to the top of a functional coating layer, and the coating layer is provided with a functional coating and a peelable protective film from bottom to top. The functional coating is poly(butylene adipate) / terephthalate, and its surface is grafted with a poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate conductive layer through plasma activation, with a sheet resistance ≤10. 6 Ω / sq, thickness 50μm; The peelable protective film is a polyhydroxybutyrate film with a thickness of 25 μm.

2. The biodegradable and environmentally friendly fiber tabletop according to claim 1, characterized in that, In the pre-impregnated material of unidirectional flax fiber and bio-based resin in the load-bearing reinforcement layer, the unidirectional flax fiber is a unidirectional layup of long flax fiber bundles with a fiber volume fraction ≥55% that has been treated with alkali and silane coupling agent KH550. The bio-based resin is an epoxy soybean oil acrylate photocurable resin, which contains 0.5wt% phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide photoinitiator.

3. The biodegradable and environmentally friendly fiber tabletop according to claim 2, characterized in that, The honeycomb core material of the core layer is a recycled paper base made from 100% recycled kraft paper, impregnated with polybutylene succinate resin with a solid content of 40% and a density ≥80kg / m³. 3 With a coating amount of 1.5 g / m 2 Surface treatment with polyethyleneimine crosslinking agent.

4. The biodegradable and environmentally friendly fiber tabletop according to claim 3, characterized in that, The outer reinforcing layer is made of plain-woven hemp fiber and a bio-based resin pre-impregnated material with an acetylated weight of 200 g / m². 2 Plain-weave hemp fiber fabric prepreg material with thermoplastic resin of furanyl dicarboxylate copolymer.

5. A method for preparing a biodegradable and environmentally friendly fiber tabletop according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Prepare a moisture-proof sealing layer, a load-bearing reinforcement layer, a core layer and an outer reinforcement layer, and stack the four layers in sequence and hot press them to form a substrate layer; S2. After cleaning the substrate layer obtained in S1, spray a mixture of cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent and fumed silica to cure and form a substrate surface treatment layer. Then roll-coat a mixture of polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers and deionized water to form an antistatic layer. Spray a mixture of castor oil-based polyester polyol, hexamethylene diisocyanate trimer and nanoalumina to cure and form a surface sealing coating. S3. A functional coating and a peelable protective film are sequentially laminated onto the substrate layer after the S2 coating is completed to form a coating layer. After roll pressing, a biodegradable and environmentally friendly fiber tabletop is obtained.

6. The method for preparing a biodegradable and environmentally friendly fiber tabletop according to claim 5, characterized in that, The substrate layer fabrication process includes the following steps: A1. Moisture-proof sealing layer forming: Polylactic acid granules are premixed with 5-8wt% maleic anhydride graft compatibilizer and 3-5wt% nano-montmorillonite with a particle size <50nm; then the mixture is fed into a twin-screw extruder for melt blending, and the extrusion temperature is controlled at 170-180℃; the melt is then cast through a T-die to a 40℃ mirror roller to form a film, and finally a film with a thickness ≥0.3mm is produced and wound up for later use; A2. Preparation of prepreg for load-bearing reinforcement layer: Long flax fiber bundles were immersed in 5wt% NaOH solution for 60 min, washed with water, and then transferred to 1wt% KH550 silane coupling agent ethanol solution for impregnation. The fibers were then dried in an oven at 110℃; subsequently, the fiber bundles were laid up unidirectionally at a volume fraction ≥55% and impregnated in an epoxy soybean oil acrylate resin bath at 50℃, with the resin containing 0.5wt% TPO photoinitiator; finally, the fibers were subjected to a 365nm wavelength, 300mW / cm² light source. 2 Pre-curing with high-intensity ultraviolet light to produce semi-cured sheets; A3. Core Layer Treatment: Hexagonal honeycomb core material is made from 100% recycled kraft paper, with each unit having a side length of 6mm; it is immersed in 40% PBS resin solution for 120s; then the solution is drained and dried in an 80℃ hot air oven for 30min; finally, PEI crosslinking agent is roller-coated, with the coating amount controlled at 1.5g / m². 2 ; A4. Preparation of outer reinforcement layer prepreg: 200g / m 2 Plain hemp fibers are arranged in an acetylation environment with acetic anhydride vapor to control the weight gain rate of 8-10%; then the fiber cloth is introduced into a two-roller thermal laminator and double-sided laminated with PBF resin film with MFI=15g / 10min at a roller temperature of 150℃. A5. Substrate lamination molding: The substrate is laminated in the following order: moisture-proof sealing layer, load-bearing reinforcement layer prepreg, core layer, and outer reinforcement layer prepreg; then it is fed into a hot press and pressed at 160℃ and 0.8MPa for 20 minutes; finally, it is cooled to 60℃ and demolded.

7. The method for preparing a biodegradable and environmentally friendly fiber tabletop according to claim 6, characterized in that, The functional coating preparation process includes the following steps: B1. Substrate surface treatment layer coating: Weigh cashew phenol glycidyl ether epoxy resin, polysaccharide anhydride curing agent, and fumed silica at a mass ratio of 40:10:1; stir at 3000 rpm for 15 min using a high-speed disperser; then spray the coating onto the substrate surface, controlling the wet film thickness to 80 μm; finally, perform step curing: 80℃ / 30 min to 120℃ / 60 min; B2. Antistatic layer coating: Polyvinylpyrrolidone, ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt, nanocellulose whiskers, and deionized water were then weighed according to a mass ratio of 15:5:3:77; ultrasonically dispersed at 500W for 30min; then rolled onto the upper surface of the substrate layer, controlling the wet film thickness to 50μm; finally dried with hot air at 60℃ for 20min. B3. Surface sealing coating construction: Finally, mix castor oil polyester polyol with OH value of 110mgKOH / g, hexamethylene diisocyanate trimer, and nano alumina at a mass ratio of 6:4:1; spray it onto the upper surface of the substrate layer under high pressure and control the wet film thickness to 100μm; finally, perform two-stage curing from 25℃ / 24h to 80℃ / 2h.

8. The method for preparing a biodegradable and environmentally friendly fiber tabletop according to claim 7, characterized in that, The preparation process of the coating layer includes the following steps: C1. Functional Coating Process: A 50 μm PBAT film was placed in a plasma chamber and treated at 300 W and 20 Pa for 120 s; subsequently, EDOT monomer was vapor-deposited and simultaneously atomized into a PSS solution; FeCl3 vapor catalyst was introduced, and the reaction was carried out at 60 °C for 30 min, forming a sheet resistance ≤10 on the substrate after functional coating. 6 Ω / sq of PEDOT:PSS layer; C2. Preparation of peelable protective film: Coat the surface of a 25μm PHB film with an acrylic-itaconic ester adhesive with a Tg=-45℃; control the adhesive layer thickness to 10μm; and then cure at 80℃ for 48h. C3. Coating layer lamination: Finally, with the functional coated conductive layer facing down, it is laminated with the functional coating using a 100℃ hot roller press at a speed of 0.3MPa and 1m / min; then the protective film adhesive side is bonded to the PBAT substrate side and rolled at room temperature.