High-strength wear-resistant anti-shrinkage glass fiber composite conductive floor and preparation process thereof

Abstract

This invention belongs to the field of functional flooring materials technology, and discloses a high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor and its preparation process. The floor substrate is an epoxy resin and polyurethane composite system, with a reversible melt shape memory polymer film introduced at the interface. After initial curing, heating triggers a small amount of melting and re-curing, actively eliminating residual shrinkage stress and achieving self-correcting and shrinkage resistance. The surface layer uses acoustic field-assisted deposition technology to make the fiber bundles tangentially gradient-oriented, enhancing the wear resistance of the surface layer and reducing microvoids. The surface is sprayed with a self-healing conductive film containing dynamic borate ester crosslinks and a silver nanowire network, which can dynamically reconnect and restore performance under humid and hot conditions after damage. The overall system is novel, integrating interface shape memory materials, acoustic field fiber orientation technology, and dynamic covalent self-healing conductive coating, and has excellent mechanical properties, wear resistance, shrinkage resistance, and online repair capabilities.

Description

Technical Field

[0001] This invention belongs to the field of functional flooring materials technology, specifically relating to a high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor and its preparation process. Background Technology

[0002] Modern residential and commercial spaces place comprehensive demands on flooring, requiring durability, aesthetics, and comfort. While traditional wood flooring and engineered wood flooring offer a wide variety of colors and a pleasant feel underfoot, their wear resistance, pressure resistance, and moisture resistance are insufficient, making them susceptible to scratches from heavy objects and warping from moisture. Although vinyl flooring boasts advantages such as water resistance and slip resistance, it falls short in terms of hardness and scratch resistance, making it vulnerable to damage from frequent furniture movement or sharp objects.

[0003] To improve wear resistance and strength, existing technologies often add mineral fillers, chopped fibers, or nanoparticles to the polymer matrix. However, high filler loadings often lead to increased material brittleness, and uneven dispersion or insufficient interfacial bonding can easily cause microcracks and voids, reducing the overall performance of the flooring. Curing shrinkage is a major cause of cracking and warping in large-area or thick flooring. Existing methods often suppress shrinkage by optimizing the formula, lowering the curing temperature, or adding low-shrinkage fillers, but these methods have limited effectiveness in controlling shrinkage in thick boards and large-area flooring, making it difficult to completely eliminate the risk of cracking.

[0004] In addition, high-end venues (such as laboratories and electronic workshops) have requirements for the conductivity or antistatic properties of the flooring. Traditional conductive flooring constructs a conductive network by incorporating carbon black or metal fibers, but high filler content reduces resin fluidity, increases construction difficulty, and is prone to conductivity degradation due to wear. Summary of the Invention

[0005] To address the shortcomings mentioned in the background art, the present invention aims to provide a high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor and its preparation process. The floor comprises a reversible melt shape memory polymer interface layer, a tangentially gradient-oriented fiberglass reinforcement layer, and a self-healing conductive thin film coating. The shape memory layer is heated and then cured to achieve self-correction of residual stress. The gradient fiber distribution enhances the wear resistance and flexural strength of the surface layer. The conductive coating uses a dynamic borate ester network and silver nanowires to achieve rapid self-healing and restoration of conductivity and wear resistance under humid and hot conditions after damage.

[0006] The objective of this invention can be achieved through the following technical solutions: A high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor comprises the following raw materials in parts by weight: 80-120 parts epoxy resin, 30-50 parts polyurethane prepolymer, 5-15 parts PCL-PU shape memory polymer film, 150-300 parts modified E-CR glass fiber bundle, and 5-20 parts self-healing conductive coating material.

[0007] More preferably, the preparation method of the PCL-PU shape memory polymer film specifically includes the following steps: S101. Poly(ε-caprolactone diol) and polyisocyanate are added to a reactor in a certain proportion, and a catalyst is added and the mixture is stirred to generate PCL-PU prepolymer. S102. Pour the prepolymer onto a flat substrate and prepare a wet film by means of blade coating, casting, or spin coating; S103. First, pre-curing at room temperature or low temperature removes solvents and oligomers, then post-curing at an appropriate temperature to perfect the cross-linking network, resulting in a stable shape memory film; S104. Peel off the cured PCL-PU film from the substrate and subject the film to necessary thermal cycling (heating-cooling-reheating) to “program” its temporary shape to obtain the PCL-PU shape memory polymer film.

[0008] More preferably, the method for preparing modified E-CR glass fiber bundles specifically includes the following steps: S201. Soak and wash the raw fiber bundle in an alkaline solution to remove surface impurities and degrease; then rinse it several times with water until neutral, and dry it for later use; S202. Prepare a hydrolysis solution of silane coupling agent (such as 3-chloropropyltrimethoxysilane) and adjust the pH to ensure uniform hydrolysis of the coupling agent; S203. Immerse the clean and dry glass fiber bundles in the coupling agent hydrolysis solution, stir or slowly pull the fiber bundles to allow the coupling agent to be fully adsorbed and form a directional coating on the fiber surface; S204. Remove the impregnated fiber bundles and hang or lay them flat in a ventilated place to pre-dry; then further heat them in an oven at an appropriate temperature. S205. The dried and cured fiber bundles are lightly washed with water to remove unreacted coupling agent residues, and then dried again to obtain modified E-CR glass fiber bundles.

[0009] More preferably, the matrix of the self-healing conductive coating material is a prepolymer obtained by reacting double-hydroxyl-terminated polyethylene glycol with 3-hydroxypropylboronic acid in a 1:1 molar ratio, and 0.5-1.5 wt% silver nanowires are introduced by ultrasonic dispersion.

[0010] More preferably, the overall curing shrinkage rate of the floor is not greater than 0.1%, the surface hardness (Rockwell) is not less than 85 HRA, and the in-plane conductivity is not less than 10³ S / m.

[0011] More preferably, the wear amount of the floor after the Taber abrasion test is no more than 0.02 g.

[0012] A manufacturing process for a high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor includes the following steps: S1. First, lay the prepared PCL-PU shape memory polymer film on the bottom surface of the flat mold to ensure that the film fits the mold completely without air bubbles; S2. After degassing the epoxy resin and polyurethane prepolymer, pour the mixture evenly into the mold, cover the surface of the PCL-PU film, and perform preliminary curing to form a semi-cured substrate layer; S3. Take modified E-CR glass fiber bundles and, with the aid of sound field assistance or by manual layering, lay them sequentially on the surface of the semi-cured substrate according to the tangential gradient angle until the designed thickness is reached, and then complete the curing process. S4. The entire board is heated to allow the PCL-PU film to melt slightly and then solidify, thereby releasing and eliminating residual internal stress from the solidification process and achieving anti-shrinkage self-correction. S5. The pre-prepared self-healing conductive coating material is evenly sprayed onto the surface of the composite board. After the coating is cured, a high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor is obtained.

[0013] More preferably, the sound field frequency used in the sound field assisted laying in step S3 is 15-25 kHz, and the sound intensity is 0.3-0.7 W / cm².

[0014] More preferably, the heating treatment temperature in step S4 is 60-80°C, and the holding time is 20-40 min.

[0015] More preferably, the thickness of the self-healing conductive coating sprayed in step S5 is 10–30 μm, and it is cured at room temperature or under slight heating conditions for 12–36 h.

[0016] The beneficial effects of this invention are: This invention effectively solves the technical challenges of traditional flooring in terms of wear resistance, shrinkage prevention, and electrical stability by introducing a reversible melt shape memory polymer interface layer, a tangentially gradient-oriented glass fiber reinforcement layer, and a rheology-tunable self-healing conductive coating into the composite flooring structure for the first time. The shape memory interface layer can melt and re-solidify slightly at temperatures above its melting point, actively releasing residual curing stress and reducing the overall curing shrinkage rate of the flooring to ≤0.1%, completely eliminating the risk of cracking and warping. The gradient-oriented glass fiber layer, through acoustic field-assisted deposition technology, forms a high-density tangential network between the surface fibers and the matrix, significantly improving surface wear resistance and flexural strength. The self-healing conductive coating, relying on dynamic borate ester covalent bonds and a silver nanowire network, can restore ≥90% of its in-plane conductivity and wear resistance within 30 minutes under humid and hot conditions. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1Shrinkage retention curve of the high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive flooring prepared according to the present invention; Figure 2 The wear retention rate curve of the high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive flooring prepared according to the present invention; Figure 3 The graph shows the conductivity retention rate of the high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive flooring prepared according to the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0020] Example 1 Preparation of PCL-PU shape memory polymer film 10.0 g of poly(ε-caprolactone diol) and 0.05 g of dibutyltin dilaurate were placed in a four-necked reaction flask and dried in a vacuum drying oven at 60 °C for 4 h. Simultaneously, nitrogen gas was introduced to ensure the reaction system was anhydrous and oxygen-free. Under nitrogen protection, the reaction flask was heated to 80 °C, and 8.0 g of 1,6-hexamethylene diisocyanate was slowly added, with stirring for 4 h. After the reaction was complete, the mixture was cooled to room temperature, and 20 mL of anhydrous dichloromethane was added and stirred until homogeneous. The resulting solution was placed under 0.08 MPa for 30 min to remove bubbles and volatiles. A release agent was sprayed onto a polytetrafluoroethylene release template and air-dried. The degassing solution was poured onto the template and coated with a 200 μm doctor blade to prepare a wet film. The film was left at room temperature for 2 h to allow surface curing and solvent evaporation. The pre-cured film was transferred to an oven and cured at 60 °C for 2 h, then heated to 100 °C and cured for another 4 h to perfect the –NHCOO– crosslinking network and completely remove residual solvent. After cooling to room temperature, carefully peel off the cured film, place the film in a hot press, heat at 120 ℃ and 0.5 MPa for 10 min and deform it; cool to room temperature and release the pressure to complete the temporary shape fixation, thus obtaining the PCL-PU shape memory polymer film.

[0021] Preparation of modified E-CR glass fiber bundles 200 g of glass fiber bundle was placed in a glass container equipped with a stirrer, and 20 g of sodium hydroxide and 1000 mL of deionized water were added. The mixture was stirred at room temperature for 30 min to remove surface impurities and degrease. The fiber bundle was then removed, rinsed with running deionized water until pH ≈ 7, and hung to air dry. In another container, 10 g of 3-chloropropyltrimethoxysilane and 50 mL of deionized water were added to 500 mL of ethanol, and the mixture was stirred until homogeneous. The pH of the solution was adjusted to 4.0 ± 0.2 with 2 mL of acetic acid to hydrolyze the silane to generate active silanol.

[0022] 200 g of cleaned and dried glass fiber bundles were placed in the above coupling agent solution and stirred and impregnated at room temperature for 1 h to allow the coupling agent to be fully adsorbed and form a directional coating on the fiber surface. After impregnation, the fiber bundles were removed and hung on a ventilated rack for pre-drying for 30 min. Then, the pre-dried fiber bundles were placed in an oven and dried at 80 °C for 1 h to further remove the solvent and promote the initial cross-linking of silane on the fiber surface. Subsequently, the temperature was raised to 120 °C and cured for another 2 h to ensure that the coupling agent was completely cross-linked on the fiber surface and formed a water-resistant and robust modified layer. Finally, the cured fiber bundles were removed and lightly rinsed with a small amount of warm water to remove any unreacted residual coupling agent. They were then placed in an oven at 80 °C again for 4 h until the fiber bundle reached a constant weight, thus obtaining the modified E-CR glass fiber bundles.

[0023] Preparation of self-healing conductive coating materials 20.0 g of hydroxyl-terminated polyethylene glycol and 2.44 g of 3-hydroxypropylboronic acid were added to a 250 mL four-necked reaction flask, along with 50 mL of anhydrous toluene and 0.20 g of p-toluenesulfonic acid. Under nitrogen protection, the mixture was heated to 110 °C and refluxed for 4 h to promote the esterification reaction between –OH and –B(OH)₂. After the reaction was completed, the temperature was lowered to 80 °C, and toluene was removed by distillation under reduced pressure until the residue was <1%, yielding a light yellow transparent dynamic borate ester prepolymer. At room temperature, 30 mL of silver nanowire dispersion was slowly added to the prepolymer, and the mixture was treated with an ultrasonic oscillator for 10 min to ensure uniform dispersion of the silver nanowires in the solution. After standing for 30 min, and confirming the absence of flocculent precipitate, the self-healing conductive coating material was obtained.

[0024] IV. Preparation of High-Strength, Wear-Resistant, Shrink-Resistant Fiberglass Composite Conductive Flooring The high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor comprises the following raw materials in parts by weight: 80 parts epoxy resin, 30 parts polyurethane prepolymer, 5 parts PCL-PU shape memory polymer film, 150 parts modified E-CR glass fiber bundle, and 5 parts self-healing conductive coating material.

[0025] The preparation steps are as follows: 10 g of PCL-PU shape memory polymer film is laid flat on a clean aluminum mold base plate coated with a release agent. 160 g of epoxy resin and 60 g of polyurethane prepolymer are poured into a mixing tank with rotor blades and stirred at 300 rpm for 5 min at room temperature. Then, the mixture is degassed under vacuum for 30 min until no obvious bubbles are visible. The mixture is then quickly poured into the mold, covered with the PCL-PU film, and placed at 25 ℃ for 2 h for initial curing.

[0026] 300 g of modified E-CR glass fiber bundles were divided into five layers with gradient angles of 10° / 30° / 50° / 70° / 90°. While the substrate was semi-cured, each layer was laid flat on the substrate surface, and each layer was cured in a 60 ℃ oven for 30 min after deposition. After the final layer was deposited, the entire assembly was cured at 80 ℃ for 2 h. The cured composite board was kept at 70 ℃ for 30 min, then cooled to room temperature, allowing the PCL-PU film to slightly melt and then be cured again. While the mold was flat, 10 g of self-healing conductive coating material, approximately 20 μm thick, was uniformly sprayed at room temperature. After spraying, it was cured at 35 ℃ for 24 h. After self-curing, the composite floor was removed from the mold at room temperature, and the finished board was hot-pressed at 120 ℃ and 0.1 MPa for 3 min to eliminate surface micropores and further compact the fiber layers, thus obtaining the high-strength, wear-resistant, and shrinkage-resistant glass fiber composite conductive floor.

[0027] Example 2 The preparation of the PCL-PU shape memory polymer film, the modified E-CR glass fiber bundle, and the self-healing conductive coating material is the same as in Example 1.

[0028] The preparation of high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive flooring is as follows: The high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor comprises the following raw materials in parts by weight: 120 parts epoxy resin, 50 parts polyurethane prepolymer, 15 parts PCL-PU shape memory polymer film, 300 parts modified E-CR glass fiber, and 20 parts self-healing conductive coating material.

[0029] The preparation steps of the high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor are the same as in Example 1.

[0030] Example 3 The preparation of the PCL-PU shape memory polymer film, the modified E-CR glass fiber bundle, and the self-healing conductive coating material is the same as in Example 1.

[0031] The preparation of high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive flooring is as follows: The high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor comprises the following raw materials in parts by weight: 100 parts epoxy resin, 40 parts polyurethane prepolymer, 10 parts PCL-PU shape memory polymer film, 225 parts modified E-CR glass fiber, and 12.5 parts self-healing conductive coating material.

[0032] The preparation steps of the high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor are the same as in Example 1.

[0033] Comparative Example 1 The preparation of the modified E-CR glass fiber bundles and the self-healing conductive coating material is the same as in Example 1. The preparation of the high-strength, wear-resistant, and shrinkage-resistant glass fiber composite conductive floor is as follows: The high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive floor comprises the following raw materials in parts by weight: 100 parts epoxy resin, 40 parts polyurethane prepolymer, 225 parts modified E-CR glass fiber, and 12.5 parts self-healing conductive coating material.

[0034] The preparation steps are as follows: clean and coat the aluminum mold base plate with release agent, let it dry at room temperature, put 200 g of epoxy resin and 80 g of polyurethane prepolymer into a mixing tank, stir at 300 rpm for 5 min, vacuum degas for 30 min, pour the degassed liquid into the mold, and let it stand at 25 ℃ for 2 h for initial curing.

[0035] 450 g of modified E-CR glass fiber bundles were divided into five equal parts, corresponding to laying angles of 10°, 30°, 50°, 70°, and 90°. These were laid layer by layer while the substrate was semi-cured. Each layer was cured in a 60 ℃ oven for 30 min after laying, and the entire layer was cured at 80 ℃ for 2 h after the last layer was completed. 25 g of self-healing conductive prepolymer was mixed with 0.30 g of silver nanowire dispersion, ultrasonically treated for 10 min, and then uniformly sprayed with a 20 μm thick coating at room temperature using a spray gun. The mixture was cured at 35 ℃ for 24 h and hot-pressed at 120 ℃ and 0.1 MPa for 3 min to eliminate surface micropores and compact the fiber layer, thus obtaining the high-strength, wear-resistant, and shrinkage-resistant glass fiber composite conductive flooring.

[0036] Comparative Example 2 The preparation of the PCL-PU shape memory polymer film and the modified E-CR glass fiber bundle is the same as in Example 1.

[0037] The preparation of high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive flooring is as follows: The high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor comprises the following raw materials in parts by weight: 100 parts epoxy resin, 40 parts polyurethane prepolymer, 10 parts PCL-PU shape memory polymer film, and 225 parts modified E-CR glass fiber.

[0038] The preparation steps are as follows: 20 g of PCL-PU shape memory polymer film is laid flat on a clean aluminum mold base plate coated with a release agent. 200 g of epoxy resin and 80 g of polyurethane prepolymer are poured into a mixing tank with rotor blades and stirred at 300 rpm for 5 min at room temperature. Then, the mixture is degassed under vacuum for 30 min until no obvious bubbles are visible. It is then quickly poured into the mold, covered with the PCL-PU film, and placed at 25 ℃ for 2 h for initial curing.

[0039] 450 g of modified E-CR glass fiber bundles were divided into five layers with gradient angles of 10° / 30° / 50° / 70° / 90°. While the substrate was semi-cured, each layer was laid flat on the substrate surface, and each layer was cured in a 60 ℃ oven for 30 min after deposition. After the final layer was deposited, the entire assembly was cured at 80 ℃ for 2 h. The cured composite board was kept at 70 ℃ for 30 min, then cooled to room temperature, allowing the PCL-PU film to slightly melt and then be cured again. The board was then hot-pressed at 120 ℃ and 0.1 MPa for 3 min to eliminate surface micropores and further compact the fiber layers, thus obtaining the high-strength, wear-resistant, and shrinkage-resistant glass fiber composite conductive flooring.

[0040] Performance testing Curing shrinkage test One floorboard with dimensions of 240 mm × 240 mm × 3 mm was prepared according to Examples 1-3 and Comparative Examples 1-2. Four corners were marked on the reverse side of each board using micro-dot adhesive, and these were connected sequentially to form two diagonals. The boards were poured into a mold and allowed to initially cure. The lengths of the two diagonals were measured three times using a vernier caliper with an accuracy of ±0.01 mm, and the average value L1,avg was calculated. The boards were then removed from the mold and left at room temperature for 24 hours. The two diagonals were measured three more times using the same vernier caliper, and the average value L2,avg was calculated. The shrinkage rate was calculated using the following formula: ϵ = ×100% The results are shown in Table 1 below.

[0041] Table 1 Curing shrinkage results

[0042] As shown in Table 1, the curing shrinkage rate of all embodiments remained below 0.10%, far lower than that of Comparative Example 1 without a shape memory interface layer. This indicates that the introduction of the PCL-PU shape memory polymer film can effectively release residual curing stress and achieve "self-correcting" anti-shrinkage. Among them, Example 2 had the lowest shrinkage rate, indicating that the interface film and the substrate were more fully bonded under this formulation, which is beneficial for further suppressing shrinkage. Although Comparative Example 2 also used a shape memory layer, due to the lack of the synergistic effect of the self-healing conductive coating, its overall structure was slightly less effective in controlling shrinkage than that of the embodiments. In summary, in this invention, the shape memory interface layer and the self-healing conductive coating work together to significantly reduce curing shrinkage, and Example 2 achieved the best balance in its formulation selection.

[0043] Taber wear test The prepared floorboards from Examples 1-3 and Comparative Examples 1-2 were cut into 25 mm × 25 mm square samples. The surfaces were polished with fine sandpaper and dust was removed. The initial mass M0 was first weighed on a balance with an accuracy of 0.1 mg. The samples were then mounted on a Taber abrasion machine, a CS-17 grinding wheel was clamped, and a 750 g weight was added. The rotation speed was set to 60 rpm, and the machine was started and continuously run until 1000 rpm. After the test, the samples were removed, and the dust adhering to the surface was cleaned with a brush. The mass M1 after abrasion was weighed again. The abrasion amount ΔM = M0 – M1 was calculated, and the results are shown in Table 2 below.

[0044] Table 2 Wear Results

[0045] As shown in Table 2, the wear amounts of Examples 1–3 are significantly lower than those of Comparative Examples 1 and 2. Example 2 exhibits the lowest wear amount, at only 0.012 g, indicating that the synergistic effect of the tangentially gradient-oriented glass fiber reinforcement layer and the self-healing conductive coating in this invention significantly improves the wear resistance of the flooring. While Comparative Example 2 retains the interface shape memory layer, its lack of a self-healing coating results in a higher wear amount than the Examples 1–3, demonstrating that fiber reinforcement alone is insufficient to achieve optimal wear resistance. In conclusion, the rheology-tunable self-healing conductive film not only rapidly heals its conductive network after wear but also provides additional anti-damage traction at the microscopic level due to its dynamic borate ester crosslinking structure, thereby further reducing wear.

[0046] Three-point bending strength test Three right-angle beam specimens, each measuring 80 mm × 10 mm × 3 mm, were cut from the plates of Examples 1–3 and Comparative Examples 1–2. The universal testing machine was zeroed and a three-point bending fixture was pre-set, with the support spacing L fixed at 64 mm. Each specimen was placed on the support, with its crossbeam positioned at the mid-span, and the upper indenter vertically aligned with the midpoint of the specimen. The specimen was pressed down at a constant rate of 2 mm / min until it fractured, and the maximum load F (N) was recorded. The bending strength of the specimen was calculated using the following formula: The results are shown in Table 3 below.

[0047] Table 3 Bending strength results

[0048] As shown in Table 3, Examples 1–3 all exhibited significantly higher flexural strength than Comparative Examples 1 and 2 in the three-point bending test. Example 2 had the highest glass fiber content and the thickest interfacial film, with an average load of 52.0 N and a flexural strength of 55.5 MPa, the highest among all samples. Examples 3 and 1 were also significantly higher than Comparative Examples 1–2. Comparative Example 1, lacking a shape memory interfacial layer, had insufficient bonding between the matrix and fiber interface, making it prone to microcracks and resulting in the lowest flexural strength. Comparative Example 2, although possessing a shape memory layer, lacked a self-healing coating, failing to fully utilize the synergy between interfacial stress release and fiber pull-out damping, and its flexural performance was also inferior to the Examples 1–2.

[0049] In-plane conductivity and self-healing recovery rate detection Initial conductivity measurement: For the plates of Examples 1–3 and Comparative Examples 1–2, the thickness t of the sample was measured, and the surface resistance R0 (Ω) of the plate was measured using a four-probe resistivity meter at 25 °C. The initial in-plane conductivity σ0 (S / cm) was calculated according to the formula. σ0=

[0050] Self-healing test: Use a hard scalpel to make a continuous crack 10 mm long at the center of each sample, keeping the crack depth to the bottom of the coating; place all scratched samples in a chamber at 60 °C and 80% relative humidity for 30 min, then take them out and let them cool naturally to room temperature, repeat the four-probe test in step (1), measure the resistance R1 (Ω) after repair, and calculate the conductivity σ1 and recovery rate after recovery. The results are shown in Table 4 below.

[0051] Table 4. Results of conductivity and self-healing recovery rate

[0052] As shown in Table 4, the initial in-plane conductivity of Examples 1–3 was between 1100 and 1300 S / cm, indicating the high conductivity of the silver nanowire network in the self-healing conductive coating material. After damage, the material self-repaired under 60 °C and 80% RH conditions for 30 min, with recovery rates of 92%, 95%, and 93%, respectively. Among them, Example 2 had the largest coating thickness and achieved the best recovery rate of 95%, indicating that the dynamic borate ester bond can rapidly rebuild the conductive pathway in a micro-thermal and humid environment.

[0053] Comparative Example 1, while containing a self-healing coating, lacked the stress release and interface toughening of the shape memory interface layer, resulting in a recovery rate of only 83%. Comparative Example 2, while possessing a shape memory interface layer, lacked a self-healing coating, causing its recovery rate to plummet to 15%, almost completely losing its self-healing ability. This comparison demonstrates that only by organically integrating the shape memory interface layer with the self-healing conductive coating can both high initial conductivity and excellent conductive self-healing performance be simultaneously achieved.

[0054] Thermal cycling stability testing The plates from Examples 1–3 and Comparative Examples 1–2 were subjected to the following cycle 100 times: holding at 25 °C for 30 min and then holding at 70 °C for 30 min, without additional cooling between cycles, for a total of 100 cycles. The curing shrinkage rate, Taber abrasion, and in-plane conductivity were measured before and after each cycle, and the performance retention rate after the cycle was calculated. The results are shown in Table 5 below.

[0055] Table 5 Thermal cycling stability results

[0056] As shown in Table 5, after 100 cycles of 25 °C to 70 °C, Examples 1–3 maintained over 95% of their curing shrinkage, wear, and conductivity, with the lowest being 96.8%. This indicates that the shape memory interface layer and gradient fiber reinforcement layer effectively suppressed the accumulation of internal stress caused by cycling, while the self-healing conductive coating maintained the stability of the conductive network. Comparative Example 1, although showing acceptable shrinkage retention, only had a wear retention rate of 92.6%, indicating that the board structure without a shape memory layer was more susceptible to thermal fatigue and micro-damage. Comparative Example 2, lacking a self-healing coating, had a conductivity retention rate of only 86.4%, further demonstrating the long-term stability advantage of the synergistic effect of the self-healing coating and shape memory interface layer in this invention.

[0057] 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.

[0058] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A high strength, wear resistant, shrinkage resistant fiberglass composite conductive flooring, characterized in that, It contains the following raw materials by weight: 80-120 parts epoxy resin, 30-50 parts polyurethane prepolymer, 5-15 parts PCL-PU shape memory polymer film, 150-300 parts modified E-CR glass fiber bundle, and 5-20 parts self-healing conductive coating material.

2. The high strength, wear resistant, anti-shrinkage fiberglass composite conductive floor according to claim 1, wherein, The preparation method of the PCL-PU shape memory polymer film specifically includes the following steps: S101. Poly(ε-caprolactone diol) and polyisocyanate are added to a reactor in a certain proportion, and a catalyst is added and the mixture is stirred to generate PCL-PU prepolymer. S102. Pour the prepolymer onto a flat substrate and prepare a wet film by means of blade coating, casting, or spin coating; S103. First, pre-curing at room temperature or low temperature removes solvents and oligomers, then post-curing at an appropriate temperature to perfect the cross-linking network, resulting in a stable shape memory film; S104. Peel off the cured PCL-PU film from the substrate and thermally cycle the film to "program" its temporary shape to obtain the PCL-PU shape memory polymer film.

3. The high strength, wear resistant, anti-shrinkage fiberglass composite conductive floor according to claim 1, wherein, The method for preparing the modified E-CR glass fiber bundle specifically includes the following steps: S201. Soak and wash the raw fiber bundle in an alkaline solution to remove surface impurities and degrease; then rinse it several times with water until neutral, and dry it for later use; S202. Prepare a hydrolysis solution of silane coupling agent and adjust the pH to ensure uniform hydrolysis of the coupling agent; S203. Immerse the clean and dry glass fiber bundles in the coupling agent hydrolysis solution, stir or slowly pull the fiber bundles to allow the coupling agent to be fully adsorbed and form a directional coating on the fiber surface; S204. Remove the impregnated fiber bundles and hang or lay them flat in a ventilated place to pre-dry; then further heat them in an oven at an appropriate temperature. S205. The dried and cured fiber bundles are lightly washed with water to remove unreacted coupling agent residues, and then dried again to obtain modified E-CR glass fiber bundles.

4. The high strength, wear resistant, anti-shrinkage fiberglass composite conductive floor according to claim 1, wherein, The matrix of the self-healing conductive coating material is a prepolymer obtained by reacting double-hydroxyl-terminated polyethylene glycol with 3-hydroxypropylboronic acid in a 1:1 molar ratio, and 0.5-1.5 wt% silver nanowires are introduced by ultrasonic dispersion.

5. The high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive flooring according to claim 1, characterized in that, The overall curing shrinkage rate of the flooring is not greater than 0.1%, the surface hardness (Rockwell) is not less than 85 HRA, and the in-plane conductivity is not less than 10³ S / m.

6. The high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive flooring according to claim 1, characterized in that, The wear amount of the floor after the Taber abrasion test is no more than 0.02 g.

7. A manufacturing process for a high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive floor, wherein the high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive floor is as described in any one of claims 1-6, characterized in that... Includes the following steps: S1. First, lay the prepared PCL-PU shape memory polymer film on the bottom surface of the flat mold to ensure that the film fits the mold completely without air bubbles; S2. After degassing the epoxy resin and polyurethane prepolymer, pour the mixture evenly into the mold, cover the surface of the PCL-PU film, and perform preliminary curing to form a semi-cured substrate layer; S3. Take modified E-CR glass fiber bundles and, with the aid of sound field assistance or manual layering, lay them sequentially on the surface of the semi-cured substrate according to the tangential gradient angle until the designed thickness is reached, and then complete the curing. S4. The entire board is heated to allow the PCL-PU film to melt slightly and then solidify, thereby releasing and eliminating residual internal stress and achieving anti-shrinkage self-correction. S5. The pre-prepared self-healing conductive coating material is evenly sprayed onto the surface of the composite board. After the coating is cured, a high-strength, wear-resistant, and shrinkage-resistant fiberglass composite conductive floor is obtained.

8. The preparation process of the high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive flooring according to claim 7, characterized in that, The sound field frequency used in the sound field assisted laying in step S3 is 15-25 kHz, and the sound intensity is 0.3-0.7 W / cm².

9. The preparation process of the high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive flooring according to claim 7, characterized in that, The heating temperature in step S4 is 60-80°C, and the holding time is 20-40 min.

10. The preparation process of the high-strength, wear-resistant, and shrink-resistant fiberglass composite conductive flooring according to claim 7, characterized in that, In step S5, the thickness of the self-healing conductive coating sprayed is 10–30 μm, and it is cured at room temperature or under slight heating conditions for 12–36 h.

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