A flexible resin composite material, a method for preparing the same, and an application thereof

Abstract

This invention relates to the field of functional composite materials and fire safety early warning technology, and particularly to a flexible resin composite material, its preparation method, and its application. This invention proposes a ternary synergistic system of graphene, liquid metal, and flexible resin. Based on the synergistic effect of graphene and liquid metal, a flexible resin composite material is constructed. Its core mechanism is as follows: the liquid metal surface has a dense oxide layer. This invention utilizes the dense oxide layer on the liquid metal surface to maintain high contact resistance, keeping the flexible resin composite material in a "standby high-resistance state" with extremely low energy consumption. When the temperature rises abnormally, the flexible resin in the composite material softens, releasing the mechanical confinement of the liquid metal. The dense oxide layer on the liquid metal surface ruptures, and the liquid metal flows out and spreads along the graphene conductive framework network, forming a "transient low-resistance path." This sudden drop in resistance can directly drive the alarm circuit without additional signal amplification, realizing a minimalist structure of "material as sensor."

Description

Technical Field

[0001] This invention relates to the field of functional composite materials and fire safety early warning technology, and in particular to a flexible resin composite material, its preparation method and application. Background Technology

[0002] With the increasing demands for fire safety and control in modern architecture, rail transportation, and new energy equipment, the development of fire early warning materials that combine high sensitivity, rapid response, and environmental adaptability has become a research hotspot in materials science and safety engineering. Traditional fire early warning technologies mostly rely on smoke, temperature, or gas sensors, which have limitations such as response lag, susceptibility to environmental interference, and difficulty in achieving distributed monitoring, thus failing to adequately meet the early fire warning needs in complex scenarios.

[0003] In recent years, functional composite materials, with their integrated structure-performance design advantages, have provided new ideas for overcoming the technical bottlenecks of traditional early warning technologies. Among them, graphene (GNP)-based composite materials have shown great potential in the field of fire early warning due to their ultra-high thermal and electrical conductivity, excellent mechanical properties, and chemical stability; while liquid metal (LM), with its unique properties such as low melting point, high thermal conductivity, and room temperature fluidity, has become an ideal functional phase for regulating the thermal response behavior of composite materials. Combining graphene with liquid metal and introducing it into a flexible resin matrix to construct flexible composite materials is expected to enable rapid sensing and signal output of temperature changes, providing a completely new technical path for early fire warning.

[0004] The core of early fire warning lies in the rapid and accurate response to abnormal temperature increases, and the temperature-sensitive characteristics of materials are key to determining warning performance. Graphene, as a two-dimensional carbon nanomaterial, possesses an efficient thermal conductivity network between its layers, enabling rapid heat transfer. Simultaneously, its electrical properties are highly sensitive to temperature changes, laying the foundation for constructing temperature-responsive sensors. However, pure graphene-based composite materials suffer from insufficient mechanical properties and a high temperature response threshold in flexible applications, limiting their practical application in fire warning scenarios. The introduction of liquid metal can effectively compensate for this deficiency: on the one hand, liquid metal, after melting upon heating, can fill the gaps between graphene sheets, forming continuous thermal and electrical conduction pathways, significantly improving the thermal response rate of graphene-based composite materials; on the other hand, the low melting point of liquid metal allows graphene-based composite materials to undergo significant structural and performance mutations at lower temperatures, thereby achieving accurate triggering and early warning of early fires. By dispersing graphene / liquid metal composite phases in a flexible resin matrix, excellent temperature response performance can be imparted to the material while maintaining its flexibility and processability, providing core material support for the construction of flexible, wearable, and distributed fire early warning systems.

[0005] However, the research on flexible fire early warning materials still faces many challenges, such as: how to achieve efficient interfacial bonding between the functional phase and the matrix to avoid phase separation and performance degradation during long-term use; how to control the temperature response threshold and response rate of composite materials to adapt them to the fire early warning needs in different scenarios; and how to improve the environmental stability and service life of flexible fire early warning materials while ensuring early warning sensitivity. Summary of the Invention

[0006] In view of this, the present invention provides a flexible resin composite material, its preparation method and application. The flexible resin composite material provided by the present invention has the advantages of high sensitivity, fast response and excellent stability.

[0007] This invention provides a flexible resin composite material comprising the following components in parts by weight: The mixture comprises 100 parts of flexible resin, 0.1-20 parts of graphene, 3-100 parts of liquid metal, 5-20 parts of crosslinking agent, and 10-100 ppm of catalyst; the flexible resin is one or more of polydimethylsiloxane and silicon-modified resin; the liquid metal includes one or more of gallium and gallium-based alloys; the gallium-based alloy includes one or two of Ga-In alloy and Ga-In-Sn alloy.

[0008] Preferably, the polydimethylsiloxane includes one or both of addition-type and condensation-type polydimethylsiloxane; the silicon-modified resin is silicon-modified polyurethane.

[0009] Preferably, the addition-type polydimethylsiloxane is a vinyl-terminated polydimethylsiloxane; the condensation-type polydimethylsiloxane is a hydroxyl-terminated polydimethylsiloxane; and the silicon-modified polyurethane includes one or more of the following: hydroxyl-terminated siloxane-modified polyurethane, isocyanate-terminated siloxane-modified polyurethane, polydimethylsiloxane soft-segment modified polyurethane, siloxane-polyether copolymer polyurethane, and silicon-containing block copolymer polyurethane.

[0010] Preferably, the crosslinking agent is a hydrogen-containing silicone oil or methyltriethoxysilane; the Si-H content of the hydrogen-containing silicone oil is 0.1~2.0 wt%.

[0011] Preferably, the catalyst is a platinum-based catalyst or an organotin catalyst; the platinum-based catalyst includes one or more of platinum and platinum complexes, and the platinum complexes include one or two of Karl Steider catalysts and chloroplatinic acid catalysts.

[0012] Preferably, the flexible resin composite material further includes a dispersant; the dispersant includes one or more of polyvinylpyrrolidone, surfactants, and siloxane-polyether copolymers.

[0013] Preferably, the flexible resin composite material further includes an interface modifier; the interface modifier includes one or more of silane coupling agents and liquid metal interface regulators; the liquid metal interface regulator includes one or more of stearic acid and mercapto compounds.

[0014] Preferably, the mass fraction of the interface modifier does not exceed 5 parts.

[0015] The present invention also provides a method for preparing the flexible resin composite material described above, comprising the following steps: (1) A flexible resin, liquid metal and graphene are mixed to obtain a liquid metal microdroplet composite resin; (2) The liquid metal microdroplet composite resin, crosslinking agent and catalyst are mixed and degassed and cured in sequence to obtain the flexible resin composite material.

[0016] The present invention also provides the application of the flexible resin composite material described in the above-described scheme or the flexible resin composite material obtained by the preparation method described in the above-described scheme in the field of open flame monitoring or temperature monitoring.

[0017] Compared with the prior art, the flexible resin composite material, its preparation method, and its application provided by the present invention have achieved the following beneficial effects: This invention proposes a ternary synergistic system of graphene, liquid metal, and flexible resin. Based on the synergistic effect of graphene and liquid metal, a flexible resin composite material is constructed. The core mechanism is as follows: the liquid metal surface has a dense oxide layer. This invention utilizes the dense oxide layer (Ga2O3) on the liquid metal surface to maintain high contact resistance, keeping the flexible resin composite material in a "standby high-resistance state" with extremely low energy consumption. When the temperature rises abnormally (e.g., equipment overheating or approaching open flame), the flexible resin in the composite material softens, releasing the mechanical confinement of the liquid metal. The dense oxide layer on the liquid metal surface ruptures, allowing the liquid metal to flow out and spread along the graphene conductive framework network, forming a "transient low-resistance path." This sudden drop in resistance can directly drive an alarm circuit without additional signal amplification, achieving a minimalist structure where "the material is the sensor."

[0018] Specifically, this invention achieves beneficial effects through the following innovations: 1) Proposing a new early warning mechanism of "high resistance standby - low resistance triggering": utilizing the dense oxide layer on the surface of liquid metal to construct an initial high resistance state, achieving low-energy standby; 2) Constructing a temperature-triggered conductive network structure: achieving a sudden change in resistance by inducing the release of liquid metal through temperature and reconstructing the conductive path along the graphene framework network; 3) Realizing a simplified system construction of "material as sensor": eliminating the need for complex signal processing modules, with resistance changes directly driving the alarm system; 4) Synergistic mechanism between graphene and liquid metal: graphene provides the conductive framework, while liquid metal provides dynamic conductivity; 5) Adjustable response temperature and sensitivity: performance regulation is achieved by adjusting the crosslinking density of the flexible resin and the content of liquid metal.

[0019] The flexible resin composite material provided by this invention is a temperature-triggered conductive fire early warning material that enables rapid response to temperature anomalies, has the ability to abruptly change from a high-resistivity state to a low-resistivity state, directly triggers the alarm without the need for an external amplification circuit, and has good flexibility and environmental stability. It is suitable for flexible fire early warning, intelligent sensing or distributed safety monitoring systems.

[0020] This invention systematically improves the microstructure, interfacial interaction mechanism, and thermal response behavior of flexible resin composites by regulating the surface functional groups of graphene, the loading of liquid metal, and the cross-linking structure of flexible resin (as the matrix). Utilizing the synergistic effect among graphene, liquid metal, and flexible resin, this invention clarifies the structural evolution and performance mutation mechanism of flexible resin composites under temperature changes. This provides a theoretical basis and technical support for developing flexible fire early warning materials with high sensitivity, rapid response, and excellent stability, promoting the development of fire early warning technology towards intelligence, flexibility, and distributed systems. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of this invention, the accompanying drawings used in the embodiments of this invention or in the prior art are briefly described below. For those skilled in the art, other drawings can be derived from the following drawings without creative effort, and all such drawings are within the protection scope of this invention.

[0022] Figure 1 Figure 1 shows the performance test results of the flexible resin composite material prepared in Example 1. Among them, a is the SEM image (scale bar is 3 μm) and EDS elemental distribution image (scale bar is 5 μm) of the flexible resin composite material prepared in Example 1, b is the XRD pattern of the flexible resin composite material and graphene prepared in Example 1, and c is the XPS curve of the flexible resin composite material and graphene prepared in Example 1. Figure 1 The label "liquid metal / graphene" in the text indicates a flexible resin composite material. Figure 2 Thermal conductivity, thermogravimetric (TGA) curves, and derivative thermogravimetric (DTG) curves of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2 are shown. Among them, a is the thermal conductivity curve of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2, b is the thermogravimetric curve of the two flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2, and c is the derivative thermogravimetric curve of the two flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2. Figure 3 The cone calorimetry test results of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2 are shown below. Among them, a is the heat release rate (HRR) of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2, b is the total heat release (THR) of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2, c is the CO release rate of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2, and d is the flue gas generation rate (TSP) curve of the three flexible resin composites and vinyl-terminated polydimethylsiloxane prepared for Test Example 2. Figure 4 The graph shows the resistance-temperature performance of the flexible resin composite material prepared in Example 1; where a is the relationship between the resistance change rate and temperature of the flexible resin composite material in Example 1, b is the resistance change of the flexible resin composite material in Example 1 from 140℃ to room temperature over time, and c is the resistance change of the flexible resin composite material in Example 1 from -20℃ to room temperature over time. Figure 5 A comparison of the dielectric constants of flexible resin composite materials at 100Hz; Figure 6 The resistivity change rate-temperature change curve of the flexible resin composite material prepared in Example 2; Figure 7 The resistance-temperature curve of the flexible resin composite material prepared in Example 3; Figure 8 The resistivity change rate-temperature change curve of the flexible resin composite material prepared in Example 4; Figure 9 The mechanical properties test results are for the flexible resin composite material prepared in Example 5. Detailed Implementation

[0023] This invention provides a flexible resin composite material comprising the following components in parts by weight: The mixture comprises 100 parts of flexible resin, 0.1-20 parts of graphene, 3-100 parts of liquid metal, 5-20 parts of crosslinking agent, and 10-100 ppm of catalyst; the flexible resin is one or more of polydimethylsiloxane and silicon-modified resin; the liquid metal includes one or more of gallium and gallium-based alloys; the gallium-based alloy is a Ga-In-Sn alloy.

[0024] The flexible resin composite material provided by the present invention comprises 100 parts by weight of flexible resin; the flexible resin is preferably one or two of polydimethylsiloxane (PDMS) and silicone-modified resin; the polydimethylsiloxane preferably includes one or two of addition-type polydimethylsiloxane and condensation-type polydimethylsiloxane; the addition-type polydimethylsiloxane is preferably vinyl-terminated polydimethylsiloxane; the condensation-type polydimethylsiloxane is preferably hydroxyl-terminated polydimethylsiloxane; the silicone-modified resin is preferably silicone. Modified polyurethane; the silicon-modified polyurethane preferably includes one or more of the following: hydroxyl-terminated siloxane-modified polyurethane, isocyanate-terminated siloxane-modified polyurethane, polydimethylsiloxane (PDMS) soft-segment modified polyurethane, siloxane-polyether copolymer polyurethane, and silicon-containing block copolymer polyurethane; the silicon-modified polyurethane is composed of polytetrahydrofuran ether diol (PTMG-2000), 4,4'-diphenylmethane diisocyanate (MDI), and α,ω-dihydroxypolydimethylsiloxane (HO-PDMS-OH, M n The siloxane-modified polyurethane was prepared by reaction (=2000).

[0025] Based on the mass fraction of the flexible resin, the flexible resin composite material provided by the present invention includes 0.1 to 20 parts of graphene, preferably 1 to 15 parts, and more preferably 5 to 10 parts.

[0026] Based on the mass fraction of the flexible resin, the flexible resin composite material provided by the present invention includes 3 to 100 parts of liquid metal, preferably 10 to 80 parts, and more preferably 30 to 50 parts.

[0027] In this invention, the liquid metal preferably includes one or more of gallium and gallium-based alloys; the melting point of the gallium-based alloy is preferably -20~40℃, more preferably -20~30℃, and even more preferably -20~20℃; the gallium-based alloy preferably includes one or two of Ga-In alloy and Ga-In-Sn alloy.

[0028] In this invention, the composition of the Ga-In-Sn alloy preferably includes 60-75 wt% Ga, 15-30 wt% In and 5-15 wt% Sn, more preferably 65-70 wt% Ga, 20-25 wt% In and 10 wt% Sn.

[0029] Based on the mass fraction of the flexible resin, the flexible resin composite material provided by the present invention includes 5 to 20 parts of crosslinking agent, preferably 10 to 15 parts.

[0030] In this invention, the crosslinking agent is preferably a hydrogen-containing silicone oil or a methyltriethoxysilane; the hydrogen-containing silicone oil is preferably a polymethylhydrosiloxane (PMHS); the PMHS preferably includes one or more of linear polymethylhydrosiloxanes, terminal polymethylhydrosiloxanes, and multifunctional polymethylhydrosiloxanes; wherein the general formula of the linear polymethylhydrosiloxane is Formula I: (CH3)3SiO-[Si(CH3)(H)-O] m -[Si(CH3)2-O] n -Si(CH3)3 Formula I; The general formula for terminal polymethylhydrosiloxanes is Formula II: H-Si(CH3)2-O-[Si(CH3)2-O] n -Si(CH3)2-H Formula II; The multifunctional polymethylhydrosiloxane is a polysiloxane containing multiple Si-H side groups or branched structures, specifically it can be one or two of methylhydrosiloxane-dimethylsiloxane copolymer and hydrogen-containing polymethylsilsesquioxane resin; the Si-H content of the hydrogen-containing silicone oil is preferably 0.1~2.0wt%, more preferably 0.5~1.5wt%, and even more preferably 1wt%.

[0031] Based on the mass fraction of the flexible resin, the flexible resin composite material provided by the present invention includes 10~100ppm of catalyst (the mass ratio of platinum in the catalyst to the flexible resin composite material), preferably 20~80ppm, more preferably 40~60ppm.

[0032] In this invention, the catalyst is preferably a platinum-based catalyst or an organotin catalyst; the platinum-based catalyst preferably includes one or more of platinum and platinum complexes; the platinum complex preferably includes one or two of Karstedt catalyst and Speier platinum catalyst; the organotin catalyst is preferably dibutyltin dilaurate (DBTDL). Using the above catalysts, this invention can achieve efficient and controllable hydrosilylation crosslinking reactions.

[0033] In this invention, the flexible resin composite material preferably further includes a dispersant; the dispersant preferably includes one or more of polyvinylpyrrolidone, siloxane-polyether copolymer and surfactant.

[0034] In this invention, the siloxane-polyether copolymer is preferably a linear block siloxane-polyether copolymer or a side-branched siloxane-polyether copolymer; the linear block siloxane-polyether copolymer preferably includes one or more of polydimethylsiloxane-polyoxyethylene block copolymer (PDMS-PEO), polydimethylsiloxane-polyoxypropylene block copolymer (PDMS-PPO), and polydimethylsiloxane-polyoxyethylene-polyoxypropylene triblock copolymer (PDMS-PEO-PPO); the structure of the side-branched siloxane-polyether copolymer is shown in Formula III: (CH3)3SiO-[Si(CH3)2-O] x -[Si(CH3)(R)-O] y -Si(CH3)3 Formula III; In formula III, R is -(CH2)3-O-(CH2CH2O) m -(CH2CH(CH3)O) n -H or its alkyl-terminated structure (e.g., -(CH2)3-O-(CH2CH2O) m -(CH2CH(CH3)O) n -CH3).

[0035] In this invention, the siloxane-polyether copolymer may specifically include one or more of the following: polyether-modified polydimethylsiloxane (PDMS-g-PEG / PPG), trisiloxane-type polyether surfactants (e.g., polyether-modified methyltrisiloxane, polyether-modified trisiloxane, or polydimethylsiloxane-graft-polyethylene oxide copolymer), and low molecular weight siloxane-polyether surfactants (e.g., methyl polyoxyethylene siloxane, polyoxyethylene ether-modified polydimethylsiloxane, or hydroxyl-terminated polyether-modified siloxane).

[0036] In this invention, the surfactant preferably includes nonionic surfactants, anionic surfactants, or amphoteric surfactants; the nonionic surfactant is preferably one or more of fatty alcohol polyoxyethylene ethers (e.g., lauryl alcohol polyoxyethylene ether, dodecyl alcohol polyoxyethylene ether, and oleyl alcohol polyoxyethylene ether), alkylphenol polyoxyethylene ethers (e.g., nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, and octylphenol polyoxyethylene ether), and polyethylene glycol surfactants; the polyethylene glycol surfactant preferably includes one or more of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 1000; the anionic surfactant is preferably sodium dodecyl sulfate or sodium dodecylbenzene sulfonate; the amphoteric surfactant is preferably a betaine surfactant (e.g., cocamidopropyl betaine, lauramide propyl betaine, and octadecyl betaine) or an imidazoline surfactant (e.g., imidazoline oleate, imidazoline laurate, and cocoyl imidazoline).

[0037] Based on the mass fraction of the flexible resin, the flexible resin composite material provided by the present invention includes 0 to 5 parts of dispersant, preferably 1 to 4 parts, and more preferably 2 to 3 parts.

[0038] In this invention, the flexible resin composite material preferably further includes an interface modifier; the interface modifier preferably includes one or more of a silane coupling agent and a liquid metal interface regulator; the silane coupling agent preferably includes one or more of γ-aminopropyltriethoxysilane and γ-methacryloyloxypropylsilane; the liquid metal interface regulator preferably includes one or more of stearic acid and a thiol compound; the thiol compound preferably includes mercaptoethanol (HS-CH2CH2-OH), mercaptoacetic acid (HS-CH2COOH), and 1-dodecylthiol (C 12 H 25 -SH), 1-octadecylthiol (C 18 H 37 One or more of the following: -SH), mercaptopropionic acid, mercaptoethylamine, and mercaptopropyltriethoxysilane.

[0039] Based on the mass fraction of the flexible resin, the flexible resin composite material provided by the present invention includes 0 to 5 parts of interface modifier, preferably 1 to 4 parts, and more preferably 2 to 3 parts.

[0040] In this invention, the sum of the mass fractions of the dispersant and the interface modifier is preferably no more than 5 parts.

[0041] The core structure of the flexible resin composite material provided by this invention is as follows: 1) Graphene constructs a conductive framework network; 2) Liquid metal is dispersed in the form of microdroplets in the flexible resin with the conductive framework network, forming a liquid metal microdroplet composite resin; 3) The dense oxide scale (Ga2O3) on the surface of the liquid metal blocks the conduction; 4) The flexible resin provides mechanical constraint for the flexible resin composite material. The working principle of the above structure in the flexible resin composite material is as follows: At room temperature, the surface of the liquid metal is covered by a dense oxide scale, which has high contact resistance, and the flexible resin composite material as a whole is in a high-resistivity state; when heated, the flexible resin in the flexible resin composite material softens, the dense oxide scale on the surface of the liquid metal breaks, and the liquid metal spreads along the graphene framework network to form a continuous conductive path, i.e., the aforementioned conductive framework network.

[0042] The present invention also provides a method for preparing the flexible resin composite material described above, comprising the following steps: (1) A flexible resin, liquid metal and graphene are mixed to obtain a liquid metal microdroplet composite resin; (2) The liquid metal microdroplet composite resin, crosslinking agent and catalyst are mixed and degassed and cured in sequence to obtain the flexible resin composite material.

[0043] This invention mixes flexible resin, liquid metal, and graphene (referred to as the first mixture) to obtain a liquid metal microdroplet composite resin. In this invention, the first mixture preferably includes the following steps: dispersing the flexible resin and graphene to obtain a dispersion, and then mixing the dispersion with the liquid metal (referred to as the second mixture).

[0044] In this invention, the dispersion is preferably one or both of ultrasonication and stirring, more preferably ultrasonication after stirring.

[0045] In this invention, the ultrasound equipment preferably includes a probe-type ultrasound device or a water bath ultrasound device; the ultrasound frequency is preferably 20~60kHz, more preferably 20~40kHz; the ultrasound power is preferably 100~800W, more preferably 200~500W; the ultrasound duration is preferably 10~120min, more preferably 20~60min; the ultrasound method is preferably intermittent ultrasound, so that the system temperature is 10~40℃. This invention, through intermittent ultrasound, can avoid system overheating.

[0046] In this invention, the stirring and mixing is preferably mechanical stirring; the mechanical stirring is preferably high-speed shear dispersion; the stirring speed is preferably 300~5000 rpm, more preferably 500~2000 rpm; and the stirring and mixing time is preferably 10~120 min, more preferably 20~60 min. This invention obtains a more uniform and stable graphene dispersion system through the above dispersion method.

[0047] In this invention, the second mixing is preferably shearing or emulsification.

[0048] In this invention, the shearing device preferably includes a rotor-stator type dispersion device; the shearing speed is preferably 1000~10000 rpm, more preferably 3000~8000 rpm, and the shearing time is preferably 5~60 min, more preferably 10~30 min. This invention, through the above shearing, breaks liquid metal into micron-sized droplets and uniformly disperses them in a flexible resin.

[0049] In this invention, the emulsification preferably includes the following steps: premixing the dispersion, organic solvent, liquid metal and dispersing aid (the dispersing aid is one or both of dispersant and interface modifier) ​​to obtain a premix, and then shearing or sonicating the premix.

[0050] In this invention, the organic solvent preferably includes one or more of ethanol, isopropanol and n-hexane.

[0051] In this invention, the organic solvent is preferably added according to the following standard: the mass ratio of the total mass of the dispersion and the organic solvent to the mass of the liquid metal is preferably 1~20:1, more preferably 5~15:1, and even more preferably 10:1.

[0052] In this invention, the content of dispersant in the premixed liquid is preferably 0.1-5 wt%, more preferably 0.5-3 wt%, and even more preferably 1-2 wt%.

[0053] In this invention, the premixing is preferably stirring; the stirring speed is preferably 300~1000 rpm, more preferably 500~700 rpm, and the stirring time is preferably 5~20 min, more preferably 10~15 min.

[0054] In this invention, the shearing speed is preferably 3000~10000 rpm, more preferably 5000~7000 rpm, and the shearing time is preferably 5~30 min, more preferably 10~20 min.

[0055] In this invention, the frequency of the ultrasound is preferably 20-40 kHz, more preferably 30 kHz; the power is preferably 100-500 W, more preferably 300 W; and the ultrasound duration is preferably 5-30 min, more preferably 15-25 min. This invention forms a stable liquid metal microdroplet dispersion system through the above-mentioned shearing or ultrasound.

[0056] In this invention, the temperature for shearing or ultrasonication is preferably 10-30°C, more preferably 15-25°C, and even more preferably 20°C. By performing shearing or ultrasonication at the above temperatures, this invention can prevent excessive changes in the oxidation state of the liquid metal.

[0057] In this invention, in the liquid metal microdroplet composite resin, liquid metal forms liquid metal microdroplets in a flexible resin. The interior of the liquid metal microdroplets is liquid metal, and the surface is a dense oxide layer formed by the oxidation of liquid metal. The diameter of the liquid metal microdroplets is distributed in the range of 0.5 to 100 micrometers.

[0058] After obtaining the liquid metal microdroplet composite resin, the present invention mixes the liquid metal microdroplet composite resin, crosslinking agent, and catalyst (denoted as the third mixture) and sequentially degasses and cures them to obtain the flexible resin composite material. In the present invention, the third mixture is preferably mechanically stirred; the stirring speed is preferably 50~500 rpm, more preferably 100~300 rpm; the third mixing time is preferably 5~30 min, more preferably 10~20 min, and even more preferably 15 min; the third mixing temperature is preferably room temperature (20~30℃). The present invention, through the third mixing under the above-mentioned stirring speed and temperature conditions, can ensure that the components are uniformly dispersed and avoid introducing a large number of air bubbles, while avoiding damage to the formed graphene framework network structure and the dispersion state of the liquid metal microdroplets.

[0059] In this invention, the degassing equipment preferably includes a vacuum drying oven or a vacuum degassing device; the degassing is preferably vacuum degassing; the vacuum degree of the vacuum degassing is preferably -0.06~-0.10 MPa (relative vacuum), more preferably -0.08~-0.095 MPa; the degassing temperature is preferably 20~60℃, more preferably 25~40℃, and the degassing time is preferably 5~60 min, more preferably 10~30 min. Through the above degassing, this invention can effectively remove air bubbles introduced into the system and avoid premature solidification or structural damage caused by excessively high temperature or excessive vacuum.

[0060] In this invention, the curing is preferably room temperature curing, heated curing, or staged curing; the room temperature curing temperature is preferably 20-30°C, and the room temperature curing time is preferably 12-48 hours, more preferably 24-36 hours; the heated curing temperature is preferably 60-150°C, more preferably 70-120°C, and the holding time is preferably 0.5-4 hours, more preferably 1-2 hours; the staged curing preferably includes sequential first curing and second curing; the first curing temperature is preferably room temperature (20-30°C), and the holding time is preferably 1-4 hours, more preferably 2-3 hours; the second curing temperature is preferably 80-120°C, more preferably 100°C, and the holding time is preferably 1-2 hours, more preferably 1.5 hours. Through the above curing process, this invention obtains a flexible resin composite material with uniform structure and stable performance, while avoiding internal defects caused by rapid curing.

[0061] The flexible resin composite material provided by this invention has adjustable properties. The specific performance control methods are as follows: 1) By adjusting the content of liquid metal, the conduction threshold of the flexible resin composite material is controlled; 2) By adjusting the content of graphene, the density of the conductive skeleton network in the flexible resin composite material is controlled; 3) By adjusting the crosslinking density, the triggering temperature of the fire warning of the flexible resin composite material is controlled; 4) By mechanical stirring and fully combining with the dispersing agent, the interfacial stability of the flexible resin composite material is improved.

[0062] The present invention also provides the application of the flexible resin composite material described in the above-described scheme or the flexible resin composite material obtained by the preparation method described in the above-described scheme in the field of open flame monitoring or temperature monitoring.

[0063] The flexible resin composite material provided by this invention can be used in the fields of open flame monitoring or temperature monitoring, such as early warning systems for fires, battery thermal runaway monitoring, cable overheating monitoring, flexible wearable safety devices, or distributed monitoring of building structures.

[0064] This invention systematically characterized the resistance response characteristics of flexible resin composite materials in a wide temperature range of -20 to 140 °C. The key application indicators such as response speed, repeatability and environmental tolerance showed good performance, and it also has a fire early warning function.

[0065] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments.

[0066] Example 1: (1) Graphene dispersion: Five parts of graphene were added to 100 parts of vinyl-terminated polydimethylsiloxane. The mixture was first pre-dispersed by mechanical stirring at a speed of 1500 rpm for 20 min. Then, it was ultrasonically dispersed at a frequency of 20 kHz and a power of 300 W for 30 min. The system temperature was controlled at 25 °C by an ice-water bath to obtain a uniform and stable graphene dispersion system.

[0067] (2) Introduction of liquid metal: Add 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%) to the graphene dispersion system prepared in step (1), and disperse it using a rotor-stator high-speed shearing device with a shearing speed of 6000 rpm and a shearing time of 20 min, so that the liquid metal forms liquid metal microdroplets and is uniformly dispersed in the resin system to obtain liquid metal microdroplet composite resin.

[0068] (3) Add crosslinking agent: Add 10 parts of hydrogen-containing silicone oil (linear polymethylhydrosiloxane) and 50 ppm of platinum catalyst to the liquid metal microdroplet composite resin prepared in step (2). Mix at low speed with a stirring speed of 200 rpm and a stirring time of 10 min at room temperature (25℃) to avoid destroying the dispersion structure of the liquid metal microdroplets and obtain a mixed system.

[0069] (4)Degassing: The mixture prepared in step (3) was placed under vacuum to remove bubbles. The degassing temperature was 25°C, the vacuum degree was -0.095MPa, and the degassing time was 20min.

[0070] (5) Curing: The degassed mixture was cured at 80°C for 2 hours to obtain a flexible resin composite material.

[0071] Example 2: The preparation method of this embodiment is the same as that of Example 1, except that the amount of graphene used is 10 parts and the amount of liquid metal used is 50 parts.

[0072] The resistivity change rate of the flexible resin composite material in this embodiment was measured as a function of temperature, and the results are as follows: Figure 6 As shown. According to Figure 6 The test results show that the resistivity change rate of the flexible resin composite material gradually decreases with increasing temperature, and the change amplitude decreases significantly after 60℃, indicating that the system's temperature response tends to stabilize. Therefore, the temperature response threshold of the flexible resin composite material is reduced to about 60℃; in the range below 60℃, the flexible resin composite material exhibits higher temperature sensitivity and response sensitivity.

[0073] Example 3: (1) Add 5 parts of graphene to 100 parts of vinyl-terminated polydimethylsiloxane and disperse by a combination of mechanical stirring (1500 rpm, 30 min) and ultrasonication (30 kHz, 300 W, 30 min) to obtain a uniform and stable graphene dispersion system.

[0074] (2) Add 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%) to the graphene dispersion system prepared in step (1), and use high-speed shearing (7000rpm, 20min) to form a uniform dispersion structure of liquid metal microdroplets to obtain liquid metal microdroplet composite resin.

[0075] (3) Add 10 parts of hydrogen-containing silicone oil (linear polymethylhydrosiloxane) and 50 ppm of Karstedt catalyst to the liquid metal microdroplet composite resin prepared in step (2), and stir for 15 min at room temperature and 300 rpm to obtain a mixed system.

[0076] (4) Place the mixed system prepared in step (3) under vacuum conditions of 25℃ and -0.095MPa for 15 min to degas.

[0077] (5) The degassed mixture was cured at 80°C for 2 hours to obtain a flexible resin composite material.

[0078] The resistance of the flexible resin composite material in this embodiment was measured as a function of temperature, and the results are as follows: Figure 7 As shown. According to Figure 7 It can be seen that the resistance of the flexible resin composite material drops sharply near 80℃, from about 10... 4 The resistance rapidly drops from MΩ to nearly 100 MΩ, spanning approximately three orders of magnitude, indicating that the conductive network within the flexible resin composite material forms rapidly at this temperature. Therefore, its response temperature can be determined to be approximately 80℃. Furthermore, the resistance change is relatively slow before 80℃, but tends to stabilize after 80℃, further suggesting that this temperature is the critical response temperature for a significant conductive transition in the system.

[0079] Example 4: (1) Add 5 parts of graphene to 100 parts of hydroxyl-terminated polydimethylsiloxane and disperse by mechanical stirring (1000 rpm, 30 min) and ultrasonication (40 kHz, 300 W, 30 min) to obtain a uniform and stable graphene dispersion system.

[0080] (2) Add 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%) to the graphene dispersion system prepared in step (1) and disperse it by high-speed shear (6000rpm, 20min) to obtain liquid metal microdroplet composite resin.

[0081] (3) Add 8 parts of methyltriethoxysilane and 0.5 parts of dibutyltin dilaurate to the liquid metal microdroplet composite resin prepared in step (2), and stir for 20 min at room temperature and 300 rpm to obtain a mixed system.

[0082] (4) Place the mixture prepared in step (3) at 25°C and under a vacuum of -0.095MPa for 15 minutes to allow it to stand and degas.

[0083] (5) The degassed mixture was cured at 30°C for 24 hours to obtain a flexible resin composite material.

[0084] The resistivity change rate of the flexible resin composite material in this embodiment was measured as a function of temperature, and the results are as follows: Figure 8 As shown. According to Figure 8 The test results show that the resistivity change rate of the flexible resin composite material undergoes a significant abrupt change at approximately 70°C, indicating the rapid formation of its internal conductive network. Therefore, 70°C can be determined as the response temperature of the flexible resin composite material. This response temperature matches the typical heat accumulation temperature range in the on-site construction environment, which can meet the requirements for temperature monitoring and safety early warning during construction.

[0085] Example 5: (1) 8 parts of graphene were added to 100 parts of silicon-modified polyurethane (siloxane-modified polyurethane prepared by reaction of polytetrahydrofuran diol (PTMG), 4,4'-diphenylmethane diisocyanate and hydroxyl-terminated polydimethylsiloxane (HO-PDMS-OH), produced by Tongli Optoelectronic Co., Ltd., and organosilicon sheet adhesive TOCA) and dispersed by mechanical stirring (1200 rpm, 60 min) to obtain a uniform and stable graphene dispersion system.

[0086] (2) Add 40 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%) to the graphene dispersion system prepared in step (1), and use high-speed shear (8000rpm, 20min) to form a dispersion system to obtain liquid metal microdroplet composite resin.

[0087] (3) Add a curing system (addition-type silane crosslinking system, specifically a hydrogen-containing silicone oil crosslinking agent and a chloroplatinic acid catalyst) to the liquid metal microdroplet composite resin prepared in step (2). The hydrogen-containing silicone oil crosslinking agent is a linear polymethylhydrosiloxane with a Si-H content of 1.0 wt% and an amount of 10 parts. The amount of chloroplatinic acid catalyst is 50 ppm (calculated as Pt). Mix the mixture at room temperature using low-speed stirring (300 rpm, 20 min) to obtain a uniform mixture system.

[0088] (4) Degas the mixture prepared in step (3) at 25°C and -0.08 MPa for 20 min.

[0089] (5) The degassed mixture was cured at room temperature (25°C) for 24 hours to obtain a flexible resin composite material.

[0090] The mechanical properties of the flexible resin composite material prepared in this embodiment were tested, and the results are as follows: Figure 9 As shown. According to Figure 9 The test results show that the elongation at break of the flexible resin composite material can reach approximately 280%, and the tensile strength maintains a stable increase within a large deformation range without obvious brittle fracture. This indicates that the flexible resin composite material can withstand a large degree of tensile deformation without failure, thus exhibiting high flexibility. This characteristic enables it to adapt to complex deformation conditions such as bending and stretching, making it suitable for wearable flexible early warning devices.

[0091] Example 6: The preparation method of this embodiment is the same as that of Example 1. The difference is that step (2) is: 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%), 3 parts of polyvinylpyrrolidone and 10 parts of ethanol are added to the graphene dispersion system. The mixture is stirred at 500 rpm for 15 min and sheared at 20°C and 7000 rpm for 20 min to form liquid metal microdroplets and disperse them evenly in the resin system to obtain liquid metal microdroplet composite resin.

[0092] Example 7: The preparation method of this embodiment is the same as that of Example 1. The difference is that step (2) is: 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%), 3 parts of polydimethylsiloxane-polyoxyethylene block copolymer (PDMS-PEO) and 10 parts of ethanol are added to the graphene dispersion system. The mixture is stirred at 500 rpm for 15 min and ultrasonicated at 20℃, 30 kHz and 300 W for 25 min to form liquid metal microdroplets and uniformly disperse them in the resin system to obtain liquid metal microdroplet composite resin.

[0093] Example 8: The preparation method of this embodiment is the same as that of Example 1. The difference is that step (2) is: 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%), 3 parts of dodecyl alcohol polyoxyethylene ether and 10 parts of ethanol are added to the graphene dispersion system. The mixture is stirred at 500 rpm for 15 min and sheared at 20°C and 7000 rpm for 20 min to form liquid metal microdroplets and uniformly disperse them in the resin system to obtain liquid metal microdroplet composite resin.

[0094] Example 9: The preparation method of this embodiment is the same as that of Example 1. The difference is that step (2) is: 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%), 3 parts of γ-aminopropyltriethoxysilane and 10 parts of ethanol are added to the graphene dispersion system. The mixture is stirred at 500 rpm for 15 min and sheared at 20°C and 7000 rpm for 20 min to form liquid metal microdroplets and uniformly disperse them in the resin system to obtain liquid metal microdroplet composite resin.

[0095] Example 10: The preparation method of this embodiment is the same as that of Example 1. The difference is that step (2) is: 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%), 3 parts of stearic acid and 10 parts of ethanol are added to the graphene dispersion system. The mixture is stirred at 500 rpm for 15 min and sheared at 20°C and 7000 rpm for 20 min to form liquid metal microdroplets and disperse them evenly in the resin system to obtain liquid metal microdroplet composite resin.

[0096] Comparative Example 1: This comparative example does not include liquid metal; the specific steps are as follows: (1) Add 5 parts of graphene to 100 parts of vinyl-terminated polydimethylsiloxane. First, use mechanical stirring for pre-dispersion at a speed of 1500 rpm for 20 min. Then, use ultrasonic dispersion at a frequency of 20 kHz, a power of 300 W, and a time of 30 min. The system temperature is controlled at 25 ℃ by using an ice-water bath to obtain a uniform and stable graphene dispersion system.

[0097] (2) Add crosslinking agent: Ten parts of hydrogen-containing silicone oil (linear polymethylhydrosiloxane) and 50 ppm of platinum catalyst were added to the graphene dispersion system. The mixture was stirred at a low speed of 200 rpm for 10 min at room temperature (25°C) to avoid damaging the dispersion structure and obtain a mixed system.

[0098] (3)Degassing: The mixture was placed under vacuum to remove bubbles. The degassing temperature was 25℃, the vacuum degree was -0.095MPa, and the degassing time was 20min.

[0099] (4) Curing: The degassed mixture was cured at 80°C for 2 hours to obtain a flexible resin composite material.

[0100] Test results show that the resistance of the flexible resin composite material prepared in this comparative example changes slowly with temperature, without any obvious abrupt change, and therefore cannot achieve an effective early warning function.

[0101] Comparative Example 2: (1) Introduction of liquid metal: 30 parts of Ga-In-Sn alloy (68.5wt%:21.5wt%:10wt%) were added to 100 parts of vinyl-terminated polydimethylsiloxane, and dispersed using a rotor-stator high-speed shearing device at a shearing speed of 6000 rpm for 20 min to obtain a liquid metal system.

[0102] (2) Add crosslinking agent: Ten parts of hydrogen-containing silicone oil (linear polymethylhydrosiloxane) and 50 ppm of platinum catalyst were added to the liquid metal system. The mixture was stirred at a low speed of 200 rpm for 10 min at room temperature (25°C) to avoid damaging the dispersion structure and obtain a mixed system.

[0103] (3)Degassing: The mixture was placed under vacuum to remove bubbles. The degassing temperature was 25℃, the vacuum degree was -0.095MPa, and the degassing time was 20min.

[0104] (4) Curing: The degassed mixture was cured at 80°C for 2 hours to obtain a flexible resin composite material.

[0105] Test results show that the conductive pathway of the flexible resin composite material prepared in this comparative example is discontinuous, the response is unstable, and it is difficult to form an effective temperature-triggered conduction behavior.

[0106] Test Example 1: The performance of the flexible resin composite material prepared in Example 1 was tested, including scanning electron microscopy (SEM) observation, energy-dispersive X-ray spectroscopy (EDS) analysis of elemental distribution, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis. The results are as follows: Figure 1 As shown.

[0107] according to Figure 1 As can be seen from point a, the introduction of liquid metal did not destroy the basic crystal structure of graphene, but rather altered its interlayer stacking through insertion and adhesion. Simultaneously, a liquid metal alloy phase with a well-defined crystal structure was introduced into the flexible resin composite material. Surface chemical state analysis confirmed the successful introduction of three metal elements, primarily existing in a metallic state, and revealed the interfacial interaction between graphene and liquid metal. These structural and chemical state characteristics provide important evidence for improving the performance of flexible resin composite materials. Figure 1 As can be seen from b in the equation, according to the Bragg equation 2d sinθ = λ, the diffraction angle (θ) corresponding to the characteristic peak decreases, indicating that the interlayer spacing (d) of graphene increases, which helps to improve the flexibility and processability of flexible resin composites. Figure 1 As can be seen from 'c', it further verifies the elemental composition of graphene and liquid metal, confirming the successful introduction of liquid metal.

[0108] Test Example 2: In this test example, three flexible resin composite materials were prepared according to the preparation method of Example 1. The preparation method was the same as in Example 1, except that: the amount of graphene was 0.1 parts and the amount of liquid metal was 3 parts, resulting in a flexible resin composite material (denoted as 0.1% graphene / 3% liquid metal); the amount of graphene was 0.2 parts and the amount of liquid metal was 3 parts, resulting in a flexible resin composite material (denoted as 0.2% graphene / 3% liquid metal); and the amount of graphene was 0.3 parts and the amount of liquid metal was 3 parts, resulting in a flexible resin composite material (denoted as 0.3% graphene / 3% liquid metal).

[0109] The prepared 0.1% graphene / 3% liquid metal, 0.2% graphene / 3% liquid metal, and 0.3% graphene / 3% liquid metal solutions were tested, with vinyl-terminated polydimethylsiloxane (pure sample) used as a control. Thermal conductivity, thermogravimetric analysis (TGA), and derivative TGA were measured. The results are as follows: Figure 2 As shown.

[0110] according to Figure 2 It can be seen that the overall thermal conductivity ( Figure 2 a) and TGA ( Figure 2 Results in (b) and (c) show that the overall thermal conductivity of the flexible resin composite material gradually increases with the increase of graphene content. Meanwhile, compared to the pure sample, the temperatures corresponding to 5wt% thermal weight loss are higher for the 0.2% graphene / 3% liquid metal and 0.3% graphene / 3% liquid metal samples, indicating that the initial decomposition temperature of the flexible resin composite material also increases with the addition of graphene. This confirms that the addition of graphene can improve the thermal conductivity and thermal stability of the flexible resin composite material.

[0111] Test Example 3: Cone calorimetry was performed on the 0.1% graphene / 3% liquid metal, 0.2% graphene / 3% liquid metal, and 0.3% graphene / 3% liquid metal prepared in Test Example 2, using vinyl-terminated polydimethylsiloxane (pure sample) as a control. The mechanism by which graphene and liquid metal regulate the combustion behavior of flexible resin composites was systematically studied. The results are as follows: Figure 3 As shown.

[0112] according to Figure 3 It can be seen that as the graphene content increases, the peak heat release rate (PHRR) of the flexible resin composite material increases. Figure 3 a) and total heat release ( Figure 3 In sample b), the CO release rate was significantly lower than that of the pure sample, with the maximum reduction reaching 66.42% (the ratio between the peak values ​​of the curves in sample a, calculated as: (1 - (the lowest peak value of the flexible resin composite) / the peak value of the pure sample) × 100%, where the lowest peak value of the flexible resin composite is the peak value of the curve with 0.3% graphene / 3% liquid metal) and 21.58% (the ratio between the final values ​​of the curves in sample b, calculated as: (1 - (the lowest value of the flexible resin composite) / the value of the pure sample) × 100%, where the lowest value of the flexible resin composite is the final value of the curve with 0.3% graphene / 3% liquid metal). Compared to the pure sample, the CO release rate of the flexible resin composite after adding graphene and liquid metal ( Figure 3 c) and total tobacco production ( Figure 3 The significant reduction in (d) indicates that the combustion intensity and smoke hazard are effectively suppressed. Its flame-retardant mechanism stems from multi-scale synergistic effects: on the one hand, graphene constructs a highly thermally conductive framework network, promoting heat diffusion and reducing local heat accumulation; on the other hand, liquid metal migrates during combustion and forms a dense insulating layer, blocking heat transfer and the escape of combustible gases; simultaneously, both synergistically promote the formation of a continuous, dense carbon layer, improving the stability of the condensed phase. This "thermal shielding-mass barrier" coupling mechanism transforms the combustion behavior of flexible resin composites from a rapid exothermic type to a confined heat transfer type, thereby achieving systematic regulation of heat release, smoke generation, and combustion path in the organosilicon system, significantly improving the flame-retardant performance and fire safety of flexible resin composites.

[0113] Test Example 4: The performance of the flexible resin composite material prepared in Example 1 was tested, including the relationship between the rate of change of resistance and temperature, the change of resistance over time from 140℃ to room temperature, and the change of resistance over time from -20℃ to room temperature. The results are as follows: Figure 4 As shown.

[0114] according to Figure 4As can be seen from 'a' in this embodiment, the resistance change rate of the flexible resin composite material prepared in this embodiment decreased from 350% at low temperature (-20℃) to about -75% at 80℃, and the overall resistance change rate changed by about 4.25 times. According to the resistance change rate formula K = (ΔR) / R0, where ΔR is the difference between the resistance at 80℃ and the initial resistance R0 at room temperature, the material resistance changed by about 5 times the initial resistance.

[0115] according to Figure 4 As can be seen, the change in resistance with temperature is represented by the resistance-temperature curves of the flexible resin composite material in the range of -20 to 140℃, as shown in the figure. It can be clearly divided into three stages: Stage I (-20 to 60℃, dormant region): At this stage, the flexible resin is in a glassy state, the liquid metal droplets are completely encapsulated by the oxide layer, and conductivity depends on the graphene tunneling effect; Stage II (60 to 80℃, trigger region): The resistance further decreases, the temperature rises causing the flexible resin to soften and enabling the liquid metal to move; microcracks initiate in the oxide layer under thermal stress and interfacial residual stress; Stage III (80 to 140℃, conductive region): The resistance continues to decrease, and the rate of change in resistance approaches 100%.

[0116] Test Example 5: The 0.1% graphene / 3% liquid metal, 0.2% graphene / 3% liquid metal, and 0.3% graphene / 3% liquid metal solutions prepared in Test Example 2 were tested, with vinyl-terminated polydimethylsiloxane (pure sample) used as a control. The dielectric constant was recorded at 100 Hz. The evolution of the micro-polarization mechanism of the system after the introduction of graphene and liquid metal was systematically analyzed, and the results are as follows. Figure 5 As shown.

[0117] according to Figure 5 It can be seen that the dielectric constant of the flexible resin vinyl-terminated polydimethylsiloxane is 0.35, exhibiting typical low polarization characteristics. With the gradual introduction of graphene and liquid metal, the dielectric constant of the flexible resin composite material shows a monotonically increasing trend. The dielectric constant of 0.1% graphene / 3% liquid metal increases to 0.52, which is 48.57% higher than that of the flexible resin. The dielectric constants of 0.2% graphene / 3% liquid metal and 0.3% graphene / 3% liquid metal are 0.65 and 0.70, respectively, which are 85.71% and 100% higher than those of the flexible resin. This significant increase indicates that graphene and liquid metal gradually form more effective polarization units in the resin system, upgrading it from a simple "insulating and protective medium" to a "functional dielectric material", enabling it to actively participate in the electric field regulation and signal optimization inside the encapsulation while carrying out bonding and sealing functions.

[0118] The embodiments of the present invention have been described above; however, these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the above embodiments of the present invention without inventive effort are within the protection scope of the present invention.

Claims

1. A flexible resin composite material, characterized by, The components include the following parts by mass: 100 parts flexible resin, 0.1-20 parts graphene, 3-100 parts liquid metal, 5-20 parts crosslinking agent and 10-100 ppm catalyst; The flexible resin is one or more of polydimethylsiloxane and silicon-modified resin; The liquid metal includes one or more of gallium and gallium-based alloys; The gallium-based alloy includes one or both of Ga-In alloy and Ga-In-Sn alloy.

2. The flexible resin composite of claim 1, wherein, The polydimethylsiloxane includes one or both of addition-type polydimethylsiloxane and condensation-type polydimethylsiloxane; The silicon-modified resin is a silicon-modified polyurethane.

3. The flexible resin composite of claim 2, wherein, The addition-type polydimethylsiloxane is a vinyl-terminated polydimethylsiloxane; The condensed polydimethylsiloxane is a hydroxyl-terminated polydimethylsiloxane; The silicon-modified polyurethane includes one or more of the following: hydroxyl-terminated siloxane-modified polyurethane, isocyanate-terminated siloxane-modified polyurethane, polydimethylsiloxane soft segment modified polyurethane, siloxane-polyether copolymer polyurethane, and silicon-containing block copolymer polyurethane.

4. The flexible resin composite material according to claim 1, characterized in that, The crosslinking agent is a hydrogen-containing silicone oil or methyltriethoxysilane; The Si-H content of the hydrogen-containing silicone oil is 0.1~2.0 wt%.

5. The flexible resin composite material according to claim 1, characterized in that, The catalyst is a platinum-based catalyst or an organotin catalyst; The platinum-based catalyst includes one or more of platinum and platinum complexes, and the platinum complexes include one or two of Karlstein catalysts and chloroplatinic acid catalysts.

6. The flexible resin composite material according to claim 1, characterized in that, The flexible resin composite material also includes a dispersant; The dispersant includes one or more of polyvinylpyrrolidone, surfactants, and siloxane-polyether copolymers.

7. The flexible resin composite material according to claim 1, characterized in that, The flexible resin composite material also includes an interface modifier; The interface modifier includes one or more of silane coupling agents and liquid metal interface regulators; The liquid metal interface modifier includes one or more of stearic acid and thiol compounds.

8. The flexible resin composite material according to claim 7, characterized in that, The mass fraction of the interface modifier shall not exceed 5 parts.

9. A method for preparing a flexible resin composite material, wherein the flexible resin composite material is the flexible resin composite material according to any one of claims 1 to 8, characterized in that, Includes the following steps: (1) A flexible resin, liquid metal and graphene are mixed to obtain a liquid metal microdroplet composite resin; (2) The liquid metal microdroplet composite resin, crosslinking agent and catalyst are mixed and degassed and cured in sequence to obtain the flexible resin composite material.

10. Use of a flexible resin composite material in the field of open flame monitoring or in the field of temperature monitoring, characterized in that The flexible resin composite material is the flexible resin composite material according to any one of claims 1 to 8 or the flexible resin composite material obtained by the preparation method according to claim 9.

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