Composite material for fire hose and preparation method thereof

Abstract

The present application relates to the technical field of composite material preparation, and specifically to a composite material for fire hoses and a preparation method thereof. The preparation method of the composite material for fire hoses is as follows: Step A, adding a matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder, melt-blending and granulating to obtain intermediate 1; Step B, adding intermediate 1, vulcanizing agent and vulcanization accelerator into an internal mixer, pre-vulcanizing and transferring to a flat vulcanizing machine for pressure vulcanization to obtain a composite material for fire hoses. The composite material for fire hoses has good flame retardant properties, stable mechanical properties, excellent tensile strength, elongation at break, aging resistance and wear resistance, and can still maintain good toughness in low temperature environments. This excellent comprehensive performance enables the fire hose composite material to work stably under various extreme conditions, thereby improving the overall performance and service life of the fire hose.

Description

Technical Field

[0001] The present application relates to the technical field of composite material preparation, and more specifically, to a composite material for fire hoses and a preparation method thereof. Background Art

[0002] As a core component of firefighting systems, fire hoses are flexible piping systems used to transport high-pressure water, foam fire extinguishing agents, or other liquid firefighting media. Their core function lies in their high-pressure, corrosion-resistant design, enabling them to quickly and reliably deliver liquid fire extinguishing agents to the fire scene, ensuring efficient and safe firefighting operations. This equipment is widely used in industrial firefighting, municipal rescue operations, and specialized firefighting operations, where its performance directly impacts the success rate of firefighting operations.

[0003] However, there are some problems with existing fire hose materials. For example, rubber hoses have good flexibility, but poor corrosion resistance and high temperature resistance. They are prone to aging after long-term use and are difficult to adapt to complex scenes such as chemical and high temperature environments. Polyvinyl chloride hoses have low costs, but poor pressure resistance, are prone to explosion, and are brittle at low temperatures, and cannot meet the needs of high-pressure or severe cold environments. Polyurethane hoses have advantages such as light weight and wear resistance, but their high cost limits their popularization and application. Although single fluororubber is resistant to high temperatures, it lacks flexibility, is easily brittle at low temperatures, and has poor adhesion to the reinforcement layer. Single polyvinylidene fluoride material has high hardness, so its resistance to bending fatigue is poor, making it difficult to meet dynamic use requirements. In response to the above defects, this application proposes a composite material for fire hoses that is resistant to high temperatures, resistant to acid and alkali corrosion, highly flexible, and resistant to high pressure, suitable for scenes such as high-pressure fire hoses and industrial hoses. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background technology, the present application provides a composite material for fire hose and a preparation method thereof.

[0005] In the first aspect, the present application provides a composite material for fire hoses, which adopts the following technical solution:

[0006] A composite material for a fire hose comprises the following raw materials in parts by weight: 40-60 parts of a base resin, 2-4 parts of a toughening agent, 5-8 parts of a reinforcing filler, 4-6 parts of a vulcanizing agent, 1-3 parts of a vulcanization accelerator and 1-3 parts of a functional additive.

[0007] Preferably, the matrix resin is composed of polyvinylidene fluoride, modified fluororubber and polyamide in a mass ratio of 10-15:5-8:1-3.

[0008] Preferably, the polyamide is an aliphatic polyamide.

[0009] Preferably, the aliphatic polyamide is PA11 and / or PA12.

[0010] Preferably, the preparation method of the modified fluororubber comprises the following preparation steps:

[0011] Step 1: Thin-pass the fluororubber raw rubber on an open mill at a temperature of 50-70°C for 3-5 times with a roller gap of 0.5-1mm, add 1-3% by mass of a silane coupling agent, and mix for 10-15 minutes to obtain a pretreated rubber compound;

[0012] Step 2: Add the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and initiator into an internal mixer, and react for 1-2 hours at 160-180° C. under nitrogen protection to obtain the grafted fluororubber;

[0013] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt-blend, and extrude into granules to obtain modified fluororubber.

[0014] Preferably, in step 2, the mass ratio of the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and initiator is 100-120:12-15:5-8:1-2.

[0015] Preferably, the mass of the thermoplastic polyurethane in step 3 is 45-55% of the mass of the grafted fluororubber.

[0016] Preferably, the melt blending temperature is 180-200° C., the screw speed is 200-400 rpm, and the mixing time is 1-2 h.

[0017] Preferably, the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder and perfluoropolyether in a mass ratio of 12-18:4-7:3-5.

[0018] Preferably, the reinforcing filler is one or more of chopped carbon fiber, aramid fiber and nano-silica.

[0019] Preferably, the vulcanizing agent is bisphenol AF; and the vulcanization accelerator is benzyltriphenylphosphonium chloride.

[0020] Preferably, the functional additive is one or more of a flame retardant, an anti-aging agent, an antistatic agent and a lubricant.

[0021] In a second aspect, the present application also provides a method for preparing a composite material for a fire hose, comprising the following steps:

[0022] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0023] After melt blending, granulation is performed to obtain intermediate 1;

[0024] Step B: Add the intermediate 1, the vulcanizing agent and the vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150-180° C. for 10-30 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180-200° C. to obtain a composite material for fire hose.

[0025] Preferably, the working conditions of the twin-screw extruder in step A are: feeding zone temperature of 150-180°C, melting zone temperature of 170-200°C, extrusion zone temperature of 185-210°C, screw speed of 200-400 rpm, and mixing time of 1-2 h.

[0026] Preferably, the pressure of the pressurized vulcanization in step B is 15-20 MPa, and the vulcanization time is 30-45 min.

[0027] In summary, this application has the following beneficial effects:

[0028] This application utilizes a matrix resin compounded by polyvinylidene fluoride, modified fluororubber and aliphatic polyamide as the main material of a composite material for fire hoses. After the three are compounded, the high temperature resistance, corrosion resistance and mechanical properties of the composite material are significantly improved. Polyvinylidene fluoride not only gives the material high rigidity and tensile strength, but also improves the material's high temperature resistance, acid and alkali resistance and oil resistance, and can resist corrosive media in firefighting scenes, such as fire extinguishing agents. By modifying the fluororubber, introducing flexible segments and grafting modifications, the elasticity and impact resistance of the material are enhanced. The selected aliphatic polyamide has excellent wear resistance and low-temperature toughness, which can compensate for the brittleness of polyvinylidene fluoride at low temperatures. After the three are compounded, through the synergistic effect of the rigid structure of polyvinylidene fluoride, the elasticity and processability optimization of fluororubber, and the low-temperature toughness and wear resistance of aliphatic polyamide, combined with vulcanization cross-linking and carbon fiber reinforcement, the fire hose composite material has high strength, flexibility, weather resistance and functional properties, meeting the stringent requirements of the fire protection field for the comprehensive performance of materials.

[0029] In the modification process of fluororubber, the present application first pre-treats the fluororubber with a silane coupling agent, and through thin-pass treatment, reduces the molecular weight and cohesion of the fluororubber, improves processing fluidity, and introduces functional groups through graft copolymerization modification. After glycidyl methacrylate is grafted, an epoxy group is introduced, and vinyl dimethyl phosphate introduces a phosphate group, giving the fluororubber polarity, which significantly improves its compatibility with polyvinylidene fluoride and polyamide. The initiator triggers a free radical reaction to promote chemical cross-linking between the fluororubber molecular chains. At the same time, the grafted monomer acts as a bridge to form a three-dimensional network structure, thereby improving the strength and high temperature resistance of the material. The grafted fluororubber is blended with thermoplastic polyurethane to enhance the high elasticity and low-temperature toughness of the composite material. The fluororubber provides strength as a continuous phase, and the thermoplastic polyurethane absorbs impact energy as a dispersed phase, significantly improving the elongation at break and impact resistance. Fluororubber has been transformed from a single material with high hardness, difficult processing and poor compatibility to a modified material that is strong, tough, easy to process and highly compatible with polar resins. This allows it to be used in fire hoses to not only give full play to the high temperature and chemical resistance advantages of fluororubber, but also make up for its brittleness defects.

[0030] This application prepares a toughening agent by compounding styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene (PTFE) powder, and perfluoropolyether (PFPE). STE is a thermoplastic elastomer with a two-phase structure consisting of a rubber phase (ethylene-butylene segments) and a plastic phase (styrene segments). It forms a dispersed phase in the matrix resin, significantly improving the composite's elongation at break and impact strength while maintaining a certain degree of rigidity. PTFE powder, with its small particle size and high hardness, acts as a rigid particle toughening agent by inducing microcracks and plastic deformation in the matrix, dissipating impact energy while improving the material's wear resistance and surface smoothness and reducing internal friction. Perfluoropolyether, with its extremely low surface tension and excellent lubricity, improves interfacial compatibility and promotes uniform dispersion of the two phases. It also reduces the melt viscosity of PVDF during processing, improving fluidity and avoiding processing difficulties. This significantly improves the flexibility, wear resistance, chemical resistance, and processing properties of fire hose composites without significantly reducing material strength. DETAILED DESCRIPTION

[0031] The present application is further described in detail below with reference to the embodiments.

[0032] The polyvinylidene fluoride (brand: FR921-1) used in the examples and comparative examples of the present application was purchased from Shanghai Suzhimei Polymer Materials Co., Ltd.; fluororubber (brand: FKM88) was purchased from AFD (Anhui) New Materials Co., Ltd.; PA11 (brand: BZMO 30) was purchased from Shabit Plastic Trading (Suzhou) Co., Ltd.; styrene-ethylene-butylene-styrene copolymer (brand: G1650M) was purchased from Dongguan Shengli New Materials Co., Ltd.; polytetrafluoroethylene powder (brand: M111) was purchased from Dongguan Zhongming Plastic Co., Ltd.; perfluoropolyether (model: HT-200) was purchased from Shanghai Ruiyi Environmental Protection Technology Co., Ltd.; short carbon fiber (8-10μm) was purchased from Changzhou Yaobang Friction Material Factory; bisphenol AF was purchased from Hubei Xinghengye Technology Co., Ltd.; benzyltriphenylphosphonium chloride was purchased from Hubei Xinghengye Technology Co., Ltd.; glycidyl methacrylate was purchased from Jinan Kaichuang Chemical Co., Ltd.; vinyl dimethyl phosphate was purchased from Hubei Keji Biomedicine Technology Co., Ltd.; thermoplastic polyurethane (brand: B90A11) was purchased from Dongguan Zhangmutou Lanqiao Plastic Raw Materials Management Department.

[0033] Examples 1-3 provide a composite material for a fire hose and a preparation method thereof.

[0034] Example 1

[0035] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a base resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the base resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 12:4:3; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0036] The preparation method of the modified fluororubber comprises the following steps:

[0037] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0038] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 100:12:5:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0039] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 45% of the mass of the grafted fluororubber.

[0040] A method for preparing a composite material for a fire hose comprises the following steps:

[0041] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0042] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0043] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0044] Example 2

[0045] A composite material for a fire hose comprises the following raw materials in parts by weight: 50 parts of a matrix resin, 3 parts of a toughening agent, 7 parts of a reinforcing filler, 5 parts of a vulcanizing agent, 2 parts of a vulcanization accelerator, and 2 parts of a functional additive, wherein the matrix resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 12:6:2, the polyamide is PA11, the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 15:6:4, the reinforcing filler is chopped carbon fiber, the vulcanizing agent is bisphenol AF, the vulcanization accelerator is benzyltriphenylphosphine chloride, and the functional additive is magnesium hydroxide.

[0046] The preparation method of the modified fluororubber comprises the following steps:

[0047] Step 1: The fluororubber raw rubber was thin-passed on an open mill at a temperature of 60° C., with a thin-pass roller gap of 0.8 mm, and 2% by mass of a silane coupling agent KH-550 was added, and the mixing was carried out for 12 minutes at a mixing speed of 400 rpm to obtain a pretreated rubber compound;

[0048] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 110:13:7:1.5 into an internal mixer, and reacting for 1.5 hours at a temperature of 170° C. and a stirring speed of 400 rpm under nitrogen protection to obtain a grafted fluororubber;

[0049] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 190°C, the screw speed is 300 rpm, the mixing time is 1.5 hours, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 50% of the mass of the grafted fluororubber.

[0050] A method for preparing a composite material for a fire hose comprises the following steps:

[0051] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0052] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 165°C, the temperature of the melting zone was 185°C, the temperature of the extrusion zone was 195°C, the screw speed was 300 rpm, and the mixing time was 1.5 h to obtain intermediate 1.

[0053] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 165° C. for 20 minutes, transfer to a flat vulcanizer, and pressurize and vulcanize at a temperature of 190° C. and a pressure of 18 MPa for 40 minutes to obtain a composite material for fire hoses.

[0054] Example 3

[0055] A composite material for a fire hose comprises the following raw materials in parts by weight: 60 parts of a matrix resin, 4 parts of a toughening agent, 8 parts of a reinforcing filler, 6 parts of a vulcanizing agent, 3 parts of a vulcanization accelerator, and 3 parts of a functional additive, wherein the matrix resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 15:8:3, the polyamide is PA11, the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 18:7:5, the reinforcing filler is chopped carbon fiber, the vulcanizing agent is bisphenol AF, the vulcanization accelerator is benzyltriphenylphosphine chloride, and the functional additive is magnesium hydroxide.

[0056] The preparation method of the modified fluororubber comprises the following steps:

[0057] Step 1: The fluororubber raw rubber was thin-passed 5 times on an open mill at a temperature of 70° C., with a thin-pass roller gap of 1 mm, and 3% by mass of a silane coupling agent KH-550 was added, and the mixture was mixed for 15 minutes at a mixing speed of 500 rpm to obtain a pretreated rubber compound;

[0058] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 120:15:8:2 into an internal mixer, and reacting for 2 hours at a temperature of 180° C. and a stirring speed of 500 rpm under nitrogen protection to obtain a grafted fluororubber;

[0059] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 200°C, the screw speed is 400 rpm, the mixing time is 2 hours, and granulate them into modified fluororubber, wherein the mass of the thermoplastic polyurethane is 55% of the mass of the grafted fluororubber.

[0060] A method for preparing a composite material for a fire hose comprises the following steps:

[0061] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0062] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 180°C, the temperature of the melting zone was 200°C, the temperature of the extrusion zone was 210°C, the screw speed was 400 rpm, and the mixing time was 2 h to obtain intermediate 1.

[0063] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 180° C. for 30 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 200° C. and a pressure of 20 MPa for 30-45 minutes to obtain a composite material for fire hoses.

[0064] Comparative Example 1

[0065] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a base resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the base resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 12:4:3; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0066] The preparation method of the modified fluororubber comprises the following steps:

[0067] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0068] Step 2: adding the pretreated rubber, vinyl dimethyl phosphate and dicumyl peroxide in a mass ratio of 100:17:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0069] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 45% of the mass of the grafted fluororubber.

[0070] A method for preparing a composite material for a fire hose comprises the following steps:

[0071] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0072] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0073] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0074] Comparative Example 2

[0075] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a base resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the base resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 12:4:3; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0076] The preparation method of the modified fluororubber comprises the following steps:

[0077] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0078] Step 2: adding the pretreated rubber, glycidyl methacrylate and dicumyl peroxide in a mass ratio of 100:17:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0079] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 45% of the mass of the grafted fluororubber.

[0080] A method for preparing a composite material for a fire hose comprises the following steps:

[0081] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0082] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0083] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0084] Comparative Example 3

[0085] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a base resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the base resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 12:4:3; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0086] The preparation method of the modified fluororubber comprises the following steps:

[0087] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0088] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 100:12:5:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0089] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 40% of the mass of the grafted fluororubber.

[0090] A method for preparing a composite material for a fire hose comprises the following steps:

[0091] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0092] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0093] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0094] Comparative Example 4

[0095] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a base resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the base resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder, and perfluoropolyether in a mass ratio of 12:4:3; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0096] The preparation method of the modified fluororubber comprises the following steps:

[0097] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0098] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 100:12:5:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0099] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 60% of the mass of the grafted fluororubber.

[0100] A method for preparing a composite material for a fire hose comprises the following steps:

[0101] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0102] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0103] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0104] Comparative Example 5

[0105] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a matrix resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the matrix resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of a styrene-ethylene-butylene-styrene copolymer and perfluoropolyether in a mass ratio of 4:1; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0106] The preparation method of the modified fluororubber comprises the following steps:

[0107] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0108] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 100:12:5:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0109] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 45% of the mass of the grafted fluororubber.

[0110] A method for preparing a composite material for a fire hose comprises the following steps:

[0111] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0112] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0113] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0114] Comparative Example 6

[0115] A composite material for a fire hose comprises the following raw materials in parts by weight: 40 parts of a matrix resin, 2 parts of a toughening agent, 5 parts of a reinforcing filler, 4 parts of a vulcanizing agent, 1 part of a vulcanization accelerator, and 1 part of a functional additive, wherein the matrix resin is composed of polyvinylidene fluoride, modified fluororubber, and polyamide in a mass ratio of 10:5:1, and the polyamide is PA11; the toughening agent is composed of a styrene-ethylene-butylene-styrene copolymer and polytetrafluoroethylene powder in a mass ratio of 3:1; the reinforcing filler is chopped carbon fiber; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphine chloride; and the functional additive is magnesium hydroxide.

[0116] The preparation method of the modified fluororubber comprises the following steps:

[0117] Step 1: The fluororubber raw rubber was thin-passed three times on an open mill at a temperature of 50° C., with a roller gap of 0.5 mm, and 1% by mass of a silane coupling agent KH was added. The mixture was mixed for 10 minutes at a mixing speed of 200 rpm to obtain a pretreated rubber compound;

[0118] Step 2: adding the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and dicumyl peroxide in a mass ratio of 100:12:5:1 into an internal mixer, and reacting the mixture under nitrogen protection at a temperature of 160° C. and a stirring speed of 300 rpm for 1 hour to obtain a grafted fluororubber;

[0119] Step 3: Add the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt blend them, the melt blending temperature is 180°C, the screw speed is 200 rpm, the mixing time is 1 hour, and granulate them to obtain modified fluororubber, wherein the mass of the thermoplastic polyurethane is 45% of the mass of the grafted fluororubber.

[0120] A method for preparing a composite material for a fire hose comprises the following steps:

[0121] Step A: Add the matrix resin, reinforcing filler, toughening agent and functional additive into a twin-screw extruder.

[0122] After melt blending, pelletizing was performed. The temperature of the twin-screw extruder's feed zone was controlled at 150°C, the temperature of the melting zone was 170°C, the temperature of the extrusion zone was 185°C, the screw speed was 200 rpm, and the mixing time was 1 h to obtain intermediate 1.

[0123] Step B: Add intermediate 1, a vulcanizing agent, and a vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150° C. for 10 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180° C. and a pressure of 15 MPa for 30 minutes to obtain a composite material for fire hoses.

[0124] Performance Testing

[0125] The performance tests of the composite materials for fire hoses prepared in Examples 1-3 and Comparative Examples 1-6 were conducted as follows:

[0126] Hardness: Tested in accordance with the national standard GB / T 531.1-2008 "Rubber, vulcanized or thermoplastic - Test method for indentation hardness - Part 1: Shore hardness method";

[0127] Tensile strength: Tested in accordance with the national standard GB / T 528-2009 "Vulcanized rubber or thermoplastic rubber - Determination of tensile stress-strain properties", Type 1;

[0128] Abrasion resistance test: The test was conducted in accordance with the national standard GB / T 40797-2021 "Rubber, vulcanized or thermoplastic — Determination of wear resistance — Vertically driven abrasive disc method". The test was conducted using an RCC-1 testing machine with a speed of 850 rpm, a striking frequency of 2.5 Hz, and a test interval of 30 minutes.

[0129] Aging resistance test: Refer to the national standard GB / T 3512-2014 "Vulcanized rubber or thermoplastic rubber hot air accelerated aging and heat resistance test" to test the elongation at break of the aged sample. The aging condition is 120℃, 72h;

[0130] Low temperature brittleness: Tested in accordance with the national standard GB / T 1682-2014 "Determination of low temperature brittleness of vulcanized rubber - Single specimen method";

[0131] Limiting oxygen index test: Tested in accordance with the national standard GB / T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method Part 2: Room temperature test";

[0132] The test results are shown in Table 1.

[0133] Table 1 Performance parameters of composite materials for fire hoses prepared in Examples 1-3 and Comparative Examples 1-6

[0134] As can be seen from Table 1, the composite material for fire hose prepared in the present application has good flame retardant properties, stable mechanical properties, excellent tensile strength and elongation at break. In addition, it also exhibits excellent aging resistance and wear resistance, and can still maintain good toughness in low temperature environments. This excellent comprehensive performance enables the fire hose composite material to work stably under various extreme conditions, thereby improving the overall performance and service life of the fire hose.

[0135] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A composite material for fire hose, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of base resin, 2-4 parts of toughening agent, 5-8 parts of reinforcing filler, 4-6 parts of vulcanizing agent, 1-3 parts of vulcanization accelerator and 1-3 parts of functional additive; The matrix resin is composed of polyvinylidene fluoride, modified fluororubber and polyamide in a mass ratio of 10-15:5-8:1-3; the polyamide is an aliphatic polyamide; the aliphatic polyamide is PA11 and / or PA12; The preparation method of the modified fluororubber comprises the following preparation steps: Step 1: Thin-pass the fluororubber raw rubber on an open mill at a temperature of 50-70°C for 3-5 times with a roller gap of 0.5-1mm, add 1-3% by mass of a silane coupling agent, and mix for 10-15 minutes to obtain a pretreated rubber compound; Step 2: Add the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and initiator into an internal mixer, and react for 1-2 hours at 160-180° C. under nitrogen protection to obtain the grafted fluororubber; Step 3: adding the grafted fluororubber and thermoplastic polyurethane into a twin-screw extruder, melt-blending, and extruding into granules to obtain modified fluororubber; In step 2, the mass ratio of the pretreated rubber, glycidyl methacrylate, dimethyl vinyl phosphate and initiator is 100-120:12-15:5-8:1-2; The mass of the thermoplastic polyurethane in step 3 is 45-55% of the mass of the grafted fluororubber; the melt blending temperature is 180-200°C, the screw speed is 200-400 rpm, and the mixing time is 1-2 hours; The toughening agent is composed of styrene-ethylene-butylene-styrene copolymer, polytetrafluoroethylene powder and perfluoropolyether in a mass ratio of 12-18:4-7:3-5; the reinforcing filler is one or more of chopped carbon fiber, aramid fiber and nano-silica; the vulcanizing agent is bisphenol AF; the vulcanization accelerator is benzyltriphenylphosphonium chloride; and the functional additive is one or more of a flame retardant, an anti-aging agent, an antistatic agent and a lubricant.

2. A method for preparing the composite material for fire hose according to claim 1, characterized in that: The method comprises the following preparation steps: Step A: adding a base resin, a reinforcing filler, a toughening agent and a functional additive into a twin-screw extruder, melt-blending and then granulating to obtain an intermediate 1; Step B: Add the intermediate 1, the vulcanizing agent and the vulcanization accelerator into an internal mixer, pre-vulcanize at a temperature of 150-180° C. for 10-30 minutes, transfer to a flat vulcanizer, and vulcanize under pressure at a temperature of 180-200° C. to obtain a composite material for fire hose.

3. The method for preparing a composite material for fire hose according to claim 2, characterized in that: The working conditions of the twin-screw extruder in step A are: feeding zone temperature of 150-180°C, melting zone temperature of 170-200°C, extrusion zone temperature of 185-210°C, screw speed of 200-400 rpm, and mixing time of 1-2 h.

4. The method for preparing a composite material for fire hose according to claim 2, characterized in that: In the step B, the pressure of the pressurized vulcanization is 15-20 MPa, and the vulcanization time is 30-45 minutes.

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