Preparation method of composite material for military protective clothing

Abstract

The invention discloses a method for preparing a composite material for military protective clothing, and relates to the technical field of clothing fabrics. The invention prepares the composite material for military protective clothing through the preparation of modified bamboo fiber, the preparation of composite fiber, the preparation of glue and the preparation of composite material. The preparation method adopted is simple to operate and has good repeatability, and the prepared composite material has good waterproof moisture permeability and heat insulation, and meets the waterproof, heat insulation and moisture permeability performance requirements of military protective clothing in outdoor environments.

Description

Technical field:

[0001] The invention relates to the technical field of clothing fabrics, and in particular to a method for preparing a composite material for military protective clothing. Background technology:

[0002] Military protective clothing is clothing that helps soldiers effectively resist, prevent and fight against adverse climatic conditions and conventional, nuclear, biological and chemical warfare to the greatest extent possible. Its main performance requirements are as follows: (1) Mechanical and physical properties, able to be exposed to adverse climatic conditions for a long time and withstand severe wear, with high tensile strength and tear strength; (2) Environmental aspects, it is required to be water-repellent, windproof, snow-proof and insect-proof; (3) Physiological aspects, it is required to be light in weight, easy to wear, with low thermal stress, breathable, moisture-permeable, sweat-free and comfortable; (4) Protective performance, it is required to be bulletproof, flame-retardant, resistant to chemical and biological agents, resistant to the long-range thermal effects of nuclear weapons, good camouflage and low noise. In addition to the above requirements, special-purpose military protective clothing should also have the properties of resistance to strong acid, liquid oxygen, liquid nitrogen and liquid ammonia. The present invention develops a new composite material for military protective clothing, which has a variety of good performance properties, especially waterproof, breathable and heat-insulating. Summary of the invention:

[0003] The technical problem to be solved by the present invention is to provide a method for preparing a composite material for military protective clothing. The preparation method is simple to operate and has good repeatability. The prepared composite material has good waterproof moisture permeability and heat insulation.

[0004] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0005] A method for preparing a composite material for military protective clothing comprises the following preparation steps:

[0006] (1) Preparation of modified bamboo fiber: dispersing bamboo fiber in ethanol, adding N-cyclopropyl-2-hydroxy-benzamide and a catalyst, heating to reflux state for heat preservation reaction, standing after the reaction, filtering, washing with ethanol, washing with water, and drying to obtain modified bamboo fiber;

[0007] (2) Preparation of composite fiber fabric: A composite fiber fabric is prepared by blending, twisting and weaving aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber;

[0008] (3) Preparation of glue solution: adding epoxy resin and curing agent to solvent, mixing evenly, to obtain glue solution;

[0009] (4) Preparation of composite materials: The composite fiber fabric prepared above is immersed in the prepared adhesive solution, taken out, dried, and cured to obtain a composite material.

[0010] In the step (1), the mass ratio of bamboo fiber, N-cyclopropyl-2-hydroxy-benzamide and catalyst is (30-50):(5-15):(0.1-5).

[0011] The catalyst in step (1) is an alkaline catalyst.

[0012] In the step (2), the mass ratio of aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber is (5-20):(1-10):(0.5-5):(0.5-5).

[0013] In the step (3), the mass ratio of epoxy resin to curing agent is (80-90):(10-20).

[0014] The solid content of the glue in step (3) is 40-60%.

[0015] In the step (3), the solvent is ethanol or an ethanol aqueous solution.

[0016] In the step (3), the curing agent is dicyandiamide.

[0017] In the step (4), the immersion temperature is 30-50° C. and the immersion time is 10-30 min.

[0018] The drying temperature in step (4) is 80-100°C.

[0019] The invention utilizes the carbonyl group in the lignin molecule contained in the bamboo fiber to undergo aldol condensation reaction with the hydroxyl group in the N-cyclopropyl-2-hydroxy-benzamide molecule to generate an ether bond, introduces cyclopropyl group, ether group and amide group into the bamboo fiber structure, thereby improving the application performance of the bamboo fiber.

[0020] Dicyandiamide is a commonly used epoxy resin curing agent in the art, but it has a high curing temperature. The present invention chemically modifies dicyandiamide for the purpose of reducing the energy consumption input cost of curing.

[0021] The curing agent is modified dicyandiamide.

[0022] The modified dicyandiamide is prepared by reacting dicyandiamide and 1-naphthylethylamine, and the structural formula is:

[0023]

[0024] The modified dicyandiamide prepared by the present invention is a new type of curing agent. Compared with the existing dicyandiamide curing agent, the curing agent can not only significantly reduce the curing temperature, but also optimize the application performance of the final composite material. This technical effect cannot be achieved by the existing dicyandiamide curing agent.

[0025] The beneficial effects of the present invention are as follows: the present invention prepares a composite material for military protective clothing through the preparation of modified bamboo fiber, the preparation of composite fiber, the preparation of glue and the preparation of composite material. The preparation method adopted is simple to operate and has good repeatability, and the prepared composite material has good waterproof moisture permeability and heat insulation, meeting the waterproof, heat insulation and moisture permeability performance requirements of military protective clothing in outdoor environments. Specific implementation method:

[0026] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments.

[0027] In the following examples and comparative examples, the epoxy resin was purchased from Jinan Yisheng Resin Co., Ltd. E-44, with an epoxy equivalent of 210-250 g / eq and a softening point of 12-20°C; the aramid fiber was purchased from DuPont Aramid Kevlar Fiber K29400D (440Dtex); the polypropylene fiber was purchased from the polypropylene monofilament fiber of Changzhou Lierdetong New Material Technology Co., Ltd.; the bamboo fiber was purchased from Shandong Xintaiyuan New Materials Technology Co., Ltd.; and the ramie fiber was purchased from Nanjing Xinhe Textile Co., Ltd.

[0028] Example 1

[0029] Preparation of composite materials:

[0030] (1) Preparation of modified bamboo fiber: 21.8 g of bamboo fiber was dispersed in 200 g of ethanol, and 4.1 g of N-cyclopropyl-2-hydroxy-benzamide and a saturated aqueous solution prepared by 0.6 g of anhydrous potassium carbonate were added, and the mixture was heated to reflux and kept warm for 5 h. After the reaction was completed, the mixture was allowed to stand, filtered, washed with ethanol, washed with water, and dried at 80° C. to obtain modified bamboo fiber;

[0031] (2) Preparation of composite fiber fabric: Aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber in a mass ratio of 10:6:1.5:0.8 were blended to form a blended single yarn with a linear density of 91.4 dtex, and then two blended single yarns were combined and twisted to obtain a blended yarn strand with a twist of 980 twists / m and a linear density of 182.8 dtex. The blended yarn strands were then used as warp and weft yarns with a warp density of 620 strands / 10 cm and a weft density of 350 strands / 10 cm, to obtain a composite fiber fabric;

[0032] (3) Preparation of glue solution: add 85g of epoxy resin and 15g of dicyandiamide curing agent to 70% ethanol solution, mix well, and obtain glue solution with solid content of 52%;

[0033] (4) Preparation of composite materials: The composite fiber fabric prepared above was immersed in the above-mentioned 45°C glue solution for 30 minutes, taken out and dried at 80°C, and cured at 195°C for 5 hours to obtain a composite material.

[0034] Example 2

[0035] The only difference between Example 2 and Example 1 is that the mass ratio of aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber is replaced with 9.5:6:2:0.8.

[0036] Preparation of composite materials:

[0037] (1) Preparation of modified bamboo fiber: 21.8 g of bamboo fiber was dispersed in 200 g of ethanol, and 4.1 g of N-cyclopropyl-2-hydroxy-benzamide and a saturated aqueous solution prepared by 0.6 g of anhydrous potassium carbonate were added, and the mixture was heated to reflux and kept warm for 5 h. After the reaction was completed, the mixture was allowed to stand, filtered, washed with ethanol, washed with water, and dried at 80° C. to obtain modified bamboo fiber;

[0038] (2) Preparation of composite fiber fabric: Aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber in a mass ratio of 9.5:6:2:0.8 are blended to form a blended single yarn with a linear density of 91.4 dtex, and then two blended single yarns are combined and twisted to obtain a blended yarn strand with a twist of 980 twists / m and a linear density of 182.8 dtex. The blended yarn strands are then used as warp and weft yarns with a warp density of 620 strands / 10 cm and a weft density of 350 strands / 10 cm, to obtain a composite fiber fabric;

[0039] (3) Preparation of glue solution: add 85g of epoxy resin and 15g of dicyandiamide curing agent to 70% ethanol solution, mix well, and obtain glue solution with solid content of 52%;

[0040] (4) Preparation of composite materials: The composite fiber fabric prepared above was immersed in the above-mentioned 45°C glue solution for 30 minutes, taken out and dried at 80°C, and cured at 195°C for 5 hours to obtain a composite material.

[0041] Example 3

[0042] The only difference between Example 3 and Example 1 is that the dicyandiamide curing agent is replaced by a modified dicyandiamide curing agent.

[0043] Preparation of modified dicyandiamide curing agent: 17.1g 1-naphthylethylamine, 9.0g dicyandiamide and 200g 70% ethanol solution were mixed, and 38% concentrated hydrochloric acid was added to adjust the pH value to 5-6, heated to boiling and then refluxed for 5h, ethanol was distilled and recovered, and then transferred to a 5℃ environment for cooling and crystallization for 12h, filtered, washed with water, and dried at 80℃ to obtain a modified dicyandiamide curing agent. Elemental analysis: Theoretical value C, 57.63; H, 6.22; Cl, ​​12.15; N, 24.00. Measured value C, 57.64; H, 6.23; Cl, ​​12.12; N, 24.01.

[0044] Preparation of composite materials:

[0045] (1) Preparation of modified bamboo fiber: 21.8 g of bamboo fiber was dispersed in 200 g of ethanol, and 4.1 g of N-cyclopropyl-2-hydroxy-benzamide and a saturated aqueous solution prepared by 0.6 g of anhydrous potassium carbonate were added, and the mixture was heated to reflux and kept warm for 5 h. After the reaction was completed, the mixture was allowed to stand, filtered, washed with ethanol, washed with water, and dried at 80° C. to obtain modified bamboo fiber;

[0046] (2) Preparation of composite fiber fabric: Aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber in a mass ratio of 10:6:1.5:0.8 were blended to form a blended single yarn with a linear density of 91.4 dtex, and then two blended single yarns were combined and twisted to obtain a blended yarn strand with a twist of 980 twists / m and a linear density of 182.8 dtex. The blended yarn strands were then used as warp and weft yarns with a warp density of 620 strands / 10 cm and a weft density of 350 strands / 10 cm, to obtain a composite fiber fabric;

[0047] (3) Preparation of glue solution: add 85g of epoxy resin and 15g of dicyandiamide curing agent to 70% ethanol solution, mix well, and obtain glue solution with solid content of 52%;

[0048] (4) Preparation of composite materials: The composite fiber fabric prepared above was immersed in the above-mentioned 45°C glue solution for 30 minutes, taken out and dried at 80°C, and cured at 135°C for 5 hours to obtain a composite material.

[0049] Comparative Example

[0050] The difference between the comparative example and Example 1 is that the bamboo fiber is not subjected to modification treatment.

[0051] Preparation of composite materials:

[0052] (1) Preparation of composite fiber fabric: Aramid fiber, polypropylene fiber, bamboo fiber and ramie fiber in a mass ratio of 10:6:1.5:0.8 are blended to form a blended single yarn with a linear density of 91.4 dtex, and then two blended single yarns are combined and twisted to obtain a blended yarn strand with 980 twists / m and a linear density of 182.8 dtex, and then the blended yarn strand is used as warp and weft yarns, with a warp density of 620 strands / 10 cm and a weft density of 350 strands / 10 cm, to obtain a composite fiber fabric;

[0053] (2) Preparation of glue solution: add 85g of epoxy resin and 15g of dicyandiamide curing agent to 70% ethanol solution, mix well, and obtain glue solution with solid content of 52%;

[0054] (3) Preparation of composite materials: The composite fiber fabric prepared above was immersed in the above-mentioned 45°C glue solution for 30 minutes, taken out and dried at 80°C, and cured at 195°C for 5 hours to obtain a composite material.

[0055] The modified bamboo fiber prepared in Example 1 was subjected to infrared analysis, and the 1680 cm -1 The absorption of amide groups at the riboflavin region indicated that N-cyclopropyl-2-hydroxy-benzamide was successfully grafted onto the bamboo fiber.

[0056] The performance of the composite materials prepared in Examples 1-3 and the comparative example was measured, and the results are shown in Table 1.

[0057] The hydrostatic pressure is measured in accordance with standard FZ / T 01004-2008 "Determination of water permeability resistance of coated fabrics". The larger the value of the hydrostatic pressure, the better the water permeability resistance.

[0058] The moisture permeability is measured in accordance with the standard GB / T 12704.1-2009 "Test method for moisture permeability of textile fabrics Part 1: Moisture absorption method". The larger the moisture permeability value, the better the moisture permeability.

[0059] The Crowe value is measured in accordance with the standard GB / T 11048-2018 "Determination of thermal resistance and moisture resistance of textiles under steady-state conditions of physiological comfort". The larger the Crowe value, the better the warmth retention.

[0060] Table 1

[0061] project Example 1 Example 2 Example 3 Comparative Example Hydrostatic pressure kPa 54.1 54.5 55.2 52.5 <![CDATA[Water vapor transmission rate g / m 2 .d]]> 5832 6014 6357 4296 CLO 5.45 5.53 5.74 5.02

[0062] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a composite material for military protective clothing, characterized in that: The method comprises the following preparation steps: (1) Preparation of modified bamboo fiber: dispersing bamboo fiber in ethanol, adding N-cyclopropyl-2-hydroxy-benzamide and a catalyst, heating to reflux state for heat preservation reaction, standing after the reaction, filtering, washing with ethanol, washing with water, and drying to obtain modified bamboo fiber; (2) Preparation of composite fiber fabric: A composite fiber fabric is prepared by blending, twisting and weaving aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber; (3) Preparation of glue solution: adding epoxy resin and curing agent to solvent, mixing evenly, to obtain glue solution; (4) Preparation of composite materials: dipping the composite fiber fabric prepared above into the glue solution prepared above, taking it out, drying it, and curing it to obtain a composite material; In the step (1), the mass ratio of bamboo fiber, N-cyclopropyl-2-hydroxy-benzamide and catalyst is (30-50):(5-15):(0.1-5); The catalyst in step (1) is a basic catalyst; In the step (3), the curing agent is modified dicyandiamide; The modified dicyandiamide is prepared by reacting dicyandiamide and 1-naphthylethylamine, and the structural formula is:

2. The method for preparing a composite material for military protective clothing according to claim 1, characterized in that: In the step (2), the mass ratio of aramid fiber, polypropylene fiber, modified bamboo fiber and ramie fiber is (5-20):(1-10):(0.5-5):(0.5-5).

3. The method for preparing a composite material for military protective clothing according to claim 1, characterized in that: In the step (3), the mass ratio of epoxy resin to curing agent is (80-90):(10-20).

4. The method for preparing a composite material for military protective clothing according to claim 1, characterized in that: The solid content of the glue in step (3) is 40-60%.

5. The method for preparing a composite material for military protective clothing according to claim 1, characterized in that: In the step (3), the solvent is ethanol or an ethanol aqueous solution.

6. The method for preparing a composite material for military protective clothing according to claim 1, characterized in that: In the step (4), the immersion temperature is 30-50° C. and the immersion time is 10-30 min.

7. The method for preparing a composite material for military protective clothing according to claim 1, characterized in that: The drying temperature in step (4) is 80-100°C.

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