High-strength flexible sling and preparation process thereof

Abstract

The invention discloses a high-strength flexible sling and a preparation process thereof, and relates to the technical field of slings. The calcium powder and the talcum powder are added into the sling, so that the strength of the sling is improved. Graphene has excellent flame retardance and strength, and the graphene is added, so that the strength and flame retardance of the sling are improved. And 3-aminopropyltrimethoxysilane is used for carrying out intercalation treatment on the graphene oxide, so that the flame retardance of the sling is enhanced. According to the invention, the flame-retardant graphene-nickel silicate compound is firstly prepared, and then the iron oxide is loaded on the flame-retardant graphene-nickel silicate compound, so that the flame retardance of the sling is further enhanced. Maleic anhydride grafted polyethylene is used for replacing polyethylene, then amination modification is carried out on a graphene-nickel silicate compound, acid anhydride reacts with amino, the compatibility between the maleic anhydride grafted polyethylene and the aminated graphene-nickel silicate compound is improved, and the dispersity of the filler is improved; therefore, the flame retardance and the strength of the sling are enhanced.

Description

Technical Field

[0001] The present invention relates to the technical field of slings, in particular to a high-strength flexible sling and a preparation process thereof. Background Art

[0002] Flexible slings are tools used in lifting operations. Their lightweight, flexible, and wear-resistant properties make them widely used in precision machinery, chemical engineering, metallurgy, aerospace, shipbuilding, and port lifting. Compared to traditional wire ropes, flexible slings offer greater tensile strength, flexibility, and minimal damage to the cargo being hoisted.

[0003] However, flexible slings manufactured using existing processes still have several drawbacks. They lack strength and are prone to damage and breakage after prolonged use. They also lack flame retardancy, posing a significant safety hazard. Therefore, developing a flexible sling with higher strength and flame retardancy is crucial to meet the demands of modern lifting operations.

[0004] In order to solve the above problems and improve the strength and flame retardancy of the flexible sling, the present invention provides a high-strength flexible sling and a preparation process thereof. Summary of the Invention

[0005] The object of the present invention is to provide a high-strength flexible sling and a preparation process thereof, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A preparation process of a high-strength flexible sling comprises the following steps:

[0008] Step 1: Take glycine and deionized water, ultrasonically disperse for 20-40 minutes, add the flame-retardant graphene-nickel silicate complex, stir for 22-26 hours, and then ultrasonically disperse for another 10-12 hours, centrifuge, filter, and dry to obtain the amino-modified graphene-nickel silicate complex;

[0009] Step 2: Take polypropylene, polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer, mix them evenly, melt-extrude, cool, stretch, roll, and weave to obtain a sling.

[0010] More optimally, the sling includes the following ingredients, calculated in parts by weight: 105-110 parts of polypropylene, 40-47 parts of polyethylene, 42-46 parts of calcium powder, 8-12 parts of amino graphene-nickel silicate complex, 6-8 parts of calcium carbonate, 4-6 parts of talc, 3-5 parts of paraffin, 2-4 parts of stearic acid, 0.2-0.5 parts of antioxidant, 1-1.5 parts of polyethylene wax, and 2-4 parts of ethylene-methyl acrylate copolymer.

[0011] More optimally, the preparation method of the flame retardant graphene-nickel silicate composite is as follows: take ferric nitrate nonahydrate and deionized water, stir evenly, add the graphene-nickel silicate composite, stir for 2-3 hours, add ammonia monohydrate, stir for 4-5 hours, and dry to obtain the flame retardant graphene-nickel silicate composite.

[0012] More optimally, the preparation method of the graphene-nickel silicate composite comprises the following steps:

[0013] S1: Take modified graphene and n-butyl lithium, stir evenly, heat to 85-90°C, react for 4-5 hours, cool, filter, wash, dry, add deionized water, ultrasonically disperse, add hexadecyltrimethylammonium bromide, stir for 2-4 hours, add ammonia water, stir for 30-40 minutes, then add dropwise an ethanol solution containing tetraethyl orthosilicate, stir for 10-14 hours, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0014] S2: Take a graphene-silicon dioxide composite, nickel nitrate hexahydrate, and urea, add dilute nitric acid, stir evenly, heat to 85-90° C., stir for 7-9 hours, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite.

[0015] More optimally, the preparation method of the modified graphene is: take graphene oxide and anhydrous methanol, mix them evenly under nitrogen protection, ultrasonically oscillate for 2-3 hours, add 3-aminopropyltrimethoxysilane, ultrasonically treat for 1-2 hours, heat to 70-71°C, reflux for 22-24 hours, cool to 25-30°C, centrifuge, wash, and vacuum dry to obtain modified graphene.

[0016] More optimally, the antioxidant is antioxidant 1010.

[0017] More optimally, the polyethylene is maleic anhydride grafted polyethylene.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention adds calcium powder and talcum powder to the sling to improve its strength. Graphene has excellent flame retardancy and strength. The addition of graphene in the present invention improves the strength and flame retardancy of the sling.

[0020] 2. The present invention uses 3-aminopropyltrimethoxysilane to intercalate graphene oxide, thereby increasing the interlayer spacing of graphene oxide, thereby increasing the specific surface area of graphene oxide, so that it has more active sites that can be compounded with nickel silicate complex, thereby enhancing the flame retardancy of the sling.

[0021] 3. The present invention first prepares a flame-retardant graphene-nickel silicate composite and then loads iron oxide thereon, thereby further enhancing the flame retardancy of the sling.

[0022] 4. The present invention uses maleic anhydride grafted polyethylene instead of polyethylene, and then performs amino modification on the graphene-nickel silicate composite. The anhydride reacts with the amino group, thereby improving the compatibility between the maleic anhydride grafted polyethylene and the amino-modified graphene-nickel silicate composite and improving the filler dispersion, thereby enhancing the flame retardancy and strength of the sling. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] The sources and models of the substances involved in the present invention are not particularly limited, and illustratively include: polypropylene: model: HH1070LRGL0B, which can be purchased from INEOS of the United States; ethylene-methyl acrylate copolymer: model: 20MA08, which can be purchased from Arkema of France; maleic anhydride grafted polyethylene: model: ZJ-800E, which can be purchased from Wuhan Huaxiang Kejie Biotechnology Co., Ltd.; graphene oxide: particle size: 0.5-3 μm, which can be purchased from Beijing Zhongke Leiming Technology Co., Ltd.

[0025] Example 1: A process for preparing a high-strength flexible sling, comprising the following steps:

[0026] Step 1: Preparation of high-strength flexible slings:

[0027] Polypropylene, maleic anhydride grafted polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer were mixed uniformly, melt-extruded, cooled, stretched, rolled, and braided to obtain a sling with a width of 80 mm and a length of 600 mm;

[0028] The sling comprises the following ingredients, calculated by weight: 108 parts of polypropylene, 45 parts of maleic anhydride grafted polyethylene, 44 parts of calcium powder, 10 parts of amino graphene-nickel silicate composite, 7 parts of calcium carbonate, 5 parts of talc, 4 parts of paraffin wax, 3 parts of stearic acid, 0.4 parts of antioxidant, 1.2 parts of polyethylene wax, and 3 parts of ethylene-methyl acrylate copolymer;

[0029] The antioxidant is antioxidant 1010;

[0030] Step 2: Preparation of modified graphene:

[0031] 0.2 g of graphene oxide and 150 mL of anhydrous methanol were mixed uniformly under nitrogen protection, ultrasonically vibrated for 2.5 h, 2 g of 3-aminopropyltrimethoxysilane was added, and ultrasonically treated for 1.5 h. The mixture was heated to 70 ° C, refluxed for 23 h, cooled to 28 ° C, centrifuged, washed, and vacuum dried to obtain modified graphene;

[0032] Step 3: Preparation of graphene-nickel silicate composite:

[0033] Take 0.1 g of modified graphene and 35 mL of n-butyl lithium, stir evenly, heat to 88 ° C, react for 4.5 hours, cool, filter, wash, and dry, add 200 mL of deionized water, ultrasonically disperse, add 0.4 g of hexadecyltrimethylammonium bromide, stir for 3 hours, add 5 mL of ammonia water, stir for 35 minutes, then add 50 mL of ethanol solution containing 5 mL of tetraethyl orthosilicate dropwise, stir for 12 hours, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0034] Take 0.2 g of graphene-silica composite, 0.5 g of nickel nitrate hexahydrate, and 1.1 g of urea, add 50 mL of 0.02 M dilute nitric acid, stir evenly, heat to 88 ° C, stir for 8 h, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite;

[0035] Step 4: Preparation of flame retardant graphene-nickel silicate composite:

[0036] Take 2 g of ferric nitrate nonahydrate and 50 mL of deionized water, stir evenly, add 0.7 g of graphene-nickel silicate composite, stir for 2.5 h, add 2 mL of ammonia monohydrate, stir for 4.5 h, and dry to obtain a flame retardant graphene-nickel silicate composite;

[0037] Step 5: Preparation of amino-modified graphene-nickel silicate composite:

[0038] Take 16 g of glycine and 200 mL of deionized water, ultrasonically disperse for 30 minutes, add 1 g of flame-retardant graphene-nickel silicate composite, stir for 24 hours, and then ultrasonically disperse for another 11 hours. Centrifuge, filter, and dry to obtain an amino-modified graphene-nickel silicate composite.

[0039] Example 2: A process for preparing a high-strength flexible sling, comprising the following steps:

[0040] Step 1: Preparation of high-strength flexible slings:

[0041] Polypropylene, maleic anhydride grafted polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer were mixed uniformly, melt-extruded, cooled, stretched, rolled, and braided to obtain a sling with a width of 80 mm and a length of 600 mm;

[0042] The sling comprises the following ingredients, calculated by weight: 105 parts of polypropylene, 40 parts of maleic anhydride grafted polyethylene, 42 parts of calcium powder, 8 parts of amino graphene-nickel silicate composite, 6 parts of calcium carbonate, 4 parts of talc, 3 parts of paraffin wax, 2 parts of stearic acid, 0.2 parts of antioxidant, 1 part of polyethylene wax, and 2 parts of ethylene-methyl acrylate copolymer;

[0043] The antioxidant is antioxidant 1010;

[0044] Step 2: Preparation of modified graphene:

[0045] 0.2 g of graphene oxide and 150 mL of anhydrous methanol were mixed under nitrogen protection, ultrasonically shaken for 2 h, 2 g of 3-aminopropyltrimethoxysilane was added, ultrasonically treated for 1 h, heated to 70 ° C, refluxed for 22 h, cooled to 25 ° C, centrifuged, washed, and vacuum dried to obtain modified graphene;

[0046] Step 3: Preparation of graphene-nickel silicate composite:

[0047] Take 0.1g modified graphene and 35mL n-butyl lithium, stir evenly, heat to 85℃, react for 4h, cool, filter, wash, dry, add 200mL deionized water, ultrasonically disperse, add 0.4g hexadecyltrimethylammonium bromide, stir for 2h, add 5mL ammonia water, stir for 30min, then add 50mL ethanol solution containing 5mL tetraethyl orthosilicate dropwise, stir for 10h, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0048] Take 0.2 g of graphene-silicon dioxide composite, 0.5 g of nickel nitrate hexahydrate, and 1.1 g of urea, add 50 mL of 0.02 M dilute nitric acid, stir evenly, heat to 85 ° C, stir for 7 h, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite;

[0049] Step 4: Preparation of flame retardant graphene-nickel silicate composite:

[0050] Take 2g of ferric nitrate nonahydrate and 50mL of deionized water, stir evenly, add 0.7g of graphene-nickel silicate composite, stir for 2h, add 2mL of ammonia monohydrate, stir for 4h, and dry to obtain a flame retardant graphene-nickel silicate composite;

[0051] Step 5: Preparation of amino-modified graphene-nickel silicate composite:

[0052] Take 16 g of glycine and 200 mL of deionized water, ultrasonically disperse for 20 minutes, add 1 g of flame-retardant graphene-nickel silicate composite, stir for 22 hours, and then ultrasonically disperse for another 10 hours. Centrifuge, filter, and dry to obtain an amino-modified graphene-nickel silicate composite.

[0053] Example 3: A process for preparing a high-strength flexible sling, comprising the following steps:

[0054] Step 1: Preparation of high-strength flexible slings:

[0055] Polypropylene, maleic anhydride grafted polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer were mixed uniformly, melt-extruded, cooled, stretched, rolled, and braided to obtain a sling with a width of 80 mm and a length of 600 mm;

[0056] The sling comprises the following ingredients, calculated by weight: 110 parts of polypropylene, 47 parts of maleic anhydride grafted polyethylene, 46 parts of calcium powder, 12 parts of amino graphene-nickel silicate composite, 8 parts of calcium carbonate, 6 parts of talc, 5 parts of paraffin wax, 4 parts of stearic acid, 0.5 parts of antioxidant, 1.5 parts of polyethylene wax, and 4 parts of ethylene-methyl acrylate copolymer;

[0057] The antioxidant is antioxidant 1010;

[0058] Step 2: Preparation of modified graphene:

[0059] 0.2 g of graphene oxide and 150 mL of anhydrous methanol were mixed uniformly under nitrogen protection, ultrasonically vibrated for 3 h, 2 g of 3-aminopropyltrimethoxysilane was added, ultrasonically treated for 2 h, heated to 71 ° C, refluxed for 24 h, cooled to 30 ° C, centrifuged, washed, and vacuum dried to obtain modified graphene;

[0060] Step 3: Preparation of graphene-nickel silicate composite:

[0061] Take 0.1 g of modified graphene and 35 mL of n-butyl lithium, stir evenly, heat to 90 ° C, react for 5 h, cool, filter, wash, and dry, add 200 mL of deionized water, ultrasonically disperse, add 0.4 g of hexadecyltrimethylammonium bromide, stir for 4 h, add 5 mL of ammonia water, stir for 40 min, then add 50 mL of ethanol solution containing 5 mL of tetraethyl orthosilicate dropwise, stir for 14 h, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0062] Take 0.2 g of graphene-silicon dioxide composite, 0.5 g of nickel nitrate hexahydrate, and 1.1 g of urea, add 50 mL of 0.02 M dilute nitric acid, stir evenly, heat to 90 ° C, stir for 9 h, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite;

[0063] Step 4: Preparation of flame retardant graphene-nickel silicate composite:

[0064] Take 2g of ferric nitrate nonahydrate and 50mL of deionized water, stir evenly, add 0.7g of graphene-nickel silicate composite, stir for 3h, add 2mL of ammonia monohydrate, stir for 5h, and dry to obtain a flame retardant graphene-nickel silicate composite;

[0065] Step 5: Preparation of amino-modified graphene-nickel silicate composite:

[0066] Take 16 g of glycine and 200 mL of deionized water, ultrasonically disperse for 40 minutes, add 1 g of flame-retardant graphene-nickel silicate composite, stir for 26 hours, and then ultrasonically disperse for another 12 hours. Centrifuge, filter, and dry to obtain an amino-modified graphene-nickel silicate composite.

[0067] Comparative Example 1: 3-aminopropyltrimethoxysilane was not used to intercalate graphene oxide, and the rest was the same as in Example 1:

[0068] Step 1: Preparation of high-strength flexible slings:

[0069] Polypropylene, maleic anhydride grafted polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer were mixed uniformly, melt-extruded, cooled, stretched, rolled, and braided to obtain a sling with a width of 80 mm and a length of 600 mm;

[0070] The sling comprises the following ingredients, calculated by weight: 108 parts of polypropylene, 45 parts of maleic anhydride grafted polyethylene, 44 parts of calcium powder, 10 parts of amino graphene-nickel silicate composite, 7 parts of calcium carbonate, 5 parts of talc, 4 parts of paraffin wax, 3 parts of stearic acid, 0.4 parts of antioxidant, 1.2 parts of polyethylene wax, and 3 parts of ethylene-methyl acrylate copolymer;

[0071] The antioxidant is antioxidant 1010;

[0072] Step 2: Preparation of graphene-nickel silicate composite:

[0073] Take 0.1 g of graphene oxide and 35 mL of n-butyl lithium, stir evenly, heat to 88 ° C, react for 4.5 hours, cool, filter, wash, and dry, add 200 mL of deionized water, ultrasonically disperse, add 0.4 g of hexadecyltrimethylammonium bromide, stir for 3 hours, add 5 mL of ammonia water, stir for 35 minutes, then add 50 mL of ethanol solution containing 5 mL of tetraethyl orthosilicate dropwise, stir for 12 hours, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0074] Take 0.2 g of graphene-silica composite, 0.5 g of nickel nitrate hexahydrate, and 1.1 g of urea, add 50 mL of 0.02 M dilute nitric acid, stir evenly, heat to 88 ° C, stir for 8 h, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite;

[0075] Step 4: Preparation of flame retardant graphene-nickel silicate composite:

[0076] Take 2 g of ferric nitrate nonahydrate and 50 mL of deionized water, stir evenly, add 0.7 g of graphene-nickel silicate composite, stir for 2.5 h, add 2 mL of ammonia monohydrate, stir for 4.5 h, and dry to obtain a flame retardant graphene-nickel silicate composite;

[0077] Step 5: Preparation of amino-modified graphene-nickel silicate composite:

[0078] Take 16 g of glycine and 200 mL of deionized water, ultrasonically disperse for 30 minutes, add 1 g of flame-retardant graphene-nickel silicate composite, stir for 24 hours, and then ultrasonically disperse for another 11 hours. Centrifuge, filter, and dry to obtain an amino-modified graphene-nickel silicate composite.

[0079] Comparative Example 2: Maleic anhydride-grafted polyethylene was not used to replace polyethylene, and the rest was the same as Example 1:

[0080] Step 1: Preparation of high-strength flexible slings:

[0081] Polypropylene, polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer were mixed uniformly, melt-extruded, cooled, stretched, rolled, and braided to obtain a sling with a width of 80 mm and a length of 600 mm;

[0082] The sling comprises the following ingredients, calculated by weight: 108 parts of polypropylene, 45 parts of polyethylene, 44 parts of calcium powder, 10 parts of amino graphene-nickel silicate composite, 7 parts of calcium carbonate, 5 parts of talc, 4 parts of paraffin wax, 3 parts of stearic acid, 0.4 parts of antioxidant, 1.2 parts of polyethylene wax, and 3 parts of ethylene-methyl acrylate copolymer;

[0083] The antioxidant is antioxidant 1010;

[0084] Step 2: Preparation of modified graphene:

[0085] 0.2 g of graphene oxide and 150 mL of anhydrous methanol were mixed uniformly under nitrogen protection, ultrasonically vibrated for 2.5 h, 2 g of 3-aminopropyltrimethoxysilane was added, and ultrasonically treated for 1.5 h. The mixture was heated to 70 ° C, refluxed for 23 h, cooled to 28 ° C, centrifuged, washed, and vacuum dried to obtain modified graphene;

[0086] Step 3: Preparation of graphene-nickel silicate composite:

[0087] Take 0.1 g of modified graphene and 35 mL of n-butyl lithium, stir evenly, heat to 88 ° C, react for 4.5 hours, cool, filter, wash, and dry, add 200 mL of deionized water, ultrasonically disperse, add 0.4 g of hexadecyltrimethylammonium bromide, stir for 3 hours, add 5 mL of ammonia water, stir for 35 minutes, then add 50 mL of ethanol solution containing 5 mL of tetraethyl orthosilicate dropwise, stir for 12 hours, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0088] Take 0.2 g of graphene-silica composite, 0.5 g of nickel nitrate hexahydrate, and 1.1 g of urea, add 50 mL of 0.02 M dilute nitric acid, stir evenly, heat to 88 ° C, stir for 8 h, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite;

[0089] Step 4: Preparation of flame retardant graphene-nickel silicate composite:

[0090] Take 2 g of ferric nitrate nonahydrate and 50 mL of deionized water, stir evenly, add 0.7 g of graphene-nickel silicate composite, stir for 2.5 h, add 2 mL of ammonia monohydrate, stir for 4.5 h, and dry to obtain a flame retardant graphene-nickel silicate composite;

[0091] Step 5: Preparation of amino-modified graphene-nickel silicate composite:

[0092] Take 16 g of glycine and 200 mL of deionized water, ultrasonically disperse for 30 minutes, add 1 g of flame-retardant graphene-nickel silicate composite, stir for 24 hours, and then ultrasonically disperse for another 11 hours. Centrifuge, filter, and dry to obtain an amino-modified graphene-nickel silicate composite.

[0093] Comparative Example 3: The graphene-nickel silicate composite was not subjected to amino modification, and the rest was the same as in Example 1:

[0094] Step 1: Preparation of high-strength flexible slings:

[0095] Polypropylene, maleic anhydride grafted polyethylene, calcium powder, flame retardant graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer were mixed evenly, melt-extruded, cooled, stretched, rolled, and braided to obtain a sling with a width of 80 mm and a length of 600 mm;

[0096] The sling comprises the following ingredients, calculated by weight: 108 parts of polypropylene, 45 parts of maleic anhydride grafted polyethylene, 44 parts of calcium powder, 10 parts of flame retardant graphene-nickel silicate composite, 7 parts of calcium carbonate, 5 parts of talc, 4 parts of paraffin wax, 3 parts of stearic acid, 0.4 parts of antioxidant, 1.2 parts of polyethylene wax, and 3 parts of ethylene-methyl acrylate copolymer;

[0097] The antioxidant is antioxidant 1010;

[0098] Step 2: Preparation of modified graphene:

[0099] 0.2 g of graphene oxide and 150 mL of anhydrous methanol were mixed uniformly under nitrogen protection, ultrasonically vibrated for 2.5 h, 2 g of 3-aminopropyltrimethoxysilane was added, and ultrasonically treated for 1.5 h. The mixture was heated to 70 ° C, refluxed for 23 h, cooled to 28 ° C, centrifuged, washed, and vacuum dried to obtain modified graphene;

[0100] Step 3: Preparation of graphene-nickel silicate composite:

[0101] Take 0.1 g of modified graphene and 35 mL of n-butyl lithium, stir evenly, heat to 88 ° C, react for 4.5 hours, cool, filter, wash, and dry, add 200 mL of deionized water, ultrasonically disperse, add 0.4 g of hexadecyltrimethylammonium bromide, stir for 3 hours, add 5 mL of ammonia water, stir for 35 minutes, then add 50 mL of ethanol solution containing 5 mL of tetraethyl orthosilicate dropwise, stir for 12 hours, centrifuge, wash, and dry to obtain a graphene-silica composite;

[0102] Take 0.2 g of graphene-silica composite, 0.5 g of nickel nitrate hexahydrate, and 1.1 g of urea, add 50 mL of 0.02 M dilute nitric acid, stir evenly, heat to 88 ° C, stir for 8 h, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite;

[0103] Step 4: Preparation of flame retardant graphene-nickel silicate composite:

[0104] Take 2 g of ferric nitrate nonahydrate and 50 mL of deionized water, stir evenly, add 0.7 g of graphene-nickel silicate composite, stir for 2.5 h, add 2 mL of ammonia monohydrate, stir for 4.5 h, and dry to obtain a flame retardant graphene-nickel silicate composite.

[0105] experiment:

[0106] The high-strength flexible slings prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were subjected to performance tests. The strength of the slings was tested, and then the limiting oxygen index of the slings was tested. The obtained data are shown in Table 1 below:

[0107] Strength (N / m) Limiting oxygen index (%) Example 1 28211 37 Example 2 28209 36 Example 3 28213 37 Comparative Example 1 28201 33 Comparative Example 2 27556 29 Comparative Example 3 27592 30

[0108] Conclusion: From the comparison of the data in the table, it can be seen that in Comparative Example 1, 3-aminopropyltrimethoxysilane is not used to intercalate graphene oxide, and the active sites are few, so the flame retardancy of the sling is reduced. In Comparative Example 2, maleic anhydride-grafted polyethylene is not used to replace polyethylene, and the dispersibility of the amino-modified graphene-nickel silicate composite is poor, so the flame retardancy and strength of the sling are reduced. In Comparative Example 3, the graphene-nickel silicate composite is not amino-modified, and the flame retardancy and strength of the sling are reduced. Examples 1 to 3 of the present invention use 3-aminopropyltrimethoxysilane to intercalate graphene oxide, which increases the interlayer spacing of graphene oxide, thereby increasing the specific surface area of graphene oxide, so that it has more active sites that can be compounded with the nickel silicate composite, thereby enhancing the flame retardancy of the sling. Maleic anhydride-grafted polyethylene replaces polyethylene, and the graphene-nickel silicate composite is then aminated. The reaction between the anhydride and amino groups enhances the compatibility between the maleic anhydride-grafted polyethylene and the amination-modified graphene-nickel silicate composite, improving filler dispersion and enhancing the sling's flame retardancy and strength. The resulting high-strength flexible sling achieves a strength of 28,200 N / m and a limiting oxygen index of 36%, demonstrating excellent flame retardancy and mechanical properties.

[0109] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

Claims

1. A process for preparing a high-strength flexible sling, characterized by: The following steps are involved: Step 1: Take glycine and deionized water, ultrasonically disperse for 20-40 minutes, add the flame-retardant graphene-nickel silicate complex, stir for 22-26 hours, and then ultrasonically disperse for another 10-12 hours, centrifuge, filter, and dry to obtain the amino-modified graphene-nickel silicate complex; Step 2: Take polypropylene, polyethylene, calcium powder, amino graphene-nickel silicate composite, calcium carbonate, talc, paraffin, stearic acid, antioxidant, polyethylene wax, and ethylene-methyl acrylate copolymer, mix them evenly, melt-extrude, cool, stretch, roll, and weave to obtain a sling.

2. The process for preparing a high-strength flexible sling according to claim 1, characterized in that: The sling includes the following ingredients, calculated by weight: 105-110 parts of polypropylene, 40-47 parts of polyethylene, 42-46 parts of calcium powder, 8-12 parts of amino graphene-nickel silicate complex, 6-8 parts of calcium carbonate, 4-6 parts of talc, 3-5 parts of paraffin, 2-4 parts of stearic acid, 0.2-0.5 parts of antioxidant, 1-1.5 parts of polyethylene wax, and 2-4 parts of ethylene-methyl acrylate copolymer.

3. The process for preparing a high-strength flexible sling according to claim 1, characterized in that: The preparation method of the flame retardant graphene-nickel silicate composite comprises the following steps: taking ferric nitrate nonahydrate and deionized water, stirring evenly, adding the graphene-nickel silicate composite, stirring for 2-3 hours, adding ammonia monohydrate, stirring for 4-5 hours, and drying to obtain the flame retardant graphene-nickel silicate composite.

4. The process for preparing a high-strength flexible sling according to claim 3, characterized in that: The preparation method of the graphene-nickel silicate composite is: The following steps are involved: S1: Take modified graphene and n-butyl lithium, stir evenly, heat to 85-90°C, react for 4-5 hours, cool, filter, wash, dry, add deionized water, ultrasonically disperse, add hexadecyltrimethylammonium bromide, stir for 2-4 hours, add ammonia water, stir for 30-40 minutes, then add dropwise an ethanol solution containing tetraethyl orthosilicate, stir for 10-14 hours, centrifuge, wash, and dry to obtain a graphene-silica composite; S2: Take a graphene-silicon dioxide composite, nickel nitrate hexahydrate, and urea, add dilute nitric acid, stir evenly, heat to 85-90° C., stir for 7-9 hours, cool, centrifuge, wash, and dry to obtain a graphene-nickel silicate composite.

5. The process for preparing a high-strength flexible sling according to claim 4, characterized in that: The modified graphene preparation method comprises: taking graphene oxide and anhydrous methanol, mixing them uniformly under nitrogen protection, ultrasonically oscillating for 2-3 hours, adding 3-aminopropyltrimethoxysilane, ultrasonically treating for 1-2 hours, heating to 70-71° C., refluxing for 22-24 hours, cooling to 25-30° C., centrifuging, washing, and vacuum drying to obtain the modified graphene.

6. The process for preparing a high-strength flexible sling according to claim 2, characterized in that: The antioxidant is antioxidant 1010.

7. The process for preparing a high-strength flexible sling according to claim 2, characterized in that: The polyethylene is maleic anhydride grafted polyethylene.

8. A high-strength flexible sling prepared according to the process for preparing a high-strength flexible sling according to any one of claims 1 to 7.