High-toughness composite fiber and application

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to a high-toughness composite fiber and application, the composite fiber comprises homo-polypropylene, silane coupling agent modified silicon carbide whisker and viscosity average molecular weight gt; the ultra-high molecular weight polyethylene swelling body comprises ultra-high molecular weight polyethylene and mineral oil with a high distillation range. The high-toughness composite fiber prepared by the invention not only retains the wear resistance and the cutting resistance of the fiber to the maximum extent, but also effectively improves the flexibility and the corrosion resistance of the fiber, ensures the knittability of the composite fiber, and can adapt to relatively severe environmental conditions; the application range of the composite fiber in the field of labor protection supplies is effectively expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and in particular relates to a high-tenacity composite fiber and its application. Background Art

[0002] High molecular weight materials, also known as polymer materials, are materials composed of high molecular weight compounds as the matrix and other additives (auxiliaries). Among them, polypropylene composites are widely used due to their excellent performance and processability. They can be combined or modified through specific processes to form fiber materials, so that the fiber materials inherit the excellent properties of polypropylene, such as chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good wear resistance and processing properties. At present, although polypropylene composite fibers are widely used in ropes, fishing nets, textiles and clothing industries due to their advantages of light weight, good coverage, high toughness, good chemical resistance, antimicrobial resistance and low price, they still have problems with mechanical properties such as tensile strength, bending and impact strength, and it is difficult to meet the needs of practical applications.

[0003] In the prior art, there are studies on the mechanical properties of polypropylene composite fibers, such as tensile strength, bending strength and impact strength, such as patent application CN106380694-carbon fiber reinforced polypropylene composite material and preparation method thereof, which solves the mechanical properties of polypropylene composite fibers, such as tensile strength, bending strength and impact strength, by adding carbon fiber, nano silicon carbide whisker and a mixture of polypropylene glycol and polyvinyl alcohol to the basic raw material of polypropylene. However, although the existing carbon fiber reinforced polypropylene composite material improves the mechanical properties of the material, it is difficult to effectively control the flexibility of the material, thereby affecting the weavability of the material and limiting the application scope of polypropylene composite fibers in the field of labor protection products. Therefore, a new technical solution is needed to solve the above technical problems. Summary of the invention

[0004] The purpose of the present invention is to provide a high-tenacity composite fiber and its application, so as to solve the problem mentioned in the above background technology that it is difficult to effectively control the flexibility of the current carbon fiber reinforced polypropylene composite material, thereby affecting the weavability of the material and limiting the application scope of the polypropylene composite fiber in the field of labor protection products.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a high-tenacity composite fiber, the raw material components of the composite fiber include homopolypropylene with a viscosity average molecular weight of 320,000 to 480,000, silane coupling agent-modified silicon carbide whiskers with a homopolypropylene content of 0.8 to 5.8 wt% and an ultra-high molecular weight polyethylene swollen body with a viscosity average molecular weight> 1 million, the ultra-high molecular weight polyethylene swollen body includes ultra-high molecular weight polyethylene and high-distillation range mineral oil in a weight ratio of 3:97 to 7:93, and the specific preparation steps of the ultra-high molecular weight polyethylene swollen body are as follows: ultra-high molecular weight polyethylene is added to high-distillation range mineral oil to prepare a 3-7 wt% suspension, and the ultra-high molecular weight polyethylene swollen body is obtained by magnetic stirring at a rotation speed of 220 to 380 rpm for swelling for 10 to 30 minutes and filtering with an 80-mesh filter screen, wherein the high-distillation range mineral oil is white oil.

[0006] Furthermore, the raw material components of the silane coupling agent modified silicon carbide whiskers include silicon carbide whiskers and silane coupling agents in a weight ratio of 1:0.2-0.8, wherein the silicon carbide whiskers are β-crystalline and their diameter and length are 200-500nm and 3-20µm, respectively, and the raw material components of the silane coupling agent are a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane in a weight ratio of 1-3:3-1.

[0007] Furthermore, the specific preparation steps of the composite fiber are: first, the silicon carbide whiskers modified by the silane coupling agent are dispersed on the surface of the homopolypropylene by heating and blending to obtain a blended spinning material, and then the blended spinning material and the ultra-high molecular weight polyethylene swelling body are melt-spun at 200-240°C, heat-stretched and heat-set to obtain a high-tenacity composite fiber.

[0008] In addition to the above technical solutions, the composite fibers are also used to prepare cut-resistant fabrics, including gloves, clothing, cloth, and the like.

[0009] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention not only makes the composite fiber have excellent wear resistance and cut resistance, effectively prolongs the service life of the polypropylene composite fiber, but also makes the silicon carbide whiskers dispersed in the polypropylene absorb the energy transmitted from the outside, increases the tensile strength and tensile modulus of the composite fiber, and effectively improves the strength and safety performance of the polypropylene composite fiber. The ultra-high molecular weight polyethylene swelling body is used as the modifier of the polypropylene dispersed with the silicon carbide whiskers modified by the silane coupling agent, which not only effectively controls the flexibility of the composite fiber and ensures the braidability of the composite fiber, but also effectively improves the corrosion resistance of the composite fiber, so that the composite fiber can adapt to relatively harsh environmental conditions, and effectively expands the application scope of the composite fiber in the field of labor protection products; 2. The present invention adopts high-distillation range mineral oil to perform swelling pretreatment on ultra-high molecular weight polyethylene, so that the system viscosity of ultra-high molecular weight polyethylene is reduced, and the mobility of macromolecular chains is effectively enhanced, so that the ultra-high molecular weight polyethylene swelled body has better dispersibility when blended with polypropylene, and the compatibility between the ultra-high molecular weight polyethylene swelled body and polypropylene is effectively improved, thereby achieving the purpose of improving the comprehensive performance of the composite fiber, and at the same time, the lubrication performance of the composite fiber can be further improved and the friction coefficient can be reduced, so that the composite fiber exhibits stronger wear resistance when subjected to friction, making up for the disadvantage of poor wear resistance of PP, and ensuring the high temperature resistance of the composite fiber; 3. The present invention adopts silane coupling agent as a modifier for silicon carbide whiskers, which can not only weaken the interaction between silicon carbide whiskers, effectively avoid whisker agglomeration, and improve the dispersibility of silicon carbide in polypropylene, but also enable the silane coupling agent to coat silicon carbide, effectively avoiding direct contact between silicon carbide and the human body, thereby improving the performance of the composite fiber while ensuring its safety and having no toxic side effects. DETAILED DESCRIPTION

[0010] The following examples are used to further illustrate the content of the present invention, but do not limit the application of the present invention. The raw materials used are all commercially available products. Embodiment 1:

[0011] This embodiment provides a high-tenacity composite fiber, which is prepared from homopolypropylene with a viscosity average molecular weight of 400,000 (the homopolypropylene purchased is a product produced by Hengli Petrochemical), silicon carbide whiskers modified by a silane coupling agent with a content of 3.5wt% (wt% is the weight content percentage) of homopolypropylene, and an ultra-high molecular weight polyethylene swelling body with a viscosity average molecular weight of 5 million; Specifically: first, silicon carbide whiskers (the silicon carbide whiskers purchased are SiCW-80 products or SiCW-90 products produced by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd.) and silane coupling agents with a weight ratio of 1:0.2 are selected to prepare silicon carbide whiskers modified by silane coupling agents, wherein β-type silicon carbide whiskers with a diameter of 200-500nm and a length of 3-20μm are used, and the silane coupling agent is a mixture of dodecylsilane coupling agent (the dodecylsilane coupling agent purchased is UP-312 product or UP-313 product produced by Nanjing Youpu Chemical Co., Ltd.) and 3-aminopropyltrimethoxysilane (3-aminopropyltrimethoxysilane purchased is KH-540 product produced by Qingdao Hengda Zhongcheng Technology Co., Ltd.) with a weight ratio of 2:3; The specific preparation process of the silane coupling agent modified silicon carbide whisker is as follows: the selected silicon carbide whisker is first ultrasonically dispersed in deionized water for 30 minutes, then a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane is added, and then the temperature is controlled at 70°C, stirred for 5 hours, and then dried to obtain the silane coupling agent modified silicon carbide whisker; Secondly, the silicon carbide whiskers modified by the silane coupling agent prepared above are dispersed on the surface of homopolypropylene by heating and blending to obtain a blended spinning material; Secondly, due to the extremely high relative molecular mass of ultra-high molecular weight polyethylene, its melt viscosity is significantly higher than other fluids, and its processing fluidity is extremely poor. When blended with other polymers, it is unevenly dispersed and has low compatibility. Therefore, it is necessary to improve the dispersibility of ultra-high molecular weight polyethylene in the matrix and its compatibility with the matrix. For this reason, the dissolution of ultra-high molecular weight polyethylene must follow the general law of polymer dissolution. It must swell first and then dissolve when in contact with the solvent. Low molecular weight white oil is used as the solvent to swell the ultra-high molecular weight polyethylene, reduce the viscosity of the system, and enhance the mobility of the macromolecular chain, so that it can be better dispersed when blended with polypropylene, and improve the compatibility between the two, thereby achieving the purpose of better improving the comprehensive performance of the composite material. The specific preparation process of the ultra-high molecular weight polyethylene swellable body is as follows: 5 parts of ultra-high molecular weight polyethylene are added to 95 parts of white oil to prepare a suspension with a solid content of 5wt%, and the suspension is swelled for 20 minutes at 130-140°C using a magnetic stirring at a speed of 220-380rpm, and then filtered with an 80-mesh filter screen, and when no white oil flows down from the filter screen, the ultra-high molecular weight polyethylene swellable body on the filter screen is collected; Then, 5% by weight of the ultra-high molecular weight polyethylene swelling body is blended with the blended spinning material by melt spinning, extruded by a twin-screw extruder at 220° C. and 250 r / min, and then pelletized by a pelletizer to obtain ultra-high molecular weight polyethylene / polypropylene composite material pellets, which are melt-spun, heat-drawn and heat-set by a twin-screw extruder at 220° C. and 250 r / min to obtain high-tenacity composite fibers; Finally, the high-tenacity composite fiber prepared as above is woven into anti-cut fabric through a textile process. The fabric includes gloves, clothing, cloth, etc. The fabric is tested according to EN388-2016, and its anti-cut grade is B, the abrasion resistance is 8000 turns, and the impact strength is 10 KJ / ㎡; the fabric can also be used in chemical scenarios after corrosion resistance testing. Embodiment 2:

[0012] This embodiment provides a high-tenacity composite fiber, which is prepared from homopolypropylene with a viscosity average molecular weight of 400,000 (the homopolypropylene purchased is a product produced by Hengli Petrochemical), silicon carbide whiskers modified by a silane coupling agent with a content of 5wt% homopolypropylene, and an ultra-high molecular weight polyethylene swelling body with a viscosity average molecular weight of 5 million; Specifically: first, silicon carbide whiskers (the silicon carbide whiskers purchased are SiCW-80 products or SiCW-90 products produced by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd.) and silane coupling agents with a weight ratio of 1:0.4 are selected to prepare silicon carbide whiskers modified by silane coupling agents, wherein β-type silicon carbide whiskers with a diameter of 200-500nm and a length of 3-20μm are used, and the silane coupling agent is a mixture of dodecylsilane coupling agent (the dodecylsilane coupling agent purchased is UP-312 product or UP-313 product produced by Nanjing Youpu Chemical Co., Ltd.) and 3-aminopropyltrimethoxysilane (3-aminopropyltrimethoxysilane purchased is KH-540 product produced by Qingdao Hengda Zhongcheng Technology Co., Ltd.) with a weight ratio of 3:2; The specific preparation process of the silane coupling agent modified silicon carbide whisker is as follows: the selected silicon carbide whisker is first ultrasonically dispersed in deionized water for 30 minutes, then a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane is added, and then the temperature is controlled at 70°C, stirred for 5 hours, and then dried to obtain the silane coupling agent modified silicon carbide whisker; Secondly, the silicon carbide whiskers modified by the silane coupling agent prepared above are dispersed on the surface of homopolypropylene by heating and blending to obtain a blended spinning material; Secondly, due to the extremely high relative molecular mass of ultra-high molecular weight polyethylene, its melt viscosity is significantly higher than other fluids, and its processing fluidity is extremely poor. When blended with other polymers, it is unevenly dispersed and has low compatibility. Therefore, it is necessary to improve the dispersibility of ultra-high molecular weight polyethylene in the matrix and its compatibility with the matrix. For this reason, the dissolution of ultra-high molecular weight polyethylene must follow the general law of polymer dissolution. It must swell first and then dissolve when in contact with the solvent. Low molecular weight white oil is used as the solvent to swell the ultra-high molecular weight polyethylene, reduce the viscosity of the system, and enhance the mobility of the macromolecular chain, so that it can be better dispersed when blended with polypropylene, and improve the compatibility between the two, thereby achieving the purpose of better improving the comprehensive performance of the composite material. The specific preparation process of the ultra-high molecular weight polyethylene swellable body is as follows: 3 parts of ultra-high molecular weight polyethylene are added to 97 parts of white oil to prepare a suspension with a solid content of 3 wt%, and the suspension is swelled for 20 minutes at 130-140° C. using a magnetic stirring at a speed of 220-380 rpm, and then filtered with an 80-mesh filter screen, and when no white oil flows down from the filter screen, the ultra-high molecular weight polyethylene swellable body on the filter screen is collected; Then, 3% by weight of the ultra-high molecular weight polyethylene swelling body is blended with the blended spinning material by melt spinning, extruded by a twin-screw extruder at 220° C. and 250 r / min, and then pelletized by a pelletizer to obtain ultra-high molecular weight polyethylene / polypropylene composite material pellets, which are melt-spun, heat-drawn and heat-set by a twin-screw extruder at 220° C. and 250 r / min to obtain high-tenacity composite fibers; Finally, the high-tenacity composite fiber prepared as above is woven into anti-cut fabric through a textile process. The fabric includes gloves, clothing, cloth, etc. The fabric is tested according to EN388-2016, and its anti-cut grade is B, the wear resistance is 6000 revolutions, and the impact strength is 7KJ / ㎡. The fabric can also be used in chemical scenarios after corrosion resistance testing. Embodiment 3:

[0013] This embodiment provides a high-tenacity composite fiber, which is prepared from homopolypropylene with a viscosity average molecular weight of 400,000 (the homopolypropylene purchased is a product produced by Hengli Petrochemical), silicon carbide whiskers modified by a silane coupling agent with a content of 1.5wt% homopolypropylene, and an ultra-high molecular weight polyethylene swelling body with a viscosity average molecular weight of 5 million; Specifically: first, silicon carbide whiskers (the silicon carbide whiskers purchased are SiCW-80 products or SiCW-90 products produced by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd.) and silane coupling agents with a weight ratio of 1:0.6 are selected to prepare silicon carbide whiskers modified by silane coupling agents, wherein β-type silicon carbide whiskers with a diameter of 200-500nm and a length of 3-20μm are used, and the silane coupling agent is a mixture of dodecylsilane coupling agent (the dodecylsilane coupling agent purchased is UP-312 product or UP-313 product produced by Nanjing Youpu Chemical Co., Ltd.) and 3-aminopropyltrimethoxysilane (3-aminopropyltrimethoxysilane purchased is KH-540 product produced by Qingdao Hengda Zhongcheng Technology Co., Ltd.) with a weight ratio of 1:1; The specific preparation process of the silane coupling agent modified silicon carbide whisker is as follows: the selected silicon carbide whisker is first ultrasonically dispersed in deionized water for 30 minutes, then a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane is added, and then the temperature is controlled at 70°C, stirred for 5 hours, and then dried to obtain the silane coupling agent modified silicon carbide whisker; Secondly, the silicon carbide whiskers modified by the silane coupling agent prepared above are dispersed on the surface of homopolypropylene by heating and blending to obtain a blended spinning material; Secondly, due to the extremely high relative molecular mass of ultra-high molecular weight polyethylene, its melt viscosity is significantly higher than other fluids, and its processing fluidity is extremely poor. When blended with other polymers, it is unevenly dispersed and has low compatibility. Therefore, it is necessary to improve the dispersibility of ultra-high molecular weight polyethylene in the matrix and its compatibility with the matrix. For this reason, the dissolution of ultra-high molecular weight polyethylene must follow the general law of polymer dissolution. It must swell first and then dissolve when in contact with the solvent. Low molecular weight white oil is used as the solvent to swell the ultra-high molecular weight polyethylene, reduce the viscosity of the system, and enhance the mobility of the macromolecular chain, so that it can be better dispersed when blended with polypropylene, and improve the compatibility between the two, thereby achieving the purpose of better improving the comprehensive performance of the composite material. The specific preparation process of the ultra-high molecular weight polyethylene swellable body is as follows: 3 parts of ultra-high molecular weight polyethylene are added to 97 parts of white oil to prepare a suspension with a solid content of 3 wt%, and the suspension is swelled for 20 minutes at 130-140° C. using a magnetic stirring at a speed of 220-380 rpm, and then filtered with an 80-mesh filter screen, and when no white oil flows down from the filter screen, the ultra-high molecular weight polyethylene swellable body on the filter screen is collected; Then, 1% by weight of the ultra-high molecular weight polyethylene swelling body is blended with the blended spinning material by melt spinning, extruded by a twin-screw extruder at 220° C. and 250 r / min, and then pelletized by a pelletizer to obtain ultra-high molecular weight polyethylene / polypropylene composite material pellets, which are melt-spun, heat-drawn and heat-set by a twin-screw extruder at 220° C. and 250 r / min to obtain high-tenacity composite fibers; Finally, the high-tenacity composite fiber prepared as above is woven into anti-cut fabric through a textile process. The fabric includes gloves, clothing, cloth, etc. The fabric is tested according to EN388-2016, and its anti-cut grade is B, the wear resistance is 2000 turns, and the impact strength is 3KJ / ㎡. The fabric can also be used in chemical scenarios after corrosion resistance testing. Embodiment 4:

[0014] This embodiment provides a high-tenacity composite fiber, which is prepared from homopolypropylene with a viscosity average molecular weight of 400,000 (the homopolypropylene purchased is a product produced by Hengli Petrochemical), silicon carbide whiskers modified by a silane coupling agent with a content of 4wt% homopolypropylene, and an ultra-high molecular weight polyethylene swelling body with a viscosity average molecular weight of 5 million; Specifically: first, silicon carbide whiskers (the silicon carbide whiskers purchased are SiCW-80 products or SiCW-90 products produced by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd.) and silane coupling agents with a weight ratio of 1:0.8 are selected to prepare silicon carbide whiskers modified by silane coupling agents, wherein β-type silicon carbide whiskers with a diameter of 200-500nm and a length of 3-20μm are used, and the silane coupling agent is a mixture of dodecylsilane coupling agent (the dodecylsilane coupling agent purchased is UP-312 product or UP-313 product produced by Nanjing Youpu Chemical Co., Ltd.) and 3-aminopropyltrimethoxysilane (3-aminopropyltrimethoxysilane purchased is KH-540 product produced by Qingdao Hengda Zhongcheng Technology Co., Ltd.) with a weight ratio of 3:3; The specific preparation process of the silane coupling agent modified silicon carbide whisker is as follows: the selected silicon carbide whisker is first ultrasonically dispersed in deionized water for 30 minutes, then a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane is added, and then the temperature is controlled at 70°C, stirred for 5 hours, and then dried to obtain the silane coupling agent modified silicon carbide whisker; Secondly, the silicon carbide whiskers modified by the silane coupling agent prepared above are dispersed on the surface of homopolypropylene by heating and blending to obtain a blended spinning material; Secondly, due to the extremely high relative molecular mass of ultra-high molecular weight polyethylene, its melt viscosity is significantly higher than other fluids, and its processing fluidity is extremely poor. When blended with other polymers, it is unevenly dispersed and has low compatibility. Therefore, it is necessary to improve the dispersibility of ultra-high molecular weight polyethylene in the matrix and its compatibility with the matrix. For this reason, the dissolution of ultra-high molecular weight polyethylene must follow the general law of polymer dissolution. It must swell first and then dissolve when in contact with the solvent. Low molecular weight white oil is used as the solvent to swell the ultra-high molecular weight polyethylene, reduce the viscosity of the system, and enhance the mobility of the macromolecular chain, so that it can be better dispersed when blended with polypropylene, and improve the compatibility between the two, thereby achieving the purpose of better improving the comprehensive performance of the composite material. The specific preparation process of the ultra-high molecular weight polyethylene swellable body is as follows: 5 parts of ultra-high molecular weight polyethylene are added to 95 parts of white oil to prepare a suspension with a solid content of 5wt%, and the suspension is swelled for 20 minutes at 130-140°C using a magnetic stirring at a speed of 220-380rpm, and then filtered with an 80-mesh filter screen, and when no white oil flows down from the filter screen, the ultra-high molecular weight polyethylene swellable body on the filter screen is collected; Then, 2% by weight of the ultra-high molecular weight polyethylene swelling body is blended with the blended spinning material by melt spinning, extruded by a twin-screw extruder at 220° C. and 250 r / min, and then pelletized by a pelletizer to obtain ultra-high molecular weight polyethylene / polypropylene composite material pellets, which are melt-spun, heat-drawn and heat-set by a twin-screw extruder at 220° C. and 250 r / min to obtain high-tenacity composite fibers; Finally, the high-tenacity composite fiber prepared as above is woven into cut-resistant fabric through a textile process. The fabric includes gloves, clothing, cloth, etc. The fabric is tested according to EN388-2016, and its cut-resistant grade is B, the abrasion resistance is 4000 revolutions, and the impact strength is 5 KJ / ㎡. The fabric can also be used in chemical scenarios after corrosion resistance testing. Embodiment 5:

[0015] This embodiment provides a high-tenacity composite fiber, which is prepared from homopolypropylene with a viscosity average molecular weight of 400,000 (the homopolypropylene purchased is a product produced by Hengli Petrochemical), silicon carbide whiskers modified by a silane coupling agent with a content of 2.5wt% homopolypropylene, and an ultra-high molecular weight polyethylene swelling body with a viscosity average molecular weight of 5 million; Specifically: first, silicon carbide whiskers (the silicon carbide whiskers purchased are SiCW-80 products or SiCW-90 products produced by Qinhuangdao Yinuo High-tech Materials Development Co., Ltd.) and silane coupling agents with a weight ratio of 1:0.5 are selected to prepare silicon carbide whiskers modified by silane coupling agents, wherein β-type silicon carbide whiskers with a diameter of 200-500nm and a length of 3-20μm are used, and the silane coupling agent is a mixture of dodecylsilane coupling agent (the dodecylsilane coupling agent purchased is UP-312 product or UP-313 product produced by Nanjing Youpu Chemical Co., Ltd.) and 3-aminopropyltrimethoxysilane (3-aminopropyltrimethoxysilane purchased is KH-540 product produced by Qingdao Hengda Zhongcheng Technology Co., Ltd.) with a weight ratio of 2:3; The specific preparation process of the silane coupling agent modified silicon carbide whisker is as follows: the selected silicon carbide whisker is first ultrasonically dispersed in deionized water for 30 minutes, then a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane is added, and then the temperature is controlled at 70°C, stirred for 5 hours, and then dried to obtain the silane coupling agent modified silicon carbide whisker; Secondly, the silicon carbide whiskers modified by the silane coupling agent prepared above are dispersed on the surface of homopolypropylene by heating and blending to obtain a blended spinning material; Secondly, due to the extremely high relative molecular mass of ultra-high molecular weight polyethylene, its melt viscosity is significantly higher than other fluids, and its processing fluidity is extremely poor. When blended with other polymers, it is unevenly dispersed and has low compatibility. Therefore, it is necessary to improve the dispersibility of ultra-high molecular weight polyethylene in the matrix and its compatibility with the matrix. For this reason, the dissolution of ultra-high molecular weight polyethylene must follow the general law of polymer dissolution. It must swell first and then dissolve when in contact with the solvent. Low molecular weight white oil is used as the solvent to swell the ultra-high molecular weight polyethylene, reduce the viscosity of the system, and enhance the mobility of the macromolecular chain, so that it can be better dispersed when blended with polypropylene, and improve the compatibility between the two, thereby achieving the purpose of better improving the comprehensive performance of the composite material. The specific preparation process of the ultra-high molecular weight polyethylene swellable body is as follows: 7 parts of ultra-high molecular weight polyethylene are added to 93 parts of white oil to prepare a suspension with a solid content of 7 wt%, and the suspension is swelled for 20 minutes at 130-140° C. using a magnetic stirring at a speed of 220-380 rpm, and then filtered with an 80-mesh filter screen, and when no white oil flows down from the filter screen, the ultra-high molecular weight polyethylene swellable body on the filter screen is collected; Then, 5% by weight of the ultra-high molecular weight polyethylene swelling body is blended with the blended spinning material by melt spinning, extruded by a twin-screw extruder at 220° C. and 250 r / min, and then pelletized by a pelletizer to obtain ultra-high molecular weight polyethylene / polypropylene composite material pellets, which are melt-spun, heat-drawn and heat-set by a twin-screw extruder at 220° C. and 250 r / min to obtain high-tenacity composite fibers; Finally, the high-tenacity composite fiber prepared as above is woven into anti-cut fabric through a textile process. The fabric includes gloves, clothing, cloth, etc. The fabric is tested according to EN388-2016, and its anti-cut grade is A, the abrasion resistance is 8000 turns, and the impact strength is 10 KJ / ㎡. The fabric can also be used in chemical scenarios after corrosion resistance testing.

[0016] Comparative Example 1: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the content of the silicon carbide whiskers modified by the silane coupling agent is 0.5 wt % of the homopolypropylene.

[0017] Comparative Example 2: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the content of the silicon carbide whiskers modified by the silane coupling agent is 8 wt % of the homopolypropylene.

[0018] Comparative Example 3: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the viscosity average molecular weight of the homopolypropylene is 250,000.

[0019] Comparative Example 4: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the viscosity average molecular weight of the homopolypropylene is 560,000, and the product purchased is produced by Sinopec Zhenhai Refining and Chemical Company.

[0020] Comparative Example 5: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the molecular weight of the ultra-high molecular weight polyethylene is 8 million.

[0021] Comparative Example 6: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the molecular weight of the ultra-high molecular weight polyethylene is 2 million.

[0022] Comparative Example 7: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the content of ultra-high molecular weight polyethylene is 0.5% of the homopolymer polypropylene.

[0023] Comparative Example 8: The high-tenacity composite fiber provided in this comparative example is prepared from homopolymerized polypropylene, silicon carbide whiskers modified by a silane coupling agent, and an ultra-high molecular weight polyethylene swollen body; The difference between this comparative example and Example 1 is that the content of ultra-high molecular weight polyethylene is 9.5% of the homopolymer polypropylene.

[0024] The following is a table of impact strength, cut resistance grade and abrasion resistance of cut-resistant fabrics woven from Examples 1-5 and Comparative Examples 1-8. The cut resistance grade and abrasion resistance are tested according to EN388-2016, and the impact strength is tested according to GB / T1843-2008 standard: ; As can be seen from the above table, silicon carbide whiskers modified by silane coupling agents and ultra-high molecular weight polyethylene swellable bodies are dispersed in homopolypropylene to obtain high-tenacity composite fibers, and then the high-tenacity composite fibers are woven into cut-resistant fabrics through a textile process. The impact strength, cut-resistant grade and wear resistance of the fabrics are related to the content of silicon carbide whiskers modified by silane coupling agents, the viscosity-average molecular weight of homopolypropylene, the molecular weight of ultra-high molecular weight polyethylene swellable bodies and the content of ultra-high molecular weight polyethylene swellable bodies. Therefore, the high-tenacity composite fibers prepared by the present invention not only retain the wear resistance and cut resistance of the fibers to the maximum extent, but also effectively improve the flexibility and corrosion resistance of the fibers, thereby ensuring the weavability of the composite fibers and being able to adapt to harsh environmental conditions, thereby effectively expanding the application scope of the composite fibers in the field of labor protection products.

Claims

1. A high-tenacity composite fiber, characterized in that: The raw material components of the composite fiber include homopolypropylene, silicon carbide whiskers modified by silane coupling agent and ultra-high molecular weight polyethylene swelling body with viscosity average molecular weight> 1 million. The ultra-high molecular weight polyethylene swelling body includes ultra-high molecular weight polyethylene and high distillation range mineral oil. The specific preparation steps are as follows: ultra-high molecular weight polyethylene is added to high distillation range mineral oil to prepare a 3-7wt% suspension, and the ultra-high molecular weight polyethylene swelling body is obtained by magnetic stirring for swelling and filtering with an 80-mesh filter.

2. A high-tenacity composite fiber according to claim 1, characterized in that: The weight ratio of the ultra-high molecular weight polyethylene to the high distillation range mineral oil is 3:97-7:93, and the high distillation range mineral oil is white oil.

3. The high-tenacity composite fiber according to claim 1, characterized in that: The rotation speed of the magnetic stirring is 220-380 rpm, and the swelling time is 10-30 min.

4. The high-tenacity composite fiber according to claim 1, characterized in that: The viscosity average molecular weight of the homopolypropylene is 320,000 to 480,000.

5. A high-tenacity composite fiber according to claim 4, characterized in that: The content of the silicon carbide whisker modified by the silane coupling agent is 0.8-5.8wt% of homopolypropylene.

6. A high-tenacity composite fiber according to claim 5, characterized in that: The raw material components of the silane coupling agent modified silicon carbide whisker include silicon carbide whisker and silane coupling agent in a weight ratio of 1:0.2-0.

8.

7. A high-tenacity composite fiber according to claim 6, characterized in that: The silicon carbide whisker is of β-crystal type and its diameter and length are 200-500nm and 3-20µm respectively.

8. The high-tenacity composite fiber according to claim 6, characterized in that: The raw material component of the silane coupling agent is a mixture of dodecylsilane coupling agent and 3-aminopropyltrimethoxysilane in a weight ratio of 1-3:3-1.

9. The high-tenacity composite fiber according to claim 1, characterized in that: The specific preparation steps of the composite fiber are: firstly, dispersing the silicon carbide whiskers modified by silane coupling agent on the surface of homopolypropylene by heating and blending to obtain a blended spinning material, and then spinning the blended spinning material and an ultra-high molecular weight polyethylene swelling body by melt spinning at 200-240°C, heat drawing and heat setting to obtain a high-tenacity composite fiber.

10. A cut-resistant fabric, characterized in that: It is prepared using a high-tenacity composite fiber as described in any one of claims 1 to 9.