High-performance flame-retardant material prepared based on PA6 recovered from sea and preparation method of high-performance flame-retardant material

Abstract

The invention discloses a preparation method of a PA6 high-performance flame-retardant material based on marine recovery, and belongs to the technical field of high polymer materials. Crushing the waste fishing net by using a crusher to obtain a granular material; metal hydroxide, a phosphorus flame retardant and a nitrogen flame retardant are selected to be organically compounded, grafting modification is performed through a surface coupling agent, and a modified flame retardant is obtained; blending a flame retardant with the granular material, adding a plasticizer and a compatilizer, and fully stirring, mixing and dispersing; adding the mixed materials into a double-screw extruder for melt blending; and carrying out water cooling on the extruded strip-shaped object, and granulating the cooled strip-shaped object in a granulator to obtain high-performance flame-retardant material particles, thereby obtaining the flame-retardant material. The waste fishing net is used as a main raw material to prepare the high-performance flame-retardant material, so that the resource utilization of wastes is realized, the demand on new raw materials is reduced, and remarkable environmental benefits are achieved, while in the prior art, primary polymer materials are mostly used as raw materials, and the effective utilization of the waste fishing net is not involved.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and specifically relates to a high-performance flame-retardant material prepared based on recycled PA6 from Chaohai and a preparation method thereof. Background Art

[0002] As the problem of marine plastic waste pollution intensifies, the harm of ocean-bound plastic (OBP) to the environment is becoming increasingly prominent. Among them, PA6 discarded fishing nets have become one of the main sources of pollution due to their large-scale use and careless disposal. my country alone produces approximately 45,000 tons of PA6 discarded fishing nets each year. These discarded fishing nets are complex in composition, containing polyvinyl chloride labels outside the polyamide matrix, cotton / polyester mixed yarns, algae, mud and other impurities. The recycling and processing process is complex and energy-intensive. At the same time, as a polymer material that is easily absorbed by water and easily hydrolyzed and degraded, the performance of PA6 material further deteriorates in high humidity and high salt environments, resulting in a significant decrease in mechanical properties. Traditional recycling and utilization technologies are difficult to meet its high value-added needs.

[0003] Furthermore, PA6 is widely used in the electronics and electrical appliance sector, but its flame retardancy is insufficient. Commonly used halogen-based flame retardants pose environmental concerns by releasing harmful fumes and gases, while halogen-free flame retardants often require high filler levels, making it difficult to balance flame retardancy with mechanical properties. Furthermore, while PA6 / PET alloys combine the excellent properties of both, direct application is limited due to the incompatibility between the two polymer interfaces. Therefore, developing a method that combines efficient flame retardancy with volume expansion technology to impart superior overall performance to OBP PA6 has become an important research direction. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a method for preparing a high-performance flame retardant material based on PA6 recycled from Chaohai, so as to solve the above problems.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing a high-performance flame retardant material based on PA6 recycled from Chaohai, comprising the following steps:

[0007] S1. Rinse the collected discarded fishing nets with clean water to remove impurities such as mud, sand, and seaweed on the surface, and dry them in an oven. Use a grinder to crush the dried fishing nets to obtain granular materials;

[0008] S2. Selecting a metal hydroxide, a phosphorus-based flame retardant, and a nitrogen-based flame retardant for organic compounding, and then performing graft modification with a surface coupling agent to obtain a modified flame retardant;

[0009] S3, blending the flame retardant with the granular material, and adding the plasticizer and the compatibilizer in a high-speed mixer to fully stir and disperse the components;

[0010] S4, adding the mixed materials to a twin-screw extruder for melt blending, setting the temperature of each section of the extruder, and controlling the screw speed;

[0011] S5. The extruded strips are cooled by water in a water tank. The cooled strips are fed into a pelletizer for pelletization to obtain high-performance flame-retardant material particles. The particles are then uniformly dispersed and processed into shapes using a twin-screw extruder to obtain flame-retardant materials.

[0012] Furthermore, the metal hydroxide is aluminum hydroxide, the phosphorus-based flame retardant is hypophosphite, the nitrogen-based flame retardant is a phosphamide compound, and the surface coupling agent is γ-glycidyloxypropyltrimethoxysilane.

[0013] Furthermore, the mass ratio of the metal hydroxide, the phosphorus-based flame retardant, and the nitrogen-based flame retardant is 2.5-3.5:1.5-2.5:0.5-1.5.

[0014] Furthermore, the plasticizer is tributyl citrate, and the compatibilizer is maleic anhydride grafted polypropylene.

[0015] Furthermore, the mass ratio of the discarded fishing net particles, the flame retardant, the plasticizer, and the compatibilizer is 95-105:14-16:6-10:4-6.

[0016] Furthermore, in step S4, the temperature of each section of the extruder is: 180-190°C in the first section, 190-200°C in the second section, 200-210°C in the third section, 210-220°C in the fourth section, and the head temperature is 220-230°C; the extrusion screw speed is controlled at 200-250r / min.

[0017] Furthermore, in step S5, the particle size of the high performance flame retardant material particles is 3-4 mm.

[0018] The beneficial effects of the present invention are:

[0019] 1. The composite flame retardant of the present invention can exert multiple flame retardant mechanisms during the combustion process of the material, significantly improving the flame retardant effect. The selected plasticizer can not only improve the processing performance of the material, making the discarded fishing net material easier to shape during the preparation process, but also increase the flexibility of the material, preventing the material from becoming brittle during use; and the selected compatibilizer can be used to enhance the compatibility between the discarded fishing net material and the flame retardant and plasticizer, thereby improving the overall performance of the material.

[0020] 2. Compared with traditional single flame retardant materials, the flame retardant prepared by the present invention has higher flame retardant performance and produces less smoke and harmful gases during combustion, which meets environmental protection requirements.

[0021] 3. This invention is the first to use discarded fishing nets as the main raw material to prepare high-performance flame-retardant materials, realizing the resource utilization of waste, reducing the demand for new raw materials, and having significant environmental benefits. Most existing technologies use virgin polymer materials as raw materials and do not involve the effective utilization of discarded fishing nets.

[0022] 4. During the preparation process, the present invention optimizes process parameters such as mixing and melt blending, as well as the addition of compatibilizers and plasticizers, effectively addressing the compatibility issues between discarded fishing net materials and additives such as flame retardants, thereby improving the overall performance of the material. Existing technologies often struggle to address compatibility and performance issues when processing discarded materials.

[0023] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and beneficial effects of the invention clearer, the present invention is described with the following drawings:

[0025] Figure 1 It is a preparation flow chart of the present invention. DETAILED DESCRIPTION

[0026] like Figure 1 As shown, the present invention provides a method for preparing a high-performance flame retardant material based on PA6 recycled from Chaohai.

[0027] Example 1

[0028] S1. The collected discarded fishing nets were rinsed with clean water to remove impurities such as mud, sand, and seaweed on the surface, and then dried in an oven at 80°C for 2.5 hours. The dried fishing nets were then crushed using a grinder to obtain granular materials with a particle size of 3 mm.

[0029] S2. Aluminum hydroxide, hypophosphite, and phosphamide compound are selected in a mass ratio of 3:2:1 for compounding, and then grafting and modifying them with γ-glycidyloxypropyltrimethoxysilane to obtain a modified flame retardant;

[0030] S3, blending the flame retardant with the granular material, and adding tributyl citrate and maleic anhydride grafted polypropylene in a high-speed mixer and stirring and mixing to disperse the components;

[0031] S4, adding the mixed materials into a twin-screw extruder for melt blending, the temperature of each section of the extruder is 185 ° C in the first section, 195 ° C in the second section, 205 ° C in the third section, 215 ° C in the fourth section, and the head temperature is 225 ° C; the extruder speed is controlled at 225 r / min;

[0032] S5. The extruded strips are cooled by water in a water tank. The cooled strips are fed into a pelletizer for pelletization to obtain high-performance flame-retardant material particles. The particles are then uniformly dispersed and processed into shapes using a twin-screw extruder to obtain flame-retardant materials.

[0033] Example 2

[0034] S1. The collected discarded fishing nets were rinsed with clean water to remove impurities such as mud, sand, and seaweed on the surface, and then dried in an oven at 80°C for 2.5 hours. The dried fishing nets were then crushed using a grinder to obtain granular materials with a particle size of 3 mm.

[0035] S2, selecting aluminum hydroxide, hypophosphite and phosphamide compound in a mass ratio of 3.5:1.5:0.5 for compounding, and then grafting and modifying with γ-glycidyloxypropyltrimethoxysilane to obtain a modified flame retardant;

[0036] S3, blending the flame retardant with the granular material, and adding tributyl citrate and maleic anhydride grafted polypropylene in a high-speed mixer and stirring and mixing to disperse the components;

[0037] S4, adding the mixed materials into a twin-screw extruder for melt blending, the temperature of each section of the extruder is 185 ° C in the first section, 195 ° C in the second section, 205 ° C in the third section, 215 ° C in the fourth section, and the head temperature is 225 ° C; the extruder speed is controlled at 225 r / min;

[0038] S5. The extruded strips are cooled by water in a water tank. The cooled strips are fed into a pelletizer for pelletization to obtain high-performance flame-retardant material particles. The particles are then uniformly dispersed and processed into shapes using a twin-screw extruder to obtain flame-retardant materials.

[0039] The difference between Example 2 and Example 1 is that the proportions of the raw materials in the flame retardant are different, but both are within the scope of protection of the present invention.

[0040] Example 3

[0041] S1. The collected discarded fishing nets were rinsed with clean water to remove impurities such as mud, sand, and seaweed on the surface, and then dried in an oven at 80°C for 2.5 hours. The dried fishing nets were then crushed using a grinder to obtain granular materials with a particle size of 3 mm.

[0042] S2, selecting aluminum hydroxide, hypophosphite and phosphamide compound in a mass ratio of 2.5:2.5:1.5 for compounding, and then grafting and modifying with γ-glycidyloxypropyltrimethoxysilane to obtain a modified flame retardant;

[0043] S3, blending the flame retardant with the granular material, and adding tributyl citrate and maleic anhydride grafted polypropylene in a high-speed mixer and stirring and mixing to disperse the components;

[0044] S4, adding the mixed materials into a twin-screw extruder for melt blending, the temperature of each section of the extruder is 185 ° C in the first section, 195 ° C in the second section, 205 ° C in the third section, 215 ° C in the fourth section, and the head temperature is 225 ° C; the extruder speed is controlled at 225 r / min;

[0045] S5. The extruded strips are cooled by water in a water tank. The cooled strips are fed into a pelletizer for pelletization to obtain high-performance flame-retardant material particles. The particles are then uniformly dispersed and processed into shapes using a twin-screw extruder to obtain flame-retardant materials.

[0046] The difference between Example 3 and Example 1 is that the proportions of the raw materials in the flame retardant are different, but both are within the scope of protection of the present invention.

[0047] In order to demonstrate the superiority of the flame retardant of the present invention, comparative examples 1 to 4 are set up, as shown in Table 2:

[0048] Comparative Example 1

[0049] Comparative Example 1 is the same as Example 1 except that a halogen flame retardant is used.

[0050] Comparative Example 2

[0051] Comparative Example 2 is the same as Example 1 except that a single halogen-free metal hydroxide system is used.

[0052] Comparative Example 3

[0053] Comparative Example 3 is the same as Example 1 except that a new phosphorus-nitrogen synergistic system is used.

[0054] Comparative Example 4

[0055] Comparative Example 4 is the same as Example 1 except that a phosphorus-based single flame retardant system is used.

[0056] The performance of the flame retardant materials of Example 1 was compared with that of Comparative Examples 1-4. The results are shown in Table 2.

[0057]

[0058] In order to prove the superiority of the solubilizing agent types of the present invention, comparative examples 5 to 7 are set here, as shown in Table 2:

[0059] Comparative Example 5

[0060] Comparative Example 5 is the same as Example 1 except that no compatibilizer is used.

[0061] Comparative Example 6

[0062] Comparative Example 6 is the same as Example 1 except that the compatibilizer is a multifunctional small molecule compound (1%).

[0063] Comparative Example 7

[0064] Comparative Example 7 is the same as Example 1 except that the compatibilizer is a macromolecular reactive compatibilizer (5%).

[0065] The alloy properties of Example 1 and Comparative Examples 5-7 are compared, as shown in Table 2:

[0066]

[0067] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai, characterized by: S1. Rinse the collected discarded fishing nets with clean water to remove impurities such as mud, sand, and seaweed on the surface, and dry them in an oven. Use a grinder to crush the dried fishing nets to obtain granular materials; S2. Selecting a metal hydroxide, a phosphorus-based flame retardant, and a nitrogen-based flame retardant for organic compounding, and then performing graft modification with a surface coupling agent to obtain a modified flame retardant; S3, blending the flame retardant with the granular material, and adding the plasticizer and the compatibilizer in a high-speed mixer to fully stir and disperse the components; S4, adding the mixed materials to a twin-screw extruder for melt blending, setting the temperature of each section of the extruder, and controlling the screw speed; S5. The extruded strips are cooled by water in a water tank. The cooled strips are fed into a pelletizer for pelletization to obtain high-performance flame-retardant material particles. The particles are then uniformly dispersed and processed into shapes using a twin-screw extruder to obtain flame-retardant materials.

2. The method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai according to claim 1, characterized in that: The metal hydroxide is aluminum hydroxide, the phosphorus-based flame retardant is hypophosphite, the nitrogen-based flame retardant is a phosphamide compound, and the surface coupling agent is γ-glycidyloxypropyltrimethoxysilane.

3. The method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai according to claim 1, characterized in that: The mass ratio of the metal hydroxide, the phosphorus-based flame retardant and the nitrogen-based flame retardant is 2.5-3.5:1.5-2.5:0.5-1.

5.

4. The method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai according to claim 1, characterized in that: The plasticizer is tributyl citrate, and the compatibilizer is maleic anhydride grafted polypropylene.

5. The method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai according to claim 1, characterized in that: The mass ratio of the discarded fishing net particles, the flame retardant, the plasticizer and the compatibilizer is 95-105:14-16:6-10:4-6.

6. The method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai according to claim 1, characterized in that: In step S4, the temperature of each section of the extruder is: 180-190°C for the first section, 190-200°C for the second section, 200-210°C for the third section, 210-220°C for the fourth section, and the head temperature is 220-230°C; the extrusion screw speed is controlled at 200-250r / min.

7. The method for preparing a high-performance flame retardant material based on recycled PA6 from Chaohai according to claim 1, characterized in that: In step S5, the particle size of the high performance flame retardant material particles is 3-4 mm.

Images