Regenerated high-density polyethylene for marine fishing net and preparation method therefor

Abstract

The present invention relates to the technical field of high-density polyethylene, and specifically relates to regenerated high-density polyethylene for a marine fishing net and a preparation method therefor. A solution comprises: mixing regenerated high-density polyethylene, high-density polyethylene, carbon black, a compatibilizer, a lubricant, a compound polyurethane elastomer and a compound antioxidant, and subjecting same to melt extrusion to obtain high-density polyethylene for a fishing net. In the solution, in order to improve the strength and comprehensive mechanical properties of polyethylene, the polyurethane elastomer is added to reinforce same; and the polyurethane elastomer is prepared by reacting hydroxyl-terminated polybutadiene with an isocyanate, and compared with a conventional polyurethane elastomer, the polyurethane elastomer has a higher compatibility with a system and a better reinforcement effect. In the solution, polyhydroxy-terminated polybutadiene and an isocyanate are pre-polymerized and then grafted with an antioxidant, i.e., 2,2'-thiobis(4-methyl-6-tert-butylphenol), and therefore a long-chain antioxidant is generated; and when the antioxidant is compounded with the antioxidant 1010, the aging resistance of a product can be effectively improved.

Description

Recycled high-density polyethylene for marine fishing nets and preparation method thereof Technical Field

[0001] The present invention relates to the technical field of high-density polyethylene, in particular to recycled high-density polyethylene for marine fishing nets and a preparation method thereof. Background Art

[0002] HDPE recycled material, also known as high-density polyethylene recycled material, is made by reusing recycled HDPE nozzle materials and HDPE products. After cleaning, dewatering, and crushing, it is passed through a granulator and granulated. However, the physical properties of HDPE recycled material are poor, and due to repeated processing, the aging performance of the material is also affected, making it unable to meet our needs in actual use.

[0003] Therefore, how to improve the comprehensive mechanical properties and anti-aging properties of recycled high-density polyethylene is a technical problem that we urgently need to solve. This solution discloses a recycled high-density polyethylene for marine fishing nets and a preparation method thereof to solve this technical problem.

[0004] Summary of the Invention

[0005] The object of the present invention is to provide a recycled high-density polyethylene for marine fishing nets and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0008] (1) Mixing hydroxyl-terminated polybutadiene with a molecular weight of 1000 to 1500 and toluene, stirring until dissolved, adding tetrabutylammonium bromide and solid sodium hydroxide, heating to 40 to 45°C, adding epichlorohydrin, reacting in a water bath at 55 to 60°C for 1.5 to 2.5 hours, collecting the filtrate by suction, adjusting the pH to neutral with sulfuric acid, and removing toluene and water by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether; mixing epoxy-terminated polybutadiene glycidyl ether, deionized water, and concentrated sulfuric acid, hydrolyzing at 25 to 30°C for 3 hours, and washing with water until neutral to obtain modified hydroxyl-terminated polybutadiene;

[0009] (2) mixing the alcohol monomer and polyoxypropylene glycol, stirring evenly, heating to 80-85° C., adding dibutyltin dilaurate, stirring for 20-30 minutes, then adding isophorone diisocyanate, pouring into a mold, vacuuming for 20-30 minutes, and curing at 45-50° C. for 7-10 days to obtain a polyurethane elastomer;

[0010] When the alcohol monomer is a modified hydroxyl-terminated polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is a hydroxyl-terminated polybutadiene with a molecular weight of 1600 to 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is a hydroxyl-terminated polybutadiene with a molecular weight of 2000 to 2500, the reaction produces polyurethane elastomer C;

[0011] (3) compounding and mixing polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer;

[0012] Recycled high-density polyethylene, high-density polyethylene, carbon black, a compatibilizer, a lubricant, a compounded polyurethane elastomer, and a compounded antioxidant are mixed and melt-extruded to obtain the polyethylene having a melting temperature of 175°C.

[0013] In a more optimized solution, in step (1), the molar ratio of terminal hydroxyl polybutadiene with a molecular weight of 1000-1500, tetrabutylammonium bromide, solid sodium hydroxide, and epichlorohydrin is 1: (0.03-0.04): (2.8-3.0): (2.8-2.9).

[0014] In a more optimized solution, in the step (3) of compounding the polyurethane elastomer, the mass ratio of the polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2: (1-1.5): (0.6-0.8).

[0015] In a more optimized solution, in step (3), the content of each component is: by mass, 90-95 parts of recycled high-density polyethylene, 5-8 parts of high-density polyethylene, 1-2 parts of carbon black, 10-12 parts of compatibilizer, 1-1.5 parts of lubricant, 8-10 parts of compounded polyurethane elastomer, and 1-2 parts of compounded antioxidant.

[0016] In a more optimized solution, the compatibilizer is maleic anhydride grafted polyethylene; the lubricant is calcium stearate; and the compound antioxidant is a mixture of a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010, with a mass ratio of (4-5):1.

[0017] A more optimized scheme, the specific preparation steps of the terminal hydroxyl polybutadiene modified antioxidant are: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under a nitrogen environment, react at 40-45°C for 4-5 hours, then heat to 70-75°C, add 2,2'-thiobis(4-methyl-6-tert-butylphenol), keep the temperature and react for 5-6 hours, collect the product after the reaction, and vacuum dry it to obtain the terminal hydroxyl polybutadiene modified antioxidant.

[0018] In a more optimized solution, the molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is (2-3):1; the amount of dibutyltin dilaurate is 1-1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is (2.5-3):1.

[0019] In a more optimized solution, in step (2), the mass ratio of the alcohol monomer to polyoxypropylene glycol is (9-10):1, and the amount of dibutyltin dilaurate is 0.1-0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl group is (1-1.2).

[0020] A more optimized solution is polyethylene prepared according to any of the above methods for preparing recycled high-density polyethylene for marine fishing nets.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The invention discloses a recycled high-density polyethylene for marine fishing nets and a preparation method thereof. The recycled high-density polyethylene, high-density polyethylene, carbon black, a compatibilizer, a lubricant, a compounded polyurethane elastomer, and a compounded antioxidant are mixed and melt-extruded to obtain the high-density polyethylene for fishing nets. In this solution, in order to improve the strength and comprehensive mechanical properties of the polyethylene, a polyurethane elastomer is added to reinforce it. The polyurethane elastomer is prepared by reacting terminal hydroxyl polybutadiene and isocyanate. Compared with conventional polyurethane elastomers, the polyurethane elastomer has higher compatibility with the system and better reinforcement effect.

[0023] On this basis, the scheme also prepares different polyurethane elastomers according to the different molecular weights of terminal hydroxyl polybutadiene, and compounding them to form compound polyurethane elastomers; the scheme first epoxidizes the hydroxyl groups at both ends of terminal hydroxyl polybutadiene with a molecular weight of 1000-1500 and then hydrolyzes them to open the ring to generate multi-hydroxyl-terminated polybutadiene. Since the terminal hydroxyl polybutadiene selected at this time has a low molecular weight, the multi-hydroxyl-terminated polybutadiene is selected to improve the cross-linking of the polyurethane elastomer, thereby improving the reinforcement effect of polyurethane elastomer A; and the terminal hydroxyl polybutadiene with a molecular weight of 1600-1800 and the terminal hydroxyl polybutadiene with a molecular weight of 2000-2500 used subsequently have larger molecular weights. If they are epoxidized and then open the ring, it will affect the reinforcement of the system. Therefore, they are only reacted with isocyanate to obtain polyurethane elastomer B and polyurethane elastomer C; the compounded elastomer obtained by compounding can reinforce polyethylene to the greatest extent.

[0024] At the same time, in order to improve the anti-aging performance of the product, the solution uses polyhydroxy-terminated polybutadiene and isocyanate pre-polymerization and then grafted with the antioxidant 2,2'-thiobis(4-methyl-6-tert-butylphenol) to generate a long-chain antioxidant. On the one hand, the antioxidant is compounded with antioxidant 1010 to effectively improve the anti-aging performance of the product; on the other hand, the migration resistance of the antioxidant in the system is greatly reduced, the anti-aging performance of the product is maintained for a long time, and the overall practicality is higher.

[0025] The present invention discloses a recycled high-density polyethylene for marine fishing nets and a preparation method thereof. The overall formula of the scheme is suitable and the process parameters of each step are appropriate. The prepared polyethylene not only has excellent mechanical properties and high strength, but also has excellent anti-aging performance and high practicality. DETAILED DESCRIPTION

[0026] 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.

[0027] In the following examples, hydroxyl-terminated polybutadiene 1 has a number average molecular weight of 1500 g / mol and a hydroxyl value of 1.5 mmol / g; hydroxyl-terminated polybutadiene 2 has a number average molecular weight of 1800 g / mol and a hydroxyl value of 1.44 mmol / g; and hydroxyl-terminated polybutadiene 3 has a number average molecular weight of 2400 g / mol and a hydroxyl value of 0.67 mmol / g. All of the above are provided by Luoyang Liming Chemical Research Institute; recycled high-density polyethylene is obtained by recycling plastic bottle caps and milk bottle caps, cutting, cleaning, and drying, with a melt index (MFI, 190°C / 5 kg) of 5.8 g / 10 min, and is provided by Xiongxian Tianhai Plastic Products Factory; polyoxypropylene glycol (N210), Mn=1000, is provided by Yantai Wanhua Polyurethane Co., Ltd.; high-density polyethylene 5000S is provided by PetroChina Daqing Petrochemical Company; and maleic anhydride-grafted polyethylene: maleic anhydride-grafted low-density polyethylene, MV206, with an MAH grafting rate of 1%, is provided by Shanghai Rizhisheng New Technology Development Co., Ltd.

[0028] Example 1: A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0029] (1) 0.01 mol of 1500 molecular weight hydroxy-terminated polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 40°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 55°C for 2.5 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified hydroxy-terminated polybutadiene.

[0030] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0031] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 80°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 45°C for 7 days to obtain a polyurethane elastomer.

[0032] When the alcohol monomer is modified terminal hydroxyl polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is terminal hydroxyl polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is terminal hydroxyl polybutadiene 3 with a molecular weight of 2400, the reaction produces polyurethane elastomer C.

[0033] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0034] (3) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 40℃ for 5h, then heat to 70℃, add 2,2'-thiobis(4-methyl-6-tert-butylphenol), keep warm and react for 6h, collect the product after the reaction, vacuum dry it to obtain terminal hydroxyl polybutadiene modified antioxidant.

[0035] The molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is 2:1; the amount of dibutyltin dilaurate is 1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0036] (4) Compounding polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:1:0.6. Mixing a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 to obtain a compounded antioxidant; the mass ratio of the terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 is 5:1.

[0037] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 8 parts of a compounded polyurethane elastomer, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0038] Example 2: A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0039] (1) 0.01 mol of 1500 molecular weight hydroxy-terminated polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 45°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 58°C for 2 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified hydroxy-terminated polybutadiene.

[0040] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0041] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 25 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0042] When the alcohol monomer is modified terminal hydroxyl polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is terminal hydroxyl polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is terminal hydroxyl polybutadiene 3 with a molecular weight of 2400, the reaction produces polyurethane elastomer C.

[0043] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0044] (3) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 45 ° C for 4.5 hours, then heat to 75 ° C, add 2,2'-thiobis (4-methyl-6-tert-butylphenol), keep warm and react for 5.5 hours, collect the product after the reaction, vacuum dry, and obtain terminal hydroxyl polybutadiene modified antioxidant.

[0045] The molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is 2:1; the amount of dibutyltin dilaurate is 1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0046] (4) Compounding polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:1:0.6. Mixing a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 to obtain a compounded antioxidant; the mass ratio of the terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 is 5:1.

[0047] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 9 parts of a compounded polyurethane elastomer, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0048] Example 3: A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0049] (1) 0.01 mol of 1500 molecular weight end-hydroxy polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 45°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 60°C for 1.5 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified end-hydroxy polybutadiene.

[0050] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0051] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0052] When the alcohol monomer is modified terminal hydroxyl polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is terminal hydroxyl polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is terminal hydroxyl polybutadiene 3 with a molecular weight of 2400, the reaction produces polyurethane elastomer C.

[0053] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0054] (3) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 45 ° C for 4.5 hours, then heat to 75 ° C, add 2,2'-thiobis (4-methyl-6-tert-butylphenol), keep warm and react for 6 hours, collect the product after the reaction is completed, and vacuum dry to obtain terminal hydroxyl polybutadiene modified antioxidant.

[0055] The molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is 2:1; the amount of dibutyltin dilaurate is 1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0056] (4) Compounding polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:1:0.6. Mixing a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 to obtain a compounded antioxidant; the mass ratio of the terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 is 5:1.

[0057] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 10 parts of a compounded polyurethane elastomer, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0058] Comparative Example 1: Example 3 was used as the control group. In Comparative Example 1, the hydroxy-terminated polybutadiene 1 was not modified. Only the hydroxy-terminated polybutadiene 1 was used to prepare the polyurethane elastomer A and the hydroxy-terminated polybutadiene-modified antioxidant, and the other steps remained unchanged.

[0059] A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0060] (1) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0061] When the alcohol monomer is hydroxyl-terminated polybutadiene 1 with a molecular weight of 1500, the reaction produces polyurethane elastomer A; when the alcohol monomer is hydroxyl-terminated polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is hydroxyl-terminated polybutadiene 3 with a molecular weight of 2400, the reaction produces polyurethane elastomer C.

[0062] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0063] (2) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take terminal hydroxyl polybutadiene 1, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 45 ° C for 4.5 hours, then heat to 75 ° C, add 2,2'-thiobis (4-methyl-6-tert-butylphenol), keep warm and react for 6 hours, collect the product after the reaction is completed, and vacuum dry to obtain terminal hydroxyl polybutadiene modified antioxidant.

[0064] The molar ratio of the terminal hydroxyl polybutadiene 1 and isophorone diisocyanate is 2:1; the amount of the dibutyltin dilaurate is 1.5wt% of the isophorone diisocyanate; and the molar ratio of the 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0065] (3) Compounding polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:1:0.6. Mixing a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 to obtain a compounded antioxidant; the mass ratio of the terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 is 5:1.

[0066] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 10 parts of a compounded polyurethane elastomer, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0067] Comparative Example 2: Example 3 was used as the control group. In Comparative Example 2, only conventional antioxidant 1010 was used, and its dosage was increased, while the other steps remained unchanged.

[0068] A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0069] (1) 0.01 mol of 1500 molecular weight end-hydroxy polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 45°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 60°C for 1.5 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified end-hydroxy polybutadiene.

[0070] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0071] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0072] When the alcohol monomer is modified terminal hydroxyl polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is terminal hydroxyl polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is terminal hydroxyl polybutadiene 3 with a molecular weight of 2400, the reaction produces polyurethane elastomer C.

[0073] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0074] (3) Compounding and mixing polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of the polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:1:0.6.

[0075] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 10 parts of a compounded polyurethane elastomer, and 3.5 parts of an antioxidant 1010, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0076] Comparative Example 3: Example 3 was used as the control group. In Comparative Example 3, no hydroxy-terminated polybutadiene 3 was introduced, and the remaining steps remained unchanged.

[0077] A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0078] (1) 0.01 mol of 1500 molecular weight end-hydroxy polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 45°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 60°C for 1.5 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified end-hydroxy polybutadiene.

[0079] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0080] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0081] When the alcohol monomer is modified terminal hydroxyl polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is terminal hydroxyl polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B.

[0082] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0083] (3) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 45 ° C for 4.5 hours, then heat to 75 ° C, add 2,2'-thiobis (4-methyl-6-tert-butylphenol), keep warm and react for 6 hours, collect the product after the reaction is completed, and vacuum dry to obtain terminal hydroxyl polybutadiene modified antioxidant.

[0084] The molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is 2:1; the amount of dibutyltin dilaurate is 1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0085] (4) Compounding polyurethane elastomer A and polyurethane elastomer B to obtain a compounded polyurethane elastomer; the mass ratio of polyurethane elastomer A to polyurethane elastomer B is 2:1. Mixing a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 to obtain a compounded antioxidant; the mass ratio of the terminal hydroxyl polybutadiene modified antioxidant to antioxidant 1010 is 5:1.

[0086] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 10 parts of a compounded polyurethane elastomer, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0087] Comparative Example 4: Taking Example 3 as the control group, the proportion of terminal hydroxyl polybutadiene 3 in Comparative Example 4 was increased, and the other steps remained unchanged.

[0088] A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0089] (1) 0.01 mol of 1500 molecular weight end-hydroxy polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 45°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 60°C for 1.5 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified end-hydroxy polybutadiene.

[0090] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0091] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0092] When the alcohol monomer is modified terminal hydroxyl polybutadiene, the reaction produces polyurethane elastomer A; when the alcohol monomer is terminal hydroxyl polybutadiene 2 with a molecular weight of 1800, the reaction produces polyurethane elastomer B; when the alcohol monomer is terminal hydroxyl polybutadiene 3 with a molecular weight of 2400, the reaction produces polyurethane elastomer C.

[0093] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0094] (3) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 45 ° C for 4.5 hours, then heat to 75 ° C, add 2,2'-thiobis (4-methyl-6-tert-butylphenol), keep warm and react for 6 hours, collect the product after the reaction is completed, and vacuum dry to obtain terminal hydroxyl polybutadiene modified antioxidant.

[0095] The molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is 2:1; the amount of dibutyltin dilaurate is 1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0096] (4) Compounding polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:1:1.2. Mixing a terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 to obtain a compounded antioxidant; the mass ratio of the terminal hydroxyl polybutadiene modified antioxidant and antioxidant 1010 is 5:1.

[0097] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 10 parts of a compounded polyurethane elastomer, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0098] Comparative Example 5: Example 3 was used as the control group. In Comparative Example 5, hydroxyl-terminated polybutadiene 2 and hydroxyl-terminated polybutadiene 3 were not introduced, and only hydroxyl-terminated polybutadiene 1 was added, and the other steps remained unchanged.

[0099] A recycled high-density polyethylene for marine fishing nets and a preparation method thereof, comprising the following steps:

[0100] (1) 0.01 mol of 1500 molecular weight end-hydroxy polybutadiene 1 and 10 mL of toluene were mixed and stirred until dissolved. Tetrabutylammonium bromide and solid sodium hydroxide were added, and the mixture was heated to 45°C. Epichlorohydrin was added and the mixture was reacted in a water bath at 60°C for 1.5 h. The filtrate was collected by filtration, and the pH was adjusted to neutral with sulfuric acid. Toluene and water were removed by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether. The epoxy-terminated polybutadiene glycidyl ether obtained by the reaction was mixed with 50 mL of deionized water and 3 drops of concentrated sulfuric acid. The mixture was hydrolyzed at 25°C for 3 h, washed with water until neutral, and water was removed by vacuum distillation at 90°C to obtain modified end-hydroxy polybutadiene.

[0101] The molar ratio of hydroxy-terminated polybutadiene 1 with a molecular weight of 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.9.

[0102] (2) The alcohol monomer and polyoxypropylene glycol were mixed, stirred evenly, heated to 85°C, dibutyltin dilaurate was added, stirred for 30 minutes, and then isophorone diisocyanate was added. The mixture was poured into a mold, vacuumed for 30 minutes, and cured at 50°C for 7 days to obtain a polyurethane elastomer.

[0103] When the alcohol monomer is modified terminal hydroxyl polybutadiene, polyurethane elastomer A is prepared by reaction.

[0104] When preparing the above polyurethane elastomer, the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1, and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer; the R value in the system, that is, the molar ratio of isocyanate to hydroxyl in the system is 1.2.

[0105] (3) Preparation of terminal hydroxyl polybutadiene modified antioxidant: take modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mix them, stir them evenly, add isophorone diisocyanate under nitrogen environment, react at 45 ° C for 4.5 hours, then heat to 75 ° C, add 2,2'-thiobis (4-methyl-6-tert-butylphenol), keep warm and react for 6 hours, collect the product after the reaction is completed, and vacuum dry to obtain terminal hydroxyl polybutadiene modified antioxidant.

[0106] The molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is 2:1; the amount of dibutyltin dilaurate is 1.5wt% of isophorone diisocyanate; and the molar ratio of 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is 3:1.

[0107] (4) Mixing the end-hydroxy polybutadiene modified antioxidant and antioxidant 1010 to obtain a compound antioxidant; the mass ratio of the end-hydroxy polybutadiene modified antioxidant and antioxidant 1010 is 5:1.

[0108] The polyethylene is obtained by mixing, by weight, 90 parts of recycled high-density polyethylene, 8 parts of high-density polyethylene, 2 parts of carbon black, 12 parts of a compatibilizer, 1.5 parts of a lubricant, 10 parts of a polyurethane elastomer A, and 1.5 parts of a compounded antioxidant, and melt-extruding the mixture. The compatibilizer is maleic anhydride-grafted polyethylene, and the lubricant is calcium stearate.

[0109] Detection experiment:

[0110] Tensile strength: The polyethylene prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was injection molded to obtain dumbbell-shaped samples at an injection temperature of 180°C. The tensile strength was tested according to the method disclosed in GB / T 1040-2006 at a tensile rate of 50 mm / min and a gauge length of 25 mm.

[0111] 200°C oxidation induction period: The oxidation induction period was tested with reference to the method disclosed in GB / T19466.6-2009. The heating rate was 20°C / min, and the temperature was raised to 200°C. The oxidation induction period at 200°C was recorded.

[0112] Migration resistance of antioxidants: The polyethylene prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was injection molded at an injection temperature of 180°C to obtain a sheet sample with a size of 15 cm × 15 cm × 1 cm. The sheet sample was immersed in 30 mL of anhydrous ethanol and placed in a 50°C water bath for 48 h. After being taken out, it was vacuum-dried at 40°C for 12 h, and the oxidation induction period at 200°C was re-measured.

[0113] Conclusion: According to the above data, the scheme modifies the terminal hydroxyl polybutadiene 1 to prepare polyurethane elastomer A, and then uses polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to achieve polyethylene reinforcement; at the same time, a compound antioxidant is used to ensure the anti-aging performance of the product.

[0114] The present invention discloses a recycled high-density polyethylene for marine fishing nets and a preparation method thereof. The overall formula of the scheme is suitable, and the process parameters of each step are appropriate. The prepared polyethylene not only has excellent mechanical properties and high strength, but also has excellent anti-aging properties and high practicality.

[0115] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing recycled high-density polyethylene for marine fishing nets, characterized in that: The following steps are involved: (1) Mixing terminal hydroxyl polybutadiene with a molecular weight of 1000 to 1500 and toluene, stirring until dissolved, adding tetrabutylammonium bromide and solid sodium hydroxide, heating to 40 to 45° C., adding epichlorohydrin, reacting in a water bath at 55 to 60° C. for 1.5 to 2.5 hours, collecting the filtrate by suction, adjusting the pH to neutral with sulfuric acid, and removing toluene and water by vacuum distillation to obtain epoxy-terminated polybutadiene glycidyl ether; mixing epoxy-terminated polybutadiene glycidyl ether, deionized water, and concentrated sulfuric acid, hydrolyzing at 25 to 30° C. for 3 hours, and washing with water until neutral to obtain modified terminal hydroxyl polybutadiene; (2) mixing the alcohol monomer and polyoxypropylene glycol, stirring evenly, heating to 80-85° C., adding dibutyltin dilaurate, stirring for 20-30 minutes, then adding isophorone diisocyanate, pouring into a mold, evacuating for 20-30 minutes, and curing at 45-50° C. to obtain a polyurethane elastomer; When the alcohol monomer is a modified terminal hydroxyl polybutadiene, the reaction produces a polyurethane elastomer A; when the alcohol monomer is a terminal hydroxyl polybutadiene with a molecular weight of 1600 to 1800, the reaction produces a polyurethane elastomer B; when the alcohol monomer is a terminal hydroxyl polybutadiene with a molecular weight of 2000 to 2500, the reaction produces a polyurethane elastomer C; (3) Compounding and mixing polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C to obtain a compounded polyurethane elastomer; the mass ratio of the polyurethane elastomer A, polyurethane elastomer B, and polyurethane elastomer C is 2:(1-1.5):(0.6-0.8); Recycled high-density polyethylene, high-density polyethylene, carbon black, a compatibilizer, a lubricant, a compounded polyurethane elastomer, and a compounded antioxidant are mixed and melt-extruded to obtain the polyethylene; The compound antioxidant is a mixture of a terminal hydroxyl polybutadiene modified antioxidant and an antioxidant 1010, with a mass ratio of (4-5):1; The specific preparation steps of the terminal hydroxyl polybutadiene modified antioxidant are: taking modified terminal hydroxyl polybutadiene, dibutyltin dilaurate and toluene, mixing, stirring evenly, adding isophorone diisocyanate under nitrogen environment, reacting at 40-45° C. for 4-5 hours, then heating to 70-75° C., adding 2,2'-thiobis(4-methyl-6-tert-butylphenol), keeping warm for reaction for 5-6 hours, collecting the product after the reaction is completed, and vacuum drying to obtain the terminal hydroxyl polybutadiene modified antioxidant.

2. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 1, characterized in that: In step (1), the molar ratio of terminal hydroxyl polybutadiene with a molecular weight of 1000 to 1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1: (0.03 to 0.04): (2.8 to 3.0): (2.8 to 2.9).

3. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 2, characterized in that: The molar ratio of terminal hydroxyl polybutadiene with a molecular weight of 1000-1500, tetrabutylammonium bromide, solid sodium hydroxide and epichlorohydrin is 1:0.03:3.0:2.

9.

4. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 1, characterized in that: In step (2), the mass ratio of the alcohol monomer to polyoxypropylene glycol is (9-10):1, the amount of dibutyltin dilaurate is 0.1-0.15wt% of the alcohol monomer; and the molar ratio of isocyanate to hydroxyl in the system is (1-1.2).

5. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 4, characterized in that: In step (2), the mass ratio of the alcohol monomer to polyoxypropylene glycol is 9.5:1; and the amount of dibutyltin dilaurate is 0.15wt% of the alcohol monomer.

6. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 1, characterized in that: In step (3), the content of each component is: by mass, 90-95 parts of recycled high-density polyethylene, 5-8 parts of high-density polyethylene, 1-2 parts of carbon black, 10-12 parts of compatibilizer, 1-1.5 parts of lubricant, 8-10 parts of compounded polyurethane elastomer, and 1-2 parts of compounded antioxidant.

7. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 6, characterized in that: The compatibilizer is maleic anhydride grafted polyethylene; and the lubricant is calcium stearate.

8. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 1, characterized in that: In the specific preparation steps of the terminal hydroxyl polybutadiene modified antioxidant, the molar ratio of the modified terminal hydroxyl polybutadiene and isophorone diisocyanate is (2-3):1; the molar ratio of the 2,2'-thiobis(4-methyl-6-tert-butylphenol) and isophorone diisocyanate is (2.5-3):

1.

9. The method for preparing recycled high-density polyethylene for marine fishing nets according to claim 8, characterized in that: The molar ratio of the modified terminal hydroxyl polybutadiene to isophorone diisocyanate is 2:1; the molar ratio of the 2,2'-thiobis(4-methyl-6-tert-butylphenol) to isophorone diisocyanate is 3:

1.

10. Polyethylene prepared according to the method for preparing recycled high-density polyethylene for marine fishing nets according to any one of claims 1 to 9.

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