High-flame-retardant regenerated polyethylene plastic and preparation process thereof

Abstract

The invention relates to the technical field of regenerated polyethylene materials, and particularly discloses a high-flame-retardant regenerated polyethylene plastic and a preparation process thereof. Comprising the following steps: S1, taking maleic anhydride polyamidoamine, adding water and ethanol, uniformly stirring, adding 1-octene, a vinyl silane coupling agent and benzoyl peroxide, stirring for reaction, and removing a solvent to obtain a modifier; s2, adding carbon black into water and ethanol, uniformly stirring, heating, adding a modifier, and performing reflux reaction to obtain modified carbon black; s3, adding double-bond phosphate and sulfydryl modified benzene diboron into tetrahydrofuran, uniformly stirring, adding high-density polyethylene and a photoinitiator, mixing, carrying out ultraviolet irradiation, filtering, taking a solid, and drying, so as to obtain modified polyethylene; s4, taking regenerated high-density polyethylene, polypropylene, modified polyethylene, calcium stearate, modified carbon black, an antioxidant, a diisocyanate cross-linking agent, dicumyl peroxide and toner, uniformly stirring, and performing melt extrusion to obtain the high-flame-retardant regenerated polyethylene plastic.

Description

Technical Field

[0001] The invention relates to the technical field of recycled polyethylene materials, and specifically discloses a highly flame-retardant recycled polyethylene plastic and a preparation process thereof. Background Art

[0002] With the increasing use of plastic products, a large amount of plastic waste is generated, causing serious pollution. In order to protect the environment and achieve resource reuse, waste plastic recycling has become an important research hotspot. The amount of waste polyethylene accounts for a large proportion of waste plastics, and it is difficult to degrade in the natural environment, so it is the focus of waste plastic recycling.

[0003] After use, waste polyethylene ages, resulting in low mechanical properties, especially impact resistance, which limits its application. At the same time, polyethylene itself is flammable and needs to be modified before use. Therefore, it is of great significance to study a highly flame-retardant recycled polyethylene plastic with good impact resistance and its preparation process. Summary of the invention

[0004] The purpose of the present invention is to provide a highly flame-retardant recycled polyethylene plastic and a preparation process thereof, so as to solve the problems raised in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solutions: a highly flame-retardant recycled polyethylene plastic and a preparation process thereof, comprising the following steps: a highly flame-retardant recycled polyethylene plastic preparation process: comprising the following steps:

[0006] S1: Take maleic anhydride polyamidoamine, add water and ethanol, stir evenly, add 1-octene, vinyl silane coupling agent, benzoyl peroxide, stir and react at 75-78°C for 5-6h, remove the solvent, and obtain a modifier;

[0007] S2: Take carbon black, add water and ethanol, stir evenly, heat to 60-70°C, add modifier, reflux reaction for 10-12h, and obtain modified carbon black;

[0008] S3: Take double-bonded phosphate and mercapto-modified phenyl diboron, add them to tetrahydrofuran and stir evenly, add high-density polyethylene and photoinitiator, stir and mix, 70-80mW / cm 2 Expose to ultraviolet light for 0.5 to 1 hour, filter out the solid, and dry to obtain modified polyethylene;

[0009] S4: Take recycled high-density polyethylene, polypropylene, modified polyethylene, calcium stearate, modified carbon black, antioxidant, diisocyanate crosslinking agent, diisopropyl peroxide, and color powder, stir evenly, and melt extrude at 160-170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0010] More optimally, the modifier includes the following raw materials, calculated by mass: 25 to 30 parts of maleic anhydride polyamidoamine, 2 to 3 parts of 1-octene, 5 to 6 parts of vinyl silane coupling agent (vinyl triethoxysilane), and 0.1 to 0.2 parts of benzoyl peroxide; the modified carbon black includes the following raw materials, calculated by mass: 12 to 15 parts of carbon black and 3 to 4 parts of modifier.

[0011] More optimally, the modified polyethylene includes the following raw materials, calculated by weight: 3 to 4 parts of double-bonded phosphate, 4 to 5 parts of mercapto-modified phenyldiboron, 150 to 200 parts of tetrahydrofuran, 20 to 30 parts of high-density polyethylene, and 0.1 to 0.2 parts of photoinitiator.

[0012] More optimally, the highly flame retardant recycled polyethylene plastic includes the following raw materials, calculated by mass: 80-90 parts of recycled high-density polyethylene, 10-15 parts of polypropylene, 10-15 parts of modified polyethylene, 2-3 parts of calcium stearate, 10-15 parts of modified carbon black, 3-4 parts of antioxidant, 1-2 parts of diisocyanate crosslinking agent, 0.02-0.03 parts of diisocyanate peroxide, and 0.2-0.3 parts of color powder.

[0013] More optimally, the diisocyanate crosslinking agent is 2,6-diisocyanate toluene.

[0014] More preferably, the toner is ultramarine blue toner.

[0015] More preferably, the polypropylene is a methyl branched copolymer polypropylene; containing 4-7% ethylene; a non-toxic, odorless, tasteless milky white highly crystalline polymer; and a density of 0.90-0.91 g / cm 3 ; Water absorption rate is 0.01%; It has excellent bending fatigue resistance (up to tens of millions of times); Melting point is 160-175℃; Decomposition temperature is 350℃.

[0016] More optimally, the high-density polyethylene has: linear structure, non-polarity; non-toxic, tasteless, odorless white particles; melting point of 130°C; melting temperature of 220-260°C; density of 0.940-0.976 g / cm3; crystallinity of 80%-90%; and softening point of 125-135°C.

[0017] More optimally, the preparation of the maleic anhydride polyamidoamine comprises the following steps: adding the dendritic macromolecular polyamidoamine to water and ethanol, stirring evenly, adding maleic anhydride, reacting at room temperature for 8 to 10 hours under nitrogen protection, adding sodium acetate and acetic anhydride, refluxing for 8 to 10 hours, filtering to remove solid impurities, and rotary evaporating to remove the solvent to obtain the maleic anhydride polyamidoamine.

[0018] More optimally, the maleic anhydride polyamidoamine comprises the following raw materials, calculated by weight: 20 to 25 parts of dendritic macromolecular polyamidoamine, 8 to 10 parts of maleic anhydride, 5 to 8 parts of sodium acetate, and 8 to 10 parts of acetic anhydride.

[0019] More optimally, the preparation of the double-bonded phosphate comprises the following steps: mixing 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 3-bromo-1-propylene, sodium carbonate, and tetrahydrofuran, stirring evenly, reacting at 50-60° C. for 3-5 hours, filtering to remove solid impurities, and removing the solvent to obtain the double-bonded phosphate;

[0020] The double-bonded phosphate comprises the following raw materials, calculated by mass: 20 to 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 to 22 parts of 3-bromo-1-propylene, 18 to 20 parts of sodium carbonate, and 120 to 150 parts of tetrahydrofuran.

[0021] More optimally, the preparation of the mercapto-modified phenyldiboron comprises the following steps: taking 1,4-phenyldiboron, 1-thioglycerol, tetrahydrofuran, and water, stirring evenly, adding magnesium sulfate, stirring at 25-30° C. for 24-25 hours, filtering to remove the magnesium sulfate, removing the solvent, cooling to precipitate a white solid, washing, and drying to obtain mercapto-modified phenyldiboron;

[0022] The mercapto-modified phenyldiboron comprises the following raw materials, calculated by weight: 15 to 20 parts of 1,4-phenyldiboron, 20 to 25 parts of 1-thioglycerol, 600 to 800 parts of tetrahydrofuran, 10 to 15 parts of water, and 25 to 30 parts of magnesium sulfate.

[0023] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: a large amount of recycled polyethylene is added to the raw material, so that resource recycling and cyclic utilization is realized; since the recycled polyethylene undergoes a certain degree of aging, the mechanical properties are reduced, especially the impact resistance is poor; the present invention prepares a modified carbon black, and the modifier used includes maleic anhydride polyamide amine, 1-octene, and a vinyl silane coupling agent; the polyamide amine used is a dendrimer structure, which helps to improve flexibility and impact resistance, improve processing performance, and help disperse carbon black; after the dendrimer polyamide amine is modified with maleic anhydride, on the one hand, the compatibility and adhesion are improved, and on the other hand, the double bonds introduced can participate in the next step of the reaction with 1-octene and the vinyl silane coupling agent; 1-octene further improves the impact resistance, and the vinyl silane coupling agent is used in the following One-step modification of carbon black; in the reaction, the addition amount of maleic anhydride polyamidoamine needs to be appropriate, too much addition leads to excessive branching, affecting the processing performance and the reaction efficiency when modifying carbon black; the present invention also introduces modified high-density polyethylene, which includes double-bonded phosphate and mercapto-modified phenyldiboron, to achieve a synergistic flame retardant effect; the reaction of this step is simple and the flame retardant component is grafted onto the polyethylene segment, reducing the aging problem caused by the precipitation of the auxiliary agent; the diisocyanate crosslinking agent used in the present invention promotes further crosslinking of the active groups between the modified carbon black and the modified polyethylene, which helps to improve the performance, but the addition amount should not be too much, too much crosslinking will lead to reduced performance and difficulty in next recycling; in summary, the present invention uses waste polyethylene as a raw material to prepare a material with good impact resistance, good flame retardancy and can be further recycled after use. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] The following parts are by mass unless otherwise specified;

[0026] Example 1: S1: Take 22 parts of dendritic macromolecular polyamidoamine, add it to 120 parts of water and 45 parts of ethanol, stir evenly, add 10 parts of maleic anhydride, react at room temperature for 9 hours under nitrogen protection, add 8 parts of sodium acetate and 9 parts of acetic anhydride, reflux for 10 hours, filter to remove solid impurities, and remove the solvent by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0027] S2: Take 26 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 2 parts of 1-octene, 5 parts of vinyl silane coupling agent, 0.1 parts of benzoyl peroxide, stir at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0028] S3: Take 15 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 4 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0029] S4: 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 parts of 3-bromo-1-propylene, 18 parts of sodium carbonate, and 150 parts of tetrahydrofuran were mixed, stirred evenly, reacted at 60° C. for 4 h, filtered to remove solid impurities, and removed the solvent to obtain a double-bonded phosphate;

[0030] S5: Take 16 parts of 1,4-phenyldiboron and 22 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 28 parts of magnesium sulfate, stir at 30°C for 25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0031] S6: Take 4 parts of double-bonded phosphate and 5 parts of mercapto-modified phenyl diboron, add them to 200 parts of tetrahydrofuran, stir evenly, add 25 parts of high-density polyethylene and 0.1 parts of photoinitiator, stir and mix, 80mW / cm 2 After irradiation for 0.8 h, the solid was filtered and dried to obtain modified polyethylene;

[0032] S7: Take 85 parts of recycled high-density polyethylene, 12 parts of polypropylene, 15 parts of modified polyethylene, 3 parts of calcium stearate, 12 parts of modified carbon black, 3 parts of antioxidant 168, mix them, add 1 part of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir evenly, and melt extrude at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0033] Example 2: S1: Take 20 parts of dendrimer polyamidoamine, add it to 120 parts of water and 45 parts of ethanol, stir evenly, add 10 parts of maleic anhydride, react at room temperature for 9 hours under nitrogen protection, add 8 parts of sodium acetate and 10 parts of acetic anhydride, reflux for 10 hours, filter to remove solid impurities, and remove the solvent by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0034] S2: Take 30 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 3 parts of 1-octene, 6 parts of vinyl silane coupling agent, 0.1 parts of benzoyl peroxide, stir at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0035] S3: Take 15 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 4 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0036] S4: 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 22 parts of 3-bromo-1-propylene, 20 parts of sodium carbonate, and 150 parts of tetrahydrofuran were mixed, stirred evenly, reacted at 60° C. for 4 h, filtered to remove solid impurities, and removed the solvent to obtain a double-bonded phosphate;

[0037] S5: Take 20 parts of 1,4-phenyldiboron and 25 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 30 parts of magnesium sulfate, stir at 30°C for 25 hours, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0038] S6: Take 4 parts of double-bonded phosphate and 5 parts of mercapto-modified phenyl diboron, add them to 200 parts of tetrahydrofuran, stir evenly, add 30 parts of high-density polyethylene and 0.1 parts of photoinitiator, stir and mix, 80mW / cm 2 After irradiation for 0.8 h, the solid was filtered and dried to obtain modified polyethylene;

[0039] S7: Take 90 parts of recycled high-density polyethylene, 15 parts of polypropylene, 15 parts of modified polyethylene, 3 parts of calcium stearate, 15 parts of modified carbon black, 4 parts of antioxidant 168, 2 parts of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir evenly, and melt extrude at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0040] Example 3: S1: Take 20 parts of dendritic macromolecular polyamidoamine, add it to 120 parts of water and 45 parts of ethanol, stir evenly, add 8 parts of maleic anhydride, react at room temperature for 9 hours under nitrogen protection, add 5 parts of sodium acetate and 8 parts of acetic anhydride, reflux for 10 hours, filter to remove solid impurities, and remove the solvent by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0041] S2: Take 25 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 2 parts of 1-octene, 5 parts of vinyl silane coupling agent, 0.1 parts of benzoyl peroxide, stir at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0042] S3: Take 12 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 3 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0043] S4: Mix 20 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 parts of 3-bromo-1-propylene, 18 parts of sodium carbonate, and 150 parts of tetrahydrofuran, stir evenly, react at 60° C. for 4 h, filter to remove solid impurities, remove the solvent, and obtain a double-bonded phosphate;

[0044] S5: Take 15 parts of 1,4-phenyldiboron and 20 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 25 parts of magnesium sulfate, stir at 30°C for 25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0045] S6: Take 3 parts of double-bonded phosphate and 4 parts of mercapto-modified phenyl diboron, add them to 200 parts of tetrahydrofuran, stir evenly, add 20 parts of high-density polyethylene and 0.1 parts of photoinitiator, stir and mix, 80mW / cm 2 After irradiation for 0.8 h, the solid was filtered and dried to obtain modified polyethylene;

[0046] S7: Take 80 parts of recycled high-density polyethylene, 10 parts of polypropylene, 10 parts of modified polyethylene, 2 parts of calcium stearate, 10 parts of modified carbon black, 3 parts of antioxidant 168, 1 part of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir evenly, and melt extrude at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0047] Comparative Example 1 (the amount of each raw material added in the modifier is changed, and the other method steps are consistent with Example 1): S1: Take 22 parts of dendritic macromolecular polyamidoamine, add 120 parts of water and 45 parts of ethanol, stir evenly, add 10 parts of maleic anhydride, react at room temperature for 9 hours under nitrogen protection, add 8 parts of sodium acetate and 9 parts of acetic anhydride, reflux for 10 hours, filter to remove solid impurities, and remove the solvent by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0048] S2: Take 16 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 5 parts of 1-octene, 10 parts of vinyl silane coupling agent, 0.1 parts of benzoyl peroxide, stir at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0049] S3: Take 15 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 4 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0050] S4: 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 parts of 3-bromo-1-propylene, 18 parts of sodium carbonate, and 150 parts of tetrahydrofuran were mixed, stirred evenly, reacted at 60° C. for 4 h, filtered to remove solid impurities, and removed the solvent to obtain a double-bonded phosphate;

[0051] S5: Take 16 parts of 1,4-phenyldiboron and 22 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 28 parts of magnesium sulfate, stir at 30°C for 25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0052] S6: Take 4 parts of double-bonded phosphate and 5 parts of mercapto-modified phenyl diboron, add them to 200 parts of tetrahydrofuran, stir evenly, add 25 parts of high-density polyethylene and 0.1 parts of photoinitiator, stir and mix, 80mW / cm 2 After irradiation for 0.8 h, the solid was filtered and dried to obtain modified polyethylene;

[0053] S7: Take 85 parts of recycled high-density polyethylene, 12 parts of polypropylene, 15 parts of modified polyethylene, 3 parts of calcium stearate, 12 parts of modified carbon black, 3 parts of antioxidant 168, mix them, add 1 part of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir evenly, and melt extrude at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0054] Comparative Example 2 (the amount of each raw material added in the modifier is changed, and the other method steps are consistent with Example 1): S1: Take 22 parts of dendritic macromolecular polyamidoamine, add 120 parts of water and 45 parts of ethanol, stir evenly, add 10 parts of maleic anhydride, react at room temperature for 9 hours under nitrogen protection, add 8 parts of sodium acetate and 9 parts of acetic anhydride, reflux for 10 hours, filter to remove solid impurities, and remove the solvent by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0055] S2: Take 36 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 1 part of 1-octene, 3 parts of vinyl silane coupling agent, 0.1 part of benzoyl peroxide, stir and react at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0056] S3: Take 15 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 4 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0057] S4: 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 parts of 3-bromo-1-propylene, 18 parts of sodium carbonate, and 150 parts of tetrahydrofuran were mixed, stirred evenly, reacted at 60° C. for 4 h, filtered to remove solid impurities, and removed the solvent to obtain a double-bonded phosphate;

[0058] S5: Take 16 parts of 1,4-phenyldiboron and 22 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 28 parts of magnesium sulfate, stir at 30°C for 25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0059] S6: Take 4 parts of double-bonded phosphate and 5 parts of mercapto-modified phenyl diboron, add them to 200 parts of tetrahydrofuran, stir evenly, add 25 parts of high-density polyethylene and 0.1 parts of photoinitiator, stir and mix, 80mW / cm 2After irradiation for 0.8 h, the solid was filtered and dried to obtain modified polyethylene;

[0060] S7: Take 85 parts of recycled high-density polyethylene, 12 parts of polypropylene, 15 parts of modified polyethylene, 3 parts of calcium stearate, 12 parts of modified carbon black, 3 parts of antioxidant 168, mix them, add 1 part of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir evenly, and melt extrude at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0061] Comparative Example 3 (changing the amount of raw materials added in the highly flame-retardant recycled polyethylene plastic, and the remaining method steps are consistent with Example 1): S1: Take 22 parts of dendritic macromolecular polyamidoamine, add 120 parts of water and 45 parts of ethanol, stir evenly, add 10 parts of maleic anhydride, react at room temperature for 9 hours under nitrogen protection, add 8 parts of sodium acetate and 9 parts of acetic anhydride, reflux for 10 hours, filter to remove solid impurities, and remove the solvent by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0062] S2: Take 26 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 2 parts of 1-octene, 5 parts of vinyl silane coupling agent, 0.1 parts of benzoyl peroxide, stir at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0063] S3: Take 15 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 4 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0064] S4: 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 parts of 3-bromo-1-propylene, 18 parts of sodium carbonate, and 150 parts of tetrahydrofuran were mixed, stirred evenly, reacted at 60° C. for 4 h, filtered to remove solid impurities, and removed the solvent to obtain a double-bonded phosphate;

[0065] S5: Take 16 parts of 1,4-phenyldiboron and 22 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 28 parts of magnesium sulfate, stir at 30°C for 25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0066] S6: Take 4 parts of double-bonded phosphate and 5 parts of mercapto-modified phenyl diboron, add them to 200 parts of tetrahydrofuran, stir evenly, add 25 parts of high-density polyethylene and 0.1 parts of photoinitiator, stir and mix, 80mW / cm 2 After irradiation for 0.8 h, the solid was filtered and dried to obtain modified polyethylene;

[0067] S7: Take 70 parts of recycled high-density polyethylene, 12 parts of polypropylene, 20 parts of modified polyethylene, 3 parts of calcium stearate, 20 parts of modified carbon black, 3 parts of antioxidant 168, mix them, 5 parts of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir them evenly, and melt extrude them at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0068] Comparative Example 4 (double-bonded phosphate, mercapto-modified phenyldiboron, and high-density polyethylene are directly added, and the remaining method steps are consistent with Example 1): S1: 22 parts of dendritic macromolecular polyamidoamine are added to 120 parts of water and 45 parts of ethanol, stirred evenly, 10 parts of maleic anhydride are added, and the reaction is carried out at room temperature for 9 hours under nitrogen protection, 8 parts of sodium acetate and 9 parts of acetic anhydride are added, refluxed for 10 hours, solid impurities are removed by filtration, and the solvent is removed by rotary evaporation to obtain maleic anhydride polyamidoamine;

[0069] S2: Take 26 parts of maleic anhydride polyamidoamine, add it to 120 parts of water and 80 parts of ethanol, stir evenly, add 2 parts of 1-octene, 5 parts of vinyl silane coupling agent, 0.1 parts of benzoyl peroxide, stir at 75°C for 6 hours, remove the solvent, and obtain a modifier;

[0070] S3: Take 15 parts of carbon black and add them to 60 parts of water and 60 parts of ethanol, stir evenly, heat to 65°C, add 4 parts of modifier, reflux for 12 hours to obtain modified carbon black;

[0071] S4: 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 parts of 3-bromo-1-propylene, 18 parts of sodium carbonate, and 150 parts of tetrahydrofuran were mixed, stirred evenly, reacted at 60° C. for 4 h, filtered to remove solid impurities, and removed the solvent to obtain a double-bonded phosphate;

[0072] S5: Take 16 parts of 1,4-phenyldiboron and 22 parts of 1-thioglycerol, add 600 parts of tetrahydrofuran and 12 parts of water, stir evenly, add 28 parts of magnesium sulfate, stir at 30°C for 25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron;

[0073] S6: 4 parts of double-bonded phosphate, 5 parts of mercapto-modified phenyldiboron, and 25 parts of high-density polyethylene are mixed evenly to obtain a mixture;

[0074] S7: Take 85 parts of recycled high-density polyethylene, 12 parts of polypropylene, 15 parts of the mixture, 3 parts of calcium stearate, 12 parts of modified carbon black, 3 parts of antioxidant 168, 1 part of 2,6-diisocyanate toluene, 0.02 parts of diisopropyl peroxide, and 0.2 parts of color powder, stir evenly, and melt extrude at 170°C to obtain highly flame-retardant recycled polyethylene plastic.

[0075] In the above examples, the test methods used are conventional methods unless otherwise specified; the raw materials used are commercially available unless otherwise specified, and the sources of the raw materials are as follows: benzoyl peroxide (CAS: 94-36-0); dendrimer polyamidoamine (TB12880, Hubei Tuobang Chemical Co., Ltd.); ethanol (CAS: 64-17-5); maleic anhydride (CAS: 108-31-6); sodium acetate (CAS: 127-09-3 ); acetic anhydride (CAS: 108-24-7); 1-octene (CAS: 111-66-0); vinyl silane coupling agent (CAS: 78-08-0); 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate (CAS: 1190-00-7); 2,6-diisocyanate toluene (CAS: 91-08-7); 1-thioglycerol (CAS: 96-27-5); 3-bromo-1-propylene (CAS: 106-9 5-6); sodium carbonate (S24152, Shanghai Yuanye); tetrahydrofuran (CAS: 109-99-9); 1,4-phenylenediboron (CAS: 4612-26-4); magnesium sulfate (S24253, Shanghai Yuanye); photoinitiator (photoinitiator 1173, CAS: 7473-98-5); calcium stearate (S24307, Shanghai Yuanye); antioxidant 168 (tri(2,4-di-tert-butyl)phenyl phosphite, CAS: 31570 -04-4, S31114, Shanghai Yuanye); diisopropylbenzene peroxide (CAS: 80-43-3); color powder (Ultramarine Blue 462, Dongguan Gangliang Plastic Pigment Co., Ltd.); recycled high-density polyethylene (recycled from plastic bottle caps and milk bottle caps, obtained after cutting, cleaning and drying, with a melt index (MFI, 190℃ / 5Kg) of 5.8g / 10min, provided by Xiongxian Tianhai Plastic Products Factory); carbon black (N330, Wuhan Jiyesheng Chemical Co., Ltd.).

[0076] Experiment: Take the highly flame-retardant recycled polyethylene plastics prepared in Examples 1 to 3 and Comparative Examples 1 to 4; (1) refer to GB / T1043.1-2008 to test the impact strength; (2) refer to GB / T2406.2-2009 to test the limiting oxygen index. (3) Take the highly flame-retardant recycled polyethylene plastics in Examples 1 to 3, take a 850°C glow wire to contact for 30 seconds to ignite, leave it for 30 seconds to extinguish, and the glue will not ignite the silk paper. Specific data are shown in the table below;

[0077]

[0078] Conclusion: Comparative Example 1 and Comparative Example 2 change the amount of each raw material added in the modifier. In Comparative Example 1, there is less maleic anhydride polyamide amine and more 1-octene and vinyl silane coupling agent. In Comparative Example 2, on the contrary, due to the influence of compatibility, degree of branching, grafting rate, etc., the performance is reduced. It can be seen that the amount of raw materials added needs to be controlled; Comparative Example 3 changes the addition ratio of each raw material in the high flame retardant recycled polyethylene plastic. First, the reduction in the addition ratio of recycled high-density polyethylene is not conducive to green environmental protection, and due to the problems of crosslinking degree and compatibility, the performance is reduced. It can be seen that the importance of the addition ratio; Comparative Example 4 physically mixes double-bonded phosphate, thiol-modified phenyldiboron, and high-density polyethylene and then adds them. The three are not grafted and composited, and the performance is not as good as the embodiment; In summary, the high flame retardant recycled polyethylene plastic prepared by the present invention has good flame retardant properties and good impact resistance. At the same time, a large amount of recycled polyethylene is added to the raw materials, which is in line with the concept of green environmental protection.

[0079] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

Claims

1. A process for preparing highly flame-retardant recycled polyethylene plastic, characterized in that: The following steps are involved: S1: Take maleic anhydride polyamidoamine, add water and ethanol, stir evenly, add 1-octene, vinyl silane coupling agent, benzoyl peroxide, stir and react at 75-78°C for 5-6h, remove the solvent, and obtain a modifier; S2: Take carbon black, add water and ethanol, stir evenly, heat to 60-70°C, add modifier, reflux reaction for 10-12h, and obtain modified carbon black; S3: Take double-bonded phosphate and mercapto-modified phenyldiboron, add them to tetrahydrofuran and stir evenly, add high-density polyethylene and photoinitiator, stir and mix, irradiate with ultraviolet light for 0.5 to 1 hour, filter and collect the solid, and dry to obtain modified polyethylene; S4: Take recycled high-density polyethylene, polypropylene, modified polyethylene, calcium stearate, modified carbon black, antioxidant, diisocyanate crosslinking agent, diisopropylbenzene peroxide, and color powder, stir evenly, and melt extrude to obtain highly flame-retardant recycled polyethylene plastic.

2. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 1, characterized in that: The modifier comprises the following raw materials, calculated by weight: 25 to 30 parts of maleic anhydride polyamidoamine, 2 to 3 parts of 1-octene, 5 to 6 parts of vinyl silane coupling agent, and 0.1 to 0.2 parts of benzoyl peroxide; the modified carbon black comprises the following raw materials, calculated by weight: 12 to 15 parts of carbon black and 3 to 4 parts of modifier.

3. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 1, characterized in that: The modified polyethylene comprises the following raw materials, calculated by weight: 3-4 parts of double-bonded phosphate, 4-5 parts of mercapto-modified phenyldiboron, 150-200 parts of tetrahydrofuran, 20-30 parts of high-density polyethylene, and 0.1-0.2 parts of photoinitiator.

4. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 1, characterized in that: The highly flame-retardant recycled polyethylene plastic includes the following raw materials, calculated by mass: 80 to 90 parts of recycled high-density polyethylene, 10 to 15 parts of polypropylene, 10 to 15 parts of modified polyethylene, 2 to 3 parts of calcium stearate, 10 to 15 parts of modified carbon black, 3 to 4 parts of antioxidant, 1 to 2 parts of diisocyanate crosslinking agent, 0.02 to 0.03 parts of diisocyanate peroxide, and 0.2 to 0.3 parts of color powder.

5. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 1, characterized in that: The preparation of the maleic anhydride polyamidoamine comprises the following steps: adding a dendritic macromolecular polyamidoamine to water and ethanol, stirring evenly, adding maleic anhydride, reacting at room temperature for 8 to 10 hours under nitrogen protection, adding sodium acetate and acetic anhydride, refluxing for 8 to 10 hours, filtering to remove solid impurities, and rotary evaporating to remove the solvent to obtain the maleic anhydride polyamidoamine.

6. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 5, characterized in that: The maleic anhydride polyamidoamine comprises the following raw materials, calculated by weight: 20 to 25 parts of dendritic macromolecular polyamidoamine, 8 to 10 parts of maleic anhydride, 5 to 8 parts of sodium acetate, and 8 to 10 parts of acetic anhydride.

7. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 1, characterized in that: The preparation of the double-bonded phosphate comprises the following steps: mixing 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 3-bromo-1-propylene, sodium carbonate and tetrahydrofuran, stirring evenly, reacting at 50-60° C. for 3-5 hours, filtering to remove solid impurities, and removing the solvent to obtain the double-bonded phosphate; The double-bonded phosphate comprises the following raw materials, calculated by mass: 20 to 22 parts of 2-aminoethyl-2,3-dihydroxypropyl-hydroxyphosphate, 20 to 22 parts of 3-bromo-1-propylene, 18 to 20 parts of sodium carbonate, and 120 to 150 parts of tetrahydrofuran.

8. The process for preparing a highly flame-retardant recycled polyethylene plastic according to claim 7, characterized in that: The preparation of the mercapto-modified phenyldiboron comprises the following steps: Take 1,4-phenyldiboron, 1-thioglycerol, tetrahydrofuran and water, stir evenly, add magnesium sulfate, stir at 25-30°C for 24-25h, filter to remove magnesium sulfate, remove solvent, cool and precipitate white solid, wash and dry to obtain mercapto-modified phenyldiboron; The mercapto-modified phenyldiboron comprises the following raw materials, calculated by weight: 15 to 20 parts of 1,4-phenyldiboron, 20 to 25 parts of 1-thioglycerol, 600 to 800 parts of tetrahydrofuran, 10 to 15 parts of water, and 25 to 30 parts of magnesium sulfate.

9. Highly flame retardant recycled polyethylene plastic prepared according to the process for preparing highly flame retardant recycled polyethylene plastic according to any one of claims 1 to 8.

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