High-strength degradable aviation trash bag material and preparation method thereof

Abstract

The application relates to the technical field of polyolefin materials, in particular to a high-strength degradable aviation garbage bag material and a preparation method thereof. The garbage bag material prepared by the application can be quickly and completely degraded and is green and environment-friendly. The density of polyethylene is limited to 0.952-0.955 g / cm 3 , and the garbage bag material is suitable for preparing a garbage bag with a thin thickness. In the application, short-chain octenyl succinic anhydride is used for modification, a moderate hydrophobic group is introduced on the surface of starch molecules, and then a longer carbon chain is introduced through the grafting of middle-chain nonene succinic anhydride to enhance the hydrophobicity. After the epoxy-modified polyvinyl alcohol is grafted with glycidyl methacrylate, the hydrophobicity of the polyvinyl alcohol is improved, and a chemical bond is formed between the hydroxyl groups on the surface of the modified boehmite powder and the epoxy-modified polyvinyl alcohol, the compatibility between the two is good, and therefore the hydrophobicity of the modified starch composite powder is improved.

Description

Technical Field

[0001] This invention relates to the field of polyolefin materials technology, specifically a high-strength biodegradable aviation waste bag material and its preparation method. Background Technology

[0002] Compared to ordinary garbage bags, aviation waste bags have higher requirements for the mechanical properties, water resistance, safety, and environmental friendliness of the materials. They need to hold large amounts of food scraps, liquid waste, and other debris from the cabin, thus requiring better mechanical and water resistance properties, as well as being odorless and capable of rapid and complete degradation after disposal to avoid pollution. Traditional biodegradable PLA materials suffer from poor water resistance and low mechanical strength, failing to meet the standards used in the aviation industry.

[0003] To address the aforementioned issues and improve mechanical and water resistance properties, this application provides a high-strength biodegradable aviation waste bag material and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to provide a high-strength biodegradable aviation waste bag material and its preparation method, so as to solve the related technical problems existing in the prior art.

[0005] To achieve the above objectives, the present invention provides the following specific technical solutions:

[0006] A method for preparing a high-strength biodegradable aviation waste bag material includes the following steps:

[0007] Step 1: Take corn starch, dry it, add anhydrous ethanol, stir evenly to obtain starch alcohol dispersion, add short-chain succinic anhydride to carry out esterification reaction of starch, and then add medium-chain succinic anhydride to carry out esterification reaction; add epoxidized soybean oil, stir, remove waste liquid, wash and filter to obtain modified starch wet material; add anhydrous ethanol to modified starch wet material, stir evenly, add modified boehmite powder and epoxy modified polyvinyl alcohol, stir, dry, cool and pulverize to obtain modified starch composite powder;

[0008] Step 2: Take pentaerythritol, polylactic acid, and sebacic acid, mix them evenly, and carry out polycondensation reaction under nitrogen atmosphere. Then cool, wash the reactants until neutral, filter, dry, and then add ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin, titanate coupling agent, urea, sorbitol, sodium dodecyl sulfate, and antioxidant. Mix evenly, extrude, granulate, and blow mold to obtain high-strength biodegradable aviation waste bag material.

[0009] In a more optimized manner, the preparation method of the modified boehmite powder is as follows: take nano-boehmite powder, add deionized water, stir evenly to obtain a boehmite suspension; take ethylene glycol distearate and deionized water, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 70-75℃, stir for 2-3 hours, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder.

[0010] Ideally, the particle size of the nanoboehmite powder is 50-200 nm.

[0011] Ideally, the density of the polyethylene is 0.952-0.955 g / cm³. 3 .

[0012] In a more optimized manner, the preparation method of the epoxy-modified polyvinyl alcohol is as follows: take cerium ammonium nitrate and deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; stir polyvinyl alcohol and deionized water evenly, adjust the pH, add the aqueous solution of cerium ammonium nitrate, add glycidyl methacrylate, stir evenly, then react for 7-9 hours, cool to room temperature, filter, wash and dry to obtain epoxy-modified polyvinyl alcohol.

[0013] More preferably, the olefin side chain of the short-chain succinic anhydride has 6-10 carbon atoms; the olefin side chain of the medium-chain succinic anhydride has 9-14 carbon atoms.

[0014] More preferably, the short-chain succinic anhydride is octenyl succinic anhydride, and the medium-chain succinic anhydride is nonenyl succinic anhydride.

[0015] Ideally, the titanium dioxide has a particle size of 20-100 nm.

[0016] In a more optimized manner, the high-strength biodegradable aviation waste bag material comprises the following raw materials, by weight: 72-78 parts polyethylene, 12-15 parts ethylene-acrylic acid copolymer, 5-8 parts pentaerythritol, 8-12 parts polylactic acid, 6-9 parts sebacic acid, 15-18 parts modified starch composite powder, 2-3 parts urea, 3-4 parts isophorone diisocyanate, 2-4 parts titanium dioxide, 2.5-4 parts paraffin wax, 1-2 parts titanate coupling agent, 1-2 parts sorbitol, 1-1.2 parts sodium dodecyl sulfate, and 0.3-0.6 parts antioxidant.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. The garbage bag material prepared by this invention is rapidly and completely degradable, making it environmentally friendly. This invention specifies the density of the polyethylene to be 0.952-0.955 g / cm³. 3This invention is suitable for preparing thin-walled garbage bags. It employs short-chain octenyl succinic anhydride modification to introduce appropriate hydrophobic groups onto the starch molecule surface; then, through grafting with medium-chain nonenyl succinic anhydride, longer carbon chains are introduced to enhance hydrophobicity. Further, residual hydroxyl groups from epoxidized soybean oil are introduced via ring-opening crosslinking. Finally, ethylene glycol distearate is used to modify nano-boehmite, transforming the hydrophilic inorganic powder into a hydrophobic filler, thus constructing a hydrophobic structure on the starch surface.

[0019] 2. The addition of ethylene glycol distearate improves the compatibility of boehmite with starch and polyethylene matrix, avoids nanoparticle agglomeration, and increases the strength of garbage bags.

[0020] 3. The addition of epoxy-modified polyvinyl alcohol can further improve the bonding between ethylene-acrylic acid copolymer and modified starch, avoid the stratification between different raw materials, make the mixing more uniform, increase the density of garbage bags, thereby improving the mechanical strength of garbage bags, increasing the water contact angle of garbage bag materials, improving hydrophobicity, solving the defects of traditional starch-modified polyethylene materials that are easy to absorb water and swell and easy to penetrate by kitchen waste liquid, and meeting the requirements of long-term use of aviation garbage bags for loading water-containing and oil-containing kitchen waste without leakage. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. It should be understood that the embodiments described herein are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should fall within the protection scope of the present invention; unless otherwise specified, the related raw materials are all conventional settings.

[0022] The sources and types of substances involved in this application are not specifically limited. Exemplary examples include: ethylene-acrylic acid copolymer: acrylic acid content of 11wt%, melt index (190℃ / 2.16kg) of 8.5g / 10min; polyethylene: density of 0.952g / cm³. 3 Melt index (190℃ / 2.16kg) is 0.06g / 10min; Polylactic acid: molecular weight: 60,000; Nano boehmite powder: particle size is 50-200nm; Titanium dioxide: particle size is 20-100nm; Polyvinyl alcohol: molecular weight: 61,000.

[0023] Implementation Method 1: A method for preparing a high-strength biodegradable aviation waste bag material, comprising the following steps:

[0024] Step 1: Preparation of epoxy-modified polyvinyl alcohol:

[0025] Take 0.5g of cerium ammonium nitrate and 30g of deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; take 100g of polyvinyl alcohol and 200g of deionized water, stir evenly, adjust the pH to 5 with hydrochloric acid, add the aqueous solution of cerium ammonium nitrate, add 5g of glycidyl methacrylate, stir evenly, then react at 50℃ for 8h, cool to room temperature, filter, wash and dry to obtain epoxy modified polyvinyl alcohol;

[0026] Step 2: Preparation of modified boehmite powder:

[0027] Take 2.5g of nano-boehmite powder, add 50g of deionized water, and stir for 30min to obtain a boehmite suspension; take 0.8g of ethylene glycol distearate and 30g of deionized water, heat to 27℃, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 72℃, stir for 2.5h, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder;

[0028] Step 3: Preparation of modified starch composite powder:

[0029] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-alcohol dispersion; adjust the pH to 8.2 by adding sodium hydroxide solution dropwise, add 3g of octenyl succinic anhydride, heat to 45℃, and stir for 95min; then adjust the pH to 7.5 with dilute hydrochloric acid solution, add 1.5g of nonenyl succinic anhydride, heat to 50℃, and react for 65min; adjust the pH to 7.2 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 50min, then adjust the pH to 7.0 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of modified boehmite powder and 6g of epoxy-modified polyvinyl alcohol, stir for 35min, dry, cool, pulverize, and sieve to obtain modified starch composite powder;

[0030] Step 4: Preparation of high-strength biodegradable aviation waste bag material:

[0031] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 158°C for 7 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0032] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 75 parts polyethylene, 13 parts ethylene-acrylic acid copolymer, 7 parts pentaerythritol, 10 parts polylactic acid, 7 parts sebacic acid, 16 parts modified starch composite powder, 2.5 parts urea, 3.5 parts isophorone diisocyanate, 3 parts titanium dioxide, 3 parts paraffin wax, 1.5 parts titanate coupling agent TC-114, 1.5 parts sorbitol, 1.1 parts sodium dodecyl sulfate, and 0.5 parts antioxidant 1010.

[0033] Implementation Method 2: Based on Implementation Method 1, adjust the parameters, including the following steps:

[0034] Step 1: Preparation of epoxy-modified polyvinyl alcohol:

[0035] Take 0.5g of cerium ammonium nitrate and 30g of deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; take 100g of polyvinyl alcohol and 200g of deionized water, stir evenly, adjust the pH to 5 with hydrochloric acid, add the aqueous solution of cerium ammonium nitrate, add 5g of glycidyl methacrylate, stir evenly, then react at 50℃ for 8h, cool to room temperature, filter, wash and dry to obtain epoxy modified polyvinyl alcohol;

[0036] Step 2: Preparation of modified boehmite powder:

[0037] Take 2.5g of nano-boehmite powder, add 50g of deionized water, and stir for 30min to obtain a boehmite suspension; take 0.8g of ethylene glycol distearate and 30g of deionized water, heat to 30℃, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 70℃, stir for 2h, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder;

[0038] Step 3: Preparation of modified starch composite powder:

[0039] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-alcohol dispersion; adjust the pH to 8.0 by adding sodium hydroxide solution dropwise, add 3g of octenyl succinic anhydride, heat to 45℃, and stir for 90min; then adjust the pH to 7.5 with dilute hydrochloric acid solution, add 1.5g of nonenyl succinic anhydride, heat to 50℃, and react for 60min; adjust the pH to 7.2 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 40min, then adjust the pH to 6.8 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of modified boehmite powder and 6g of epoxy-modified polyvinyl alcohol, stir for 30min, dry, cool, pulverize, and sieve to obtain modified starch composite powder;

[0040] Step 4: Preparation of high-strength biodegradable aviation waste bag material:

[0041] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 155°C for 6 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0042] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 72 parts polyethylene, 12 parts ethylene-acrylic acid copolymer, 5 parts pentaerythritol, 8 parts polylactic acid, 6 parts sebacic acid, 15 parts modified starch composite powder, 2 parts urea, 3 parts isophorone diisocyanate, 2 parts titanium dioxide, 2.5 parts paraffin wax, 1 part titanate coupling agent TC-114, 1 part sorbitol, 1 part sodium dodecyl sulfate, and 0.3 parts antioxidant 1010.

[0043] Implementation Method 3: Based on Implementation Method 1, adjust the parameters, including the following steps:

[0044] Step 1: Preparation of epoxy-modified polyvinyl alcohol:

[0045] Take 0.5g of cerium ammonium nitrate and 30g of deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; take 100g of polyvinyl alcohol and 200g of deionized water, stir evenly, adjust the pH to 5 with hydrochloric acid, add the aqueous solution of cerium ammonium nitrate, add 5g of glycidyl methacrylate, stir evenly, then react at 50℃ for 8h, cool to room temperature, filter, wash and dry to obtain epoxy modified polyvinyl alcohol;

[0046] Step 2: Preparation of modified boehmite powder:

[0047] Take 2.5g of nano-boehmite powder, add 50g of deionized water, and stir for 30min to obtain a boehmite suspension; take 0.8g of ethylene glycol distearate and 30g of deionized water, heat to 30℃, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 75℃, stir for 3h, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder;

[0048] Step 3: Preparation of modified starch composite powder:

[0049] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-alcohol dispersion; adjust the pH to 8.5 by adding sodium hydroxide solution dropwise, add 3g of octenyl succinic anhydride, heat to 45℃, and stir for 100min; then adjust the pH to 8.0 with dilute hydrochloric acid solution, add 1.5g of nonenyl succinic anhydride, heat to 50℃, and react for 70min; adjust the pH to 7.5 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 60min, then adjust the pH to 7.2 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of modified boehmite powder and 6g of epoxy-modified polyvinyl alcohol, stir for 40min, dry, cool, pulverize, and sieve to obtain modified starch composite powder;

[0050] Step 4: Preparation of high-strength biodegradable aviation waste bag material:

[0051] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 160°C for 8 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0052] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 78 parts polyethylene, 15 parts ethylene-acrylic acid copolymer, 8 parts pentaerythritol, 12 parts polylactic acid, 9 parts sebacic acid, 18 parts modified starch composite powder, 3 parts urea, 4 parts isophorone diisocyanate, 4 parts titanium dioxide, 4 parts paraffin wax, 2 parts titanate coupling agent TC-114, 2 parts sorbitol, 1.2 parts sodium dodecyl sulfate, and 0.6 parts antioxidant 1010.

[0053] Implementation Method 4: Based on Implementation Method 1, perform single octenyl succinic anhydride esterification modification, including the following steps:

[0054] Step 1: Preparation of epoxy-modified polyvinyl alcohol:

[0055] Take 0.5g of cerium ammonium nitrate and 30g of deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; take 100g of polyvinyl alcohol and 200g of deionized water, stir evenly, adjust the pH to 5 with hydrochloric acid, add the aqueous solution of cerium ammonium nitrate, add 5g of glycidyl methacrylate, stir evenly, then react at 50℃ for 8h, cool to room temperature, filter, wash and dry to obtain epoxy modified polyvinyl alcohol;

[0056] Step 2: Preparation of modified boehmite powder:

[0057] Take 2.5g of nano-boehmite powder, add 50g of deionized water, and stir for 30min to obtain a boehmite suspension; take 0.8g of ethylene glycol distearate and 30g of deionized water, heat to 27℃, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 72℃, stir for 2.5h, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder;

[0058] Step 3: Preparation of modified starch composite powder:

[0059] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-alcohol dispersion; adjust the pH to 8.2 by adding sodium hydroxide solution dropwise, add 3g of octenyl succinic anhydride, heat to 45℃, and stir for 95min; adjust the pH to 7.2 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 50min, then adjust the pH to 7.0 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of modified boehmite powder and 6g of epoxy-modified polyvinyl alcohol, stir for 35min, dry, cool, pulverize and sieve to obtain modified starch composite powder;

[0060] Step 4: Preparation of high-strength biodegradable aviation waste bag material:

[0061] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 158°C for 7 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0062] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 75 parts polyethylene, 13 parts ethylene-acrylic acid copolymer, 7 parts pentaerythritol, 10 parts polylactic acid, 7 parts sebacic acid, 16 parts modified starch composite powder, 2.5 parts urea, 3.5 parts isophorone diisocyanate, 3 parts titanium dioxide, 3 parts paraffin wax, 1.5 parts titanate coupling agent TC-114, 1.5 parts sorbitol, 1.1 parts sodium dodecyl sulfate, and 0.5 parts antioxidant 1010.

[0063] Implementation Method 5: Based on Implementation Method 1, a single nonenyl succinic anhydride esterification modification is performed, including the following steps:

[0064] Step 1: Preparation of epoxy-modified polyvinyl alcohol:

[0065] Take 0.5g of cerium ammonium nitrate and 30g of deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; take 100g of polyvinyl alcohol and 200g of deionized water, stir evenly, adjust the pH to 5 with hydrochloric acid, add the aqueous solution of cerium ammonium nitrate, add 5g of glycidyl methacrylate, stir evenly, then react at 50℃ for 8h, cool to room temperature, filter, wash and dry to obtain epoxy modified polyvinyl alcohol;

[0066] Step 2: Preparation of modified boehmite powder:

[0067] Take 2.5g of nano-boehmite powder, add 50g of deionized water, and stir for 30min to obtain a boehmite suspension; take 0.8g of ethylene glycol distearate and 30g of deionized water, heat to 27℃, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 72℃, stir for 2.5h, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder;

[0068] Step 3: Preparation of modified starch composite powder:

[0069] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-alcohol dispersion; adjust the pH to 7.8 by adding sodium hydroxide solution dropwise, add 1.5g of nonenyl succinic anhydride, heat to 50℃, and react for 65min; adjust the pH to 7.2 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 50min, then adjust the pH to 7.0 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of modified boehmite powder and 6g of epoxy-modified polyvinyl alcohol, stir for 35min, dry, cool, pulverize and sieve to obtain modified starch composite powder;

[0070] Step 4: Preparation of high-strength biodegradable aviation waste bag material:

[0071] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 158°C for 7 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0072] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 75 parts polyethylene, 13 parts ethylene-acrylic acid copolymer, 7 parts pentaerythritol, 10 parts polylactic acid, 7 parts sebacic acid, 16 parts modified starch composite powder, 2.5 parts urea, 3.5 parts isophorone diisocyanate, 3 parts titanium dioxide, 3 parts paraffin wax, 1.5 parts titanate coupling agent TC-114, 1.5 parts sorbitol, 1.1 parts sodium dodecyl sulfate, and 0.5 parts antioxidant 1010.

[0073] Implementation Method 6: Based on Implementation Method 1, without modifying boehmite, the following steps are included:

[0074] Step 1: Preparation of epoxy-modified polyvinyl alcohol:

[0075] Take 0.5g of cerium ammonium nitrate and 30g of deionized water, stir evenly to obtain an aqueous solution of cerium ammonium nitrate; take 100g of polyvinyl alcohol and 200g of deionized water, stir evenly, adjust the pH to 5 with hydrochloric acid, add the aqueous solution of cerium ammonium nitrate, add 5g of glycidyl methacrylate, stir evenly, then react at 50℃ for 8h, cool to room temperature, filter, wash and dry to obtain epoxy modified polyvinyl alcohol;

[0076] Step 2: Preparation of modified starch composite powder:

[0077] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-alcohol dispersion; adjust the pH to 8.2 by adding sodium hydroxide solution dropwise, add 3g of octenyl succinic anhydride, heat to 45℃, and stir for 95min; then adjust the pH to 7.5 with dilute hydrochloric acid solution, add 1.5g of nonenyl succinic anhydride, heat to 50℃, and react for 65min; adjust the pH to 7.2 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 50min, then adjust the pH to 7.0 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of nano-boehmite powder and 6g of epoxy-modified polyvinyl alcohol, stir for 35min, dry, cool, pulverize, and sieve to obtain modified starch composite powder;

[0078] Step 3: Preparation of high-strength biodegradable aviation waste bag material:

[0079] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 158°C for 7 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0080] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 75 parts polyethylene, 13 parts ethylene-acrylic acid copolymer, 7 parts pentaerythritol, 10 parts polylactic acid, 7 parts sebacic acid, 16 parts modified starch composite powder, 2.5 parts urea, 3.5 parts isophorone diisocyanate, 3 parts titanium dioxide, 3 parts paraffin wax, 1.5 parts titanate coupling agent TC-114, 1.5 parts sorbitol, 1.1 parts sodium dodecyl sulfate, and 0.5 parts antioxidant 1010.

[0081] Implementation Method 7: Based on Implementation Method 1, without modifying polyvinyl alcohol, including the following steps:

[0082] Step 1: Preparation of modified boehmite powder:

[0083] Take 2.5g of nano-boehmite powder, add 50g of deionized water, and stir for 30min to obtain a boehmite suspension; take 0.8g of ethylene glycol distearate and 30g of deionized water, heat to 27℃, stir evenly, add dropwise to the boehmite suspension, mix evenly, heat to 72℃, stir for 2.5h, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder;

[0084] Step 2: Preparation of modified starch composite powder:

[0085] Take 100g of corn starch, dry it, add 90g of anhydrous ethanol, stir evenly to obtain a starch-ethanol dispersion; adjust the pH to 8.2 by adding sodium hydroxide solution dropwise, add 3g of octenyl succinic anhydride, heat to 45℃, and stir for 95min; then adjust the pH to 7.5 with dilute hydrochloric acid solution, add 1.5g of nonenyl succinic anhydride, heat to 50℃, and react for 65min; adjust the pH to 7.2 with dilute hydrochloric acid solution, add 4g of epoxidized soybean oil, stir for 50min, then adjust the pH to 7.0 with dilute hydrochloric acid solution, let stand, remove the upper waste liquid, wash and filter to obtain modified starch wet material; add 30g of anhydrous ethanol to 85g of modified starch wet material, stir evenly, add 2.5g of modified boehmite powder and 6g of polyvinyl alcohol, stir for 35min, dry, cool, pulverize, and sieve to obtain modified starch composite powder;

[0086] Step 3: Preparation of high-strength biodegradable aviation waste bag material:

[0087] Pentaerythritol, polylactic acid, and sebacic acid were mixed evenly and subjected to a polycondensation reaction at 158°C for 7 hours under a nitrogen atmosphere. The mixture was then cooled to room temperature, washed until neutral, filtered, and dried. Ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin wax, titanate coupling agent TC-114, urea, sorbitol, sodium dodecyl sulfate, and antioxidant 1010 were then added and mixed evenly. The mixture was extruded, granulated, and blow-molded to obtain a high-strength biodegradable aviation waste bag material with a thickness of 0.05 mm.

[0088] The high-strength biodegradable aviation waste bag material comprises the following raw materials in parts by weight: 75 parts polyethylene, 13 parts ethylene-acrylic acid copolymer, 7 parts pentaerythritol, 10 parts polylactic acid, 7 parts sebacic acid, 16 parts modified starch composite powder, 2.5 parts urea, 3.5 parts isophorone diisocyanate, 3 parts titanium dioxide, 3 parts paraffin wax, 1.5 parts titanate coupling agent TC-114, 1.5 parts sorbitol, 1.1 parts sodium dodecyl sulfate, and 0.5 parts antioxidant 1010.

[0089] Test methods: The garbage bag materials prepared in Examples 1-7 were used for performance testing. The tensile strength of the garbage bag materials was tested using a universal testing machine. The water contact angle of the garbage bag materials was tested. The garbage bag materials were cut into equal sizes and buried in the same soil, and their weight loss rate was tested after 180 days. The data obtained are shown in Table 1 below:

[0090] Table 1

[0091]

[0092] Results and Discussion: In Implementation 4, a single octenyl succinic anhydride esterification modification resulted in a loose starch structure, increased gaps, and decreased density, leading to a decline in the mechanical and hydrophobic properties of the garbage bag material. In Implementation 5, a single nonenyl succinic anhydride esterification modification was performed. Without short-chain octenyl succinic anhydride ester grafting, the starch grafting efficiency was poor, the amount of hydrophobic groups grafted decreased, hydrophobicity decreased, surface coating was uneven, density decreased, and the mechanical properties of the garbage bag material declined. In Implementation 6, no boehmite modification was performed. Boehmite is hydrophilic and prone to agglomeration, resulting in uneven dispersion and a decline in the mechanical and hydrophobic properties of the garbage bag material. In Implementation 7, no polyvinyl alcohol modification was performed, resulting in a decline in the mechanical and hydrophobic properties of the garbage bag material. In the embodiments of this application, the epoxy-modified polyvinyl alcohol, after grafting with glycidyl methacrylate, improved the hydrophobicity of polyvinyl alcohol and formed chemical bonds with the hydroxyl groups on the surface of the modified boehmite powder. The good compatibility between the two improved the performance of the garbage bag material. This invention employs short-chain octenyl succinic anhydride modification to introduce appropriate hydrophobic groups onto the surface of starch molecules. Further, grafting with medium-chain nonenyl succinic anhydride introduces longer carbon chains to enhance hydrophobicity. Residual hydroxyl groups from epoxidized soybean oil ring-opening crosslinking are then introduced. Finally, ethylene glycol distearate is used to modify boehmite nanoparticles, transforming the hydrophilic inorganic powder into a hydrophobic filler, thereby improving the waterproofness of the garbage bag. The addition of ethylene glycol distearate improves the compatibility of boehmite with starch and the polyethylene matrix, prevents nanoparticle agglomeration, and increases the strength of the garbage bag.

[0093] For those skilled in the art, it is obvious that the present invention is not limited to the details disclosed in the exemplary embodiments described above. The present invention can be implemented in other specific ways without departing from its spirit and essential characteristics. Therefore, the foregoing embodiments should be considered exemplary rather than restrictive from any perspective. The scope of protection of the present invention is defined by the appended claims. Therefore, all variations falling within the meaning and scope of the equivalent elements of the claims should be attributed to the scope of the present invention.

Claims

1. A method for preparing a high-strength biodegradable aviation waste bag material, characterized in that: Includes the following steps: Step 1: Take corn starch, dry it, add anhydrous ethanol, stir evenly to obtain starch alcohol dispersion, add short-chain succinic anhydride to carry out esterification reaction of starch, then add medium-chain succinic anhydride to carry out esterification reaction; add epoxidized soybean oil, stir, remove waste liquid, wash and filter to obtain modified starch wet material; Anhydrous ethanol was added to the modified starch wet material and stirred evenly. Modified boehmite powder and epoxy-modified polyvinyl alcohol were added, stirred, dried, cooled, and pulverized to obtain modified starch composite powder. Step 2: Take pentaerythritol, polylactic acid, and sebacic acid, mix them evenly, and carry out polycondensation reaction under nitrogen atmosphere. Then cool, wash the reactants until neutral, filter, dry, and then add ethylene-acrylic acid copolymer, polyethylene, modified starch composite powder, isophorone diisocyanate, titanium dioxide, paraffin, titanate coupling agent, urea, sorbitol, sodium dodecyl sulfate, and antioxidant. Mix evenly, extrude, granulate, and blow mold to obtain high-strength biodegradable aviation waste bag material.

2. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 1, characterized in that: The modified boehmite powder is prepared as follows: take nano boehmite powder, add deionized water, stir evenly to obtain boehmite suspension; take ethylene glycol distearate and deionized water, stir evenly, add dropwise to boehmite suspension, mix evenly, heat to 70-75℃, stir for 2-3 hours, let stand, wash, filter, dry, and sieve to obtain modified boehmite powder.

3. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 2, characterized in that: The particle size of the nanoboehmite powder is 50-200 nm.

4. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 1, characterized in that: The density of the polyethylene is 0.952-0.955 g / cm³. 3 .

5. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 1, characterized in that: The preparation method of the epoxy-modified polyvinyl alcohol is as follows: take cerium ammonium nitrate and deionized water, stir evenly to obtain cerium ammonium nitrate aqueous solution; add polyvinyl alcohol and deionized water, stir evenly, adjust pH, add cerium ammonium nitrate aqueous solution, add glycidyl methacrylate, stir evenly, then react for 7-9 hours, cool to room temperature, filter, wash and dry to obtain epoxy-modified polyvinyl alcohol.

6. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 1, characterized in that: The short-chain succinic anhydride has 6-10 carbon atoms in its olefin side chain; the medium-chain succinic anhydride has 9-14 carbon atoms in its olefin side chain.

7. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 6, characterized in that: The short-chain succinic anhydride is octenyl succinic anhydride, and the medium-chain succinic anhydride is nonenyl succinic anhydride.

8. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 1, characterized in that: The titanium dioxide has a particle size of 20-100 nm.

9. The method for preparing a high-strength biodegradable aviation waste bag material according to claim 1, characterized in that: The high-strength biodegradable aviation waste bag material comprises the following raw materials, by weight: 72-78 parts polyethylene, 12-15 parts ethylene-acrylic acid copolymer, 5-8 parts pentaerythritol, 8-12 parts polylactic acid, 6-9 parts sebacic acid, 15-18 parts modified starch composite powder, 2-3 parts urea, 3-4 parts isophorone diisocyanate, 2-4 parts titanium dioxide, 2.5-4 parts paraffin wax, 1-2 parts titanate coupling agent, 1-2 parts sorbitol, 1-1.2 parts sodium dodecyl sulfate, and 0.3-0.6 parts antioxidant.

10. The garbage bag material prepared by the method for preparing a high-strength biodegradable aviation garbage bag material according to any one of claims 1-9.

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