An extrusion blow molded article containing straw and a method of making the same

Abstract

The application discloses a straw-containing extrusion blow molding product and a preparation method thereof, and relates to the technical field of packaging materials. The straw-containing extrusion blow molding product comprises the following components in percentage by weight: base resin 76-83.5%, ethylene octene copolymer / coupling agent synergistically modified straw master batch 12.5-20%, and color master batch 4-5%. The straw-containing extrusion blow molding product and the preparation method thereof disclose a new application of ethylene octene copolymer, and the ethylene octene copolymer can be used as an elastomer for improving the compatibility of straw and base resin. The straw master batch modified by the ethylene octene copolymer / coupling agent is introduced into the base resin, the compatibility of the straw and the base resin is significantly improved, the problems, such as poor strength of the straw / polyethylene composite material extrusion blow molding product, are solved, and the use of plastic materials is reduced.

Description

Technical Field

[0001] This invention relates to the field of packaging materials technology, and in particular to an extruded blow-molded product containing straw and its preparation method. Background Technology

[0002] Plastic products, if not properly recycled after use, are seriously harming the Earth's ecological environment due to their non-degradable nature. Extruded blow-molded products, used as packaging containers for food, cosmetics, pharmaceuticals, and daily necessities, are characterized by high consumption frequency and large usage volume; reducing plastic use is an inevitable trend for future development. Plant fibers, due to their renewable, readily available, and low-cost advantages, show broad application prospects in the field of polymer composites. Straw, the residue after harvesting crops such as wheat and rice, is an abundant resource; discarding it would result in enormous waste. Therefore, incorporating straw into polymers can achieve high-value utilization of straw materials and reduce plastic usage, aligning with the environmental protection concept of sustainable development.

[0003] Straw is mainly composed of cellulose, hemicellulose, lignin, and other organic matter, and is rich in hydroxyl groups, exhibiting polarity. Polyolefins and other polymers, on the other hand, are non-polar. This results in poor compatibility between plant fibers like straw and the polymer matrix, and directly introducing straw into polymers can negatively impact the processing technology and mechanical properties of the finished product. To improve the compatibility between plant fibers and polymers, numerous publications and patents have reported on related treatment methods, including alkali treatment, acetylation treatment, coupling agent treatment, peroxide treatment, permanganate treatment, and isocyanate treatment.

[0004] Chinese patent CN112980208B discloses a method for preparing a wheat straw / polypropylene composite material. This method uses a titanate coupling agent and maleic anhydride-grafted polypropylene wax to increase the compatibility between wheat straw and polypropylene, thereby improving the mechanical properties of the composite material. Chinese patent CN114539747B describes a one-step reaction extrusion and granulation process using hydroxymethyl urea / straw suspension and polylactic acid to obtain a composite material with good mechanical properties. Chinese patent CN113881208B discloses a method for preparing isoleucine-grafted modified straw, resulting in a straw / polylactic acid composite material with high mechanical strength and low water absorption. However, extrusion blow molding processes have higher requirements for the compatibility between straw and the matrix resin, easily leading to poor preform plasticization and melt fracture. The compatibility problem between straw and the matrix resin limits the widespread use of straw extrusion blow molded products; therefore, it is urgent to solve this problem through technological innovation. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect of poor compatibility between straw and matrix resin, and to provide an extruded blow-molded product containing straw with good mechanical properties, while reducing the use of plastic materials.

[0006] Another object of the present invention is to provide the use of an ethylene octene copolymer as an elastomer for improving the compatibility of straw with matrix resin.

[0007] Another object of the present invention is to provide a method for preparing an extruded blow-molded article containing straw.

[0008] Specifically, the following technical solutions are included:

[0009] In one aspect, an extruded blow-molded article containing straw is provided, comprising straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent.

[0010] While ethylene octene copolymers have been widely used in polymer formulation technology, they are generally applied as toughening agents. This invention utilizes ethylene octene copolymers to improve the compatibility between straw and matrix resin. The good flowability of ethylene octene copolymers allows them to better encapsulate straw particles. Introducing ethylene octene copolymers into coupling agent-modified straw increases the contact area between the matrix resin and the straw. Under the synergistic effect of the coupling agent, the compatibility between straw and matrix resin can be significantly improved, thereby imparting excellent mechanical properties to the product.

[0011] Furthermore, the extruded blow-molded product containing straw comprises, by weight percentage, the following components:

[0012] Matrix resin 76-83.5%,

[0013] 12.5-20% of straw masterbatch is synergistically modified with ethylene octene copolymer / coupling agent.

[0014] Masterbatch 4-5%.

[0015] Furthermore, the preparation method of the ethylene-octene copolymer / coupling agent synergistic modified straw masterbatch includes the following steps:

[0016] S1. Coupling agent modified rice husk straw: Take rice husk straw for later use, prepare a mixed solution of ethanol and water, add silane coupling agent while stirring the above solution, then add hydrolysis catalyst acetic acid, adjust the pH to 3.5-5.5, and hydrolyze for 5-10 minutes to obtain the treatment solution. Spray the treatment solution evenly onto the surface of rice husk straw, then stir evenly in a high-speed mixer. Finally, put the rice husk straw into an oven at 60-70℃ and dry for 6-10 hours. After cooling, the coupling agent modified rice husk straw is obtained.

[0017] S2. Preparation of straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent: Paraffin oil is uniformly sprayed onto the surface of high-density polyethylene and ethylene octene copolymer. After the surface of the high-density polyethylene and ethylene octene copolymer particles is completely wetted by paraffin oil, they are poured into the main feed hopper of a twin-screw extruder. At the same time, the rice husk straw modified with coupling agent obtained in step S1 is poured into the side feed hopper. The side feed screw feeds the material to the twin screw extruder, and the extrusion granulation yields straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent.

[0018] Preferably, in the method for preparing the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch, the coupling agent modified rice husk straw obtained in step S1 comprises the following components by weight:

[0019] 100 parts rice husk straw, 8-12 parts ethanol, 1-3 parts silane coupling agent, and 0.8-1.2 parts water.

[0020] Furthermore, in the method for preparing the ethylene octene copolymer / coupling agent synergistic modification of straw masterbatch, the silane coupling agent is at least one of vinyltrimethoxysilane, γ-aminopropyltriethoxysilane (KH550), γ-methacryloyloxypropyltrimethoxysilane (KH570), and γ-glycidoxypropyltrimethoxysilane (KH560).

[0021] Furthermore, in the preparation method of the ethylene octene copolymer / coupling agent synergistic modification of straw masterbatch, the particle size of the rice husk straw is 80-200 mesh.

[0022] Furthermore, in the preparation method of the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch, the extrusion temperature of the extrusion granulation is 160-190℃ and the rotation speed is 50-150rpm.

[0023] Furthermore, the matrix resin is high-density polyethylene.

[0024] Furthermore, by weight percentage, the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch comprises the following components:

[0025] 20-50% of rice husk straw modified with coupling agent

[0026] High-density polyethylene 20-50%,

[0027] 10-30% ethylene-octene copolymer

[0028] Paraffin oil 0.8-1.2%.

[0029] In a second aspect, a method for preparing an extruded blow-molded product containing straw as described in the first aspect is provided, comprising the following steps: adding a matrix resin, a color masterbatch, and straw masterbatch synergistically modified with an ethylene octene copolymer / coupling agent to a high-speed mixer, and blowing the mixed material through an extrusion blow molding machine to obtain an extruded blow-molded product containing straw.

[0030] Furthermore, the extrusion temperature of the extrusion blow molding machine is 160-190℃, and the blowing pressure is 0.3-0.7MPa.

[0031] This invention improves the compatibility of straw with the matrix resin by introducing ethylene-octene copolymer / coupling agent synergistic modification of straw masterbatch into extruded blow-molded products. This results in straw-containing extruded blow-molded products with excellent mechanical properties, reduces the use of plastic materials, and gives the products a unique appearance and plant fiber aroma. Compared with existing technologies, the straw-containing extruded blow-molded products and their preparation method provided by this invention have the following beneficial effects:

[0032] 1. No equipment modification is required; it can be produced directly on existing extrusion blow molding machines.

[0033] 2. The introduction of rice husk straw gives blow-molded products a unique aroma and appearance.

[0034] 3. Rice husk straw, as a filler, has a certain strength. After synergistic modification with ethylene octene copolymer / coupling agent, its compatibility with the matrix resin is improved, the strength of the product is increased, and the drop performance of the product meets the requirements for use.

[0035] 4. Without affecting the performance of the product, the amount of plastic used in the product can be reduced by up to 8%. Since straw materials are low in cost, the overall cost of the product can be reduced while achieving environmental protection and plastic reduction.

[0036] 5. This method is versatile and can be used in the production of hollow products such as blow-molded buckets, bottles, and boxes. Attached Figure Description

[0037] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 The extruded blow-molded bottle containing straw prepared in Example 1 of the present invention (left) and the extruded blow-molded bottle containing straw prepared in Example 3 (right);

[0039] Figure 2This is a SEM image of the cross-section of the body of the extruded blow-molded bottle containing straw in Embodiment 4 of the present invention after liquid nitrogen embrittlement.

[0040] Figure 3 This is a SEM image of the cross-section of the extruded blow-molded bottle containing straw, which is a comparative example of the present invention, after being subjected to liquid nitrogen embrittlement. Detailed Implementation

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0043] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0044] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0045] To better understand the technical content of the present invention, the technical solution of the present invention will be further introduced and explained below with reference to specific embodiments.

[0046] Unless otherwise specified, the parts mentioned in this invention refer to parts by weight.

[0047] Preparation method of straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent:

[0048] S1. Coupling agent modified rice husk straw: Take rice husk straw for later use (the particle size of rice husk straw is 80-200 mesh), prepare a mixed solution of ethanol and water, add silane coupling agent while stirring the above solution, then add hydrolysis catalyst acetic acid, adjust the pH to 3.5-5.5, and hydrolyze for 5-10 minutes to obtain the treatment solution. Spray the treatment solution evenly onto the surface of rice husk straw, then stir evenly in a high-speed mixer. Finally, put the rice husk straw into an oven at 60-70℃ and dry for 6-10 hours. After cooling, the coupling agent modified rice husk straw is obtained.

[0049] S2. Preparation of straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent: Paraffin oil is uniformly sprayed onto the surface of high-density polyethylene and ethylene octene copolymer. After the surface of the high-density polyethylene and ethylene octene copolymer particles is completely wetted with paraffin oil, they are poured into the main feed hopper of a twin-screw extruder. At the same time, the coupling agent-modified rice husk straw obtained in step S1 is poured into the side feed hopper. The side feed screw feeds the straw into the twin-screw extruder, and the extrusion granulation yields the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch. The extrusion temperature is 160-190℃, and the rotation speed is 50-150 rpm.

[0050] Preparation method of extruded blow-molded products containing straw:

[0051] A matrix resin, color masterbatch, and straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent were added to a high-speed mixer. The mixed material was then blow-molded using an extrusion blow molding machine to obtain an extruded blow-molded product containing straw. The extrusion temperature of the extrusion blow molding machine was 160-190℃, and the blowing pressure was 0.3-0.7MPa. In the examples and comparative examples below, the straw-containing extruded blow-molded products were all 1.5L capacity straw-containing extruded blow-molded bottles with handles. During the blow molding process, the bottle thickness was adjusted to 1.2±0.1mm by adjusting the die gap.

[0052] Performance Testing – Strength Testing and Microstructure Observation of Blow Molded Products:

[0053] To test the effect of ethylene-octene copolymer / coupling agent synergistic modification of straw masterbatch on the strength of blow-molded products, the compressive strength and drop performance of blow-molded bottles were tested. The compressive strength test was conducted by placing empty bottles with caps vertically on a universal testing machine (AGS-J, Shimadzu Instruments (Suzhou) Co., Ltd.) at a compression speed of 100 mm / min. The maximum pressure was recorded as the compressive strength. Ten bottles of each type were tested, and the average value was taken. The drop test involved adding a specified weight of liquid to the bottle and then dropping it from a height of 1.2 m three times: vertical drop, horizontal drop, and side drop. Ten bottles were tested for each batch, and the number of broken bottles was recorded and the breakage rate was calculated. A 0% drop breakage rate was required; if cracking or breakage was found during the drop test, the test was considered a failure. Generally, the drop strength of the product meets the requirements when the compressive strength can be maintained at 85% of that of the pure resin product.

[0054] The drop performance of blow-molded products is closely related to the tensile strength of the material. To further characterize the effect of adding rice husk straw and ethylene octene copolymer on the material strength, the tensile properties of the material were tested. Simultaneously, the cross-sectional morphology of the samples was observed using scanning electron microscopy after brittle fracture in liquid nitrogen. The reasons for the strength change were further analyzed. Generally, the better the compatibility between the matrix resin and the filler, the higher the strength of the composite material. The specific test method is as follows: The blow-molded bottle body was cut into dumbbell-shaped samples with a length, width, and thickness of 100mm × 10mm × 1.5mm using a punching machine. The tensile strength of the samples was tested using an AGS-J universal testing machine (Shimadzu Instruments (Suzhou) Co., Ltd.) at a tensile rate of 50mm / min. The fracture surface of the samples after brittle fracture was sputter-coated with gold and observed using a Phenom ProX scanning electron microscope (Themo Scientific).

[0055] Raw materials used in the examples and comparative examples:

[0056] Rice husks and straw: 80-200 mesh.

[0057] Matrix resin: High-density polyethylene, grade HHM5502LW.

[0058] Ethylene octene copolymer (POE): grade Exxon Vistamaxx POE 6202.

[0059] Silane coupling agent: at least one of γ-methacryloxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

[0060] Color masterbatch: Green masterbatch for PE carrier.

[0061] Paraffin oil: density 0.845-0.890 g / cm³ 3 The distillation temperature is greater than 300℃.

[0062] Example 1

[0063] An extruded blow-molded product containing straw, comprising the following components by weight percentage:

[0064] The matrix resin (high-density polyethylene) is 83.5%, the straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent is 12.5%, and the color masterbatch is 4%.

[0065] The ethylene octene copolymer / coupling agent synergistic modified straw masterbatch, by weight percentage, comprises the following components:

[0066] The mixture consists of 40% rice husk straw modified with coupling agent, 49% high-density polyethylene, 10% ethylene octene copolymer, and 1% paraffin oil.

[0067] The method for preparing the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch includes the following steps:

[0068] S1. Coupling agent modified rice husk straw: Take 100 parts by weight of rice husk straw (particle size of 80 mesh) for later use, prepare a mixed solution of ethanol and water (9 parts ethanol and 1 part water), add 2 parts of silane coupling agent (γ-methacryloyloxypropyltrimethoxysilane KH570) while stirring the above solution, then add acetic acid as a hydrolysis catalyst, adjust the pH to 4.5, and after hydrolysis for 5 min, obtain the treatment solution. Spray the treatment solution evenly onto the surface of rice husk straw, then stir evenly in a high-speed mixer, and finally put the rice husk straw into an oven at 60℃ and dry for 10 h. After cooling, the coupling agent modified rice husk straw is obtained.

[0069] S2. Preparation of straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent: Paraffin oil was uniformly sprayed onto the surface of high-density polyethylene and ethylene octene copolymer. After the surface of the high-density polyethylene and ethylene octene copolymer particles was completely wetted with paraffin oil, they were poured into the main feed hopper of a twin-screw extruder. At the same time, the coupling agent-modified rice husk straw obtained in step S1 was poured into the side feed hopper. The side feed screw fed the straw into the twin-screw extruder, and the extrusion granulation yielded the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch. The extrusion temperature was 180℃ and the rotation speed was 100 rpm.

[0070] The method for preparing the straw-containing extruded blow-molded product includes the following steps: adding a base resin, color masterbatch, and straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent to a high-speed mixer; then blowing the mixed material through an extrusion blow molding machine to obtain the straw-containing extruded blow-molded product. The extrusion temperature of the extrusion blow molding machine is 170℃, and the blowing pressure is 0.6MPa.

[0071] Example 2

[0072] The difference between Example 2 and Example 1 is that the weight percentage of the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch in the extruded blow-molded product containing straw is 16%, the weight percentage of the matrix resin is 80%, the silane coupling agent used in the preparation method of the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is γ-aminopropyltriethoxysilane KH550, the particle size of rice husk straw is 200 mesh, and other formulations and process conditions are the same as in Example 1.

[0073] Example 3

[0074] The difference between Example 3 and Example 1 is that the weight percentage of the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch in the extruded blow-molded product containing straw is 20%, and the weight percentage of the matrix resin is 76%. Other formulations and process conditions are the same as in Example 1.

[0075] Example 4

[0076] The difference between Example 4 and Example 3 is that the POE weight percentage in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is 20%, and the high-density polyethylene weight percentage content in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is 39%. Other formulations and process conditions are the same as in Example 3.

[0077] Example 5

[0078] The difference between Example 5 and Example 3 is that the POE weight percentage in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is 30%, and the high-density polyethylene weight percentage content in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is 29%. Other formulations and process conditions are the same as in Example 3.

[0079] Comparative Example 1

[0080] The difference between Comparative Example 1 and Example 1 is that the extruded blow-molded product is composed of 96% high-density polyethylene and 4% color masterbatch by weight percentage, while the other conditions are the same as in Example 1.

[0081] Comparative Example 2

[0082] The difference between Comparative Example 2 and Example 1 is that the weight percentage of the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch in the extruded blow-molded product containing straw is 8%, and the weight percentage of the matrix resin is 88%. Other formulations and process conditions are the same as in Example 1.

[0083] Comparative Example 3

[0084] The difference between Comparative Example 3 and Example 1 is that the weight percentage of the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch in the extruded blow-molded product containing straw is 25%, and the weight percentage of the matrix resin is 71%. Other formulations and process conditions are the same as in Example 1.

[0085] Comparative Example 4

[0086] The difference between Comparative Example 4 and Example 3 is that no ethylene octene copolymer was added to the straw masterbatch, while the other formulations and process conditions were the same as in Example 3.

[0087] Comparative Example 5

[0088] The difference between Comparative Example 5 and Example 3 is that the POE weight percentage in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is 40%, and the high-density polyethylene weight percentage content in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch is 19%. Other formulations and process conditions are the same as in Example 3.

[0089] Comparative Example 6

[0090] The difference between Comparative Example 6 and Example 3 is that the rice husk straw in the straw masterbatch was not modified by the coupling agent, while the other formulations and process conditions were the same as in Example 3.

[0091] The formulation composition (weight percentage, %) of the straw-containing extruded blow-molded products of Examples 1-5 and Comparative Examples 1-6 is shown in Table 1 below.

[0092] Table 1. Formulation composition (weight percentage, %) of straw-containing extruded blow-molded products of Examples 1-5 and Comparative Examples 1-6

[0093]

[0094] Performance tests were conducted on the extruded blow-molded products (blow-molded bottles) containing straw from Examples 1-5 and Comparative Examples 1-6. The test results are shown in Table 2 below, where the reduction in plastic content is equal to the weight percentage of rice husk straw modified with coupling agent added to the blow-molded bottle.

[0095] Table 2. Performance test results of extruded blow-molded products containing straw from Examples 1-5 and Comparative Examples 1-6.

[0096]

[0097]

[0098] Note: - indicates that the product failed to form.

[0099] Figure 1The straw-containing extruded blow-molded bottle (left) prepared in Example 1 and the straw-containing extruded blow-molded bottle (right) prepared in Example 3 are both 1.5L capacity straw-containing extruded blow-molded products. The bottle body thickness is controlled between 1.1-1.3mm to ensure that the volume and weight of the blow-molded products in the examples and comparative examples are similar. Inspection of the product appearance reveals that the surface of both products is relatively smooth, indicating that adding straw masterbatch at this weight content will not make the product surface rough. As the straw masterbatch content increases, the number of straw particles on the product surface can be clearly observed to gradually increase.

[0100] The formulations of each embodiment and comparative example are shown in Table 1, and the performance test results are shown in Table 2. Based on the formulations and test results, the following findings were made:

[0101] Compared to blow-molded products made from straw masterbatch without ethylene octene copolymer / coupling agent synergistic modification (Comparative Example 1), the straw-containing extruded blow-molded products of Examples 1-5, by adding 12.5-20% by weight of ethylene octene copolymer / coupling agent synergistic modified straw masterbatch, can reduce the amount of plastic used in blow-molded bottles by 5-8%. Performance test results from Examples 1-3 show that the compressive strength of blow-molded bottles decreases with increasing weight content of ethylene octene copolymer / coupling agent synergistic modified straw masterbatch. Examples 4 and 5 have the same weight content of ethylene octene copolymer / coupling agent synergistic modified straw masterbatch as in Example 3, but the increased weight content of ethylene octene copolymer in the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch has little effect on tensile strength. In addition, comparing the test results of Examples 1-5 with those of Comparative Example 1, it can be seen that with the addition of straw masterbatch synergistically modified by ethylene octene copolymer / coupling agent, the compressive strength of blow-molded bottles decreased. The lowest compressive strength was found in Example 5, which had a compressive strength of 764 N, which was 86.6% of that of Comparative Example 1, exceeding 85%. Therefore, the extruded blow-molded products containing straw prepared in Examples 1-5 maintained good drop resistance and did not break in the drop test.

[0102] When the amount of ethylene octene copolymer / coupling agent synergistic modified straw masterbatch added to extruded blow-molded products containing straw is too small (Comparative Example 2), although its strength and drop resistance meet the standards, the plastic reduction is only 3.2%. When the amount of ethylene octene copolymer / coupling agent synergistic modified straw masterbatch added to extruded blow-molded products containing straw is too large (Comparative Example 3), although the plastic reduction is 10%, the excessive addition of straw makes blow-molded bottles difficult to form.

[0103] The performance test results of Examples 3-5, Comparative Examples 3 and 4 show that when no ethylene octene copolymer is added to the straw masterbatch (Comparative Example 4) or the content of ethylene octene copolymer is too high (Comparative Example 5), the tensile strength of the material and the compressive strength of the blow-molded bottle are significantly reduced compared with Comparative Example 1. Figure 2 This is a SEM image of the cross-section of the body of the extruded blow-molded bottle containing straw in Embodiment 4 of the present invention after liquid nitrogen embrittlement. Figure 3 This is a SEM image of the cross-section of the extruded blow-molded bottle containing straw (Comparative Example 4 of this invention) after liquid nitrogen embrittlement. From... Figures 2-3 As can be seen, the cross-section of the extruded blow-molded bottle containing straw in Example 4 is rough, and no separation of straw from the matrix resin is observed. This indicates that the interface between the straw and the matrix resin is well-bonded after synergistic modification with ethylene octene copolymer / coupling agent, allowing both straw and resin to bear load simultaneously, with the straw breaking preferentially. In contrast, the straw masterbatch of the extruded blow-molded bottle in Comparative Example 4, lacking ethylene octene copolymer, suffers from poor flowability of the matrix resin, preventing it from effectively encapsulating the straw particles. A significant gap exists between the straw and resin, failing to fully utilize the coupling agent's function. It is evident that coupling agent alone cannot effectively solve the problem of poor compatibility between straw and resin, leading to a significant reduction in the strength of the product in Comparative Example 4 and a drop breakage rate of 30%. When the weight content of ethylene octene copolymer in the straw masterbatch is too high (Comparative Example 5), although the compatibility between straw and matrix resin is good, the low strength of the ethylene octene copolymer itself means that excessive addition will significantly reduce the strength, resulting in a drop breakage rate of 20%.

[0104] The performance test results of Example 4 and Comparative Example 6 show that if the rice husk straw in the straw masterbatch is not modified by the coupling agent, the tensile strength and compressive strength of the product are significantly reduced, and the drop breakage rate reaches 60%.

[0105] In summary, compared with products not using the embodiments of this invention, the straw-containing extruded blow-molded products prepared using the embodiments of this invention can reduce the amount of plastic by up to 8%, while maintaining a compressive strength of at least 85% of that of the base resin product. Simultaneously, the product surface is smooth, meeting the usage requirements. Furthermore, the embodiments of this invention are versatile and can be used in the production of hollow products such as blow-molded buckets, bottles, and boxes.

[0106] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An extruded blow-molded product containing straw, characterized in that, By weight percentage, it includes the following components: Matrix resin 76-83.5%, 12.5-20% of straw masterbatch is synergistically modified with ethylene octene copolymer / coupling agent. Masterbatch 4-5%; The matrix resin is high-density polyethylene; The ethylene octene copolymer / coupling agent synergistic modified straw masterbatch, by weight percentage, comprises the following components: 20-50% rice husk straw modified with coupling agent High-density polyethylene 20-50%, 10-30% ethylene octene copolymer Paraffin oil 0.8-1.2%.

2. The extruded blow-molded product containing straw as described in claim 1, characterized in that, The method for preparing the ethylene octene copolymer / coupling agent synergistic modified straw masterbatch includes the following steps: S1. Coupling agent modified rice husk straw: Take rice husk straw for later use, prepare a mixed solution of ethanol and water, add silane coupling agent while stirring the above solution, then add hydrolysis catalyst acetic acid, adjust the pH to 3.5-5.5, and hydrolyze for 5-10 minutes to obtain the treatment solution. Spray the treatment solution evenly onto the surface of rice husk straw, then stir evenly in a high-speed mixer. Finally, put the rice husk straw into an oven at 60-70℃ and dry for 6-10 hours. After cooling, the coupling agent modified rice husk straw is obtained. S2. Preparation of straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent: Paraffin oil is uniformly sprayed onto the surface of high-density polyethylene and ethylene octene copolymer. After the surface of the high-density polyethylene and ethylene octene copolymer particles is completely wetted by paraffin oil, they are poured into the main feed hopper of a twin-screw extruder. At the same time, the rice husk straw modified with coupling agent obtained in step S1 is poured into the side feed hopper. The side feed screw feeds the material to the twin screw extruder, and the extrusion granulation yields straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent.

3. The extruded blow-molded product containing straw as described in claim 2, characterized in that, In the method for preparing straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent, the silane coupling agent is at least one of vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

4. The extruded blow-molded product containing straw as described in claim 2, characterized in that, In the preparation method of the ethylene octene copolymer / coupling agent synergistic modification of straw masterbatch, the particle size of the rice husk straw is 80-200 mesh.

5. The extruded blow-molded product containing straw as described in claim 2, characterized in that, In the preparation method of the straw masterbatch synergistically modified by ethylene octene copolymer / coupling agent, the extrusion temperature of the extrusion granulation is 160-190℃ and the rotation speed is 50-150rpm.

6. The method for preparing an extruded blow-molded article containing straw as described in claim 1, characterized in that, Includes the following steps: The matrix resin, color masterbatch, and straw masterbatch synergistically modified with ethylene octene copolymer / coupling agent are added to a high-speed mixer. The mixed material is then blow-molded through an extrusion blow molding machine to obtain extruded blow-molded products containing straw.

7. The method for preparing an extruded blow-molded article containing straw as described in claim 6, characterized in that, The extrusion temperature of the blow molding machine is 160-190℃, and the blowing pressure is 0.3-0.7MPa.

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