Extrusion blow molding product containing straw and preparation method thereof

Abstract

The invention 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: 76 to 83.5 percent of matrix resin, 12.5 to 20 percent of straw master batch synergistically modified by ethylene-octene copolymer / coupling agent, and 4 to 5 percent of color master batch. The invention discloses a straw-containing extrusion blow-molded product and a preparation method thereof, and discloses a new application of an ethylene-octylene copolymer, and the ethylene-octylene copolymer can be used as an elastomer for improving the compatibility of straw and matrix resin. According to the invention, the straw master batch synergistically modified by the ethylene-octene copolymer / coupling agent is introduced into the matrix resin, so that the compatibility of the straw and the matrix resin is remarkably improved, the problems of poor strength of a straw / polyethylene composite material extrusion blow molding product and the like are solved, and the use of plastic materials is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of packaging materials, in particular to an extrusion blow-molded product containing straw and a preparation method thereof. Background Art

[0002] If plastic products are not properly recycled after use, they are seriously endangering the earth's ecological environment due to their difficult-to-degrade properties. Among them, extrusion blow molding products are packaging containers for food, cosmetics, medicines, and daily necessities. They are characterized by high consumption frequency and large usage. Reducing the use of plastics is an inevitable trend for future development. Plant fibers have shown broad application prospects in the field of polymer composites due to their advantages such as renewability, easy access, and low cost. Among them, straw is the remaining part of crops such as wheat and rice after harvesting seeds. The material resources are abundant. If it is discarded, it will cause great waste. Therefore, introducing straw materials into polymers can not only achieve high-value utilization of straw materials, but also reduce the use of plastics, which is in line with the environmental protection concept of sustainable development.

[0003] Straw is mainly composed of cellulose, hemicellulose, lignin and other organic matter. It is rich in hydroxyl groups and is polar, while polymers such as polyolefins are non-polar. This leads to poor compatibility between plant fibers such as straw and polymer matrices. Directly introducing straw into polymers will affect the processing technology and mechanical properties of the products. In order to improve the compatibility between plant fibers and polymers, many literatures and patents have reported 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. The method uses a titanate coupling agent and maleic anhydride grafted polypropylene wax to increase the compatibility of wheat straw and polypropylene, thereby improving the mechanical properties of the composite material. In Chinese patent CN114539747B, a hydroxymethyl urea / straw suspension and polylactic acid are extruded and granulated by a one-step reaction to obtain a composite material with good mechanical properties. Chinese patent CN113881208B discloses a method for preparing isoleucine grafted modified straw to obtain a straw / polylactic acid composite material with high mechanical strength and low water absorption. However, the extrusion blow molding process has higher requirements on the compatibility of straw and matrix resin, and is prone to poor plasticization of the mold and then melt fracture. The compatibility problem between straw and matrix resin limits the promotion and use of straw extrusion blow molding products, so it is urgent to solve the compatibility problem between straw and matrix resin 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, provide an extrusion blow-molded product containing straw with good mechanical properties, and reduce the use of plastic materials.

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

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

[0008] The specific technical solutions include the following:

[0009] In a first aspect, a straw-containing extrusion blow-molded product is provided, including straw masterbatch synergistically modified by ethylene octene copolymer / coupling agent.

[0010] Although ethylene octene copolymer has been widely used in the field of polymer formulation technology, it is generally used as a toughening agent. The present invention uses ethylene octene copolymer to improve the compatibility between straw and matrix resin. The good fluidity of ethylene octene copolymer enables it to better wrap straw particles. After the ethylene octene copolymer is introduced into the straw modified by the coupling agent, the contact area between the matrix resin and the straw can be increased. Under the synergistic effect of the coupling agent, the compatibility between the straw and the matrix resin can be significantly improved, thereby giving the product good mechanical properties.

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

[0012] Base resin 76-83.5%,

[0013] Ethylene octene copolymer / coupling agent synergistically modified straw masterbatch 12.5-20%,

[0014] Masterbatch 4-5%.

[0015] Furthermore, the method for preparing the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch comprises the following steps:

[0016] S1. Coupling agent modified rice husk straw: take rice husk straw for use, prepare a mixed solution of ethanol and water, add a silane coupling agent while stirring the solution, then add acetic acid as a hydrolysis catalyst, adjust the pH to 3.5-5.5, hydrolyze for 5-10 minutes to obtain a treatment solution, spray the treatment solution evenly on the surface of the rice husk straw, then stir evenly in a high-speed mixer, finally put the rice husk straw into an oven at 60-70°C and dry for 6-10 hours, and obtain the coupling agent modified rice husk straw after cooling;

[0017] S2. Preparation of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch: spray paraffin oil evenly on the surface of high-density polyethylene and ethylene octene copolymer, pour them into the main barrel of the twin-screw extruder after the surface of the high-density polyethylene and ethylene octene copolymer particles are completely soaked with paraffin oil, and pour the coupling agent-modified rice husk straw obtained in step S1 into the side feeding barrel, and extrude and feed the side feeding screw to the twin screw to obtain ethylene octene copolymer / coupling agent synergistically modified straw masterbatch by extrusion granulation.

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

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

[0020] Furthermore, in the preparation method of the ethylene-octene copolymer / coupling agent synergistically modified straw masterbatch, the silane coupling agent is at least one of vinyltrimethoxysilane, γ-aminopropyltriethoxysilane (KH550), γ-methacryloxypropyltrimethoxysilane (KH570), and γ-glycidyloxypropyltrimethoxysilane (KH560).

[0021] Furthermore, in the method for preparing the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch, the particle size of the rice husk straw is 80-200 meshes.

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

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

[0024] Furthermore, the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch comprises the following components in terms of weight percentage:

[0025] Coupling agent modified rice husk straw 20-50%,

[0026] High density polyethylene 20-50%,

[0027] Ethylene octene copolymer 10-30%,

[0028] Paraffin oil 0.8-1.2%.

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

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

[0031] The present invention improves the compatibility of straw with the matrix resin by introducing the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch into the extrusion blow molded product, thereby obtaining an extrusion blow molded product containing straw with good mechanical properties, and reducing the use of plastic materials, giving the product a unique appearance and plant fiber aroma. Compared with the prior art, the extrusion blow molded product containing straw provided by the present invention and the preparation method thereof have the following beneficial effects:

[0032] 1. No equipment modification is required and it can be directly prepared on the existing extrusion blow molding machine.

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

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

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

[0036] 5. This method is universal and can be used for the production of hollow products such as blow-molded barrels, bottles, and boxes. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

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

[0039] Figure 2This is a SEM image of the cross section of the bottle body of the extrusion blow-molded bottle containing straw in Example 4 of the present invention after being brittle fractured by liquid nitrogen;

[0040] Figure 3 This is a SEM image of the cross section of the extrusion blow-molded bottle containing straw in comparative example 4 of the present invention after being brittlely fractured by liquid nitrogen. DETAILED DESCRIPTION

[0041] 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.

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

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

[0044] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0045] In order to more fully understand the technical content of the present invention, the technical solution of the present invention is further introduced and illustrated in conjunction with specific embodiments below.

[0046] Unless otherwise specified, the parts described in the present invention are all parts by weight.

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

[0048] S1. Coupling agent modified rice husk straw: take rice husk straw for 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, hydrolyze for 5-10 minutes to obtain a treatment solution, spray the treatment solution evenly on the surface of the rice husk straw, then stir evenly in a high-speed mixer, finally put the rice husk straw into an oven at 60-70°C and dry for 6-10 hours, and obtain the coupling agent modified rice husk straw after cooling;

[0049] S2. Preparation of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch: Paraffin oil is evenly sprayed on the surface of high-density polyethylene and ethylene octene copolymer, and after the surface of high-density polyethylene and ethylene octene copolymer particles are completely infiltrated by paraffin oil, they are poured into the main barrel of the twin-screw extruder, and the coupling agent-modified rice husk straw obtained in step S1 is poured into the side feeding barrel, and the side feeding screw is extruded and fed to the twin screw, and the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch is obtained by extrusion granulation. The extrusion temperature of extrusion granulation is 160-190°C, and the rotation speed is 50-150rpm.

[0050] Preparation method of extrusion blow molding products containing straw:

[0051] Add base resin, masterbatch, and ethylene octene copolymer / coupling agent synergistically modified straw masterbatch into a high-speed mixer, and blow mold the mixed material through an extrusion blow molding machine to obtain an extrusion blow molded product containing straw. The extrusion temperature of the extrusion blow molding machine is 160-190° C., and the blowing pressure is 0.3-0.7 MPa. Among them, the extrusion blow molded products containing straw prepared in the following examples and comparative examples are all extrusion blow molded bottles containing straw with a capacity of 1.5 L and a handle, and the bottle body thickness is 1.2±0.1 mm by adjusting the die gap during the blow molding process.

[0052] Performance test - strength test and microscopic morphology observation of blow molded products:

[0053] In order to test the effect of ethylene octene copolymer / coupling agent synergistically modified 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 carried out by placing an empty bottle with a cap vertically on a universal testing machine (AGS-J, Shimadzu Instruments (Suzhou) Co., Ltd.), with a compression speed of 100mm / min. The maximum pressure was taken as its compressive strength. Ten bottles of each type were tested and the average value was taken. The drop test was to add a specified weight of liquid to the bottle, and then drop it at a height of 1.2m for a total of 3 times, namely vertical drop, plane drop and side drop. Ten samples were made for each batch, and the number of broken bottles was recorded and the breakage rate was calculated. The drop breakage rate was required to be 0%. If cracking and damage were found in the drop test, the test was judged to be unsuccessful. Usually, when the compressive strength can be maintained at 85% of that of pure resin products, the drop strength of the product can meet the requirements.

[0054] The drop performance of blow-molded products is closely related to the tensile strength of the material. In order to further characterize the effect of the addition of rice husk straw and ethylene-octene copolymer on the strength of the material, the tensile properties of the material were tested, and the cross-sectional morphology of the specimens was observed using a scanning electron microscope after they were brittle fractured 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 specimens with a length, width and thickness of 100mm×10mm×1.5mm using a punching machine, and the tensile strength of the specimens was tested using an AGS-J universal testing machine (Shimadzu Instruments (Suzhou) Co., Ltd.) at a tensile rate of 50mm / min. The cross-section of the specimen after brittle fracture was sprayed with gold and observed using a Phenom ProX scanning electron microscope (Themo Scientific).

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

[0056] Rice husk straw: 80-200 mesh.

[0057] Matrix resin: high-density polyethylene, brand name HHM5502LW.

[0058] Ethylene octene copolymer (POE): the brand is Exxon Vistamaxx POE 6202.

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

[0060] Masterbatch: Green masterbatch with PE carrier.

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

[0062] Example 1

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

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

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

[0066] Coupling agent modified rice husk straw 40%, high density polyethylene 49%, ethylene octene copolymer 10%, paraffin oil 1%.

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

[0068] S1. Coupling agent modified rice husk straw: 100 parts of rice husk straw (particle size of 80 mesh) were taken for use by weight, and a mixed solution of ethanol and water (9 parts of ethanol and 1 part of water) was prepared. While stirring the above solution, 2 parts of silane coupling agent (γ-methacryloxypropyltrimethoxysilane KH570) were added, and then acetic acid as a hydrolysis catalyst was added, and the pH was adjusted to 4.5. After hydrolysis for 5 minutes, a treatment solution was obtained, and the treatment solution was evenly sprayed on the surface of the rice husk straw, and then stirred evenly in a high-speed mixer. Finally, the rice husk straw was placed in an oven at 60°C and dried for 10 hours. After cooling, the coupling agent-modified rice husk straw was obtained;

[0069] S2. Preparation of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch: Paraffin oil is evenly sprayed on the surface of high-density polyethylene and ethylene octene copolymer, and after the surface of high-density polyethylene and ethylene octene copolymer particles are completely infiltrated by paraffin oil, they are poured into the main barrel of the twin-screw extruder, and the coupling agent-modified rice husk straw obtained in step S1 is poured into the side feeding barrel, and the side feeding screw is extruded and fed to the twin screw, and the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch is obtained by extrusion granulation. The extrusion temperature of the extrusion granulation is 180°C and the rotation speed is 100rpm.

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

[0071] Example 2

[0072] The difference between Example 2 and Example 1 is that the weight percentage of the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch in the extrusion blow molded product containing straw is 16%, the weight percentage of the base resin is 80%, the silane coupling agent used in the preparation method of the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch is γ-aminopropyltriethoxysilane KH550, the particle size of the rice husk straw is 200 mesh, and the other formulas and process conditions are the same as those 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 synergistically modified straw masterbatch in the straw-containing extrusion blow-molded product is 20%, and the weight percentage of the base resin is 76%. Other formulas and process conditions are the same as those in Example 1.

[0075] Example 4

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

[0077] Example 5

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

[0079] Comparative Example 1

[0080] The difference between Comparative Example 1 and Example 1 is that the extrusion blow molded product is composed of 96% high-density polyethylene and 4% masterbatch by weight, and other conditions are the same as those 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 synergistically modified straw masterbatch in the extrusion blow-molded product containing straw is 8%, and the weight percentage of the base resin is 88%. Other formulas and process conditions are the same as those 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 synergistically modified straw masterbatch in the extrusion blow-molded product containing straw is 25%, and the weight percentage of the base resin is 71%. Other formulas and process conditions are the same as those in Example 1.

[0085] Comparative Example 4

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

[0087] Comparative Example 5

[0088] The difference between Comparative Example 5 and Example 3 is that the weight percentage of POE in the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch is 40%, the weight percentage of high-density polyethylene in the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch is 19%, and the other formulas and process conditions are the same as those 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 is not modified by a coupling agent, and the other formulas and process conditions are the same as those in Example 3.

[0091] The formula compositions (weight percentage, %) of the extrusion blow-molded products containing straw of Examples 1-5 and Comparative Examples 1-6 are shown in Table 1 below.

[0092] Table 1 Composition of the extrusion blow molded products containing straw in Examples 1-5 and Comparative Examples 1-6 (weight percentage, %)

[0093]

[0094] The performance of the straw-containing extrusion blow-molded products (blow-molded bottles) of Examples 1-5 and Comparative Examples 1-6 was tested, and the test results are shown in Table 2 below, where the amount of plastic reduction is equal to the weight percentage content of the coupling agent-modified rice husk straw added to the blow-molded bottle.

[0095] Table 2 Performance test results of straw-containing extrusion blow molding products of Examples 1-5 and Comparative Examples 1-6

[0096]

[0097]

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

[0099] Figure 1The extrusion blow molded bottle containing straw prepared in Example 1 of the present invention (left) and the extrusion blow molded bottle containing straw prepared in Example 3 (right) are extrusion blow molded products containing straw with a capacity of 1.5L. The thickness of the bottle body is controlled at 1.1-1.3mm to ensure that the volume and weight of the blow molded products in the embodiment and the comparative example are similar. Checking the appearance of the products, it can be found that the surfaces of the products are relatively smooth, indicating that adding the straw masterbatch at this weight content will not make the surface of the product rough. As the content of the straw masterbatch increases, it can be clearly observed that the number of straw particles on the surface of the product gradually increases.

[0100] The formulations of the embodiments and comparative examples are shown in Table 1, and the performance test results are shown in Table 2. Combining the formulations with the test results, the following findings are made:

[0101] Compared with the blow molded products made of straw masterbatch modified by ethylene octene copolymer / coupling agent (Comparative Example 1), the straw-containing extrusion blow molded products of Examples 1-5 can reduce the plastic usage of blow molded bottles by 5-8% by adding 12.5-20% by weight of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch. It can be seen from the performance test results of Examples 1-3 that with the increase of the weight content of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch, the compressive strength of the blow molded bottle decreases. The weight content of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch added in Examples 4 and 5 is the same as that in Example 3, while the weight content of ethylene octene copolymer in the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch is increased, which has little effect on tensile strength. In addition, by comparing the test results of Examples 1-5 with those of Comparative Example 1, it can be seen that with the addition of the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch, the compressive strength of the blow-molded bottle decreases. Among them, Example 5 has the lowest compressive strength, which is 764N, 86.6% of that of Comparative Example 1, exceeding 85%. Therefore, the anti-drop performance of the extrusion blow-molded products containing straw obtained in Examples 1-5 remains good, and no damage occurs in the drop test.

[0102] When the amount of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch added to the extrusion blow molding product containing straw is too little (Comparative Example 2), although its strength and anti-drop performance meet the standards, the plastic reduction is only 3.2%. When the amount of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch added to the extrusion blow molding product containing straw is too much (Comparative Example 3), although the plastic reduction is 10%, the addition of excessive straw makes it difficult to blow mold the blow molding bottle.

[0103] From the performance test results of Examples 3-5, Comparative Example 3 and Comparative Example 4, it can be found that when no ethylene octene copolymer is added to the straw masterbatch (Comparative Example 4) or the ethylene octene copolymer content 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 bottle body of the extrusion blow-molded bottle containing straw in Example 4 of the present invention after being brittle fractured by liquid nitrogen; Figure 3 This is a SEM image of the cross section of the extrusion blow-molded bottle containing straw in comparative example 4 of the present invention after being brittle fractured by liquid nitrogen. Figure 2-Figure 3 It can be seen that the cross section of the bottle body of the extrusion blow molding bottle containing straw in Example 4 is rough, and there is no separation phenomenon between straw and matrix resin, indicating that the interface of straw and matrix resin after ethylene octene copolymer / coupling agent synergistic modification is good, straw and resin can bear force at the same time, and straw will break preferentially; and the straw masterbatch of the extrusion blow molding bottle containing straw in Comparative Example 4 is not added with ethylene octene copolymer, and the poor fluidity of matrix resin makes it unable to wrap straw particles well, straw and resin have obvious gap, and the effect of coupling agent cannot be fully exerted. It can be seen that the problem of poor compatibility between straw and resin cannot be effectively solved by coupling agent alone, which leads to a significant reduction in strength of comparative example 4 products and a drop breakage rate of 30%. When the weight content of ethylene octene copolymer in straw masterbatch is too high (Comparative Example 5), although straw and matrix resin have good compatibility, ethylene octene copolymer itself has low strength, and excessive addition will significantly reduce strength, resulting in a drop breakage rate of 20%.

[0104] From the performance test results of Example 4 and Comparative Example 6, it can be found that if the rice husk straw in the straw masterbatch is not modified by a 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 the products without the solution of the embodiment of the present invention, the plastic reduction of the extrusion blow-molded products containing straw prepared by the solution of the embodiment of the present invention can reach 8%, and the compressive strength is still maintained at least 85% of the base resin product. At the same time, the surface of the product is smooth, which can meet the use requirements of the product. In addition, the solution of the present invention is versatile and can be used for the production of hollow products such as blow-molded barrels, bottles, and boxes.

[0106] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. An extrusion blow-molded product containing straw, characterized in that: Including straw masterbatch modified by ethylene octene copolymer / coupling agent synergistically.

2. The straw-containing extrusion blow-molded product according to claim 1, characterized in that: By weight percentage, it includes the following components: Base resin 76-83.5%, Ethylene octene copolymer / coupling agent synergistically modified straw masterbatch 12.5-20%, Masterbatch 4-5%.

3. The extrusion blow molded product containing straw according to any one of claims 1 to 2, characterized in that: The method for preparing the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch comprises the following steps: S1. Coupling agent modified rice husk straw: take rice husk straw for use, prepare a mixed solution of ethanol and water, add a silane coupling agent while stirring the solution, then add acetic acid as a hydrolysis catalyst, adjust the pH to 3.5-5.5, hydrolyze for 5-10 minutes to obtain a treatment solution, spray the treatment solution evenly on the surface of the rice husk straw, then stir evenly in a high-speed mixer, finally put the rice husk straw into an oven at 60-70°C and dry for 6-10 hours, and obtain the coupling agent modified rice husk straw after cooling; S2. Preparation of ethylene octene copolymer / coupling agent synergistically modified straw masterbatch: spray paraffin oil evenly on the surface of high-density polyethylene and ethylene octene copolymer, pour them into the main barrel of the twin-screw extruder after the surface of the high-density polyethylene and ethylene octene copolymer particles are completely soaked with paraffin oil, and pour the coupling agent-modified rice husk straw obtained in step S1 into the side feeding barrel, and extrude and feed the side feeding screw to the twin screw to obtain ethylene octene copolymer / coupling agent synergistically modified straw masterbatch by extrusion granulation.

4. The extrusion blow-molded product containing straw according to claim 3, characterized in that: In the preparation method of the ethylene-octene copolymer / coupling agent synergistically modified straw masterbatch, the silane coupling agent is at least one of vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-glycidyloxypropyltrimethoxysilane.

5. The straw-containing extrusion blow-molded product according to claim 3, characterized in that: In the method for preparing the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch, the particle size of the rice husk straw is 80-200 meshes.

6. The extrusion blow-molded product containing straw according to claim 3, characterized in that: In the method for preparing the ethylene octene copolymer / coupling agent synergistically modified straw masterbatch, the extrusion temperature of the extrusion granulation is 160-190° C. and the rotation speed is 50-150 rpm.

7. The straw-containing extrusion blow-molded product according to claim 2, characterized in that: The matrix resin is high-density polyethylene.

8. The straw-containing extrusion blow-molded product according to claim 2, characterized in that: The ethylene octene copolymer / coupling agent synergistically modified straw masterbatch comprises the following components by weight percentage: Coupling agent modified rice husk straw 20-50%, High density polyethylene 20-50%, Ethylene octene copolymer 10-30%, Paraffin oil 0.8-1.2%.

9. The method for preparing an extrusion blow-molded product containing straw according to claim 2, characterized in that: The following steps are involved: Add base resin, masterbatch and ethylene octene copolymer / coupling agent synergistically modified straw masterbatch into a high-speed mixer, blow-mold the mixed materials through an extrusion blow molding machine to obtain an extrusion blow-molded product containing straw.

10. The method for preparing an extrusion blow-molded product containing straw according to claim 9, characterized in that: The extrusion temperature of the extrusion blow molding machine is 160-190°C, and the blowing pressure is 0.3-0.7MPa.

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