Composite composition for rotational plastic, polyvinyl rotational plastic and application

Abstract

The invention relates to the technical field of high polymer materials, in particular to a composite composition for rotational plastic, polyvinyl rotational plastic and application. The composite composition for the rotational molding material comprises a component A and a component B, wherein the component A comprises polyethylene resin, modified polyethylene resin, polyethylene wax and alkylphenol polyoxyethylene ether; the component B comprises a modified fiber material, an antioxidant, a flame retardant, an inorganic filler and a light stabilizer; wherein the modified polyethylene resin is polyethylene resin modified by a polysiloxane compound; the modified fiber material is a fiber material modified by organic acid or inorganic acid. The rotational plastic prepared from the composite composition for the rotational plastic provided by the invention has the mechanical properties of environmental stress cracking resistance and high impact resistance.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of high polymer materials, in particular to a composite composition for rotational molding material, a polyethylene-based rotational molding material and application. BACKGROUND

[0002] Rotational molding is a low-pressure, shear-free, long-cycle thermal cycle processing technology. Although traditional LLDPE for rotational molding has good fluidity, it has the following shortcomings: (1) poor thermal stability, yellowing and bubbles are prone to occur in thick-walled parts; (2) large shrinkage, large box / shell is prone to warping; (3) poor environmental stress cracking resistance. In the prior art, the addition of inorganic fillers, antioxidants or single silicone masterbatch can improve the heat resistance and dimensional stability to some extent, but the poor interfacial compatibility between the filler and the matrix leads to a decrease in toughness; the silicone masterbatch mainly provides processing lubrication, and the performance drops significantly after long-term aging. On the other hand, although natural fibers have the advantages of light weight, heat insulation and low carbon, they are prone to oxidative degradation during the rotational molding cycle, which leads to interfacial voids and reduces the impact strength. Therefore, there is an urgent need for a composite composition for rotational molding material that can simultaneously improve the thermal stability, environmental stress cracking resistance and mechanical properties of the rotational molding material. SUMMARY

[0003] The present disclosure provides a composite composition for rotational molding material, a polyethylene-based rotational molding material and application to solve the problems in the related art.

[0004] According to a first aspect of an embodiment of the present disclosure, a composite composition for rotational molding material is provided, which comprises the following components:

[0005] Component A: polyethylene resin, modified polyethylene resin, polyethylene wax and alkylphenol polyoxyethylene ether;

[0006] Component B: modified fiber material, antioxidant, flame retardant, inorganic filler and light stabilizer;

[0007] wherein the mass ratio of component A and component B is selected from (90-110):(10-15);

[0008] The modified polyethylene resin is a polyethylene resin modified by a polysiloxane compound;

[0009] The modified fiber material is a fiber material modified by an organic acid or an inorganic acid;

[0010] The organic acid is selected from succinic acid, citric acid or oxalic acid; the inorganic acid is selected from hydrochloric acid, sulfuric acid or nitric acid; and the fiber material is selected from bamboo fiber, mullite fiber or basalt fiber.

[0011] In an aspect of the embodiments of the present disclosure, the polyethylene resin includes a linear low density polyethylene resin and a high density polyethylene resin. Specifically, a mass ratio of the linear low density polyethylene resin and the high density polyethylene resin in the polyethylene resin is selected from 5-10:1.

[0012] In an aspect of the embodiments of the present disclosure, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076, antioxidant CA, antioxidant 168, antioxidant 2246, antioxidant 300, antioxidant 3114, and antioxidant 330.

[0013] In an aspect of the embodiments of the present disclosure, preferably, the antioxidant is selected from antioxidant 1010, antioxidant 1076, antioxidant CA, or antioxidant 330.

[0014] In an aspect of the embodiments of the present disclosure, the flame retardant is selected from ammonium polyphosphate, aluminum hydroxide, magnesium hydroxide, melamine polyphosphate, resorcinol bis(diphenyl phosphate), decabromodiphenyl ethane, or brominated epoxy resin.

[0015] In an aspect of the embodiments of the present disclosure, preferably, the flame retardant is selected from ammonium polyphosphate, aluminum hydroxide, magnesium hydroxide, or melamine polyphosphate.

[0016] In an aspect of the embodiments of the present disclosure, the inorganic filler is selected from at least one of calcium carbonate, kaolin, talc powder, mica powder, montmorillonite, silicon oxide, and zinc oxide.

[0017] In an aspect of the embodiments of the present disclosure, preferably, the inorganic filler is selected from calcium carbonate and silicon oxide.

[0018] In an aspect of the embodiments of the present disclosure, the light stabilizer is selected from UV-531, UV-770, UV-944, UV-326, UV-329, UV-234, UV-1577, or UV-384.

[0019] In an aspect of the embodiments of the present disclosure, preferably, the light stabilizer is selected from UV-531, UV-326, or UV-234.

[0020] In an aspect of the embodiments of the present disclosure, the alkylphenol polyoxyethylene ether is selected from nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether, or dodecylphenol polyoxyethylene ether. Specifically, the alkylphenol polyoxyethylene ether is OP-10.

[0021] In one aspect of the embodiments of this disclosure, in component A, based on the total mass of component A, the mass percentage of the modified polyethylene resin is selected from 15%-25%; the mass percentage of the polyethylene wax is selected from 2%-5%; the mass percentage of the alkylphenol polyoxyethylene ether is selected from 0.25%-1%; and the remainder is polyethylene resin.

[0022] In one aspect of this disclosure, in component B, the mass percentage of the modified fiber material is selected from 50% to 85% based on the total mass of component B.

[0023] In one aspect of this disclosure, the modified polyethylene resin is a polyethylene resin modified with aminoalkyl block polysiloxane; the aminoalkyl block polysiloxane-modified polyethylene resin is prepared by the following steps:

[0024] Step 1-a: Add aminoalkyl block polysiloxane, polyethylene resin and calcium stearate to a high-speed mixer and mix at 60℃-80℃ for 30-60 min;

[0025] The aminoalkyl block polysiloxane has a structure represented by the following formula I:

[0026]

[0027] Wherein, the value of m+n is selected from an integer between 5 and 20; preferably between 10 and 15; at least one of R1, R2, R3, and R4 is selected from the following groups:

[0028] , , ;

[0029] The remainder is selected from C1-10 alkyl or C1-10 alkoxy;

[0030] Among them, R 11 and R 12 Each is independently selected from C1-5 alkyl or C1-5 alkoxy.

[0031] Step 2-a: Transfer the mixture obtained in step 1-a to a twin-screw extruder and melt-blend it at 200℃-240℃ with a screw speed of 185-220 r / min. After extrusion granulation, dry the mixture to obtain the masterbatch of the aminoalkyl block polysiloxane modified polyethylene resin.

[0032] In one aspect of this disclosure, the mass ratio of the aminoalkyl block polysiloxane, polyethylene resin, and calcium stearate is selected from (5-15):(85-95):(1-3).

[0033] In one aspect of the embodiments of this disclosure, the aminoalkyl block polysiloxane has a structure represented by the following formula I-1:

[0034]

[0035] Among them, R 11 and R 12 Each is independently selected from C1-5 alkyl groups; R1 is selected from C1-10 alkyl groups.

[0036] In one aspect of the embodiments of this disclosure, the aminoalkyl block polysiloxane has a structure represented by the following formulas I-2:

[0037]

[0038] The aminoalkyl block polysiloxane is prepared by the following steps:

[0039] Step 1-b: Under nitrogen protection, add N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, n-propyltrimethoxysilane and anhydrous methanol to a four-necked flask equipped with a reflux condenser, a drying tube, a dropping funnel and an electric stirrer, and then add a mixed solution of methanol and water dropwise at room temperature while stirring.

[0040] Step 2-b: After the addition is complete, heat to 80℃-85℃ and reflux for 2-4 hours to obtain the aminoalkyl block polysiloxane.

[0041]

[0042] In one aspect of this disclosure, the modified fiber material is bamboo fiber modified with succinic acid;

[0043] The succinic acid-modified bamboo fiber is prepared through the following steps:

[0044] Step 1-c: Provide bamboo fiber; add the bamboo fiber to a potassium hydroxide solution and perform alkalization treatment at 40℃-50℃; after the alkalization treatment, filter, wash and dry to obtain alkalized bamboo fiber;

[0045] Step 2-c: Add the alkalized bamboo fiber to an aqueous solution of succinic acid and perform a first acidification treatment at 40℃-50℃. After filtration, washing and drying, the bamboo fiber after the first acidification treatment is obtained.

[0046] Step 3-c: Add the bamboo fiber that has undergone the first acidification treatment to an acetone solution of succinic acid, and add DMAP and EDC. Heat to 70℃-80℃ and reflux for 2-3 hours. After the reaction is completed, filter, wash and dry to obtain the bamboo fiber modified with succinic acid.

[0047] According to a second aspect of the present disclosure, a polyethylene-based rotational molding compound is provided, which is obtained by rotational molding of the aforementioned rotational molding compound using a composite composition.

[0048] According to a third aspect of the present disclosure, the aforementioned polyethylene-based rotomolded plastic is provided for use in the preparation of rotomolded articles.

[0049] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0050] As can be seen from the above embodiments, the rotomolded plastic prepared by the composite composition for rotomolding provided in this disclosure has good thermal stability, resistance to environmental stress cracking, and mechanical properties.

[0051] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0052] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0053] Figure 1 This is a schematic diagram of the process for preparing succinic acid-modified bamboo fiber from bamboo fiber. Detailed Implementation

[0054] The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. The embodiments described herein are illustrative in nature and are used to provide a basic understanding of this application. The embodiments of this application should not be construed as limiting this application.

[0056] For the sake of brevity, this article only discloses a few specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0057] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0058] In this description, unless otherwise stated, "above" and "below" include the stated number.

[0059] Unless otherwise stated, the terms used in this disclosure have their common meanings as commonly understood by those skilled in the art. Unless otherwise stated, the values ​​of the parameters mentioned in this disclosure can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this disclosure).

[0060] The term "about" is used to describe and indicate small variations. When used in conjunction with an event or situation, the term may refer to examples in which the event or situation occurred precisely or in examples in which the event or situation occurred very approximately. For example, when used in conjunction with numerical values, the term may refer to a range of variation less than or equal to ±10% of the numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. Additionally, quantities, ratios, and other numerical values ​​are sometimes presented in range format herein. It should be understood that such range format is for convenience and brevity and should be interpreted flexibly to include not only numerical values ​​explicitly specified as range limits but also all individual numerical values ​​or subranges covered within the range, as if each numerical value and subrange were explicitly specified.

[0061] The list of items connected by the terms "at least one of," "at least one of," "at least one of," or other similar terms can mean any combination of the listed items. For example, if items A and B are listed, then the phrase "at least one of A and B" means only A; only B; or A and B. In another instance, if items A, B, and C are listed, then the phrase "at least one of A, B, and C" means only A; or only B; only C; A and B (excluding C); A and C (excluding B); B and C (excluding A); or all of A, B, and C. Item A may contain a single component or multiple components. Item B may contain a single component or multiple components. Item C may contain a single component or multiple components.

[0062] In this disclosure, the term "alkyl" refers to an aliphatic hydrocarbon group, which can be straight-chain or branched. Branched refers to one or more lower alkyl groups, such as methyl, ethyl, or propyl, that link a linear alkyl chain. "Lower alkyl" refers to a group containing about 1 to about 6 carbon atoms in the chain, which can be straight-chain or branched.

[0063] In this disclosure, the term "alkoxy" refers to -O-alkyl. Alkoxy can refer to a straight-chain, branched, or cyclic, saturated or unsaturated oxy-hydrocarbon chain, including, for example, methoxy, ethoxy, propoxy, isopropoxy, butoxy, tert-butoxy, and pentoxy. Alkoxy may optionally be substituted by one or more alkoxy substituents ("substituted alkoxy").

[0064] In this disclosure, bamboo fiber is used as raw material, and succinic acid-modified bamboo fiber is obtained through alkalization, first acidification, and second acidification. The preparation process is as follows: Figure 1 As shown.

[0065] The present disclosure will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present disclosure are obtained through conventional commercial means. Unless otherwise specified, all contents mentioned below are mass contents. Unless otherwise specified, it is understood that the process is carried out at room temperature.

[0066] Example

[0067] The raw materials used in the examples are shown in Table 1 below:

[0068] Table 1

[0069]

[0070] Example 1:

[0071] Example 1 includes the following steps:

[0072] 1. Preparation of succinic acid-modified bamboo fiber:

[0073] Bamboo fiber is provided; the bamboo fiber is washed, dried, crushed, and then sieved; 250g of bamboo fiber with a particle size of 60-80 mesh is selected; the bamboo fiber is added to 1200mL of 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization treatment; after alkalization treatment, water is added to make the pH value of the solution less than 11; then the solution is filtered, washed, and dried to obtain alkalized bamboo fiber.

[0074] All the alkalized bamboo fibers were added to 800 mL of a 10 wt% succinic acid aqueous solution and stirred at 250 r / min for 1.5 h at 50 °C for the first acidification treatment. After filtration, washing, and drying, the bamboo fibers after the first acidification treatment were obtained. The bamboo fibers after the first acidification treatment were added to 300 mL of a 5 wt% succinic acid-acetone solution, along with 3 g DMAP and 5 g EDC. The mixture was heated to 80 °C and refluxed for 3 h. After the reaction was completed, the bamboo fibers modified with succinic acid in Example 1 were obtained after filtration, washing, and drying. The reaction process is as follows: Figure 1 As shown in the image.

[0075] The above steps can be repeated multiple times to prepare sufficient amounts of succinic acid-modified bamboo fiber for the following reaction.

[0076] 2. Preparation of polyethylene resin modified with aminoalkyl block polysiloxane:

[0077] Under nitrogen protection, 145 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 57 g of n-propyltrimethoxysilane, and 60 g of anhydrous methanol were added to a 1000 mL four-necked flask equipped with a reflux condenser, a drying tube, a dropping funnel, and an electric stirrer. The mixture was stirred (150 r / min), and a mixture of methanol and water (obtained by mixing 14.4 g of water and 58 g of methanol) was added dropwise at room temperature at a dropping rate of 0.16 mL / s. After the addition was complete, the temperature was raised to 85 °C, and the reaction was refluxed for 3 h. The reactants were collected to obtain the aminoalkyl block polysiloxane of Example 1. The Mn of the aminoalkyl block polysiloxane of Example 1 was determined to be approximately 1900 by gel permeation chromatography.

[0078] The above steps can be repeated multiple times to prepare sufficient amounts of aminoalkyl block polysiloxanes for the following reactions.

[0079] The aforementioned aminoalkyl block polysiloxane, polyethylene resin (LL 3001.32), and calcium stearate were added to a high-speed mixer at a mass ratio of 8:90:2 and mixed at 80°C for 30 min. The mixture was then transferred to a twin-screw extruder and melt-blended at 220°C with a screw speed of 200 r / min. After extrusion granulation, the resulting granules were dried in a vacuum drying oven at 80°C for 4 h to obtain the masterbatch of aminoalkyl block polysiloxane modified polyethylene resin of Example 1.

[0080] 3. Preparation of polyethylene material for rotational molding:

[0081] Provided are 22 parts by weight of the aforementioned prepared aminoalkyl block polysiloxane, 2.5 parts by weight of polyethylene wax, 0.5 parts by weight of alkylphenol polyoxyethylene ether (OP-10), and 75 parts by weight of polyethylene resin (65 parts by weight of linear low-density polyethylene resin LL 3001.32 + 10 parts by weight of high-density polyethylene resin HMN TR-942). The raw materials consist of 6 parts by weight of HDPE, 6 parts by weight of the aforementioned succinic acid-modified bamboo fiber, 0.5 parts by weight of antioxidant 1010, 1 part by weight of magnesium hydroxide flame retardant, 1 part by weight of calcium carbonate powder (1250 mesh), 1 part by weight of silicon dioxide (1000 mesh), and 0.5 parts by weight of UV-531. These raw materials are added to a high-speed mixer and mixed for 5 minutes. The mixture is then transferred to a twin-screw extruder for blending and granulation. The twin-screw extruder temperatures are set as follows: Zone 1: 80℃, Zone 2: 130℃, Zone 3: 180℃, Zone 4: 230℃, Zone 5: 230℃, Zone 6: 230℃, Zone 7: 230℃, Zone 8: 230℃, Zone 9: 230℃, Zone 10: 230℃, Zone 11: 230℃, and the die head temperature is 230℃. The rotation speed is set to 200 r / min. The granules obtained by blending and granulation were injection molded using a micro-injection molding device to obtain the test sample of Example 1.

[0082] Example 2:

[0083] Example 2 includes the following steps:

[0084] 1. Preparation of alkalized bamboo fiber:

[0085] Bamboo fiber (from a bamboo product factory, natural bamboo fiber) was provided; the bamboo fiber was washed, dried, crushed, and then sieved; 250g of bamboo fiber with a particle size of 60-80 mesh was selected; the bamboo fiber was added to 1200mL of 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization treatment; after the alkalization treatment, water was added to make the pH value of the solution less than 11; then filtered, washed, and dried to obtain the alkalized bamboo fiber of Example 2;

[0086] 2. Preparation of polyethylene resin modified with aminoalkyl block polysiloxane:

[0087] Under nitrogen protection, 145 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 57 g of n-propyltrimethoxysilane, and 60 g of anhydrous methanol were added to a 1000 mL four-necked flask equipped with a reflux condenser, a drying tube, a dropping funnel, and an electric stirrer. The mixture was stirred (150 r / min) and a mixture of methanol and water (obtained by mixing 14.4 g of water and 58 g of methanol) was added dropwise at room temperature. The dropping rate of the mixture was 0.16 mL / s. After the addition was complete, the temperature was raised to 85 °C and the reaction was refluxed for 3 h. The reactants were collected to obtain the aminoalkyl block polysiloxane of Example 2.

[0088] The above steps can be repeated multiple times to prepare sufficient amounts of aminoalkyl block polysiloxanes for the following reactions.

[0089] The aforementioned aminoalkyl block polysiloxane, polyethylene resin (LL 3001.32), and calcium stearate were added to a high-speed mixer at a mass ratio of 8:90:2 and mixed at 80°C for 30 min. The mixture was then transferred to a twin-screw extruder and melt-blended at 220°C with a screw speed of 200 r / min. After extrusion granulation, the resulting granules were dried in a vacuum drying oven at 80°C for 4 h to obtain the masterbatch of aminoalkyl block polysiloxane modified polyethylene resin of Example 1.

[0090] 3. Preparation of polyethylene material for rotational molding:

[0091] Provided are 22 parts by weight of the aforementioned prepared aminoalkyl block polysiloxane, 2.5 parts by weight of polyethylene wax, 0.5 parts by weight of alkylphenol polyoxyethylene ether (OP-10), and 75 parts by weight of polyethylene resin (65 parts by weight of linear low-density polyethylene resin LL 3001.32 + 10 parts by weight of high-density polyethylene resin HMN TR-942). The following raw materials were added to a high-speed mixer and mixed for 5 minutes: 6 parts by weight of HDPE, 6 parts by weight of the aforementioned alkali-treated bamboo fiber, 0.5 parts by weight of antioxidant 1010, 1 part by weight of magnesium hydroxide flame retardant, 1 part by weight of calcium carbonate powder (1250 mesh), 1 part by weight of silicon dioxide (1000 mesh), and 0.5 parts by weight of UV-531. The mixture was then transferred to a twin-screw extruder for blending and granulation. The twin-screw extruder temperatures were set as follows: Zone 1: 80°C, Zone 2: 130°C, Zone 3: 180°C, Zone 4: 230°C, Zone 5: 230°C, Zone 6: 230°C, Zone 7: 230°C, Zone 8: 230°C, Zone 9: 230°C, Zone 10: 230°C, Zone 11: 230°C, and Die head: 230°C. The rotation speed was set to 200 r / min. The granules obtained by blending and granulation were injection molded using a micro-injection molding device to obtain the test sample of Example 2.

[0092] The main difference between Example 2 and Example 1 is that Example 2 uses alkalized bamboo fiber instead of the succinic acid modified bamboo fiber in Example 1.

[0093] Example 3:

[0094] The steps in Example 3 are the same as in Example 1, except that the process for preparing the modified bamboo fiber is as follows:

[0095] Bamboo fiber (from a bamboo product factory, natural bamboo fiber) is provided. The bamboo fiber is washed, dried, and pulverized, then sieved. 250g of bamboo fiber with a particle size of 60-80 mesh is selected. The bamboo fiber is added to 1200mL of a 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization. After alkalization, water is added to adjust the pH of the solution to less than 11. The solution is then filtered, washed, and dried to obtain the alkalized bamboo fiber.

[0096] All the alkalized bamboo fibers were added to 800 mL of a 5 wt% aqueous solution of acetic acid and stirred at 250 r / min for 1.5 h at 50 °C for the first acidification treatment. After filtration, washing and drying, the bamboo fibers after the first acidification treatment were obtained. The bamboo fibers after the first acidification treatment were added to 300 mL of a 5 wt% acetic acid-acetone solution, along with 3 g DMAP and 5 g EDC. The mixture was heated to 80 °C and refluxed for 3 h. After the reaction was completed, the bamboo fibers modified with acetic acid in Example 3 were obtained by filtration, washing and drying.

[0097] Example 4:

[0098] The steps in Example 4 are the same as in Example 1, except that the process for preparing the modified bamboo fiber is as follows:

[0099] Bamboo fiber (from a bamboo product factory, natural bamboo fiber) is provided. The bamboo fiber is washed, dried, and pulverized, then sieved. 250g of bamboo fiber with a particle size of 60-80 mesh is selected. The bamboo fiber is added to 1200mL of a 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization. After alkalization, water is added to adjust the pH of the solution to less than 11. The solution is then filtered, washed, and dried to obtain the alkalized bamboo fiber.

[0100] All the alkalized bamboo fibers were added to 800 mL of a 10 wt% lactic acid aqueous solution and stirred at 250 r / min for 1.5 h at 50 °C for the first acidification treatment. After filtration, washing, and drying, the bamboo fibers with the first acidification treatment were obtained. The bamboo fibers with the first acidification treatment were added to 300 mL of a 5 wt% lactic acid acetone solution, along with 3 g DMAP and 5 g EDC. The solution was heated to 80 °C and refluxed for 3 h. After the reaction was completed, the bamboo fibers were filtered, washed, and dried to obtain the lactic acid modified bamboo fibers of Example 4.

[0101] Example 5:

[0102] Example 5 includes the following steps:

[0103] 1. Preparation of succinic acid-modified bamboo fiber:

[0104] Bamboo fiber (from a bamboo product factory, natural bamboo fiber) is provided. The bamboo fiber is washed, dried, and pulverized, then sieved. 250g of bamboo fiber with a particle size of 60-80 mesh is selected. The bamboo fiber is added to 1200mL of a 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization. After alkalization, water is added to adjust the pH of the solution to less than 11. The solution is then filtered, washed, and dried to obtain the alkalized bamboo fiber.

[0105] All the alkalized bamboo fibers were added to 800 mL of a 10 wt% aqueous solution of succinic acid and stirred at 250 r / min for 1.5 h at 50 °C for the first acidification treatment. After filtration, washing and drying, the bamboo fibers after the first acidification treatment were obtained. The bamboo fibers after the first acidification treatment were added to 300 mL of a 5 wt% succinic acid-acetone solution, along with 3 g DMAP and 5 g EDC. The mixture was heated to 80 °C and refluxed for 3 h. After the reaction was completed, the bamboo fibers modified with succinic acid in Example 5 were obtained by filtration, washing and drying.

[0106] 2. Preparation of polysiloxane-modified polyethylene resin:

[0107] Polydimethylsiloxane, polyethylene resin (LL 3001.32), and calcium stearate were added to a high-speed mixer at a mass ratio of 8:90:2 and mixed at 80°C for 30 min. The mixture was then transferred to a twin-screw extruder and melt-blended at 220°C with a screw speed of 200 r / min. After extrusion granulation, the resulting granules were dried in a vacuum drying oven at 80°C for 4 h to obtain the masterbatch of polysiloxane-modified polyethylene resin of Example 5.

[0108] 3. Preparation of polyethylene material for rotational molding:

[0109] Provided are 22 parts by weight of the aforementioned polysiloxane-modified polyethylene resin, 2.5 parts by weight of polyethylene wax, 0.5 parts by weight of alkylphenol polyoxyethylene ether (OP-10), and 75 parts by weight of polyethylene resin (65 parts by weight of linear low-density polyethylene resin LL 3001.32 + 10 parts by weight of high-density polyethylene resin HMN TR-942). The raw materials consist of 6 parts by weight of HDPE, 6 parts by weight of the aforementioned succinic acid-modified bamboo fiber, 0.5 parts by weight of antioxidant 1010, 1 part by weight of magnesium hydroxide flame retardant, 1 part by weight of calcium carbonate powder (1250 mesh), 1 part by weight of silicon dioxide (1000 mesh), and 0.5 parts by weight of UV-531. These raw materials are added to a high-speed mixer and mixed for 5 minutes. The mixture is then transferred to a twin-screw extruder for blending and granulation. The twin-screw extruder temperatures are set as follows: Zone 1: 80℃, Zone 2: 130℃, Zone 3: 180℃, Zone 4: 230℃, Zone 5: 230℃, Zone 6: 230℃, Zone 7: 230℃, Zone 8: 230℃, Zone 9: 230℃, Zone 10: 230℃, Zone 11: 230℃, and the die head temperature is 230℃. The rotation speed is set to 200 r / min. The granules obtained by blending and granulation were injection molded using a micro-injection molding device to obtain the test sample of Example 5.

[0110] The main difference between Example 5 and Example 1 is that Example 5 did not prepare the aminoalkyl block polysiloxane prepared in this application, but instead used ordinary silicone for modification.

[0111] Example 6:

[0112] Example 6 includes the following steps:

[0113] 1. Preparation of succinic acid-modified bamboo fiber:

[0114] Bamboo fiber (from a bamboo product factory, natural bamboo fiber) is provided. The bamboo fiber is washed, dried, and pulverized, then sieved. 250g of bamboo fiber with a particle size of 60-80 mesh is selected. The bamboo fiber is added to 1200mL of a 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization. After alkalization, water is added to adjust the pH of the solution to less than 11. The solution is then filtered, washed, and dried to obtain the alkalized bamboo fiber.

[0115] All the alkalized bamboo fibers were added to 800 mL of a 10 wt% aqueous solution of succinic acid and stirred at 250 r / min for 1.5 h at 50 °C for the first acidification treatment. After filtration, washing and drying, the bamboo fibers after the first acidification treatment were obtained. The bamboo fibers after the first acidification treatment were added to 300 mL of a 5 wt% succinic acid-acetone solution, along with 3 g DMAP and 5 g EDC. The mixture was heated to 80 °C and refluxed for 3 h. After the reaction was completed, the bamboo fibers modified with succinic acid in Example 5 were obtained by filtration, washing and drying.

[0116] 2. Preparation of aminosilane-modified polyethylene resin:

[0117] γ-aminopropyltriethoxysilane, polyethylene resin (LL 3001.32), and calcium stearate were added to a high-speed mixer at a mass ratio of 8:90:2 and mixed at 80°C for 30 min. The mixture was then transferred to a twin-screw extruder and melt-blended at 220°C with a screw speed of 200 r / min. After extrusion granulation, the resulting granules were dried in a vacuum drying oven at 80°C for 4 h to obtain the masterbatch of aminosilane-modified polyethylene resin of Example 6.

[0118] 3. Preparation of polyethylene material for rotational molding:

[0119] Provided are 22 parts by weight of the aforementioned aminosilane-modified polyethylene resin, 2.5 parts by weight of polyethylene wax, 0.5 parts by weight of alkylphenol polyoxyethylene ether (OP-10), and 75 parts by weight of polyethylene resin (65 parts by weight of linear low-density polyethylene resin LL 3001.32 + 10 parts by weight of high-density polyethylene resin HMN TR-942). The raw materials consist of 6 parts by weight of HDPE, 6 parts by weight of the aforementioned succinic acid-modified bamboo fiber, 0.5 parts by weight of antioxidant 1010, 1 part by weight of magnesium hydroxide flame retardant, 1 part by weight of calcium carbonate powder (1250 mesh), 1 part by weight of silicon dioxide (1000 mesh), and 0.5 parts by weight of UV-531. These raw materials are added to a high-speed mixer and mixed for 5 minutes. The mixture is then transferred to a twin-screw extruder for blending and granulation. The twin-screw extruder temperatures are set as follows: Zone 1: 80℃, Zone 2: 130℃, Zone 3: 180℃, Zone 4: 230℃, Zone 5: 230℃, Zone 6: 230℃, Zone 7: 230℃, Zone 8: 230℃, Zone 9: 230℃, Zone 10: 230℃, Zone 11: 230℃, and the die head temperature is 230℃. The rotation speed is set to 200 r / min. The granules obtained by blending and granulation were injection molded using a micro-injection molding device to obtain the test sample of Example 6.

[0120] The main difference between Example 6 and Example 1 is that Example 6 did not prepare the aminoalkyl block polysiloxane prepared in this application, but instead used aminosilane for modification.

[0121] Example 7:

[0122] The steps in Example 7 are the same as in Example 1, except that the bamboo fiber in Example 1 is replaced with an equal mass of mullite fiber (fiber diameter: 3-5 μm, commercially available).

[0123] Comparative Example 1:

[0124] Comparative Example 1 includes the following steps:

[0125] 1. Preparation of polyethylene resin modified with aminoalkyl block polysiloxane:

[0126] Under nitrogen protection, 145 g of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 57 g of n-propyltrimethoxysilane, and 60 g of anhydrous methanol were added to a 1000 mL four-necked flask equipped with a reflux condenser, a drying tube, a dropping funnel, and an electric stirrer. The mixture was stirred (150 r / min) and a mixture of methanol and water (obtained by mixing 14.4 g of water and 58 g of methanol) was added dropwise at room temperature. The dropping rate of the mixture was 0.16 mL / s. After the addition was complete, the temperature was raised to 85 °C and the reaction was refluxed for 3 h. The reactants were collected to obtain the aminoalkyl block polysiloxane of Comparative Example 1.

[0127] The aforementioned aminoalkyl block polysiloxane, polyethylene resin (LL 3001.32), and calcium stearate were added to a high-speed mixer at a mass ratio of 8:90:2 and mixed at 80°C for 30 min. The mixture was then transferred to a twin-screw extruder and melt-blended at 220°C with a screw speed of 200 r / min. After extrusion granulation, the resulting granules were dried in a vacuum drying oven at 80°C for 4 h to obtain the masterbatch of polyethylene resin modified with aminoalkyl block polysiloxane as in Comparative Example 1.

[0128] 2. Preparation of polyethylene material for rotational molding:

[0129] Provided are 22 parts by weight of the aforementioned aminosilane-modified polyethylene resin, 2.5 parts by weight of polyethylene wax, 0.5 parts by weight of alkylphenol polyoxyethylene ether (OP-10), and 75 parts by weight of polyethylene resin (65 parts by weight of linear low-density polyethylene resin LL 3001.32 + 10 parts by weight of high-density polyethylene resin HMN TR-942). The mixture consisted of HDPE, 0.5 parts by weight of antioxidant 1010, 1 part by weight of magnesium hydroxide flame retardant, 2 parts by weight of calcium carbonate powder (1250 mesh), 2 parts by weight of silica (1000 mesh), and 0.5 parts by weight of UV-531. These raw materials were added to a high-speed mixer and mixed for 5 minutes. The mixture was then transferred to a twin-screw extruder for blending and granulation. The twin-screw extruder temperatures were set as follows: Zone 1: 80℃, Zone 2: 130℃, Zone 3: 180℃, Zone 4: 230℃, Zone 5: 230℃, Zone 6: 230℃, Zone 7: 230℃, Zone 8: 230℃, Zone 9: 230℃, Zone 10: 230℃, Zone 11: 230℃, and Die Head: 230℃. The rotation speed was set to 200 r / min. The granules obtained from the blending and granulation were injection molded using a micro-injection molding device to obtain the test sample for Comparative Example 1.

[0130] The main difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not involve bamboo fiber materials.

[0131] Comparative Example 2:

[0132] Comparative Example 2 includes the following steps:

[0133] 1. Preparation of succinic acid-modified bamboo fiber:

[0134] Bamboo fiber (from a bamboo product factory, natural bamboo fiber) is provided. The bamboo fiber is washed, dried, and pulverized, then sieved. 250g of bamboo fiber with a particle size of 60-80 mesh is selected. The bamboo fiber is added to 1200mL of a 5wt% potassium hydroxide solution and stirred at 250r / min for 1.5h at 45℃ for alkalization. After alkalization, water is added to adjust the pH of the solution to less than 11. The solution is then filtered, washed, and dried to obtain the alkalized bamboo fiber.

[0135] All the alkalized bamboo fibers were added to 800 mL of a 10 wt% succinic acid aqueous solution and stirred at 250 r / min for 1.5 h at 50 °C for the first acidification treatment. After filtration, washing and drying, the bamboo fibers after the first acidification treatment were obtained. The bamboo fibers after the first acidification treatment were added to 300 mL of a 5 wt% succinic acid acetone solution, along with 3 g DMAP and 5 g EDC. The mixture was heated to 80 °C and refluxed for 3 h. After the reaction was completed, the bamboo fibers modified with succinic acid in Comparative Example 2 were obtained by filtration, washing and drying.

[0136] 2. Preparation of polyethylene material for rotational molding:

[0137] Provides 2.5 parts by weight of polyethylene wax, 0.5 parts by weight of alkylphenol polyoxyethylene ether (OP-10), and 97 parts by weight of polyethylene resin (83 parts by weight of linear low-density polyethylene resin LL 3001.32 + 14 parts by weight of high-density polyethylene resin HMN TR-942). The raw materials consist of 6 parts by weight of HDPE, 6 parts by weight of the aforementioned succinic acid-modified bamboo fiber, 0.5 parts by weight of antioxidant 1010, 1 part by weight of magnesium hydroxide flame retardant, 1 part by weight of calcium carbonate powder (1250 mesh), 1 part by weight of silicon dioxide (1000 mesh), and 0.5 parts by weight of UV-531. These raw materials are added to a high-speed mixer and mixed for 5 minutes. The mixture is then transferred to a twin-screw extruder for blending and granulation. The twin-screw extruder temperatures are set as follows: Zone 1: 80℃, Zone 2: 130℃, Zone 3: 180℃, Zone 4: 230℃, Zone 5: 230℃, Zone 6: 230℃, Zone 7: 230℃, Zone 8: 230℃, Zone 9: 230℃, Zone 10: 230℃, Zone 11: 230℃, and the die head temperature is 230℃. The rotation speed is set to 200 r / min. The granules obtained from blending and granulation were injection molded using a micro-injection molding device to obtain the test sample of Comparative Example 2.

[0138] The main difference between Comparative Example 2 and Example 1 is that Comparative Example 2 does not involve polyethylene resin modified with aminoalkyl block polysiloxane.

[0139] Performance tests of Examples 1-6 and Comparative Examples 1-2:

[0140] (1) Environmental stress cracking resistance was tested according to GB / T1842-2008, using nonylphenol polyoxyethylene ether or an aqueous solution of 10% by volume as reagent, and the environmental stress cracking time (F50) was recorded.

[0141] (2) Impact resistance: The test shall be conducted in accordance with the test method of GB / T1843-2008.

[0142] The test results are shown in Table 2.

[0143] Table 2

[0144]

[0145] As can be seen, compared with Examples 2-6 and Comparative Examples 1-2, Example 1 shows significant improvements in environmental stress cracking resistance and impact resistance. This is because the bamboo fiber surface is rich in carboxyl groups (such as...) after modification with succinic acid. Figure 1As shown in the diagram, the carboxyl groups on the surface of bamboo fiber bond with the side-chain amino groups of aminoalkyl-block polysiloxane during the melting stage. This not only enhances impact resistance, but also forms a network-like crack-arresting structure in the wall thickness direction of the bamboo fiber. When exposed to solvents or surfactants, this structure can reduce stress concentration, thereby improving resistance to environmental stress cracking. Compared to Examples 3 and 4, which also use organic acids, succinic acid (butanoic acid) is a dicarboxylic acid, thus allowing for... Figure 1 As shown, carboxyl groups are formed on the surface of bamboo fibers (i.e., one end is bonded to the hydroxyl groups on the surface of the modified bamboo fibers, while the carboxyl groups at the other end are exposed). In contrast, Example 3 used acetic acid modification, and Example 4 used lactic acid modification, neither of which resulted in the carboxyl groups being exposed. The performance of Example 7 is also significantly inferior to that of Example 1. This is because the surface of bamboo fibers naturally has abundant hydroxyl groups, which can be used for carboxyl modification, a property not possessed by inorganic fibers such as mullite. The performance of Example 6 is also significantly inferior to that of Example 1. This is because small molecule silane compounds are prone to volatilization and migration at high temperatures, while the aminoalkyl block polysiloxane prepared in Example 1, as a block polymer, is not easily volatilized or migrated at high temperatures.

[0146] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein.

Claims

1. A composite composition for rotomolding, characterized in that, The composite composition for rotomolding comprises the following components: Component A: Polyethylene resin, modified polyethylene resin, polyethylene wax, and alkylphenol polyoxyethylene ether; Component B: Modified fiber materials, antioxidants, flame retardants, inorganic fillers, and light stabilizers; The mass ratio of component A to component B is selected from (90-110):(10-15); The modified polyethylene resin is a polyethylene resin modified with polysiloxane compounds; The modified fiber material is a fiber material modified with organic acid or inorganic acid; The organic acid is selected from succinic acid, citric acid or oxalic acid; the inorganic acid is selected from hydrochloric acid, sulfuric acid or nitric acid; the fiber material is selected from bamboo fiber, mullite fiber or basalt fiber.

2. The composite composition for rotomolding according to claim 1, characterized in that, The rotomolded plastic composite additive meets at least one of the following conditions: (1) The polyethylene resin comprises linear low-density polyethylene resin and high-density polyethylene resin; (2) The antioxidant is selected from at least one of antioxidant 1010, antioxidant 1076, antioxidant CA, antioxidant 168, antioxidant 2246, antioxidant 300, antioxidant 3114 and antioxidant 330; (3) The flame retardant is selected from ammonium polyphosphate, aluminum hydroxide, magnesium hydroxide, melamine polyphosphate, resorcinol bis(diphenyl phosphate), decabromodiphenyl ethane or brominated epoxy resin; (4) The inorganic filler is selected from at least one of calcium carbonate, kaolin, talc, mica powder, montmorillonite, silicon dioxide and zinc oxide; (5) The light stabilizer is selected from UV-531, UV-770, UV-944, UV-326, UV-329, UV-234, UV-1577 or UV-384; (6) The alkylphenol polyoxyethylene ether is selected from nonylphenol polyoxyethylene ether, octylphenol polyoxyethylene ether or dodecylphenol polyoxyethylene ether.

3. The composite composition for rotomolding according to claim 1, characterized in that, In component A, based on the total mass of component A, the mass percentage of the modified polyethylene resin is selected from 15%-25%; the mass percentage of the polyethylene wax is selected from 2%-5%; the mass percentage of the alkylphenol polyoxyethylene ether is selected from 0.25%-1%; and the remainder is polyethylene resin.

4. The composite composition for rotomolding according to claim 1, characterized in that, In component B, the mass percentage of the modified fiber material is selected from 50% to 85% based on the total mass of component B.

5. The composite composition for rotomolding according to any one of claims 1-4, characterized in that, The modified polyethylene resin is a polyethylene resin modified with aminoalkyl block polysiloxane; the aminoalkyl block polysiloxane-modified polyethylene resin is prepared by the following steps: Step 1-a: Add aminoalkyl block polysiloxane, polyethylene resin and calcium stearate to a high-speed mixer and mix at 60℃-80℃ for 30-60 min; The aminoalkyl block polysiloxane has a structure represented by the following formula I: Wherein, the value of m+n is selected from integers between 5 and 20; at least one of R1, R2, R3, and R4 is selected from the following groups: 、 、 ； The remainder is selected from C1-10 alkyl or C1-10 alkoxy; Among them, R 11 and R 12 Each is independently selected from C1-5 alkyl or C1-5 alkoxy; Step 2-a: Transfer the mixture obtained in step 1-a to a twin-screw extruder and melt-blend it at 200℃-240℃ with a screw speed of 185-220 r / min. After extrusion granulation, dry the mixture to obtain the masterbatch of the aminoalkyl block polysiloxane modified polyethylene resin.

6. The composite composition for rotomolding according to claim 5, characterized in that, The aminoalkyl block polysiloxane has a structure represented by the following formula I-1: Among them, R 11 and R 12 Each is independently selected from C1-5 alkyl groups; R1 is selected from C1-10 alkyl groups.

7. The composite composition for rotomolding according to claim 6, characterized in that, The aminoalkyl block polysiloxane has a structure represented by the following formula I-2: The aminoalkyl block polysiloxane is prepared by the following steps: Step 1-b: Under nitrogen protection, add N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, n-propyltrimethoxysilane and anhydrous methanol to a four-necked flask equipped with a reflux condenser, a drying tube, a dropping funnel and an electric stirrer, and then add a mixed solution of methanol and water dropwise at room temperature while stirring. Step 2-b: After the addition is complete, heat to 80℃-85℃ and reflux for 2-4 hours to obtain the aminoalkyl block polysiloxane. 。 8. The composite composition for rotomolding according to claim 1, characterized in that, The modified fiber material is bamboo fiber modified with succinic acid; The succinic acid-modified bamboo fiber is prepared through the following steps: Step 1-c: Provide bamboo fiber; add the bamboo fiber to a potassium hydroxide solution and perform alkalization treatment at 40℃-50℃; after the alkalization treatment, filter, wash and dry to obtain alkalized bamboo fiber; Step 2-c: Add the alkalized bamboo fiber to an aqueous solution of succinic acid and perform a first acidification treatment at 40℃-50℃. After filtration, washing and drying, the bamboo fiber after the first acidification treatment is obtained. Step 3-c: Add the bamboo fiber that has undergone the first acidification treatment to an acetone solution of succinic acid, and add DMAP and EDC. Heat to 70℃-80℃ and reflux for 2-3 hours. After the reaction is completed, filter, wash and dry to obtain the bamboo fiber modified with succinic acid.

9. A polyethylene-based rotomolded plastic, characterized in that, The polyethylene-based rotational molding compound is obtained by rotational molding of the rotational molding compound according to any one of claims 1-8 using a composite composition.

10. The application of the polyethylene-based rotational molding compound according to claim 9 in the preparation of rotational molded articles.

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