A high weather-resistant PE protective material and its preparation method and application

Abstract

The present invention relates to the field of polyethylene protective material preparation, and specifically discloses a highly weather-resistant PE protective material and a preparation method and application thereof, wherein the PE protective material comprises the following raw materials in parts by weight: 110 to 150 parts of high-density polyethylene, 50 to 70 parts of linear low-density polyethylene, 1 to 2.4 parts of stabilizer, 1 to 3 parts of modified titanium dioxide, 0.6 to 2 parts of antioxidant, 1 to 2 parts of lubricant and 1 to 2.4 parts of stabilizer. The polyethylene protective material disclosed by the present invention has excellent weather resistance, is suitable for long-term use in outdoor environments, has excellent mechanical properties and good processability.

Description

Technical Field

[0001] The invention relates to the field of polyethylene material preparation, and specifically discloses a highly weather-resistant PE protective material, a preparation method thereof, and applications thereof. Background Art

[0002] Polyethylene material is a type of plastic product commonly used to protect the surface of sheets. As a high-end protective material, it has wear resistance, impact resistance, chemical resistance, and self-lubricating properties that are unmatched by other engineering plastics. It has unique advantages in various fields of the national economy, especially in wear-resistant transportation, equipment linings, and various mechanical parts. The development and application of its products have broad prospects and are attracting widespread attention.

[0003] However, polyethylene is susceptible to degradation from UV light under long-term use or in adverse environmental conditions. Prolonged exposure to UV rays in outdoor environments can cause polyethylene to age and become brittle, significantly shortening its service life. Due to its unique molecular structure, polyethylene's surface is relatively soft and easily scratched, reducing its appearance and durability.

[0004] Patent application number 201611036267.1 discloses a composite polyethylene alloy pipe and its preparation method. The pipe comprises a three-layer composite structure, comprising, from the inside out, a high-temperature resistant polyethylene pipe layer, a fiber-wound reinforcement layer, and an antioxidant polyethylene protective layer. The antioxidant polyethylene protective layer comprises the following components, calculated by weight: 120 parts polyethylene, 2.5 parts heat stabilizer, 6 parts stearic acid, and 5 parts antioxidant. This invention utilizes a novel formulation and preparation process, resulting in a composite polyethylene alloy pipe with excellent compressive strength, high operating temperatures, and low production costs, effectively improving product performance and expanding its scope of application. However, the antioxidant polyethylene protective layer is susceptible to degradation by ultraviolet light, leading to aging and brittleness, and may have insufficient weather resistance, limiting its application in outdoor environments.

[0005] In view of this, the present invention discloses a highly weather-resistant PE protective material, which is particularly important. Summary of the Invention

[0006] In response to the shortcomings of the prior art, the present invention provides a highly weather-resistant PE protective material, a preparation method thereof, and applications thereof. The polyethylene protective material disclosed in the present invention has excellent weather resistance, is suitable for long-term use in outdoor environments, and has excellent mechanical properties and good processability.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] On the one hand, the present invention provides a highly weather-resistant PE protective material, which comprises the following raw materials in parts by weight: 110 to 150 parts of high-density polyethylene, 50 to 70 parts of linear low-density polyethylene, 1 to 3 parts of modified titanium dioxide, 0.6 to 2 parts of antioxidant, 1 to 2 parts of lubricant and 1 to 2.4 parts of stabilizer.

[0009] In some embodiments of the present invention, the preparation steps of the stabilizer are as follows:

[0010] Deionized water and sodium hydroxymethyl cellulose are added to a reactor, dispersed by magnetic stirring, and then a modifier is added and stirred for 1 to 2 hours. Then, citric acid is added and stirred for 20 to 30 minutes to obtain the stabilizer.

[0011] In some embodiments of the present invention, the modifying agent is soy protein.

[0012] In some embodiments of the present invention, the mass ratio of the sodium hydroxymethyl cellulose to the modifier is 1:(1-3).

[0013] Preferably, the mass ratio of the sodium hydroxymethyl cellulose to the modifier is 1:2.

[0014] In some embodiments of the present invention, the viscosity of the sodium hydroxymethyl cellulose is 2000-4000 mPa·s at 25°C.

[0015] Preferably, the viscosity of the sodium hydroxymethyl cellulose is 3000 mPa·s at 25°C.

[0016] Preferably, the added amount of citric acid is 8-12% of the mass of sodium hydroxymethyl cellulose.

[0017] Further preferably, the added amount of citric acid is 10% of the mass of sodium hydroxymethyl cellulose.

[0018] The applicant introduced soy protein to modify sodium hydroxymethyl cellulose. The soy protein particles were adsorbed on the surface of the long chain of sodium hydroxymethyl cellulose with a specific viscosity and polymerized through interaction to form a stable complex, which further improved the structural strength of the long chain of sodium hydroxymethyl cellulose. This may be because the soy protein and sodium hydroxymethyl cellulose achieved a stable combination through electrostatic adsorption. When the stabilizer was added to the PE protective material system, it also improved the uniformity and stability of the system, further improving the mechanical strength of the PE protective material.

[0019] In some embodiments of the present invention, the preparation steps of the modified titanium dioxide are as follows:

[0020] Titanium dioxide and deionized water are added to a reactor, dispersed by ultrasonication, and heated to 60-70° C., 3-aminopropyltriethoxysilane and conjugated linoleic acid are then added, stirred for reaction for 2-3 hours, filtered, washed, and dried to obtain the modified titanium dioxide.

[0021] In some embodiments of the present invention, the mass ratio of titanium dioxide, 3-aminopropyltriethoxysilane and conjugated linoleic acid is 10:(1-2):(0.6-1).

[0022] Preferably, the mass ratio of titanium dioxide, 3-aminopropyltriethoxysilane and conjugated linoleic acid is 10:1.5:0.8.

[0023] The applicant modified titanium dioxide by adding 3-aminopropyltriethoxysilane. The modifier containing amino active groups covered the surface of the titanium dioxide particles, changing the surface state of the titanium dioxide particles and significantly improving the dispersibility of titanium dioxide, thereby greatly improving the ultraviolet resistance of the system. At the same time, the applicant also added conjugated linoleic acid to further improve the modification effect and modification durability of the modifier containing amino active groups on titanium dioxide. When titanium dioxide modified with 3-aminopropyltriethoxysilane and conjugated linoleic acid was added to the PE protective material system, the weather resistance of the system was also improved to a certain extent. This may be due to the cross-linking between the conjugated bonds introduced by conjugated linoleic acid and the polyethylene double bonds in the system, forming a more stable chemical bond, which synergistically cooperated with the stabilizer specifically added to the system to further improve the weather resistance of the PE protective material.

[0024] In some embodiments of the present invention, the antioxidant is a combination of antioxidant 168 and antioxidant 1010.

[0025] Preferably, the mass ratio of the antioxidant 168 to the antioxidant 1010 is (1-3):1.

[0026] Further preferably, the mass ratio of the antioxidant 168 to the antioxidant 1010 is 2:1.

[0027] Preferably, the lubricating grease is at least one of calcium stearate and zinc stearate.

[0028] On the other hand, the present invention also provides a method for preparing a highly weather-resistant PE protective material, comprising the following steps: sequentially adding high-density polyethylene, linear low-density polyethylene, a stabilizer, modified titanium dioxide, an antioxidant, and a lubricant into a blender, stirring for 30 to 50 minutes, extruding through a die head through a twin-screw extruder, and pelletizing, with the extrusion temperature controlled at 210-220° C., to obtain the highly weather-resistant PE protective material.

[0029] In another aspect, the present invention further provides an application of the above-mentioned high-weather-resistant PE protective material or the high-weather-resistant PE protective material obtained by the above-mentioned preparation method in the field of plastic-coated steel wire ropes.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The polyethylene protective material disclosed in the present invention achieves excellent weather resistance by adding modified sodium hydroxymethyl cellulose as a stabilizer of the system and synergizing with modified titanium dioxide, making it suitable for long-term use in outdoor environments, and has excellent mechanical properties and good processability.

[0032] (2) The present invention introduces soy protein to modify sodium hydroxymethyl cellulose. Soy protein particles are adsorbed on the surface of sodium hydroxymethyl cellulose long chains of specific viscosity and polymerize through interaction to form a stable complex, which further improves the structural strength of the sodium hydroxymethyl cellulose long chains. When the stabilizer is added to the PE protective material system, it also improves the uniformity and stability of the system, further improving the mechanical strength of the PE protective material.

[0033] (3) The present invention modifies titanium dioxide by adding 3-aminopropyltriethoxysilane, thereby significantly improving the dispersibility of titanium dioxide, thereby further improving the ultraviolet resistance of the system; at the same time, the applicant also adds conjugated linoleic acid to further improve the modification effect and modification durability of titanium dioxide. When titanium dioxide modified with aminobenzoic acid and conjugated linoleic acid is added to the PE protective material system, the weather resistance of the system is also improved to a certain extent. The stabilizer specifically added to the synergistic system further improves the weather resistance of the PE protective material. DETAILED DESCRIPTION

[0034] The present invention will be described below in conjunction with specific embodiments. It should be noted that the following examples are illustrative of the present invention and are intended only to illustrate the present invention and are not intended to limit the present invention. Other combinations and various modifications within the scope of the present invention may be made without departing from the spirit or scope of the present invention.

[0035] Unless otherwise specified, the following reagents can be easily obtained from commercial companies. High-density polyethylene and linear low-density polyethylene were purchased from Kunshan Jinkaiwo Plastic Co., Ltd., and sodium hydroxymethylcellulose (viscosity 3000 mPa·s, 25° C.) was purchased from Shanghai Macklin Co., Ltd.

[0036] Preparation Example 1

[0037] The preparation steps of the stabilizer are as follows:

[0038] Add 50 mL of deionized water and 5 g of sodium hydroxymethyl cellulose into the reactor, disperse by magnetic stirring at 800 r / min, then add 10 g of soy protein, stir for 1.5 h, then add 0.5 g of citric acid, stir for 25 min to obtain the stabilizer.

[0039] Preparation Example 2

[0040] The preparation steps of the stabilizer are the same as those in Preparation Example 1, except that the amount of soy protein added is 17.5 g.

[0041] Preparation Example 3

[0042] The preparation steps of modified titanium dioxide are as follows:

[0043] 10 g of titanium dioxide and 100 mL of deionized water were added to the reactor, dispersed by ultrasonication, and heated to 65°C. 1.5 g of 3-aminopropyltriethoxysilane and 0.8 g of conjugated linoleic acid were then added, and the mixture was stirred for 2.5 h. The modified titanium dioxide was obtained by filtration, washing with deionized water three times, and drying at 70°C for 10 h.

[0044] Preparation Example 4

[0045] The preparation steps of the modified titanium dioxide were the same as those in Preparation Example 3, except that 2.5 g of 3-aminopropyltriethoxysilane was added.

[0046] Preparation Example 5

[0047] The preparation steps of modified titanium dioxide are the same as those in Preparation Example 3, except that the amount of conjugated linoleic acid added is 1.2 g.

[0048] Preparation Example 6

[0049] The preparation steps of modified titanium dioxide are as follows:

[0050] 10 g of titanium dioxide and 100 mL of deionized water were added to the reactor, dispersed by ultrasonication, and heated to 65°C. 1.5 g of 3-aminopropyltriethoxysilane was added and stirred for 2.5 h. The modified titanium dioxide was obtained by filtration, washing with deionized water three times, and drying at 70°C for 10 h.

[0051] Unless otherwise specified, the antioxidants used in the following examples and comparative examples are a mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 2:1, and the lubricants used are sodium stearate.

[0052] Example 1

[0053] A highly weather-resistant PE protective material comprises the following raw materials in parts by weight: 130 parts of high-density polyethylene, 60 parts of linear low-density polyethylene, 1.7 parts of a stabilizer, 2 parts of modified titanium dioxide, 1.3 parts of an antioxidant, and 1.5 parts of a lubricant.

[0054] The preparation method of the highly weather-resistant PE protective material of this embodiment comprises the following steps: adding high-density polyethylene, linear low-density polyethylene, a stabilizer, modified titanium dioxide, an antioxidant, and a lubricant to a blender in sequence, stirring for 40 minutes, extruding through a die head of a twin-screw extruder, and pelletizing, with the extrusion temperature controlled at 215°C, to obtain the highly weather-resistant PE protective material.

[0055] The stabilizer used in this example was obtained from Preparation Example 1, and the modified titanium dioxide used was obtained from Preparation Example 3.

[0056] Example 2

[0057] A highly weather-resistant PE protective material comprises the following raw materials in parts by weight: 150 parts of high-density polyethylene, 70 parts of linear low-density polyethylene, 2.4 parts of a stabilizer, 3 parts of modified titanium dioxide, 2 parts of an antioxidant, and 2 parts of a lubricant.

[0058] The preparation method of the highly weather-resistant PE protective material of this embodiment comprises the following steps: adding high-density polyethylene, linear low-density polyethylene, a stabilizer, modified titanium dioxide, an antioxidant, and a lubricant to a blender in sequence, stirring for 30 minutes, extruding through a die head of a twin-screw extruder, and pelletizing, with the extrusion temperature controlled at 210°C, to obtain the highly weather-resistant PE protective material.

[0059] The stabilizer used in this example was obtained from Preparation Example 1, and the modified titanium dioxide used was obtained from Preparation Example 3.

[0060] Example 3

[0061] A highly weather-resistant PE protective material comprises the following raw materials in parts by weight: 110 parts of high-density polyethylene, 50 parts of linear low-density polyethylene, 1 part of a stabilizer, 1 part of modified titanium dioxide, 0.6 parts of an antioxidant, and 1 part of a lubricant.

[0062] The preparation method of the highly weather-resistant PE protective material of this embodiment comprises the following steps: adding high-density polyethylene, linear low-density polyethylene, a stabilizer, modified titanium dioxide, an antioxidant, and a lubricant to a blender in sequence, stirring for 50 minutes, extruding through a die head of a twin-screw extruder, and pelletizing, with the extrusion temperature controlled at 210° C., to obtain the highly weather-resistant PE protective material.

[0063] The stabilizer used in this example was obtained from Preparation Example 1, and the modified titanium dioxide used was obtained from Preparation Example 3.

[0064] Example 4

[0065] A highly weather-resistant PE protective material and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the stabilizer used is obtained from Preparation Example 2.

[0066] Example 5

[0067] A highly weather-resistant PE protective material and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that the modified titanium dioxide used is obtained from Preparation Example 4.

[0068] Example 6

[0069] A highly weather-resistant PE protective material and a preparation method thereof. The specific implementation manner is the same as that of Example 1, except that the modified titanium dioxide used is obtained from Preparation Example 5.

[0070] Example 7

[0071] A highly weather-resistant PE protective material and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that the modified titanium dioxide used is obtained from Preparation Example 6.

[0072] Example 8

[0073] A highly weather-resistant PE protective material and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that an equal amount of sodium hydroxymethyl cellulose is used to replace the stabilizer.

[0074] Comparative Example 1

[0075] A highly weather-resistant PE protective material and a preparation method thereof. The specific implementation method is the same as that of Example 1, except that an equal amount of titanium dioxide is used to replace modified titanium dioxide.

[0076] Performance testing:

[0077] The highly weather-resistant PE protective materials prepared in Examples 1-8 and Comparative Example 1 were prepared into samples with a size of 20 cm*10 cm*5 mm. Samples were exposed to a xenon light source in a flashlight aging test chamber in accordance with GB / T164222-1999. The aging time was 35 days, and the samples were then taken out for testing. The test conditions were: 6 kW water-cooled xenon lamp, operating temperature of 51±2°C, blackboard temperature of 68±2°C, relative humidity of the workroom of 55±2%, rainfall cycle of 20 min / 100 min (raining time / no raining time), and radiation intensity of the light source of 590±10 W / m 2 The aging test was carried out, and the following performance tests were carried out together with the samples before aging. The specific test results are shown in Table 1:

[0078] (1) Tensile property test: The tensile properties of the samples prepared in Examples 1 to 8 and Comparative Example 1 before and after the aging test were tested according to the standard GB / T1040-1992;

[0079] (2) Impact resistance test: The impact resistance of the samples prepared in Examples 1 to 8 and Comparative Example 1 before and after the aging test was tested according to the standard GB / T1843-2008.

[0080] Table 1

[0081]

[0082] As can be seen from Table 1, the tensile strength and impact strength of the PE protective materials provided by Examples 1 to 3 of the present invention are significantly improved before aging, and the loss of tensile strength and impact strength after aging is small.

[0083] From the comparison between Example 4 and Example 1, it can be seen that when the amount of soy protein added to prepare the stabilizer is changed, the tensile strength and impact strength of the PE protective material before and after aging will decrease.

[0084] By comparing Example 5 and Example 6 with Example 1, it can be seen that when the added amount of 3-aminopropyltriethoxysilane and conjugated linoleic acid is changed when preparing modified titanium dioxide, the tensile strength and impact strength of the PE protective material will decrease to varying degrees. In particular, after aging, the tensile strength and impact strength of the PE protective material decrease significantly, and the aging resistance deteriorates.

[0085] From the comparison between Example 7 and Example 1, it can be seen that when titanium dioxide is modified with only 3-aminopropyltriethoxysilane, the compatibility of the system is reduced, which in turn leads to a decrease in the mechanical properties of the PE protective material during long-term use.

[0086] From the comparison between Example 8 and Example 1, it can be seen that when sodium hydroxymethyl cellulose is directly added as a stabilizer, the impact strength of the PE protective material before and after aging will decrease, which is caused by the poor stability of the system.

[0087] From the comparison between Comparative Example 1 and Example 1, it can be seen that when titanium dioxide is directly added, the dispersibility of titanium dioxide in the system will drop sharply, which will further reduce the modification effect of the system after the addition of titanium dioxide, affecting the aging resistance of the PE protective material.

[0088] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A highly weather-resistant PE protective material, characterized in that: The PE protective material comprises the following raw materials in parts by weight: 110 to 150 parts of high-density polyethylene, 50 to 70 parts of linear low-density polyethylene, 1 to 3 parts of modified titanium dioxide, 0.6 to 2 parts of antioxidant, 1 to 2 parts of lubricant and 1 to 2.4 parts of stabilizer; The preparation steps of the stabilizer are as follows: Add deionized water and sodium hydroxymethyl cellulose into a reactor, disperse by magnetic stirring, add a modifier, stir for 1 to 2 hours, add citric acid, stir for 20 to 30 minutes, and obtain the stabilizer; The modifier is soybean protein; The mass ratio of the sodium hydroxymethyl cellulose to the modifier is 1:(1-3); The viscosity of the sodium hydroxymethyl cellulose is 2000-4000 mPa·s at 25°C; The preparation steps of the modified titanium dioxide are as follows: Add titanium dioxide and deionized water into a reactor, disperse by ultrasonication, heat to 60-70°C, add 3-aminopropyltriethoxysilane and conjugated linoleic acid, stir and react for 2-3h, filter, wash and dry to obtain the modified titanium dioxide; The mass ratio of the titanium dioxide, 3-aminopropyltriethoxysilane and conjugated linoleic acid is 10:(1-2):(0.6-1).

2. A highly weather-resistant PE protective material according to claim 1, characterized in that: The antioxidant is a compound of antioxidant 168 and antioxidant 1010.

3. A method for preparing the highly weather-resistant PE protective material according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: adding high-density polyethylene, linear low-density polyethylene, a stabilizer, modified titanium dioxide, an antioxidant and a lubricant into a mixer in sequence, stirring for 30 to 50 minutes, extruding through a die head of a twin-screw extruder, and pelletizing, and controlling the extrusion temperature at 210 to 220° C. to obtain the high weather-resistant PE protective material.

4. Use of the highly weather-resistant PE protective material according to any one of claims 1 to 2 or the highly weather-resistant PE protective material obtained by the preparation method according to claim 3 in the field of plastic-coated steel wire ropes.

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