Corrosion-resistant and aging-resistant PVC (polyvinyl chloride) material and preparation method thereof

Abstract

The invention relates to the technical field of materials, and discloses a corrosion-resistant and aging-resistant PVC material and a preparation method thereof.The PVC material is prepared from polyvinyl chloride resin, an elastomer, an expanded vermiculite additive, a lubricant, a heat stabilizer, a pigment, an ultraviolet absorbent and a processing aid through mixing and melt extrusion processes; wherein the expanded vermiculite additive is prepared by modifying the surface of expanded vermiculite with a polymeric macromolecular substance containing a natural antioxidant aid gallic acid and a silica chain segment, and the existence of the macromolecular substance can improve the permeation of a corrosion medium between the expanded vermiculite and the polyvinyl chloride and improve the corrosion resistance of the polyvinyl chloride. Besides, a gallic acid structure contained in the macromolecular substance contains a hindered phenol antioxidant structure, and a silicon-oxygen chain segment is relatively high in bond energy and can be cooperated with each other, so that the thermo-oxidative aging resistance of the polyvinyl chloride can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and in particular to a corrosion-resistant and aging-resistant PVC material and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a thermoplastic polymer made from vinyl chloride monomer via free radical polymerization. Since its introduction, PVC has become one of the most widely used plastics worldwide, second only to polyethylene (PE) in production volume, thanks to its low price, excellent flame retardancy, good insulation properties, and widespread availability of raw materials. PVC is widely used in a variety of fields, including building materials, industrial products, daily necessities, pipes, wire and cable, and packaging films.

[0003] With the continuous deepening of application, polyvinyl chloride is used more and more widely in the field of cable sheathing. However, since the laying and maintenance of some wires and cables are relatively difficult, the performance requirements of polyvinyl chloride are relatively high, especially corrosion resistance and aging resistance. Although polyvinyl chloride itself has certain corrosion resistance, it is difficult to meet the use requirements of cables in outdoor environments for a long time. Therefore, improving the performance of polyvinyl chloride is of great significance to its continued development and further application.

[0004] Prior art typically involves adding particulate filler modifiers, such as calcium carbonate and nano-silica, to polyvinyl chloride (PVC) to improve its hardness, wear resistance, heat distortion temperature, thermal stability, and weatherability, while also reducing mold shrinkage, extrusion swell, and cost. However, inorganic fillers inherently interact with PVC, hindering uniform dispersion. Consequently, the advantages of inorganic materials are often limited. The present invention addresses these challenges by providing a PVC material that addresses these challenges. Summary of the Invention

[0005] In order to solve the problems mentioned in the background technology, the purpose of the present invention is to provide a corrosion-resistant and aging-resistant PVC material and a preparation method thereof.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A corrosion-resistant and aging-resistant PVC material, comprising the following raw materials in parts by weight:

[0008] 65-85 parts of polyvinyl chloride resin, 5-10 parts of elastomer, 2-6 parts of expanded vermiculite additive, 0.5-1 part of lubricant, 1-3 parts of heat stabilizer, 5-15 parts of colorant, 0.5-1.5 parts of ultraviolet absorber, and 0.5-1.5 parts of processing aid.

[0009] As a further embodiment of the present invention, the elastomer is at least one of ABS elastomer, SEBS elastomer or SBS elastomer.

[0010] As a further embodiment of the present invention, the preparation method of the expanded vermiculite additive is as follows:

[0011] Step 1: Under the action of an alkaline catalyst, an excess of dichlorosilane modifier is used to modify expanded vermiculite to form a precursor;

[0012] Step 2: Add gallic acid derivatives to the precursor and carry out chain extension polymerization with an excess of dichlorosilane modifier to obtain expanded vermiculite additive.

[0013] As a further embodiment of the present invention, the alkaline catalyst is triethylamine or pyridine.

[0014] As a further embodiment of the present invention, the dichlorosilane modifier is any one of dimethyldichlorosilane, dibutylsilyldichloride, dichlorodihexylsilane, di-n-octyldichlorosilane or bis(trimethylsiloxy)dichlorosilane.

[0015] As a further embodiment of the present invention, the gallic acid derivative is prepared by reacting gallic acid and glycidol as raw materials in the presence of a phase transfer catalyst.

[0016] As a further embodiment of the present invention, the molar ratio of gallic acid to glycidol is 1:1.

[0017] As a further embodiment of the present invention, the phase transfer catalyst is any one of tetramethylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate or N,N-dimethylbenzylamine.

[0018] As a further embodiment of the present invention, the lubricant is polyethylene wax or paraffin; the heat stabilizer is a calcium zinc stabilizer or a barium zinc stabilizer; the colorant is any one of titanium dioxide, carbon black or calcium carbonate; the ultraviolet absorber is ultraviolet absorber UV-234 or ultraviolet absorber UV-326; and the processing aid is processing aid ACR.

[0019] A method for preparing a corrosion-resistant and aging-resistant PVC material comprises the following steps:

[0020] The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 300-500r / min, and mechanically stir and mix for 10-20min to obtain a premix;

[0021] The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 170-180°C, the temperature of the second zone to 180-190°C, the temperature of the third zone to 190-200°C, the temperature of the fourth zone to 200-210°C, and the screw speed to 50-60rpm. After the melt extrusion process, the PVC material can be obtained.

[0022] Beneficial effects of the present invention:

[0023] The present invention prepares an expanded vermiculite additive by modifying the surface of expanded vermiculite with a polymeric macromolecular substance containing gallic acid, a natural antioxidant, and siloxane segments. The macromolecular substance can produce a transition effect between polyvinyl chloride (PVC) and expanded vermiculite, effectively improving their compatibility and enabling the expanded vermiculite to efficiently exert its own function. The additive not only enhances the PVC but also utilizes a layered structure to form a physical barrier layer within the PVC material, preventing the penetration of corrosive media and improving the corrosion resistance of the PVC. Furthermore, the gallic acid structure contained in the macromolecular substance contains a hindered phenol antioxidant structure, and the siloxane segments have high bond energy. The macromolecular substance cooperates synergistically to effectively improve the heat-oxidative aging resistance of the PVC.

[0024] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] Example 1

[0027] A corrosion-resistant and aging-resistant PVC material, comprising the following raw materials in parts by weight:

[0028] 65 parts of polyvinyl chloride resin, 5 parts of ABS elastomer, 2 parts of expanded vermiculite additive, 0.5 parts of lubricant polyethylene wax, 1 part of calcium zinc stabilizer, 5 parts of colorant titanium dioxide, 0.5 parts of ultraviolet absorber UV-234, and 0.5 parts of processing aid ACR.

[0029] The preparation method of the PVC material comprises the following steps:

[0030] The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 300r / min, and mechanically stir and mix for 20min to obtain a premix;

[0031] The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 175°C, the temperature of the second zone to 185°C, the temperature of the third zone to 195°C, the temperature of the fourth zone to 200°C, and the screw speed to 50rpm. After the melt extrusion process, the PVC material can be obtained.

[0032] Example 2

[0033] A corrosion-resistant and aging-resistant PVC material, comprising the following raw materials in parts by weight:

[0034] 70 parts of polyvinyl chloride resin, 6 parts of SBS elastomer, 5 parts of expanded vermiculite additive, 0.6 parts of lubricant polyethylene wax, 2 parts of barium zinc stabilizer, 10 parts of colorant carbon black, 1 part of ultraviolet absorber UV-326, and 1 part of processing aid ACR.

[0035] The preparation method of the PVC material comprises the following steps:

[0036] The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 400r / min, and mechanically stir and mix for 15 minutes to obtain a premix;

[0037] The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 175°C, the temperature of the second zone to 185°C, the temperature of the third zone to 195°C, the temperature of the fourth zone to 200°C, and the screw speed to 50rpm. After the melt extrusion process, the PVC material can be obtained.

[0038] Example 3

[0039] A corrosion-resistant and aging-resistant PVC material, comprising the following raw materials in parts by weight:

[0040] 85 parts of polyvinyl chloride resin, 10 parts of SEBS elastomer, 6 parts of expanded vermiculite additive, 1 part of lubricant polyethylene wax, 3 parts of calcium zinc stabilizer, 15 parts of colorant carbon black, 1.5 parts of ultraviolet absorber UV-326, and 1.5 parts of processing aid ACR.

[0041] The preparation method of the PVC material comprises the following steps:

[0042] The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 500r / min, and mechanically stir and mix for 10 minutes to obtain a premix;

[0043] The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 175°C, the temperature of the second zone to 185°C, the temperature of the third zone to 195°C, the temperature of the fourth zone to 200°C, and the screw speed to 50rpm. After the melt extrusion process, the PVC material can be obtained.

[0044] The expanded vermiculite additive in the above embodiment is prepared by the following method:

[0045] Step 1: Disperse 1.5 g of expanded vermiculite in 1,4-dioxane, then add 4 g of dimethyldichlorosilane and 0.5 g of triethylamine to the resulting dispersion. After the addition is complete, raise the temperature to 60° C. and stir for 4 h to form a precursor.

[0046] Step 2: Lower the temperature to 40°C, add 3.2g of gallic acid derivative to the precursor, stir and mix, then continue to raise the temperature to 80°C, continue stirring for 16 hours, centrifuge the product, wash and vacuum dry it, and then you can get the expanded vermiculite additive.

[0047] The preparation method of the gallic acid derivative is as follows:

[0048] 0.3 g of gallic acid, 0.13 g of glycidol and toluene were added to a reactor filled with nitrogen. After the addition was completed, stirring was started and mixed evenly. Then, 0.01 g of tetrabutylammonium bromide was added to the reactor. The temperature was then raised to 75° C. and stirring was maintained at this temperature for 6 hours. The solvent was evaporated and the product was obtained through a purification process.

[0049] Comparative Example 1

[0050] A corrosion-resistant and aging-resistant PVC material, comprising the following raw materials in parts by weight:

[0051] 70 parts of polyvinyl chloride resin, 6 parts of SBS elastomer, 5 parts of expanded vermiculite, 0.6 parts of lubricant polyethylene wax, 2 parts of barium zinc stabilizer, 10 parts of colorant carbon black, 1 part of ultraviolet absorber UV-326, and 1 part of processing aid ACR.

[0052] The preparation method of the PVC material comprises the following steps:

[0053] The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 400r / min, and mechanically stir and mix for 15 minutes to obtain a premix;

[0054] The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 175°C, the temperature of the second zone to 185°C, the temperature of the third zone to 195°C, the temperature of the fourth zone to 200°C, and the screw speed to 50rpm. After the melt extrusion process, the PVC material can be obtained.

[0055] Comparative Example 2

[0056] A corrosion-resistant and aging-resistant PVC material, comprising the following raw materials in parts by weight:

[0057] 70 parts of polyvinyl chloride resin, 6 parts of SBS elastomer, 0.6 parts of lubricant polyethylene wax, 2 parts of barium zinc stabilizer, 10 parts of colorant carbon black, 1 part of ultraviolet absorber UV-326, and 1 part of processing aid ACR.

[0058] The preparation method of the PVC material comprises the following steps:

[0059] The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 400r / min, and mechanically stir and mix for 15 minutes to obtain a premix;

[0060] The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 175°C, the temperature of the second zone to 185°C, the temperature of the third zone to 195°C, the temperature of the fourth zone to 200°C, and the screw speed to 50rpm. After the melt extrusion process, the PVC material can be obtained.

[0061] Performance Testing

[0062] According to the standard GB / T 1040.1-2018, the tensile strength of the sample was tested, and the tensile rate was set to 100 mm / min;

[0063] After the test is completed, the test pieces of the same batch are placed in an oven at 120℃ for accelerated thermal oxidative aging treatment for 48 hours. After that, the treated test pieces are taken out and subjected to tensile performance test. The aging resistance of the test pieces is evaluated by calculating the tensile strength retention rate.

[0064] A test piece with a size of 4cm×4cm×5mm was placed in a 40% sulfuric acid solution for 48 hours and then taken out. The corrosion resistance of the test piece was evaluated by calculating the weight loss rate before and after treatment. The calculation formula is [(m1-m2) / m1]×100%, where m1 is the weight of the test piece before treatment and m2 is the weight of the test piece after testing.

[0065] The test results are recorded in the following table:

[0066] Tensile strength / MPa Tensile strength retention rate / % Weight loss rate / % Example 1 49.8 98.1 1.2 Example 2 50.3 98.3 0.9 Example 3 50.2 98.1 1.0 Comparative Example 1 46.5 74.5 3.4 Comparative Example 2 40.6 72.8 3.8

[0067] Analysis shows that the effect of using unsurface-modified expanded vermiculite as an additive to modify polyvinyl chloride is not good. On the one hand, this is because the expanded vermiculite cannot be evenly dispersed due to compatibility issues. It is not only difficult to effectively exert its own effects, but also difficult to form a continuous physical barrier layer. At the same time, it is also impossible to utilize the antioxidant effect of gallic acid, resulting in a significant decline in various performances.

[0068] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal description of the claims, or if they include equivalent structural elements that are not substantially different from the literal description of the claims, then these other embodiments should also be included in the scope of the claims.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A corrosion-resistant and aging-resistant PVC material, characterized in that: According to parts by weight, the following raw materials are included: 65-85 parts of polyvinyl chloride resin, 5-10 parts of elastomer, 2-6 parts of expanded vermiculite additive, 0.5-1 part of lubricant, 1-3 parts of heat stabilizer, 5-15 parts of colorant, 0.5-1.5 parts of ultraviolet absorber, and 0.5-1.5 parts of processing aid.

2. The corrosion-resistant and aging-resistant PVC material according to claim 1, characterized in that: The elastomer is at least one of ABS elastomer, SEBS elastomer or SBS elastomer.

3. The corrosion-resistant and aging-resistant PVC material according to claim 1, characterized in that: The preparation method of the expanded vermiculite additive is as follows: Step 1: Under the action of an alkaline catalyst, an excess of dichlorosilane modifier is used to modify expanded vermiculite to form a precursor; Step 2: Add gallic acid derivatives to the precursor and carry out chain extension polymerization with an excess of dichlorosilane modifier to obtain expanded vermiculite additive.

4. The corrosion-resistant and aging-resistant PVC material according to claim 3, characterized in that: The alkaline catalyst is triethylamine or pyridine.

5. The corrosion-resistant and aging-resistant PVC material according to claim 3, characterized in that: The dichlorosilane modifier is any one of dimethyldichlorosilane, dibutylsilyldichloride, dichlorodihexylsilane, di-n-octyldichlorosilane or bis(trimethylsiloxy)dichlorosilane.

6. The corrosion-resistant and aging-resistant PVC material according to claim 3, characterized in that: The gallic acid derivative is prepared by reacting gallic acid and glycidol as raw materials under the action of a phase transfer catalyst.

7. The corrosion-resistant and aging-resistant PVC material according to claim 6, characterized in that: The molar ratio of the gallic acid to the glycidol is 1:

1.

8. The corrosion-resistant and aging-resistant PVC material according to claim 6, characterized in that: The phase transfer catalyst is any one of tetramethylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate or N,N-dimethylbenzylamine.

9. The corrosion-resistant and aging-resistant PVC material according to claim 1, characterized in that: The lubricant is polyethylene wax or paraffin; the heat stabilizer is calcium zinc stabilizer or barium zinc stabilizer; the colorant is any one of titanium dioxide, carbon black or calcium carbonate; the ultraviolet absorber is ultraviolet absorber UV-234 or ultraviolet absorber UV-326; and the processing aid is processing aid ACR.

10. A method for preparing the corrosion-resistant and aging-resistant PVC material according to claim 1, characterized in that: The following steps are involved: The first step is to weigh all the raw materials according to their weight, put them into a high-speed mixer, control the stirring speed to 300-500r / min, and mechanically stir and mix for 10-20min to obtain a premix; The second step is to put the premix into a twin-screw extruder, control the temperature of the extruder zone 1 to 170-180°C, the temperature of the second zone to 180-190°C, the temperature of the third zone to 190-200°C, the temperature of the fourth zone to 200-210°C, and the screw speed to 50-60rpm. After the melt extrusion process, the PVC material can be obtained.