A corrosion-resistant and aging-resistant PVC material and its preparation method

Abstract

This invention relates to the field of materials technology and discloses a corrosion-resistant and aging-resistant PVC material and its preparation method. The PVC material comprises polyvinyl chloride resin, elastomer, expanded vermiculite additive, lubricant, heat stabilizer, colorant, ultraviolet absorber, and processing aids, and is prepared by mixing and melt extrusion. The expanded vermiculite additive is obtained by modifying the surface of expanded vermiculite with a polymeric macromolecule containing natural antioxidant gallic acid and silica segments. The presence of the macromolecule improves the barrier between expanded vermiculite and PVC, preventing the penetration of corrosive media and enhancing the corrosion resistance of PVC. Furthermore, the gallic acid structure contained in the macromolecule includes a hindered phenolic antioxidant structure, and the silica segments have high bond energies; these components synergistically improve the heat and oxygen aging resistance of PVC.

Description

Technical Field

[0001] This invention relates to the field of materials technology, specifically to a corrosion-resistant and aging-resistant PVC material and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) is a thermoplastic polymer made from vinyl chloride monomer through a free radical polymerization reaction. Since its introduction, PVC has become one of the world's most widely used plastics due to its advantages such as low price, excellent flame retardancy, good insulation properties, and wide availability of raw materials, second only to polyethylene (PE) in production volume. PVC has a wide range of applications, covering building materials, industrial products, daily necessities, pipes, wires and cables, and packaging films, among others.

[0003] With the deepening of applications, polyvinyl chloride (PVC) is being used more and more widely in the field of cable sheathing. However, due to the difficulty in laying and maintaining some wires and cables, the performance requirements of PVC are relatively high, especially its corrosion resistance and aging resistance. Although PVC itself has a certain degree of corrosion resistance, it is difficult to meet the requirements of cables that are in outdoor environments for a long time. Therefore, improving the performance of PVC is of great significance for its sustainable development and further application.

[0004] Existing technologies typically involve blending particulate filler modifiers, such as calcium carbonate and nano-silica, into polyvinyl chloride (PVC) to improve the hardness, wear resistance, heat distortion temperature, thermal stability, and weather resistance of the product, while reducing molding shrinkage, extrusion swell effect, and cost. However, inorganic fillers themselves present interfacial problems with PVC, making it difficult to achieve uniform dispersion. Therefore, the advantages of inorganic materials are often not fully realized. Based on this, the present invention provides a PVC material that solves the problems of existing technologies. Summary of the Invention

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

[0006] The objective of this invention can be achieved through the following technical solutions:

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

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

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

[0010] As a further aspect 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 derivative to the precursor and carry out chain extension polymerization with excess 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, dibutylsilane, dichlorodihexylsilane, di-n-octyldichlorosilane, or bis(trimethylsiloxy)dichlorosilane.

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

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

[0017] As a further aspect 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 wax; 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.

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

[0020] Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed to 300-500 r / min, and mechanically mix for 10-20 minutes to obtain a premix.

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

[0022] The beneficial effects of this invention are:

[0023] This invention prepares an expanded vermiculite additive by modifying the surface of expanded vermiculite with a polymeric macromolecule containing natural antioxidant gallic acid and silicon oxide segments. The macromolecule creates a transition effect between polyvinyl chloride (PVC) and expanded vermiculite, effectively improving their compatibility and allowing the expanded vermiculite to function efficiently. It not only strengthens PVC but also forms a physical barrier layer within the PVC material using its layered structure, preventing the penetration of corrosive media and improving the corrosion resistance of PVC. Furthermore, the gallic acid structure within the macromolecule contains hindered phenolic antioxidant structures, and the silicon oxide segments have high bond energies; these components synergistically improve the heat and oxygen aging resistance of PVC.

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

[0025] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

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

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

[0029] The method for preparing the PVC material includes the following steps:

[0030] Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed at 300 r / min, and mechanically mix for 20 minutes to obtain a premix.

[0031] The second step is to feed the premixed material into a twin-screw extruder, control the temperature of zone one to be 175℃, zone two to be 185℃, zone three to be 195℃, and zone four to be 200℃, and the screw speed to be 50 rpm. After melt extrusion, PVC material can be obtained.

[0032] Example 2

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

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

[0035] The method for preparing the PVC material includes the following steps:

[0036] Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed at 400 r / min, and mechanically mix for 15 minutes to obtain a premix.

[0037] The second step is to feed the premixed material into a twin-screw extruder, control the temperature of zone one to be 175℃, zone two to be 185℃, zone three to be 195℃, and zone four to be 200℃, and the screw speed to be 50 rpm. After melt extrusion, PVC material can be obtained.

[0038] Example 3

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

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

[0041] The method for preparing the PVC material includes the following steps:

[0042] Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed at 500 r / min, and mechanically mix for 10 minutes to obtain a premix.

[0043] The second step is to feed the premixed material into a twin-screw extruder, control the temperature of zone one to be 175℃, zone two to be 185℃, zone three to be 195℃, and zone four to be 200℃, and the screw speed to be 50 rpm. After melt extrusion, PVC material can be obtained.

[0044] The expanded vermiculite additives in the above embodiments were prepared using the following method:

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

[0046] Step 2: Lower the temperature to 40℃, add 3.2g of gallic acid derivative to the precursor, stir and mix well, then raise the temperature to 80℃ and continue stirring for 16h. Centrifuge the product, wash and vacuum dry it to obtain the expanded vermiculite additive.

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

[0048] 0.3g gallic acid, 0.13g glycidol and toluene were added to a nitrogen-filled reactor. After the addition was complete, stirring was started and the mixture was homogeneous. Then, 0.01g tetrabutylammonium bromide was added to the reactor, and the temperature was raised to 75°C. The mixture was stirred at this temperature for 6 hours. The solvent was then evaporated and removed, and the product was obtained through purification.

[0049] Comparative Example 1

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

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

[0052] The method for preparing the PVC material includes the following steps:

[0053] Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed at 400 r / min, and mechanically mix for 15 minutes to obtain a premix.

[0054] The second step is to feed the premixed material into a twin-screw extruder, control the temperature of zone one to be 175℃, zone two to be 185℃, zone three to be 195℃, and zone four to be 200℃, and the screw speed to be 50 rpm. After melt extrusion, PVC material can be obtained.

[0055] Comparative Example 2

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

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

[0058] The method for preparing the PVC material includes the following steps:

[0059] Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed at 400 r / min, and mechanically mix for 15 minutes to obtain a premix.

[0060] The second step is to feed the premixed material into a twin-screw extruder, control the temperature of zone one to be 175℃, zone two to be 185℃, zone three to be 195℃, and zone four to be 200℃, and the screw speed to be 50 rpm. After melt extrusion, PVC material can be obtained.

[0061] Performance testing

[0062] According to 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℃ and subjected to accelerated thermo-oxidative aging treatment for 48 hours. The tensile properties of the treated test pieces are then tested, and the aging resistance of the test pieces is evaluated by calculating the tensile strength retention rate.

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

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

[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 using unmodified expanded vermiculite as an additive to modify polyvinyl chloride is not very effective. This is partly due to compatibility issues, which prevent the expanded vermiculite from dispersing evenly. This not only makes it difficult to exert its own effects efficiently but also makes it difficult to form a continuous physical barrier layer. Furthermore, it is impossible to utilize the antioxidant effect of gallic acid, resulting in a significant decline in various properties.

[0068] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of these embodiments are merely to aid in understanding the method and core ideas of the present invention, including the best mode, and to enable any person skilled in the art to practice the present invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements similar to those expressed in the claims, or if they include equivalent structural elements that are not substantially different from those expressed in the claims, then these other embodiments should also be included within the scope of the claims.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A corrosion-resistant and aging-resistant PVC material, characterized in that, By weight, it includes the following ingredients: The composition includes 65-85 parts polyvinyl chloride resin, 5-10 parts elastomer, 2-6 parts expanded vermiculite additive, 0.5-1 part lubricant, 1-3 parts heat stabilizer, 5-15 parts colorant, 0.5-1.5 parts ultraviolet absorber, and 0.5-1.5 parts processing aid. 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 derivative to the precursor and carry out chain extension polymerization with excess dichlorosilane modifier to obtain expanded vermiculite additive; The dichlorosilane modifier is any one of dimethyldichlorosilane, dibutylsilane dichloride, dichlorodihexylsilane, di-n-octyldichlorosilane, or bis(trimethylsiloxy)dichlorosilane; The gallic acid derivative is prepared by reacting gallic acid and glycidol as raw materials under the action of a phase transfer catalyst.

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 alkaline catalyst is triethylamine or pyridine.

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

1.

5. The corrosion-resistant and aging-resistant PVC material according to claim 1, characterized in that, The phase transfer catalyst is any one of tetramethylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate, or N,N-dimethylbenzylamine.

6. The corrosion-resistant and aging-resistant PVC material according to claim 1, characterized in that, The lubricant is polyethylene wax or paraffin wax; 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.

7. A method for preparing the corrosion-resistant and aging-resistant PVC material as described in claim 1, characterized in that, Includes the following steps: Step 1: Weigh all the raw materials according to the specified weight proportions, put them into a high-speed mixer, control the mixing speed to 300-500 r / min, and mechanically mix for 10-20 minutes to obtain a premix. The second step is to feed the premixed material into a twin-screw extruder, control the temperature of the first zone of the extruder to be 170-180℃, the second zone to be 180-190℃, the third zone to be 190-200℃, and the fourth zone to be 200-210℃, and the screw speed to be 50-60 rpm. After the melt extrusion process, PVC material can be obtained.