High-performance PVC material for joint and preparation method thereof

Abstract

The invention relates to the technical field of materials, and discloses a high-performance PVC (polyvinyl chloride) material for joints and a preparation method thereof, the PVC material is prepared by taking PVC resin as a base material and taking chlorinated polyvinyl chloride, a nitrile rubber material, a fiber modified substance and the like as auxiliary materials through mixing and melt extrusion processes; wherein the fiber modified substance is prepared by grafting a macromolecular polymer containing a large number of hindered amine antioxidant groups on the surface of glass fiber, and the macromolecular polymer can be intertwined with a polyvinyl chloride molecular chain, so that the compatibility between the glass fiber and a polyvinyl chloride base material is improved; by adding the hindered amine antioxidant group, the glass fiber efficiently exerts the self-reinforcing advantage, the mechanical strength of the polyvinyl chloride material is improved, the hindered amine antioxidant group can effectively exert the antioxidant effect, and the oxidation resistance of the polyvinyl chloride material is improved.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a high-performance PVC material for a joint and a preparation method thereof. Background Art

[0002] PVC plastic waterstop is a flexible waterstop extruded with polyvinyl chloride as the base material. It is generally used in construction joints and deformation joints during concrete pouring and is integrated with concrete. It is widely used in engineering projects such as tunnels, culverts, water diversion aqueducts, water dams, liquid storage structures, underground facilities, etc. due to its high quality, low price and easy construction. Plastic waterstop makes full use of the elastic deformation characteristics of polyvinyl chloride resin to prevent leakage and seepage in the joints of building structures, and has the characteristics of corrosion resistance and good durability. However, when PVC plastic waterstop encounters multi-directional structures, the quality of the joints is difficult to guarantee. Therefore, the development of joints with excellent comprehensive performance is of great significance to the further application of PVC plastic waterstop.

[0003] Since polyvinyl chloride itself can resist corrosion from acids, alkalis, oils and solvents, and has good electrical insulation, easy installation and low cost, using polyvinyl chloride as the base material for structural parts has a positive effect on the anti-seepage of PVC plastic waterstop.

[0004] However, since PVC plastic waterstop is difficult to reconstruct, higher requirements are placed on the long-term performance of the joints. Plastic parts will inevitably age during long-term use, resulting in a significant decrease in material properties, which in turn greatly reduces the waterstop's anti-seepage effect. Therefore, aging-resistant modification of polyvinyl chloride is the key to its use in the production of waterproof belt joints.

[0005] In the prior art, the aging resistance of polyvinyl chloride is generally improved by adding antioxidants, such as antioxidant 1010, antioxidant 1076, etc. However, these small molecular substances have migration and precipitation phenomena and cannot ensure that polyvinyl chloride maintains long-term antioxidant properties. Summary of the invention

[0006] 1. Technical issues to be solved

[0007] In view of the deficiencies in the prior art, the present invention provides a high-performance PVC material for a joint and a preparation method thereof.

[0008] (II) Technical solution

[0009] A method for preparing a high-performance PVC material for a joint. The PVC material is made of the following raw materials measured in parts by weight:

[0010] 75-85 parts of PVC resin, 15-25 parts of chlorinated polyvinyl chloride, 6-15 parts of nitrile rubber, 2-8 parts of fiber modification substances, 5-10 parts of plasticizers, 1-3 parts of heat stabilizers, 1-2 parts of lubricants, 5-10 parts of color powder, 1-1.5 parts of processing aid ACR;

[0011] The preparation method comprises the following steps:

[0012] The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 800-1000r / min to obtain a premix;

[0013] The second step is to put the premix into a twin-screw extruder, control the temperature of each zone in sequence: zone 1 170-180°C, zone 2 180-190°C, zone 3 190-200°C, zone 4 200-210°C, zone 5 190-200°C, the screw speed is 50-60rpm, and perform melt extrusion process to obtain PVC material.

[0014] As a further embodiment of the present invention, the preparation method of the fiber-modified material is as follows:

[0015] Step 1: dispersing glass fibers in an ethanol aqueous solution, and modifying the glass fibers with an aminosilane coupling agent to obtain organic glass fibers;

[0016] Step 2: Add the organic glass fiber to toluene, perform ultrasonic treatment, add an excess of polyglycidyl ether to the formed dispersion, stir at 70-80°C for 2-4 hours, lower the temperature to 40-50°C, then add the hindered amine chain extender and the phase transfer catalyst, stir and mix evenly, then raise the temperature to 90-100°C, keep stirring and keep warm for 12-18 hours, stop heating, cool and discharge, and obtain the fiber modified material.

[0017] As a further embodiment of the present invention, the aminosilane coupling agent is selected from any one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane or N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0018] As a further embodiment of the present invention, the volume fraction of the ethanol aqueous solution is 60-70%.

[0019] As a further embodiment of the present invention, the polyglycidyl ether is at least one of pentaerythritol tetraglycidyl ether, glycerol triglycidyl ether or ethylene glycol diglycidyl ether.

[0020] As a further embodiment of the present invention, the preparation method of the hindered amine chain extender is as follows:

[0021] N-(4-anilinophenyl)maleimide and mercaptosuccinic acid are added to tetrahydrofuran, stirred and dissolved, and then nitrogen is passed through, heated to 60-65°C, triethylamine is added, and the mixture is kept warm for 12-16 hours under constant stirring. The solvent is removed under reduced pressure, and a hindered amine chain extender is obtained through a purification process.

[0022] As a further embodiment of the present invention, the molar ratio of N-(4-anilinophenyl)maleimide to mercaptosuccinic acid is 1:1.

[0023] As a further embodiment of the present invention, the phase transfer catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate or tetrabutylammonium chloride.

[0024] In the above technical scheme, the surface of the glass fiber is first modified by an aminosilane coupling agent to obtain an amino-modified organic glass fiber. Then, a polyglycidyl ether is used as a connector, one end of which undergoes a ring-opening reaction with the amino group of the organic glass fiber, and the other end undergoes a ring-opening esterification with the substituted carboxyl group in the structure of a hindered amine chain extender under the action of a phase transfer catalyst. During the reaction, the excess polyglycidyl ether in the system will undergo continuous ring-opening esterification with the hindered amine chain extender, thereby grafting a polymer with a macromolecular structure on the surface of the glass fiber to obtain a fiber-modified substance.

[0025] The hindered amine chain extender is prepared by using N-(4-anilinophenyl)maleimide and mercaptosuccinic acid as raw materials through a click reaction.

[0026] As a further embodiment of the present invention, the plasticizer is dioctyl phthalate or dibutyl phthalate; the heat stabilizer is calcium zinc stabilizer or barium zinc stabilizer; the lubricant is polyethylene wax or paraffin; and the color powder is any one of calcium carbonate, carbon black or titanium dioxide.

[0027] A high-performance PVC material for a joint is prepared by adopting the above preparation method.

[0028] (III) Beneficial technical effects

[0029] The fiber-modified material is prepared by using a macromolecular polymer containing a large number of hindered amine antioxidant groups in a grafted structure on the surface of the glass fiber. Firstly, the presence of the macromolecular polymer can be entangled with the polyvinyl chloride molecular chain during the melt extrusion process to form an interwoven molecular chain structure, which is beneficial to improving the compatibility between the glass fiber and the polyvinyl chloride material, and is also beneficial to the glass fiber to efficiently exert its own reinforcement advantage and improve the mechanical strength of the polyvinyl chloride material. The presence of the hindered amine antioxidant group can effectively exert an antioxidant effect and improve the antioxidant performance of the polyvinyl chloride material. In addition, since the hindered amine antioxidant structure is limited to the surface of the glass fiber, it cannot migrate and precipitate, thereby ensuring the long-term antioxidant performance of the polyvinyl chloride material. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. Preferred embodiments of the present invention are given below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0031] Example 1

[0032] A high-performance PVC material for a joint is made of the following raw materials measured in parts by weight:

[0033] 75 parts of PVC resin, 15 parts of chlorinated polyvinyl chloride, 6 parts of nitrile rubber, 2 parts of fiber modification substances, 5 parts of plasticizer dioctyl phthalate, 1 part of calcium zinc stabilizer, 1 part of lubricant polyethylene wax, 5 parts of calcium carbonate, 1 part of processing aid ACR;

[0034] The preparation method of the PVC material comprises the following steps:

[0035] The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 1000 r / min to obtain a premix;

[0036] In the second step, the premix is ​​put into a twin-screw extruder, and the temperature of each zone is controlled as follows: 175°C in zone 1, 185°C in zone 2, 195°C in zone 3, 205°C in zone 4, and 195°C in zone 5. The screw speed is 50rpm, and a melt extrusion process is performed to obtain PVC material.

[0037] Example 2

[0038] A high-performance PVC material for a joint is made of the following raw materials measured in parts by weight:

[0039] 80 parts of PVC resin, 20 parts of chlorinated polyvinyl chloride, 10 parts of nitrile rubber, 7.5 parts of fiber modification substances, 6 parts of plasticizer dibutyl phthalate, 2 parts of barium zinc stabilizer, 1.5 parts of lubricant paraffin, 6 parts of carbon black, 1.2 parts of processing aid ACR;

[0040] The preparation method of the PVC material comprises the following steps:

[0041] The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 1000 r / min to obtain a premix;

[0042] In the second step, the premix is ​​put into a twin-screw extruder, and the temperature of each zone is controlled as follows: 175°C in zone 1, 185°C in zone 2, 195°C in zone 3, 205°C in zone 4, and 195°C in zone 5. The screw speed is 50rpm, and a melt extrusion process is performed to obtain PVC material.

[0043] Example 3

[0044] A high-performance PVC material for a joint is made of the following raw materials measured in parts by weight:

[0045] 85 parts of PVC resin, 25 parts of chlorinated polyvinyl chloride, 15 parts of nitrile rubber, 8 parts of fiber modification substances, 10 parts of plasticizer dibutyl phthalate, 3 parts of barium zinc stabilizer, 2 parts of lubricant paraffin, 10 parts of titanium dioxide, 1.5 parts of processing aid ACR;

[0046] The preparation method of the PVC material comprises the following steps:

[0047] The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 800-1000r / min to obtain a premix;

[0048] In the second step, the premix is ​​put into a twin-screw extruder, and the temperature of each zone is controlled as follows: 175°C in zone 1, 185°C in zone 2, 195°C in zone 3, 205°C in zone 4, and 195°C in zone 5. The screw speed is 50rpm, and a melt extrusion process is performed to obtain PVC material.

[0049] The fiber-modified material in the above examples is prepared by the following method:

[0050] Step 1, 3.5 g of glass fiber is dispersed in a 60% by volume ethanol aqueous solution, and then 1.6 g of 3-aminopropyltriethoxysilane is added to the formed dispersion. After the addition, the mixture is stirred at 70° C. for 6 h, the material is centrifuged, washed and vacuum dried to obtain an organic glass fiber;

[0051] Step 2: Add 2.6 g of organic glass fiber to toluene, perform ultrasonic treatment, add 10.5 g of pentaerythritol tetraglycidyl ether to the formed dispersion, stir at 75 ° C for 3 h, lower the temperature to 40 ° C, then add 8 g of hindered amine chain extender and 0.2 g of tetrabutylammonium bromide, stir and mix evenly, then raise the temperature to 95 ° C, keep stirring for 16 h, stop heating, cool and discharge, and obtain the fiber modified material.

[0052] The preparation method of the hindered amine chain extender is as follows:

[0053] 0.8 g of N-(4-anilinophenyl)maleimide and 0.45 g of mercaptosuccinic acid were added to tetrahydrofuran, stirred thoroughly to dissolve, and then nitrogen was passed through, heated to 65° C., 0.1 g of triethylamine was added, and the mixture was kept warm for 15 h under constant stirring. The solvent was removed under reduced pressure, and a hindered amine chain extender was obtained through purification.

[0054] Comparative Example 1

[0055] A high-performance PVC material for a joint is made of the following raw materials measured in parts by weight:

[0056] 80 parts of PVC resin, 20 parts of chlorinated polyvinyl chloride, 10 parts of nitrile rubber, 7.5 parts of glass fiber, 6 parts of plasticizer dibutyl phthalate, 2 parts of barium zinc stabilizer, 1.5 parts of lubricant paraffin, 6 parts of carbon black, 1.2 parts of processing aid ACR;

[0057] The preparation method of the PVC material comprises the following steps:

[0058] The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 1000 r / min to obtain a premix;

[0059] In the second step, the premix is ​​put into a twin-screw extruder, and the temperature of each zone is controlled as follows: 175°C in zone 1, 185°C in zone 2, 195°C in zone 3, 205°C in zone 4, and 195°C in zone 5. The screw speed is 50rpm, and a melt extrusion process is performed to obtain PVC material.

[0060] Comparative Example 2

[0061] A high-performance PVC material for a joint is made of the following raw materials measured in parts by weight:

[0062] 80 parts of PVC resin, 20 parts of chlorinated polyvinyl chloride, 10 parts of nitrile rubber, 6 parts of plasticizer dibutyl phthalate, 2 parts of barium zinc stabilizer, 1.5 parts of lubricant paraffin, 6 parts of carbon black, 1.2 parts of processing aid ACR;

[0063] The preparation method of the PVC material comprises the following steps:

[0064] The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 1000 r / min to obtain a premix;

[0065] In the second step, the premix is ​​put into a twin-screw extruder, and the temperature of each zone is controlled as follows: 175°C in zone 1, 185°C in zone 2, 195°C in zone 3, 205°C in zone 4, and 195°C in zone 5. The screw speed is 50rpm, and a melt extrusion process is performed to obtain PVC material.

[0066] Test Case

[0067] a. The PVC materials in the embodiments and comparative examples were made into test samples that met the specifications. According to the standard GB / T1040.1-2018, the tensile strength of the samples was tested, and the tensile rate was set to 100 mm / min;

[0068] b. Place the sample in an oven at 120°C for accelerated aging. Take it out after 2 days of aging, observe the sample phenomenon, and evaluate the antioxidant performance. The test results are shown in the following table:

[0069] Tensile strength / MPa Phenomenon Example 1 53.4 No obvious phenomenon Example 2 53.8 No obvious phenomenon Example 3 53.5 No obvious phenomenon Comparative Example 1 48.1 Yellowing and softening Comparative Example 2 41.9 Yellowing, softening and slight cracking

[0070] 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 principle of the present invention, the present invention can also be improved and modified, 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 expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

[0071] Based on the ideal embodiment of the present invention, through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A method for preparing a high-performance PVC material for a joint, characterized in that: The PVC material is made of the following raw materials measured in parts by weight: 75-85 parts of PVC resin, 15-25 parts of chlorinated polyvinyl chloride, 6-15 parts of nitrile rubber, 2-8 parts of fiber modification substances, 5-10 parts of plasticizers, 1-3 parts of heat stabilizers, 1-2 parts of lubricants, 5-10 parts of color powder, 1-1.5 parts of processing aid ACR; The preparation method comprises the following steps: The first step is to add the raw materials weighed by weight into a high-speed mixer, and mechanically stir and mix them at a stirring rate of 800-1000r / min to obtain a premix; The second step is to put the premix into a twin-screw extruder, control the temperature of each zone in sequence: zone 1 170-180°C, zone 2 180-190°C, zone 3 190-200°C, zone 4 200-210°C, zone 5 190-200°C, the screw speed is 50-60rpm, and perform melt extrusion process to obtain PVC material.

2. The method for preparing a high-performance PVC material for a joint according to claim 1, characterized in that: The preparation method of the fiber modified material is as follows: Step 1: dispersing glass fibers in an ethanol aqueous solution, and modifying the glass fibers with an aminosilane coupling agent to obtain organic glass fibers; Step 2: Add the organic glass fiber to toluene, perform ultrasonic treatment, add an excess of polyglycidyl ether to the formed dispersion, stir at 70-80°C for 2-4 hours, lower the temperature to 40-50°C, then add the hindered amine chain extender and the phase transfer catalyst, stir and mix evenly, then raise the temperature to 90-100°C, keep stirring and keep warm for 12-18 hours, stop heating, cool and discharge, and obtain the fiber modified material.

3. The method for preparing a high-performance PVC material for a joint according to claim 2, characterized in that: The aminosilane coupling agent is selected from any one of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane or N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

4. The method for preparing a high-performance PVC material for a joint according to claim 2, characterized in that: The volume fraction of the ethanol aqueous solution is 60-70%.

5. The method for preparing a high-performance PVC material for a joint according to claim 2, characterized in that: The polyglycidyl ether is at least one of pentaerythritol tetraglycidyl ether, propylene glycol triglycidyl ether or ethylene glycol diglycidyl ether.

6. The method for preparing a high-performance PVC material for a joint according to claim 2, characterized in that: The preparation method of the hindered amine chain extender is as follows: N-(4-anilinophenyl)maleimide and mercaptosuccinic acid are added to tetrahydrofuran, stirred and dissolved, and then nitrogen is passed through, heated to 60-65°C, triethylamine is added, and the mixture is kept warm for 12-16 hours under constant stirring. The solvent is removed under reduced pressure, and a hindered amine chain extender is obtained through a purification process.

7. The method for preparing a high-performance PVC material for a joint according to claim 6, characterized in that: The molar ratio of the N-(4-anilinophenyl)maleimide to mercaptosuccinic acid is 1:

1.

8. The method for preparing a high-performance PVC material for a joint according to claim 2, characterized in that: The phase transfer catalyst is any one of tetrabutylammonium bromide, tetrabutylammonium hydrogen sulfate or tetrabutylammonium chloride.

9. The method for preparing a high-performance PVC material for a joint according to claim 1, characterized in that: The plasticizer is dioctyl phthalate or dibutyl phthalate; the heat stabilizer is calcium zinc stabilizer or barium zinc stabilizer; the lubricant is polyethylene wax or paraffin; the color powder is any one of calcium carbonate, carbon black or titanium dioxide.

10. A high-performance PVC material for joints, characterized in that: The method is prepared according to any one of claims 1 to 9.