Preparation method of antibacterial PE water supply pipe

Abstract

The invention relates to the technical field of preparation of water supply pipes, in particular to a preparation method of an antibacterial PE (polyethylene) water supply pipe, which comprises the following steps: adding HDPE (high-density polyethylene), modified polyvinyl chloride, nano silver-loaded SiO2 particles and nano TiO2, and preparing the PE water supply pipe with an antibacterial function under the cooperation of equipment such as a mixer, a stirrer, a granulator and an extruder. The nano silver-loaded SiO2 particles and the nano TiO2 have unique antibacterial and photocatalytic performance, the nano silver-loaded SiO2 particles and the nano TiO2 have unique antibacterial and photocatalytic performance, and the nano silver-loaded SiO2 particles and the nano TiO2 have the antibacterial and photocatalytic functions by means of silver ions released from the surfaces of the nano silver-loaded SiO2 particles, so that the nano silver-loaded SiO2 particles and the nano TiO2 have the antibacterial and photocatalytic functions, and the antibacterial and photocatalytic functions of the nano silver-loaded SiO2 particles and the nano TiO2 are greatly improved. According to the present invention, the nanometer TiO2 can effectively kill and inhibit the growth of bacteria on the inner wall of the pipeline so as to ensure the clean and safe water quality, and the nanometer TiO2 can activate the photocatalytic reaction under the illumination condition so as to decompose the organic matters and the part of the inorganic pollutants in the water, such that the water quality purity is further improved;

Description

Technical Field

[0001] The invention relates to the technical field of water supply pipe preparation, and in particular to a method for preparing an antibacterial PE water supply pipe. Background Art

[0002] PE water pipe, that is, water pipe made of polyethylene (PE) material, is a leader in the water pipe industry and is widely used in many fields due to its excellent performance. PE water pipe is mainly used to transport clean drinking water, irrigation water or industrial water, etc. to ensure the safety and hygiene of water quality. PE material has excellent corrosion resistance and can resist the erosion of various chemicals, thereby extending the service life of the pipe. PE water pipe has good flexibility and can adapt to the uneven settlement of the foundation and reduce pipe damage caused by foundation problems. Moreover, PE water pipe has a low low-temperature brittle point and can maintain good toughness in a cold environment and is not easy to break. Therefore, PE water pipe is used for water supply in many areas.

[0003] PE water pipes have certain deficiencies in antibacterial performance. Due to its material characteristics, after long-term use, the inner wall of the pipe is prone to become a breeding ground for bacteria, especially in sections where the water flow is slow or stagnant, where bacterial reproduction is more significant, which may affect water quality safety and bring potential risks to people's health. In order to solve this problem, nanosilver materials are added during the production process of PE water pipes to enhance their antibacterial properties. Nanosilver, due to its tiny particle size and unique physical and chemical properties, can release silver ions. These silver ions have a strong bactericidal effect and can effectively inhibit and kill bacteria in the water, thereby ensuring the safety of water quality. However, although the addition of nanosilver can significantly improve the antibacterial properties of PE water pipes, it also brings some new problems. The addition of nanosilver materials often leads to a decrease in the toughness of PE materials, which means that the pipes are more likely to be damaged or broken when subjected to external forces. In addition, the addition of nanosilver may also affect the aging resistance of PE materials, resulting in a shortened service life of the pipes. Therefore, while pursuing antibacterial properties, it is necessary to weigh its impact on the mechanical properties and durability of the material. Ensuring that PE water pipes have good antibacterial properties while maintaining sufficient strength and durability is a current problem. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing an antibacterial PE water supply pipe, which can prepare a PE water supply pipe having good antibacterial properties and maintaining sufficient strength and durability.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing an antibacterial PE water supply pipe, the preparation method comprising the following steps:

[0006] Step S1, first prepare nano silver-loaded SiO2 particles, select high-density polyethylene HDPE, modified polyvinyl chloride, nano silver-loaded SiO2 particles, nano TiO2, coupling agent, polyethylene wax, stearic acid, zinc stearate, tetrapropylammonium hydroxide C 12 H 29 NO, antioxidants and lubricants as raw materials;

[0007] Step S2, first add high-density polyethylene HDPE, modified polyvinyl chloride, nano silver-loaded SiO2 particles, nano TiO2 and polyethylene wax into the mixer, then add stearic acid, zinc stearate, tetrapropylammonium hydroxide C 12 H 29 NO were mixed thoroughly to obtain mixture A;

[0008] Step S3, then transferring the mixture A to a low-speed mixer for ventilation cooling, adding an antioxidant, and stirring for 20 to 30 minutes to obtain a mixture B;

[0009] Step S4, adding mixture B to a two-roll mill and fully mixing at a preset temperature, while adding p-phenylenediamine lubricant, and mixing to obtain mixture C;

[0010] Step S5, transferring the mixture C to a granulator for extrusion granulation to obtain a masterbatch, and feeding the masterbatch to a twin-screw extruder for extrusion molding to obtain the antibacterial PE water supply pipe.

[0011] Preferably, in step S1, the coupling agent selected is silane coupling agent KH-570, and the antioxidant and lubricant are oleamide and p-phenylenediamine respectively.

[0012] Preferably, in step S1, the specific steps of preparing nano silver-loaded SiO2 particles are as follows:

[0013] Step S1.1, preparing SiO2 particles by a sol-gel method, adding 2.0-2.4 mL of tetraethyl orthosilicate to a mixed aqueous solution of 0.3-0.4 g of hexadecyltrimethoxyammonium bromide and 8 mL of ammonia water, stirring the mixture at 20-30° C. to obtain a product A, and washing the product A with alcohol and ultrapure water;

[0014] Step S1.2, placing product A in a box-type muffle furnace, setting the temperature at 600-650°C to calcine product A at high temperature to prepare SiO2 particles, further stabilizing the structure of the SiO2 particles, and then using 3-aminopropyltriethoxysilane to perform surface amino modification on the SiO2 particles to obtain product B;

[0015] Step S1.3: Using a reducing agent and a silver source, silver nanoparticles are loaded on the surface of SiO2 particles by a reduction method to prepare nano-silver-loaded SiO2 particles.

[0016] Preferably, in step S1.3, the reducing agent used is NaBH4 and the silver source used is AgNO3.

[0017] Preferably, in step S1, the temperature condition of the mixer is 100-110° C., and the stirring rate is 500-2000 r / min.

[0018] Preferably, the heating temperature of the mixer is increased to 110-120°C.

[0019] Preferably, the ventilation volume in the low-speed mixer is 3 to 12 L / h.

[0020] Preferably, the temperature of the mixture B after cooling is 45-50°C.

[0021] Preferably, the preset temperature of the twin-roll mill is 120-150° C., and the steam pressure of the twin-roll mill is 0.4-0.5M.

[0022] Preferably, in step S5, the die head temperature of the granulator is 180-220°C, the extrusion speed of the twin-screw extruder is 3-5 m / min, the temperature of the feeding zone of the twin-screw extruder is 50-55°C, the temperature of the preheating zone is 50°C higher than the temperature of the feeding zone, the temperature of the melting zone is set to 150°C-170°C, the temperature of the mixing zone is set to 160-170°C, and the temperature of the cooling zone is 100-110°C.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The method proposed in the present invention prepares a PE water supply pipe with antibacterial function by adding high-density polyethylene (HDPE), modified polyvinyl chloride, nano-silver-loaded SiO2 particles and nano-TiO2, and with the cooperation of equipment such as a mixer, a stirrer, a granulator and an extruder. The method not only gives the pipe good strength and toughness, so that it can withstand high water pressure and external environmental stress, and ensure the stability and safety of the water supply system, but also the nano-silver-loaded SiO2 particles and nano-TiO2, these two nano materials each have unique antibacterial and photocatalytic properties. The nano-silver-loaded SiO2 particles can effectively kill and inhibit the growth of bacteria on the inner wall of the pipe by virtue of the silver ions released on their surface, ensuring the cleanliness and safety of the water quality, while the nano-TiO2 can activate the photocatalytic reaction under light conditions, decompose organic matter and some inorganic pollutants in the water, and further improve the purity of the water quality. The synergistic effect of the two nano materials enables the PE water supply pipe to achieve a qualitative leap in antibacterial performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] A method for preparing an antibacterial PE water supply pipe, the preparation method comprising the following steps:

[0028] Step S1, first prepare nano silver-loaded SiO2 particles, select high-density polyethylene HDPE, modified polyvinyl chloride, nano silver-loaded SiO2 particles, nano TiO2, coupling agent, polyethylene wax, stearic acid, zinc stearate, tetrapropylammonium hydroxide C 12 H 29 NO, antioxidants and lubricants are used as raw materials, and the coupling agent selected is silane coupling agent KH-570. The molecular structure of KH-570 contains a methacryloyloxy functional group with an unsaturated double bond structure and three hydrolyzable methoxy functional groups. This dual reactivity allows it to improve the bonding, adhesion and compatibility between inorganic materials and organic polymers through a two-way chemical reaction. H-570 can be used to improve the mechanical and electrical properties of glass fiber reinforced and inorganic filler-containing thermosetting and thermoplastic resins, especially that Some thermosetting resins, peroxide-cured rubbers and thermoplastic resins that are cured by reactive free radical mechanisms. It can also significantly improve the dry and wet mechanical strength and electrical properties of unsaturated polyester composites filled with inorganic fillers. Copolymerization modification: KH-570 can be copolymerized with vinyl acetate, acrylic acid or methacrylic acid monomers to synthesize silane-modified polymers that can be cross-linked and cured at room temperature. Such polymers are widely used in coatings, adhesives and sealants, providing excellent adhesion and durability. The antioxidant and lubricant are oleamide and p-phenylenediamine respectively.

[0029] The specific steps for preparing nano silver-loaded SiO2 particles are as follows:

[0030] Step S1.1, preparing SiO2 particles by a sol-gel method, adding 2.0-2.4 mL of tetraethyl orthosilicate to a mixed aqueous solution of 0.3-0.4 g of hexadecyltrimethoxyammonium bromide and 8 mL of ammonia water, stirring the mixture at 20-30° C. to obtain a product A, and washing the product A with alcohol and ultrapure water;

[0031] Step S1.2, placing product A in a box-type muffle furnace, setting the temperature at 600-650°C to calcine product A at high temperature to prepare SiO2 particles, further stabilizing the structure of the SiO2 particles, and then using 3-aminopropyltriethoxysilane to perform surface amination modification on the SiO2 particles to obtain product B, and the amination modification is to enhance the binding ability of the SiO2 particles with other substances;

[0032] Step S1.3, using a reducing agent and a silver source, loading silver nanoparticles on the surface of SiO2 particles by a reduction method to prepare nano-silver-loaded SiO2 particles (Ag-SiO2), wherein the reducing agent used is NaBH4, and the silver source used is AgNO3. By using an in-situ reduction technique, silver particles can be effectively deposited on the surface of SiO2 particles, thereby preparing a nano-scale Ag-SiO2 composite material. The silver nanoparticles are precisely anchored on the surface of the SiO2 particles, and the prepared SiO2 particles show a uniform size distribution, which promotes uniform mixing between the SiO2 particles and the PE matrix, thereby reducing the probability of forming material interface defects;

[0033] Step S2, first add high-density polyethylene (HDPE), modified polyvinyl chloride, nano-silver-loaded SiO2 particles, nano-TiO2 and polyethylene wax into a mixer, stir at 100-110°C for 20-40 minutes at 500-2000 r / min, then add stearic acid, zinc stearate, tetra-tetrapropylammonium hydroxide C 12 H 29 NO are fully mixed, and the heating temperature is increased to 110-120°C to obtain a mixture A, nano-silver-loaded SiO2 particles;

[0034] Step S3, then transferring the mixture A to a low-speed mixer and performing ventilation cooling at a ventilation rate of 3 to 12 L / h, and adding an antioxidant, which is mainly used to prevent photo-oxidative degradation of the plastic and improve the weather resistance of the plastic, stirring for 20 to 30 minutes, and obtaining a mixture B cooled to 45 to 50° C. in a low-speed stirring barrel;

[0035] Step S4, adding mixture B to a double-roll mill and fully mixing at a preset temperature, while adding p-phenylenediamine lubricant, oleic acid amide lubricant has good internal and external lubrication performance, suitable for the processing of various plastics, adjusting the temperature of the double-roll mill to a preset temperature, the preset temperature is 120-150°C, the steam pressure of the double-roll mill is 0.4-0.5M, rubber and plastic as polymer materials, the molecular chain structure is complex, at an appropriate temperature, the molecular chain can obtain enough heat energy, so as to achieve effective flow and shaping, the double-roll mill is set in a temperature range of 120-150°C, which is conducive to the breaking and reorganization of the polymer material molecular chain, making the material soft and plastic, and having processability, the high temperature makes the rubber mixture gradually soften, heat, and stick to the surface of the roller, through the rotation and mutual extrusion of the roller, the raw materials are fully mixed to ensure that the components are evenly distributed, thereby improving the quality and performance of the product, and obtaining mixture C after mixing;

[0036] Step S5, transferring the mixture C to a granulator for extrusion granulation to obtain a masterbatch, the die head temperature of the granulator is 180-220°C, the masterbatch is fed into a twin-screw extruder, extruded to obtain the antibacterial PE water supply pipe, the extrusion speed is 3-5m / min, and the temperature from the feed zone to the extrusion die body section usually shows a trend of gradually increasing or maintaining stability to ensure that the plastic can gradually soften, melt and mix evenly. Excessive temperature may cause the plastic to decompose, yellow, discolor or generate bubbles, affecting product quality. Different plastic materials have different melting points, thermal stability and processing temperature ranges. Therefore, the temperature of the feed zone of the twin-screw extruder is adjusted to 50-55°C, the temperature of the preheating zone is 50°C higher than that of the feed zone, the temperature of the melting zone is set to 150°C-170°C, and the temperature of the mixing zone is set to 160-170°C, while the temperature of the cooling zone is 100-110°C.

[0037] After adding Ag-SiO2, the tensile strength and elongation at break of the PE composite pipe first increased and then decreased. When the addition amount of Ag-SiO2 particles was 2%, the tensile strength and elongation at break of the PE / Ag-SiO2 composite pipe reached the maximum value, which were 19.8MPa and 190%, respectively. After adding Ag-SiO2, the tensile strength and elongation at break of the PE / Ag-SiO2 composite pipe first increased. The reason is that Ag-SiO2 nanoparticles have a smaller size and a larger specific surface area, which can better Adsorbed and fused to the PE matrix. In addition, after modification by 3-aminopropyl triethoxysilane coupling agent, the organic silicon oxygen groups grafted on the Ag-SiO2 nanoparticles can increase the compatibility between the nanoparticles and PE, making the bonding between the nanoparticles and the resin interface tighter. More importantly, the nano antibacterial particles can enhance the heterogeneous nucleation of PE, making its grains more refined and increasing the crystallinity of PE, thereby improving the tensile strength and elongation at break of the PE / Ag-SiO2 composite pipe. After adding Ag-SiO2, the antibacterial properties of the PE composite pipe are significantly improved. With the continuous increase in the amount of Ag-SiO2 added, the antibacterial rate of the PE pipe continues to increase. When the amount of Ag-SiO2 added is 2%, the antibacterial rates of the PE composite pipe against Escherichia coli and Staphylococcus aureus reach 94.2% and 91.5%, respectively, which meets the requirements of the antibacterial plastic standard.

[0038] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an antibacterial PE water supply pipe, characterized in that: The preparation method thereof comprises the following steps: Step S1, first prepare nano silver-loaded SiO2 particles, select high-density polyethylene HDPE, modified polyvinyl chloride, nano silver-loaded SiO2 particles, nano TiO2, coupling agent, polyethylene wax, stearic acid, zinc stearate, tetrapropylammonium hydroxide C 12 H 29 NO, antioxidants and lubricants as raw materials; Step S2, first add high-density polyethylene HDPE, modified polyvinyl chloride, nano silver-loaded SiO2 particles, nano TiO2 and polyethylene wax into the mixer, then add stearic acid, zinc stearate, tetrapropylammonium hydroxide C 12 H 29 NO were mixed thoroughly to obtain mixture A; Step S3, then transferring the mixture A to a low-speed mixer for ventilation cooling, adding an antioxidant, and stirring for 20 to 30 minutes to obtain a mixture B; Step S4, adding mixture B to a two-roll mill and fully mixing at a preset temperature, while adding p-phenylenediamine lubricant, and mixing to obtain mixture C; Step S5, transferring the mixture C to a granulator for extrusion granulation to obtain a masterbatch, and feeding the masterbatch to a twin-screw extruder for extrusion molding to obtain the antibacterial PE water supply pipe.

2. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In the step S1, the coupling agent selected is silane coupling agent KH-570, and the antioxidant and lubricant are oleamide and p-phenylenediamine respectively.

3. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In step S1, the specific steps of preparing nano silver-loaded SiO2 particles are as follows: Step S1.1, preparing SiO2 particles by a sol-gel method, adding 2.0-2.4 mL of tetraethyl orthosilicate to a mixed aqueous solution of 0.3-0.4 g of hexadecyltrimethoxyammonium bromide and 8 mL of ammonia water, stirring the mixture at 20-30° C. to obtain a product A, and washing the product A with alcohol and ultrapure water; Step S1.2, placing product A in a box-type muffle furnace, setting the temperature at 600-650°C to calcine product A at high temperature to prepare SiO2 particles, further stabilizing the structure of the SiO2 particles, and then using 3-aminopropyltriethoxysilane to perform surface amino modification on the SiO2 particles to obtain product B; Step S1.3: Using a reducing agent and a silver source, silver nanoparticles are loaded on the surface of SiO2 particles by a reduction method to prepare nano-silver-loaded SiO2 particles.

4. The method for preparing an antibacterial PE water supply pipe according to claim 3, characterized in that: In step S1.3, the reducing agent used is NaBH4 and the silver source used is AgNO3.

5. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In the step S1, the temperature of the mixer is 100-110° C., and the stirring rate is 500-2000 r / min.

6. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In step S2, the heating temperature of the mixer is increased to 110-120°C.

7. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In step S3, the ventilation volume in the low-speed mixer is 3 to 12 L / h.

8. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In the step S3, the temperature of the mixture B after cooling is 45-50°C.

9. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In step S4, the preset temperature of the twin-roll mill is 120-150° C., and the steam pressure of the twin-roll mill is 0.4-0.5M.

10. The method for preparing an antibacterial PE water supply pipe according to claim 1, characterized in that: In step S5, the die head temperature of the granulator is 180-220°C, the extrusion speed of the twin-screw extruder is 3-5 m / min, the temperature of the feeding zone of the twin-screw extruder is 50-55°C, the temperature of the preheating zone is 50°C higher than the temperature of the feeding zone, the temperature of the melting zone is set to 150°C-170°C, the temperature of the mixing zone is set to 160-170°C, and the temperature of the cooling zone is 100-110°C.

Images