Plastic pipe with visual stable period and light degradation function and preparation method and application thereof

Abstract

The application discloses a plastic pipeline with visual stable period and light degradation function and a preparation method and application thereof, belongs to the technical field of pipeline materials and application, and solves the technical problems of existing plastic pipeline post-treatment difficulty and environmental pollution. The plastic pipeline has a visual stable period, the stable period length is adjustable, and after the stable period is over, the color change of the photocatalysis system in the pipeline formula indicates the start of the plastic degradation period. The composite pipeline formula comprises a base resin and an additive. When the composite pipeline structure is a multilayer composite pipeline or a single-layer composite pipeline, the pipeline structure comprises a light degradation function additive composite layer or a light degradation function composite area, and the light degradation function additive with the visual stable period. The layer or area pipeline formula comprises the base resin, the additive and the light degradation function additive with the visual stable period, so that the pipeline has the ability to maintain good mechanical properties within the preset stable period and realize rapid degradation after the stable period is over.

Description

Technical Field

[0001] This invention relates to the field of pipe materials and application technology, specifically to plastic pipes with visible stabilization period and photodegradation function, as well as their preparation methods and applications. Background Technology

[0002] In the existing technology, plastic sleeves (such as PVC, PE, and PP pipes) pre-embedded in building construction and plastic drainage or transportation pipes temporarily used in remote areas face significant technical challenges and environmental problems after their use functions are completed. Specifically, (1) after the main building structure is completed, the pre-embedded sleeves are difficult to disassemble manually due to their tight adhesion to the concrete, which is costly and can easily damage the concrete structure. (2) for temporary pipes in remote areas, traditional plastic pipes are difficult to degrade naturally under natural conditions. If they are recycled, a lot of labor, transportation, and recycling costs will be required; if they are directly buried on site, they will pollute the soil and damage the landscape for a long time. These problems all stem from the long-term stability of traditional plastic pipes and their lack of ability to degrade on their own after the end of their service life, which leads to complicated post-treatment and potential environmental hazards.

[0003] Currently, the mainstream plastic pipes on the market are mainly traditional plastic pipes. These pipes do not degrade under natural conditions and easily cause environmental pollution when discarded after their service life. The known new technology involves photodegradable plastic pipes, which degrade under light conditions. However, due to the uncontrollable nature of light conditions in the environment—with random fluctuations in light intensity and duration, and varying degrees of shading in different scenarios—existing photodegradable plastic pipes suffer from unpredictable lifespans and a lack of indication functions, leading to pipe breakage and damage, which can cause safety accidents or economic losses. Therefore, there is an urgent need to develop a photodegradable plastic pipe with a lifespan indication function to solve these problems. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, this invention provides a plastic pipe with visualized stabilization period and photodegradation capabilities, along with its preparation method and applications. This pipe features visualized stabilization period control and performance maintenance, allowing the stabilization period to be adjusted arbitrarily from a few days to several years according to actual application needs, with the stabilization period status indicated visually. After the stabilization period ends, degradation can be achieved under light conditions. The pipe can be adjusted to change from a specific color to white before visual degradation, which is environmentally friendly and fully meets the needs of subsequent disassembly or degradation control, making it widely applicable.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: The plastic pipe provided by the present invention has a visual stabilization period and photodegradation function. It is a composite pipe structure with a visual stabilization period, an adjustable stabilization period duration, and an adjustable photodegradation function. After the stabilization period expires, the color change of the photocatalytic system in the pipe formulation indicates the start of the plastic degradation period. The formulation of the composite pipe includes: matrix resin and additives. When the composite pipe structure is a multi-layer composite pipe structure, its structure includes an outer pipe layer, an inner pipe layer, and a photodegradable functional additive composite layer. The outer and inner layers are composed of a base plastic resin and additives, and have specific light transmittance. The base resin used for the outer and inner pipe layers includes PVC, PE, PP, PET, and PS, any one or more of these. The light transmittance requirements for the inner pipe layer are: PVC pipe outer and inner layers >85%; PE pipe outer and inner layers >75%; PP pipe outer and inner layers >85%; the intermediate photodegradable functional additive composite layer is opaque or has a light transmittance ≤70%. When the composite pipeline structure is a single-layer composite pipeline structure, its structure includes a photodegradable composite zone; The photodegradable functional additive composite layer or photodegradable functional composite zone contains a photodegradable functional additive with a visible stabilization period. The pipeline formulation of this layer or zone includes: matrix resin, additives, and a photodegradable functional additive with a visible stabilization period, enabling it to maintain good mechanical properties of the pipeline within a preset stabilization period and achieve rapid degradation by light after the stabilization period ends. That is, after the stabilization period ends, under light conditions, the photogenerated electron-hole pairs generated by the photocatalyst in the photodegradation functional additive can exert a photocatalytic effect on substances outside the photodegradation additive. With the release of this photocatalytic activity, the color of the pipe changes accordingly. The color change of the photocatalytic system indicates the start of the plastic degradation period.

[0006] Preferably, when the composite pipe structure is a single-layer composite pipe structure, the photodegradation functional composite area accounts for 100%; or the composite pipe structure includes a normal area and a photodegradation functional composite area, and the two are arranged at intervals along the circumference of the pipe.

[0007] Preferably, the functional additive with visible stability period and photodegradation function is specifically composed of a photoresponsive catalyst or modified photoresponsive catalyst, a photocatalyst photogenerated electron-hole depletion agent, and a photogenerated electron-hole depletion agent complex.

[0008] Preferably, the photoresponsive catalyst or modified photoresponsive catalyst specifically comprises photoresponsive NiO, MnO, BiTiO3, TiO2, ZnO, WO3, MoO2, MoS2, Co3O4, C3N4, SiC, CdSe, and NaTiO3, as well as photoresponsive modified NiO, modified MnO, modified BiTiO3, modified TiO2, modified ZnO, modified WO3, modified MoO2, modified MoS2, modified Co3O4, modified C3N4, modified SiC, modified CdSe, and modified NaTiO3, any one or more of these.

[0009] Preferably, the photocatalyst photogenerated electron-hole consumable is a reversible redox couple or a photogenerated electron-hole pair scavenger, and the reversible redox couple is specifically I3. - / I - I2 / I - Cu 2+ / Cu + and Fe 3+ / Fe 2+ The photogenerated electron-hole pair trapping agent is any one or more of the following: disodium ethylenediaminetetraacetate, AgNO3-HCOOH, (NH4)2C2O4, K2S2O8, AgNO3-triethanolamine, and KBrO3-NaHCO3.

[0010] Preferably, the photogenerated electron-hole consumable complex is specifically starch and a metal ion chelating agent, wherein the metal ion chelating agent is ethylenediamine disuccinic acid, 2,4,6-tris(2-pyridyl)triazine, 8-hydroxyquinoline and disodium erythrophenonesodium disulfonic acid hydrate, any one or more thereof.

[0011] Preferably, the mass fraction of the functional additive with visible stability period and photodegradation function added relative to 100 parts of matrix resin is adjusted within the range of 0.005 to 50, so that the plastic pipes have different visible stability periods, different stability period durations and different photodegradation performance.

[0012] Preferably, the matrix resin of the composite pipe specifically includes any one or more of the following components: PVC types include: PVC-SG-3, PVC-SG-5, PVC-SG-7, PVC-SG-8, PVC-BY1600, PVC-BY4000, PVC-LP-400, PVC-S1001, and PVC-P-1000. HDPE types include: HDPE-7600M, HDPE-GH201, HDPE-23050; LDPE types include LD 6524.BA, LP2306, LD 15022.BA; LLDPE types include: DNDB7149, DGDB 2463BK-3, RELENE® LL20DS010; PP class includes: PP-4420, PP-1200, PP-RP2400, PP-H5416, PP-PA14D; PS series includes: PS-550P, PS-GP5000, PS-POLYREX® PG-383, PS-666H, PS-202, PS-634; The PET class includes: PET-CP-318, PET-YS-W01, PET-KP3755, PET-PT X174, PET-FR530, and any one or more of these.

[0013] Preferably, the types of additives include, but are not limited to, processing aids, heat stabilizers, lubricants, fillers, antioxidants, coupling agents, and transparent nucleating agents.

[0014] Preferably, the processing aid is ACR acrylate copolymer; The heat stabilizer is any one of Ca / Zn heat stabilizer, HSt, ZnSt, or BaSt. The lubricant is any one of stearic acid, paraffin wax, or softening oil; The filler is CaCO3; The antioxidant is antioxidant 1010 or antioxidant DLTP; The coupling agent is TTS; The transparent nucleating agent is MDBS sorbitol.

[0015] Preferably, the composite pipe has an outer diameter of 50-110 mm, a thickness of 1.8-3.2 mm, and an inner diameter of 48.2-106.8 mm; The stabilization period of composite pipes under natural light ranges from 5 days to 2 years. After the stabilization period, under light intensity of 0.1-50 mW / cm², the pipes will stabilize. 2 Under ultraviolet light, it can be completely degraded in 7-30 days, or under natural light, it can be completely degraded in 1-24 months.

[0016] Preferably, the mechanical and physical performance indicators of the composite pipeline during the stabilization period include the following: (1) Tensile strength: PVC pipe ≥40 MPa, PE pipe ≥22 MPa, PP pipe ≥30 MPa; (2) Vicat softening temperature: PVC pipe ≥74 °C, PE pipe ≥120 °C, PP pipe ≥131 °C; (3) Ring stiffness: PVC pipe ≥ 6 kN / m 2 PE pipe ≥8 kN / m 2 PP pipe ≥5 kJ / m 2 ; (4) Impact strength: PP pipe ≥ 5 kJ / m 2 .

[0017] The preparation method of the above-mentioned plastic pipe with visible stability and photodegradation function includes the following steps: S1. Ingredients and Mixing: Weigh the base resin, additives and functional auxiliaries with visible stability and photodegradation functions according to a specific ratio, and heat mix them in a high-speed mixer so that the auxiliaries are uniformly adsorbed on the surface of the resin particles. S2. Extrusion molding: The mixture is extruded in a conical twin-screw extruder. The temperature of each section of the die, neck and body, as well as the screw speed, are strictly controlled to ensure the dimensional accuracy and surface quality of the pipe. S3. Sizing and Cooling: The pipe after extrusion molding is sized in a sizing box using the internal pressure internal diameter method and then cooled in a spray cooling water tank. S4. Traction and Cutting: The cooled and shaped pipe is stably pulled by a tracked traction machine and finally cut into a specified length by a cutting machine.

[0018] An application method for plastic pipes with visualized stabilization period and photodegradation functions. Visual indication: The pipe displays a specific color during the stabilization period, and the color changes after the stabilization period ends, visually indicating that it has entered the degradation stage; details are as follows: When the mass fraction of the functional additive with visible stability and photodegradation function added is less than 0.5 parts relative to 100 parts of the matrix resin, the pipe appears white; when the mass fraction of the functional additive added is between 0.5 and 50 parts, the plastic pipe appears one of the following specific colors: brown, coffee, tan, gray, blue, blue-brown, dark blue, green, scarlet, or purplish-red. The mechanism of visualization indication is as follows: During the stabilization period, under sunlight irradiation, the photogenerated electron-hole consumable in the photodegradation aid inhibits the photocatalytic activity of the photocatalyst, preventing the photogenerated electron-hole pairs generated by the photocatalyst from exerting photocatalytic activity on substances outside the aid; after the stabilization period, the photogenerated electron-hole consumable becomes ineffective, and the photogenerated electron-hole pairs generated by the photocatalyst under light conditions can exert photocatalytic activity on substances outside the photodegradation aid. With the release of this photocatalytic activity, the pipe color changes accordingly, that is, the pipe changes from a specific color to white before visual degradation begins, thus achieving visualization indication of the degradation stage.

[0019] Stabilization period controllability: By adjusting the type and ratio of functional additives, the stabilization period of the pipeline can be precisely controlled according to the actual application demand cycle; Photodegradation characteristics after stabilization period: After the stabilization period, the photodegradation activity of the photodegradation functional additive will be activated, triggering the breakage and degradation reaction of the plastic polymer chain, resulting in rapid degradation of the pipe under light conditions; as degradation proceeds, the pipe material gradually decomposes into fragments, thus eliminating the need for complex manual dismantling or recycling transportation.

[0020] This invention provides a plastic pipe with a visible stabilization period and photodegradation function. It has the following beneficial effects: (1) The plastic pipe with visual stabilization period and photodegradation function of the present invention aims to solve the problems of difficult post-processing and environmental pollution of existing plastic pipes. It proposes a functional additive with visual stabilization period and photodegradation function, so that the stabilization period can be controlled and the mechanical properties of the pipe can be maintained during the stabilization period. After the stabilization period, the photodegradation characteristics can be adjusted. After the stabilization period is over, the color change of the photocatalytic system in the pipe formula indicates the start of the plastic degradation period. The pipe can be adjusted to change from a specific color to white to visualize the degradation performance, which significantly reduces the cost of later pipe dismantling and waste transportation.

[0021] (2) The plastic pipe with visualized stabilization period and photodegradation function of the present invention, its preparation method and application, can achieve arbitrary adjustment of the stabilization period according to actual application needs, ranging from 5 days to 2 years. The stabilization period status is visualized, the stabilization period is controlled and the performance is maintained. After the stabilization period, it can be degraded. The pipe can be adjusted to change from a specific color to white to visualize the degradation performance. It is harmless to the environment and meets the actual needs of disassembly or degradation control in the later stage. It has a wide range of applications. It is especially suitable for the use of plastic sleeves for pre-embedded holes in building construction and temporary drainage or transportation pipelines in remote areas. Attached Figure Description

[0022] Figure 1 These are schematic diagrams of the pipe structures in Embodiments 1-3, 10-12, and 19-21 of the present invention; Figure 2 These are schematic diagrams of the pipe structures in embodiments 4-6, 13-15, and 22-24 of the present invention; Figure 3 These are schematic diagrams of the pipe structures in Embodiments 7-9, 16-18, and 25-27 of the present invention.

[0023] In the diagram: 1. Outer layer of the pipe, 2. Inner layer of the pipe, 3. Liquid flow hole, 4. Photodegradable functional additive composite layer, 401. Ordinary area, 402. Photodegradable functional additive composite area. Detailed Implementation

[0024] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0025] The plastic pipe provided by this invention has a visual stabilization period and photodegradation function. It is a composite pipe structure with a visual stabilization period, an adjustable stabilization period duration, and an adjustable photodegradation function. After the pipe stabilizes, the pipe color can be adjusted to indicate the start of the plastic degradation period. After the stabilization period is over, the color change of the photocatalytic system in the pipe formulation indicates the start of the plastic degradation period. The pipe can be adjusted to change from a specific color to white to begin the visual degradation process. The composite pipe formulation includes: matrix resin and additives. When the composite pipe structure is a multi-layer composite pipe structure, its structure includes an outer pipe layer, an inner pipe layer, and a photodegradable functional additive composite layer. The outer and inner layers are composed of a base plastic resin and additives, and have specific light transmittance. The base resin used for the outer and inner pipe layers includes PVC, PE, PP, PET, PS, any one or more of these. The light transmittance requirements for the inner pipe layer are as follows: PVC pipe outer and inner layers >85%; PE pipe outer and inner layers >75%; PP pipe outer and inner layers >85%; the intermediate photodegradable functional additive composite layer is opaque or has a light transmittance ≤70%.

[0026] When the composite pipe structure is a single-layer composite pipe structure, the photodegradation functional composite area accounts for 100%; or the composite pipe structure includes a normal area and a photodegradation functional composite area, and the two are distributed at intervals along the circumference of the pipe.

[0027] The photodegradable functional additive composite layer or photodegradable functional composite zone contains a photodegradable functional additive with a visible stabilization period. The pipeline formulation of this layer or zone includes: a matrix resin, additives, and a photodegradable functional additive with a visible stabilization period, enabling it to maintain good mechanical properties of the pipeline within a preset stabilization period and achieve rapid degradation by light after the stabilization period ends.

[0028] After the stabilization period ends, under illumination, the photogenerated electron-hole pairs produced by the photocatalyst in the photodegradation functional aid can exert a photocatalytic effect on substances outside the photodegradation aid. The release of this photocatalytic activity causes a corresponding change in the pipe color, and the color change of the photocatalytic system indicates the start of the plastic degradation period. The functional aid with visualized stabilization period and photodegradation function is based on materials and the principle of visualized stabilization period, as disclosed in the authorized invention patent ZL201910388040.0 applied for by our research group. This patent discloses a photocatalytic system with photoresponsive switching and self-indication, as well as its preparation method and application. Specifically, the prepared photocatalytic system consists of a photoresponsive catalyst or modified photoresponsive catalyst, a photocatalyst photogenerated electron-hole consumable, and a photogenerated electron-hole consumable complex. Photoresponsive catalysts or modified photoresponsive catalysts specifically include photoresponsive NiO, MnO, BiTiO3, TiO2, ZnO, WO3, MoO2, MoS2, Co3O4, C3N4, SiC, CdSe, and NaTiO3, as well as photoresponsive modified NiO, modified MnO, modified BiTiO3, modified TiO2, modified ZnO, modified WO3, modified MoO2, modified MoS2, modified Co3O4, modified C3N4, modified SiC, modified CdSe, and modified NaTiO3, any one or more of these. Photocatalysts that consume photogenerated electron-hole pairs specifically include reversible redox couples or photogenerated electron-hole pair trapping agents; reversible redox couples specifically include I3... - / I - I2 / I - Cu 2+ / Cu + and Fe 3+ / Fe 2+The photogenerated electron-hole pair trapping agent is any one or more of the following: disodium ethylenediaminetetraacetate, AgNO3-HCOOH, (NH4)2C2O4, K2S2O8, AgNO3-triethanolamine, and KBrO3-NaHCO3. The photogenerated electron-hole consumable complex is specifically starch and a metal ion chelating agent. The metal ion chelating agent is any one or more of the following: ethylenediaminedisuccinic acid, 2,4,6-tris(2-pyridyl)triazine, 8-hydroxyquinoline, and disodium sulfonate hydrate. A photocatalytic system with a photoresponsive switch and self-indicating properties is constructed by utilizing the color change before and after the reaction of the photogenerated electron-hole consumable agent with its complex. In the initial stage of illumination, the photocatalytic system has a certain color and does not exhibit photocatalytic activity. After a certain period of illumination, the color of the photocatalytic system changes, indicating highly efficient photocatalytic activity. This photocatalytic system, added as a filler to plastics, provides controllable, self-indicating degradation. This results in high stability during the plastic's service life and high degradation efficiency during its disposal. Furthermore, the color change of the photocatalytic system indicates to the user the start of the plastic's disposal period.

[0029] The mass fraction of functional additives with visible stability period and photodegradation function can be adjusted from 0.005 to 50 parts relative to 100 parts of matrix resin, thereby giving plastic pipes different visible stability periods, different stability period durations and different photodegradation performance.

[0030] The composite pipe of the present invention has an outer diameter of 50-110 mm, a thickness of 1.8-3.2 mm, and an inner diameter of 48.2-106.8 mm.

[0031] The mechanical and physical properties of composite pipelines during the stabilization period include the following: (1) Tensile strength: PVC pipe ≥40 MPa, PE pipe ≥22 MPa, PP pipe ≥30 MPa; (2) Vicat softening temperature: PVC pipe ≥74 °C, PE pipe ≥120 °C, PP pipe ≥131 °C; (3) Ring stiffness: PVC pipe ≥ 6 kN / m 2 PE pipe ≥8 kN / m 2 PP pipe ≥5 kJ / m 2 ; (4) Impact strength: PP pipe ≥ 5 kJ / m 2 .

[0032] The stabilization period of composite pipes under natural light ranges from 5 days to 2 years. After the stabilization period, under light intensity of 0.1-50 mW / cm², the pipes will stabilize. 2Under ultraviolet light, it can be completely degraded in 7-30 days, or under natural light, it can be completely degraded in 1-24 months.

[0033] The method for preparing a plastic pipe with visible stability and photodegradation function according to the present invention includes the following steps: S1. Ingredients and Mixing: Weigh the base resin, additives and functional auxiliaries with visible stability and photodegradation functions according to a specific ratio, and heat mix them in a high-speed mixer so that the auxiliaries are uniformly adsorbed on the surface of the resin particles. S2. Extrusion molding: The mixture is extruded in a conical twin-screw extruder. The temperature of each section of the die, neck and body, as well as the screw speed, are strictly controlled to ensure the dimensional accuracy and surface quality of the pipe. S3. Sizing and Cooling: The pipe after extrusion molding is sized in a sizing box using the internal pressure internal diameter method and then cooled in a spray cooling water tank. S4. Traction and Cutting: The cooled and shaped pipe is stably pulled by a tracked traction machine and finally cut into a specified length by a cutting machine.

[0034] The present invention relates to a method for applying plastic pipes with visible stabilization period and photodegradation function, specifically including the following aspects: Visual indication: The pipeline displays a specific color during the stabilization period, and the color changes after the stabilization period ends, visually indicating that it has entered the degradation stage; Stabilization period controllability: By adjusting the type and ratio of functional additives, the stabilization period of the pipeline can be precisely controlled according to the actual application demand cycle; Photodegradation characteristics after stabilization period: After the stabilization period, the photodegradation activity of the photodegradation functional additive will be activated, triggering the breakage and degradation reaction of the plastic polymer chain, resulting in rapid degradation of the pipe under light conditions; as degradation proceeds, the pipe material gradually decomposes into fragments and into environmentally harmless substances, thus eliminating the need for complex manual dismantling or recycling transportation.

[0035] The following examples will be used for a detailed discussion.

[0036] (a) PVC pipes Example 1 The PVC plastic pipe of the present invention, which features a visible stability period and photodegradation function, is prepared by extrusion process. It involves directly mixing plastic resin, various additives, and functional auxiliaries with visible stability and photodegradation functions. The specific pipe structure is as follows: Figure 1 As shown, the composite pipe of the present invention includes a photodegradable functional additive composite layer 4 and a liquid flow hole 3 in the middle of the pipe. The photodegradable functional additive composite layer 4 includes a composite layer of PVC resin, additives, and functional additives with visible stability and photodegradation function.

[0037] The specific implementation steps are explained below: S1. Ingredients and Mixing: Accurately weigh the following materials according to the mass ratio of PVC plastic resin (PVC-SG-5), ACR processing aid acrylate copolymer, Ca / Zn heat stabilizer, lubricant including external lubricant stearic acid and internal lubricant paraffin wax, and functional additives with visible stability and photodegradation functions in the range of 100:5:1:0.5:10. The specific components of the functional additives with visible stability and photodegradation functions are TiO2 and I3. - / I - Starch and 2,4,6-tris(2-pyridyl)triazine.

[0038] In a high-speed mixer with a temperature of 110-115 ℃ and a volume of 500-1000 L, PVC resin, Ca / Zn heat stabilizer, ACR processing aid, lubricant, and functional additives with visible stability period and photodegradation function are added in sequence. The mixture is then hot-mixed at 900 rpm for 8-12 min to ensure that the various additives are uniformly adsorbed on the surface of the PVC resin particles.

[0039] S2. Extrusion Molding: After the temperature drops to 50 ℃, continue cold mixing at 100 rpm for 6-10 min. Then, use a conical twin-screw extruder for extrusion molding, strictly controlling the die (feed inlet) temperature to 180 ℃, the neck temperature to 170 ℃, and the body temperatures to 170, 140, and 110 ℃ for the front, middle, and rear sections respectively. The screw cooling temperature should be maintained at 80–100 ℃, and the screw speed should be 20–40 rpm.

[0040] S3. Sizing and Cooling: Using the internal pressure inner diameter method, after extrusion molding, the inner and outer diameters are accurately positioned in a sizing box with an air pressure of 0.02–0.05 MPa and a water temperature of 15–20 ℃, ensuring the roundness and smoothness of the pipe. Cooling is then performed in a spray cooling water bath at 15–25 ℃.

[0041] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0042] The aforementioned plastic pipe, featuring visible stabilization and photodegradation capabilities, has an outer diameter of 110 mm, a thickness of 3.2 mm, and an inner diameter of 106.8 mm. Its tensile strength is ≥40 MPa, Vicat softening temperature is ≥74 ℃, and ring stiffness is ≥6 kN / m. 2 Its density is 1350-1550 kg / m³ 3 Both the inner and outer walls are smooth.

[0043] This pipeline is suitable for temporary projects and field facility construction in remote areas. It allows for arbitrary adjustment during the stabilization period, and depending on the actual application requirements, the pipeline appears blue / blue-brown during the stabilization period and turns white after the stabilization period ends. At this point, under sunlight or light intensity of 20 mW / cm², it will be suitable for use in such environments. 2 Under simulated light source conditions, plastic pipes can degrade rapidly, and can be completely degraded in one month.

[0044] Example 2 Same as Example 1, except that in the functional additives with visible stability and photodegradation function, TiO2 is replaced with modified TiO2, while all other conditions and parameters are the same.

[0045] Example 3 Same as Example 1, except that the component of the functional additive with visible stability and photodegradation function is changed from TiO2 to NiO, while all other conditions and parameters are the same.

[0046] Example 4 The PVC plastic pipe of the present invention, featuring a visible stabilization period and photodegradation function, is manufactured using an extrusion process. It comprises an outer layer, an inner layer, and a composite layer of photodegradation functional additives. Liquid flow holes are provided inside the pipe body. Figure 2 As shown, the multi-layer composite pipe of the present invention includes an outer pipe layer 1, an inner pipe layer 2, a liquid flow hole 3 in the middle, and a middle photodegradable functional additive composite layer 4. The middle photodegradable functional additive composite layer 4 comprises a composite layer of PVC resin, additives, and functional additives with visible stability and photodegradation function, and is opaque.

[0047] The specific implementation steps are explained below.

[0048] S1. Ingredients and Mixing: According to the mass ratio of PVC resin PVC-SG-5, transparent MDBS modifier (MDBS sorbitol), ACR processing aid acrylate polymer, Ca / Zn heat stabilizer, and lubricant (external lubricant stearic acid and internal lubricant paraffin wax) of 100:8:5:1:0.5, accurately weigh 2 parts of each of the above materials and use them to prepare the outer layer 1 and inner layer 2 of the pipe respectively.

[0049] Weigh out 1 part of PVC resin and 1 part of the functional additive with visible stability and photodegradation function, according to a mass ratio of 100:10, and use them for the photodegradation functional additive composite layer. The specific components of the functional additive with visible stability and photodegradation function are MnO and Cu. 2+ / Cu + Starch and 2,4,6-tris(2-pyridyl)triazine. The above raw materials were dried at 60 °C for 2 h.

[0050] In a high-speed mixer with a temperature of 110-115 ℃ and a volume of 500-1000 L, PVC resin, Ca / Zn heat stabilizer, transparent MBS modifier, ACR processing aid, and lubricant are added sequentially and hot-mixed at 900 rpm for 8-12 min to ensure that the various additives are uniformly adsorbed on the surface of the plastic granules, thus preparing the outer layer 1 and inner layer 2 of the pipe. Using the same preparation conditions as for outer layer 1 and inner layer 2, the photodegradable functional additive composite layer material is added to the high-speed mixer to obtain the photodegradable functional additive composite layer material.

[0051] S2. Extrusion Molding: After the temperature drops to 50 ℃, continue cold mixing at 100 rpm for 6-10 min. Subsequently, extrusion plasticization is performed in a conical twin-screw extruder using a three-layer co-extrusion die. The extrusion thicknesses of the three dies are set to 0.4 mm, 1.0 mm, and 0.4 mm, respectively. The outer layer material, PVC resin and photodegradable functional additive composite layer material, and inner layer material are added to the three die inlets, respectively. The die (inlet) temperature is strictly controlled at 180 ℃, the neck temperature at 170 ℃, and the body temperature at 170, 140, and 110 ℃ for the front, middle, and rear sections, respectively. The screw cooling temperature is maintained at 80~100 ℃, and the screw speed is 20–40 rpm.

[0052] S3. Sizing and Cooling: Using the internal pressure inner diameter method, after extrusion molding, the inner and outer diameters are accurately positioned in a sizing box with an air pressure of 0.02–0.05 MPa and a water temperature of 15–20 ℃, ensuring the roundness and smoothness of the pipe. Cooling is then performed in a spray cooling water bath at 15–25 ℃.

[0053] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0054] The aforementioned plastic pipe, featuring a visible stabilization period and photodegradation capabilities, has an outer diameter of 50 mm, an inner diameter of 48.2 mm, and a thickness of 1.8 mm. Both the inner and outer layers are 0.4 mm thick, and the photodegradation additive layer is 1.0 mm thick. The inner and outer layers are composite layers of plastic and various additives, with a light transmittance >85%.

[0055] The pipe has a tensile strength ≥40 MPa, a Vicat softening temperature ≥74 ℃, and a ring stiffness ≥6 kN / m. 2 Its density is 1350-1550 kg / m³ 3 The inner and outer walls are smooth. This pipe is used for pre-embedded pipes in building construction. Its stabilization period is adjustable from 5 days to 2 years to meet construction needs. During the stabilization period, it exhibits stable properties and good performance. The photodegradation additive layer remains purplish-red and does not degrade or fade under sunlight. After the stabilization period, the color changes to white, remaining stable under sunlight or light intensity of 20 mW / cm². 2 Under simulated light source conditions, the photodegradable functional additive layer can be rapidly degraded first, and then the photodegradable functional additive continues to degrade the inner layer 1 and the outer layer 2 of the pipe. The plastic pipe can be degraded in at most one month.

[0056] Example 5 Same as Example 4, except that the component of the functional additive with visible stability and photodegradation function is modified with MoS2 instead of MnO, while all other conditions and parameters are the same.

[0057] Example 6 Same as Example 4, except that the component of the functional additive with visible stability and photodegradation function is changed from MnO to MoS2, while all other conditions and parameters are the same.

[0058] Example 7 The PVC plastic pipe of the present invention, featuring a visible stabilization period and photodegradation function, is manufactured using an extrusion process. It includes a general zone and a composite zone containing photodegradation functional additives. Liquid flow holes are provided inside the pipe body. Figure 3 As shown, the photodegradable functional additive composite layer 4 of the present invention is a structure in which a general region 401 and a photodegradable functional additive composite region 402 are alternately distributed. The general region of the plastic pipe is composed of plastic masterbatch and various plastic additives. The photodegradable functional additive composite region is composed of plastic, a functional additive with visible stability and photodegradation function, and various plastic additives.

[0059] The specific implementation steps are explained below.

[0060] S1. Ingredients and Mixing: In the general area, weigh out one part of the above materials according to the mass ratio of PVC resin (PVC-SG-5), ACR processing aid acrylate copolymer, Ca / Zn heat stabilizer, and lubricant (external lubricant stearic acid and internal lubricant paraffin wax) of 100:5:1:0.5.

[0061] In the photodegradable functional additive composite area, one part of the above materials is weighed according to the mass ratio of PVC plastic resin, ACR processing aid (acrylate polymer), Ca / Zn heat stabilizer, and lubricant (external lubricant stearic acid and internal lubricant paraffin wax) of 100:5:1:0.5. Then, one part of the functional additive with visible stability and photodegradability is weighed according to the mass ratio of PVC resin to the functional additive with visible stability and photodegradability of 100:10. The specific components of the functional additive with visible stability and photodegradability are modified ZnO, disodium ethylenediaminetetraacetate, starch, and ethylenediaminedisuccinic acid.

[0062] Following the method described in Example 1, the materials of the ordinary zone 401 and the photodegradable functional additive composite zone 402 are respectively placed in a high-speed mixer with a temperature of 110-115 ℃ and a volume of 500-1000 L, and PVC resin, Ca / Zn heat stabilizer, ACR processing aid, and lubricant are added in sequence. The mixture is hot-mixed at 900 rpm for 8-12 min to ensure that the various additives are uniformly adsorbed on the surface of the plastic particles, thereby preparing the mixture of the ordinary zone 401 and the photodegradable functional additive composite zone 402.

[0063] S2. Extrusion Molding: After the temperature drops to 50℃, continue cold mixing at 100 rpm for 6-10 minutes. Then, use a conical twin-screw extruder for extrusion plasticization, employing a zoned co-extrusion die. Add the mixture of ordinary zone 401 and photodegradable functional additive composite zone 402 to the two dies respectively. Strictly control the die (feed inlet) temperature to 180℃, the die neck temperature to 170℃, and the machine body temperatures to 170℃, 140℃, and 110℃ for the front, middle, and rear sections respectively. Maintain the screw cooling temperature at 80~100℃ and the screw speed at 20–40 rpm.

[0064] S3. Sizing and Cooling: Using the internal pressure inner diameter method, after extrusion molding, the inner and outer diameters are accurately positioned in a sizing box with an air pressure of 0.02–0.05 MPa and a water temperature of 15–20 ℃, ensuring the roundness and smoothness of the pipe. Cooling is then performed in a spray cooling water bath at 15–25 ℃.

[0065] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0066] The aforementioned plastic pipe, which features a visible stabilization period and photodegradation capabilities, has an outer diameter of 90 mm, a thickness of 2.8 mm, an inner diameter of 87.2 mm, a tensile strength ≥40 MPa, a Vicat softening temperature ≥74 ℃, and a ring stiffness ≥6 kN / m. 2 Its density is approximately 1350-1550 kg / m³3 The inner and outer walls are smooth.

[0067] This pipeline is used for construction facilities and drainage in remote areas. The pipeline itself is opaque. During the stable period of visibility and properties, the photodegradable functional additive composite area appears brownish-brown, and the overall performance of the pipeline is good. After the stable period, the photodegradable functional additive composite area turns white. Under sunlight or light intensity of 20 mW / cm², the pipeline exhibits good performance. 2 Under simulated light source conditions, the photodegradation functional additive composite zone can be broken down and degraded in at most one month.

[0068] Example 8 Same as Example 7, except that the component of the functional additive with visible stability period and photodegradation function is modified ZnO instead of modified Co3O4, while all other conditions and parameters are the same.

[0069] Example 9 Same as Example 7, except that the component of the functional additive with visible stability period and photodegradation function is modified ZnO instead of modified C3N4, while all other conditions and parameters are the same.

[0070] (II) PE Pipes Example 10 The PE plastic pipe of the present invention, which features a visible stability period and photodegradation function, is prepared by extrusion process. It involves directly mixing plastic resin, various additives, and functional auxiliaries with visible stability period and photodegradation function. The specific structure is as follows: Figure 1 As shown, the multilayer composite pipe of the present invention includes a photodegradable functional additive composite layer 4 and a liquid flow hole 3 in the middle passage. The photodegradable functional additive composite layer 4 is a composite layer of PE resin, additives, and functional additives with visible stability and photodegradation function, and is opaque.

[0071] The specific implementation steps are explained below.

[0072] S1. Ingredients and Mixing: Accurately weigh the following materials according to a mass ratio of 100:100:2:1:0.5: PE resin (LDPE), CaCO3 filler, stabilizers HSt and ZnSt, lubricant (softening oil), and coupling agent (TTS). Weigh one part of the functional additive with visible stability and photodegradation functions according to a mass ratio of 100:10: PE resin to the functional additive with visible stability and photodegradation functions. The specific components of the functional additive with visible stability and photodegradation functions are BiTiO3 and I2 / I... -Starch and ethylenediamine disuccinic acid. In a high-speed mixer with a temperature of 60-90 ℃ and a volume of 500-1000 L, PE resin, stabilizer, CaCO3 filler, lubricant, coupling agent, and functional additives with visible stability period and photodegradation function are added in sequence. The mixture is hot-mixed at 600 rpm for 5-10 min to ensure that the various additives are uniformly adsorbed on the surface of the PE resin particles.

[0073] S2. Extrusion Molding: After thorough mixing, extrusion molding is carried out using a twin-screw extruder. The die (feed inlet) temperature is strictly controlled at 140 ℃, the neck temperature is 140 ℃, and the body temperature is 140, 100, and 90 ℃ for the front, middle, and rear sections, respectively. The screw cooling temperature is maintained at 70~80 ℃, and the screw speed is 10–50 rpm.

[0074] S3. Sizing and Cooling: Using the vacuum inner diameter method, after extrusion molding, the material is sizing in a sizing chamber with an air pressure of 0.02–0.04 MPa and a water temperature of 30–50 ℃. After evacuation, the vacuum degree is 4 × 10⁻⁶. 4 pa, accurately locate the inner and outer diameters, and ensure the roundness and smoothness of the pipe. Cool in a spray cooling water bath at 15–25 ℃.

[0075] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0076] The present invention relates to a PE plastic pipe with visible stabilization period and photodegradation function. The pipe has an outer diameter of 90 mm, a thickness of 2.8 mm, and an inner diameter of 87.2 mm. Its tensile strength is ≥22 MPa, Vicat softening temperature is ≥120 ℃, and ring stiffness is ≥8 kN / m. 2 Its density is 940-960 kg / m³ 3 Both the inner and outer walls are smooth.

[0077] This pipeline is suitable for temporary projects and field facility construction in remote areas. It allows for arbitrary adjustment during the stabilization period, which can range from 5 days to 2 years depending on the specific application requirements. The pipeline appears brown during the stabilization period and turns white afterward, at which point it will be visible under sunlight or at a light intensity of 30 mW / cm². 2 Under simulated light source conditions, the pipe can degrade rapidly, and can be completely degraded in 1 month.

[0078] Example 11 Same as Example 10, except that the component of the functional additive with visible stability and photodegradation function is replaced with WO3 instead of BiTiO3, while all other conditions and parameters are the same.

[0079] Example 12 Same as Example 10, except that the component of the functional additive with visible stability period and photodegradation function is replaced with Co3O4 instead of BiTiO3, while all other conditions and parameters are the same.

[0080] Example 13 The PE plastic pipe of the present invention, featuring a visible stabilization period and photodegradation function, is manufactured using an extrusion process. It comprises an outer layer, an inner layer, and a composite layer of photodegradation functional additives. Liquid flow holes are provided inside the pipe body. Figure 2 As shown, the multi-layer composite pipe of the present invention includes an outer pipe layer 1, an inner pipe layer 2, a liquid flow hole 3 in the middle, and a photodegradable functional additive composite layer 4 in the middle. The outer pipe layer 1 and the inner pipe layer 2 have a light transmittance >75%. The photodegradable functional additive composite layer 4 is a composite layer of PE resin, additives, and functional additives with visual stability and photodegradation function, and is opaque.

[0081] The specific implementation steps are explained below.

[0082] S1. Ingredients and Mixing: Accurately weigh two parts each of the following materials according to a mass ratio of 100:100:2:1:0.5:5: PE resin LDPE, CaCO3 filler, HST stabilizer, softening oil lubricant, TTS coupling agent, and EVA (ethylene-vinyl acetate copolymer). These two parts will be used for the outer and inner layers of the pipe, respectively. Weigh one part of PE resin and one part of the functional additive with visible stability and photodegradability, according to a mass ratio of 100:10. The specific components of the functional additive with visible stability and photodegradability are SiC, AgNO3-HCOOH, starch, and disodium thiocyanate disulfonate hydrate. In a high-speed mixer with a temperature of 60-90 ℃ and a volume of 500-1000 L, PE resin, heat stabilizer, CaCO3 filler, lubricant, coupling agent, and EVA are added sequentially and hot-mixed at 600 rpm for 5-10 min to ensure that the various additives are uniformly adsorbed on the surface of the PE resin particles, thus preparing the outer layer and inner layer materials. Under the same conditions as the outer and inner layer materials, the photodegradable functional additive composite layer material is added to the high-speed mixer to obtain the photodegradable functional additive composite layer material.

[0083] S2. Extrusion Molding: After thorough mixing, extrusion molding is performed using a twin-screw extruder. A three-layer co-extrusion die is used for extrusion plasticization, with the extrusion thicknesses of the three dies set to 0.4 mm, 1.0 mm, and 0.4 mm, respectively. The outer layer material, PE resin, and functional additive composite material with visible stability and photodegradation capabilities are added to the three die inlets, respectively. The die (inlet) temperature and the die neck temperature are strictly controlled at 140 ℃. The machine body temperatures are set at 140, 100, and 90 ℃ for the front, middle, and rear sections, respectively. The screw cooling temperature is maintained at 70–80 ℃, and the screw speed is 10–50 rpm.

[0084] S3. Sizing and Cooling: Using the vacuum inner diameter method, after extrusion molding, the material is sizing in a sizing chamber with an air pressure of 0.02–0.04 MPa and a water temperature of 30–50 ℃. After evacuation, the vacuum degree is 4 × 10⁻⁶. 4 pa, accurately locate the inner and outer diameters, and ensure the roundness and smoothness of the pipe. Cool in a spray cooling water bath at 15–25 ℃.

[0085] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0086] The plastic pipe prepared by this invention has a visible stabilization period and photodegradation function. The pipe has an outer diameter of 50 mm, an inner diameter of 48.2 mm, and a thickness of 1.8 mm, with both the inner and outer layers being 0.4 mm thick, and the photodegradation functional additive layer being 1.0 mm thick. The pipe has a tensile strength ≥22 MPa, a Vicat softening temperature ≥120 ℃, and a ring stiffness ≥8 kN / m. 2 Its density is 940-960 kg / m³ 3 The inner and outer walls are smooth.

[0087] This pipe is used for pre-embedded pipes in building construction. Its stabilization period is adjustable from 5 days to 2 years to meet construction needs. During the stabilization period, it exhibits stable properties and good performance. The photodegradation additive layer is initially brown, but does not degrade or fade under strong light. After the stabilization period, the color changes, becoming white overall. It also exhibits good performance under sunlight or light intensity of 30 mW / cm². 2 Under simulated light source conditions, plastic pipes can be degraded in one month.

[0088] Example 14 Same as Example 13, except that the component of the functional additive with visible stability and photodegradation function is SiC replaced with modified CdSe, while all other conditions and parameters are the same.

[0089] Example 15 Same as Example 13, except that the component of the functional additive with visible stability and photodegradation function is SiC replaced with modified NiO, while all other conditions and parameters are the same.

[0090] Example 16 The PE plastic pipe of the present invention, featuring a visible stabilization period and photodegradation function, is manufactured using an extrusion process. It includes a general zone and a composite zone containing photodegradation functional additives. Liquid flow holes are provided inside the pipe body. Figure 3 As shown, the middle of the pipe is a liquid flow hole 3, and the photodegradable functional additive composite layer 4 is a structure in which a general zone 401 and a photodegradable functional additive composite zone 402 are alternately distributed. The general zone of the composite pipe is composed of PE resin masterbatch and various additives. The photodegradable functional additive composite zone is composed of PE resin, functional additives with visible stability and photodegradation function, and various additives.

[0091] The specific implementation steps are explained below.

[0092] S1. Ingredients and Mixing: In the general zone 401, according to the mass ratio of PE resin LDPE, CaCO3 filler, stabilizer ZnSt, lubricant softening oil, and coupling agent TTS, accurately weigh one part of the above materials.

[0093] In the photodegradable functional additive composite zone 402, the mass ratio of PE resin (LDPE), CaCO3 filler, stabilizer (ZnSt), lubricant (softening oil), and coupling agent (TTS) is 100:100:2:1:0.5. One part of these materials is accurately weighed. Then, one part of the functional additive with visible stability and photodegradability is weighed, following a mass ratio of PE resin to the functional additive with visible stability and photodegradability of 100:10. The specific components of the functional additive with visible stability and photodegradability are MoO2, KBrO3-NaHCO3, starch, and disodium sulfonate hydrate. In a high-speed mixer with a temperature of 60-90 ℃ and a volume of 500-1000 L, the PE resin, stabilizer, CaCO3 filler, lubricant, coupling agent, and functional additive with visible stability and photodegradability are added sequentially. In another high-speed mixer, PE resin, heat stabilizer, CaCO3 filler, lubricant, and coupling agent are added sequentially and hot-mixed at 600 rpm for 5-10 minutes to ensure that the various additives are uniformly adsorbed on the surface of the PE resin particles, resulting in a mixture of ordinary zone 401 and photodegradable functional additive composite zone 402.

[0094] S2. Extrusion Molding: After thorough mixing, extrusion molding is performed using a twin-screw extruder. A zoned co-extrusion die is used, with the mixture of ordinary zone 401 and photodegradable functional additive composite zone 402 added to the two dies respectively. The die (feed inlet) temperature is strictly controlled at 140 ℃, the die neck temperature at 140 ℃, and the machine body temperatures at 140, 100, and 90 ℃ for the front, middle, and rear sections respectively. The screw cooling temperature is maintained at 70–80 ℃, and the screw speed is 10–50 rpm.

[0095] S3. Sizing and Cooling: Using the vacuum inner diameter method, after extrusion molding, the material is sizing in a sizing chamber with an air pressure of 0.02–0.04 MPa and a water temperature of 30–50 ℃. After evacuation, the vacuum degree is 4 × 10⁻⁶. 4 pa, accurately locate the inner and outer diameters, and ensure the roundness and smoothness of the pipe. Cool in a spray cooling water bath at 15–25 ℃.

[0096] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0097] The present invention relates to a PE plastic pipe with a visible stabilization period and photodegradation function. The pipe has an outer diameter of 75 mm, a thickness of 2.3 mm, and an inner diameter of 72.7 mm. The stabilization period can be arbitrarily adjusted. Its tensile strength is ≥22 MPa, Vicat softening temperature is ≥120 ℃, and ring stiffness is ≥8 kN / m. 2 Its density is 940-960 kg / m³ 3 The inner and outer walls are smooth.

[0098] This pipe is used for construction and drainage in remote areas, and the pipe body is opaque. By adjusting the mass ratio of functional additives with visual stability and photodegradation capabilities to the matrix resin within a range of 0.005 to 50, the plastic pipe can have different visual stability periods, adjustable from 5 days to 2 years. During the stable period, the photodegradation functional additive composite area 402 appears gray, and the overall performance of the pipe is good. After the stability period ends, the photodegradation functional additive composite area 402 turns white under sunlight or light intensity of 30 mW / cm². 2 Under simulated light source conditions, the photodegradation functional additive composite zone can be broken down and degraded in at most one month.

[0099] Example 17 Same as Example 16, except that the component of the functional additive with visible stability and photodegradation function is replaced with ZnO instead of MoO2, while all other conditions and parameters are the same.

[0100] Example 18 Same as Example 16, except that the component of the functional additive with visible stability and photodegradation function is modified with MnO instead of MoO2, while all other conditions and parameters are the same.

[0101] (III) PP Pipes Example 19 The PP plastic pipe of the present invention, which features a visible stability period and photodegradation function, is prepared by extrusion process. It involves directly mixing plastic resin, various additives, and functional auxiliaries with visible stability period and photodegradation function. The specific structure is as follows: Figure 1 As shown, the composite pipe of the present invention includes a photodegradable functional additive composite layer 4 and a liquid flow hole 3 in the middle of the pipe. The photodegradable functional additive composite layer 4 is a composite layer of PP resin, additives, and functional additives with visible stability and photodegradation function, and is opaque.

[0102] The specific implementation steps are explained below.

[0103] S1. Ingredients and Mixing: Accurately weigh the PP resin PP1200, HDPE, antioxidant 1010, and stabilizer BaSt in a mass ratio of 100:20:0.6:0.1. Weigh one part of the functional additive with visible stability and photodegradation functions, according to a mass ratio of PP resin, HDPE, and the functional additive with visible stability and photodegradation functions of 100:10. The specific components of the functional additive with visible stability and photodegradation functions are C3N4 and Fe. 3+ / Fe 2+ Starch and 8-hydroxyquinoline. The mixture was dried at 80 °C for 2 h.

[0104] S2. Extrusion Molding: After thorough mixing, extrusion molding is carried out using a single-screw extruder. The die (feed inlet) temperature is strictly controlled at 190 ℃, the neck temperature at 200 ℃, and the body temperature at 190, 170, and 50 ℃ for the front, middle, and rear sections, respectively. The screw cooling temperature is maintained at 70–80 ℃, and the screw speed is 10–50 rpm.

[0105] S3. Sizing and Cooling: Using the vacuum inner diameter method, after extrusion molding, the material is sizing in a sizing chamber with an air pressure of 0.02–0.04 MPa and a water temperature of 30–50 ℃. After evacuation, the vacuum degree is 4 × 10⁻⁶. 4 pa, accurately locate the inner and outer diameters, and ensure the roundness and smoothness of the pipe. Cool in a spray cooling water bath at 15–25 ℃.

[0106] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0107] The present invention relates to a plastic pipe with a visible stabilization period and photodegradation function. The pipe has an outer diameter of 75 mm, a thickness of 2.3 mm, and an inner diameter of 72.7 mm. Its tensile strength is ≥30 MPa, Vicat softening temperature is ≥131 ℃, and impact strength is ≥5 kJ / m. 2 Its density is 890-910 kg / m³ 3 Both the inner and outer walls are smooth.

[0108] This pipeline is suitable for temporary projects and field facility construction in remote areas. It allows for arbitrary adjustment during the stabilization period, which can range from 5 days to 2 years depending on the specific application requirements. The pipeline appears dark blue during the stabilization period and turns white after the stabilization period ends, at which point it will be visible under sunlight or at a light intensity of 50 mW / cm². 2 Under simulated light source conditions, the pipe can degrade rapidly, and can be completely degraded in one month.

[0109] Example 20 Same as Example 19, except that the component of the functional additive with visible stability and photodegradation function is C3N4 replaced with CdSe, while all other conditions and parameters are the same.

[0110] Example 21 Same as Example 19, except that the component of the functional additive with visible stability and photodegradation function is modified with SiC instead of C3N4, while all other conditions and parameters are the same.

[0111] Example 22 The PP plastic pipe of the present invention, which features a visible stabilization period and photodegradation function, is prepared using an extrusion process, such as... Figure 2 As shown, the multi-layer composite pipe includes an outer pipe layer 1, an inner pipe layer 2, a liquid flow channel 3, and a middle photodegradable functional additive composite layer 4. The middle photodegradable functional additive composite layer 4 is an opaque composite layer comprising PP resin, additives, and functional additives with visual stability and photodegradation functions. The light transmittance of the outer pipe layer 1 and the inner pipe layer 2 is >85%.

[0112] The specific implementation steps are explained below.

[0113] S1. Ingredients and Mixing: Accurately weigh two parts each of PP resin PP1200, HDPE, antioxidant 1010, stabilizer BaSt, and sorbitol-based transparent nucleating agent MDBS at a mass ratio of 100:20:0.6:0.1:0.1, and use one part for the outer layer and one part for the inner layer of the pipe. Weigh one part each of PP resin and HDPE plastic and functional additives with visible stability and photodegradability at a mass ratio of 100:10. The specific components of the functional additives with visible stability and photodegradability are modified NaTiO3, K2S2O8, starch, and 8-hydroxyquinoline. Dry each layer mixture at 80 °C for 2 h.

[0114] S2. Extrusion Molding: After thorough mixing, extrusion molding is performed using a single-screw extruder. A three-layer co-extrusion die is used for extrusion plasticization, with the extrusion thicknesses of the three dies set to 0.4 mm, 1.0 mm, and 0.4 mm, respectively. The outer layer material, PP resin, HDPE plastic, and functional additive composite material with visible stability and photodegradability are added to the three die inlets, respectively. The die (inlet) temperature is strictly controlled at 190 ℃, the die neck temperature at 200 ℃, and the machine body temperatures at 190, 170, and 50 ℃ for the front, middle, and rear sections, respectively. The screw cooling temperature is maintained at 70~80 ℃, and the screw speed is 10–50 rpm.

[0115] S3. Sizing and Cooling: Using the vacuum inner diameter method, after extrusion molding, the material is sizing in a sizing chamber with an air pressure of 0.02–0.04 MPa and a water temperature of 30–50 ℃. After evacuation, the vacuum degree is 4 × 10⁻⁶. 4 pa, accurately locate the inner and outer diameters, and ensure the roundness and smoothness of the pipe. Cool in a spray cooling water bath at 15–25 ℃.

[0116] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0117] This invention produces a PP plastic pipe with a visible stabilization period and photodegradation function. The pipe has an outer diameter of 50 mm, an inner diameter of 48.2 mm, and a thickness of 1.8 mm, with both the inner and outer layers being 0.4 mm thick, and a photodegradation functional additive layer being 1.0 mm thick. The pipe exhibits a tensile strength ≥30 MPa, a Vicat softening temperature ≥131 ℃, and an impact strength ≥5 kJ / m. 2 Its density is 890-910 kg / m³ 3 The inner and outer walls are smooth.

[0118] This pipe is used for pre-embedded pipes in the construction industry. Its stabilization period is adjustable from 5 days to 2 years to meet construction needs. During the stabilization period, it exhibits stable properties and good performance. The photodegradation additive layer initially appears crimson and does not degrade or fade under strong light. After the stabilization period, the color changes, becoming entirely white. It remains white under sunlight or light intensity of 50 mW / cm². 2 Under simulated light source conditions, biodegradable plastic pipes can degrade in up to one month. Example 23 Same as Example 22, except that the component of the functional additive with visible stability and photodegradation function is changed from C3N4 to NaTiO3, while all other conditions and parameters are the same.

[0119] Example 24 Same as Example 22, except that the components of the functional additive with visible stability and photodegradation function are changed: C3N4 is replaced with modified MoO2, and K2S2O8 is replaced with AgNO3-triethanolamine, while all other conditions and parameters are the same.

[0120] Example 25 The PP plastic pipe of the present invention, featuring a visible stabilization period and photodegradation function, is manufactured using an extrusion process. It comprises a general zone and a composite zone containing photodegradation functional additives. Liquid flow holes are provided inside the pipe body. Figure 3 As shown, the photodegradable functional composite layer 4 of the present invention is a structure in which a general region 401 and a photodegradable functional additive composite region 402 are alternately distributed. The general region 401 of the plastic pipe is composed of plastic masterbatch and various plastic additives. The photodegradable functional additive composite region 402 is composed of plastic, a functional additive with visible stability and photodegradation function, and various plastic additives.

[0121] The specific implementation steps are explained below.

[0122] S1. Ingredients and Mixing: In the general zone 401, accurately weigh one part of the following materials according to the mass ratio of PP resin PP1200, HDPE, antioxidant DLTP, UV absorber UV-9, and stabilizer BaSt of 100:20:0.6:0.9:0.1. In the photodegradable functional additive composite zone 402, accurately weigh one part of the following materials according to the mass ratio of PP resin PP1200, HDPE, antioxidant DLTP, and stabilizer BaSt of 100:20:0.6:0.1, and weigh one part of the functional additive with visible stability and photodegradability according to the mass ratio of PP resin and HDPE to the functional additive with visible stability and photodegradability of 100:10. The specific components of the functional additive with visible stability and photodegradability are modified BiTiO3, AgNO3-triethanolamine, starch, and 2,4,6-tris(2-pyridyl)triazine. Dry the mixture at 80 °C for 2 h.

[0123] S2. Extrusion Molding: After thorough mixing, extrusion molding is performed using a single-screw extruder. A zoned co-extrusion die is used, with the mixture from the ordinary zone and the photodegradable functional additive composite zone added to the two dies respectively. The die (feed inlet) temperature is strictly controlled at 190 ℃, the die neck temperature at 200 ℃, and the machine body temperatures at 190, 170, and 50 ℃ for the front, middle, and rear sections respectively. The screw cooling temperature is maintained at 70~80 ℃, and the screw speed is 10–50 rpm.

[0124] S3. Sizing and Cooling: Using the vacuum inner diameter method, after extrusion molding, the material is sizing in a sizing chamber with an air pressure of 0.02–0.04 MPa and a water temperature of 30–50 ℃. After evacuation, the vacuum degree is 4 × 10⁻⁶. 4 pa, accurately locate the inner and outer diameters, and ensure the roundness and smoothness of the pipe. Cool in a spray cooling water bath at 15–25 ℃.

[0125] S4. Traction and Cutting: A tracked traction machine is used to stably and evenly pull the cooled and shaped pipes to ensure dimensional accuracy and surface quality. The finished pipes are then cut into commonly used lengths such as 4 m and 6 m using a cutting machine.

[0126] The PP plastic pipe prepared by this invention has a visible stabilization period and photodegradation function. The pipe has an outer diameter of 110 mm, a thickness of 2.7 mm, and an inner diameter of 107.3 mm. The stabilization period can be arbitrarily adjusted. Its tensile strength is ≥30 MPa, Vicat softening temperature is ≥131 ℃, and impact strength is ≥5 kJ / m. 2 Its density is 890-910 kg / m³ 3 The inner and outer walls are smooth.

[0127] This pipe is used for construction and drainage in remote areas, and the pipe body is opaque. By adjusting the mass ratio of functional additives with visual stability and photodegradation capabilities to the matrix resin within the range of 0.005 to 50, the plastic pipe can have different visual stability periods, adjustable from 5 days to 2 years. During the stable period, the photodegradation functional additive composite area 402 appears green and exhibits good performance. After the stability period ends, the photodegradation functional additive composite area 402 turns white under sunlight or light intensity of 50 mW / cm². 2 Under simulated light source conditions, the photodegradation functional additive composite zone can be broken down and degraded in at most one month.

[0128] Example 26 Same as Example 25, except that the component of the functional additive with visible stability period and photodegradation function is modified BiTiO3 instead of modified WO3, while all other conditions and parameters are the same.

[0129] Example 27 Same as Example 25, except that the component of the functional additive with visible stability and photodegradation function is replaced with (NH4)2C2O4 instead of AgNO3-triethanolamine, while all other conditions and parameters are the same.

[0130] The plastic pipes prepared in Examples 1-27 above can all achieve both a visible stabilization period and photodegradation functionality. Furthermore, by adjusting the mass ratio of the functional additives with both visual stabilization and photodegradation functions to the matrix resin within the range of 0.005 to 50, the stabilization period of the plastic pipes can be controllably adjusted from 5 days to 2 years. After the stabilization period, the simulated light source intensity ranges from 0.1 to 50 mW / cm². 2 All of these can enable functional additives with visible stability and photodegradation functions to activate photodegradability, thereby causing the plastic pipes to degrade.

[0131] Application Scenario 1: Plastic sleeves for pre-embedded holes in building construction In building construction, plastic sleeves (usually PVC, PE, and PP pipes) are typically pre-embedded before concrete pouring to reserve holes for pipes to penetrate walls, floors, or waterproofing structures. These pre-embedded sleeves only serve as formwork during the construction phase; once the main building structure is completed, these sleeves usually no longer bear any structural or functional responsibility. Existing sleeves use traditional plastic pipes, which are long-term stable materials and difficult to degrade naturally during the building's lifespan. Therefore, they are generally manually dismantled after the construction period. However, since the sleeves are often bonded to the concrete, this increases the difficulty of manual dismantling and can easily damage the concrete structure.

[0132] The present invention relates to a plastic pipe with a visible stabilization period and photodegradation function, used for manufacturing pre-embedded sleeves. The pipe includes: the construction period can be used as the stabilization period, and the stabilization period can be controlled by adjusting the type of functional additives with visible stabilization period and photodegradation function; within the set stabilization period, the pipe maintains its original mechanical properties such as strength, rigidity, and thermal stability, and meets various construction conditions such as transportation, construction, pouring, and subsequent installation.

[0133] After the stabilization period, the pipe degrades under sunlight, requiring only water flushing to remove pipe fragments; complex manual dismantling is unnecessary. Because this type of embedded pipe degrades under sunlight, does not bear long-term structural loads, and has no impact on building structural safety, the plastic pipe of this invention, with its visible stabilization period and photodegradation capabilities, meets the requirements of this scenario.

[0134] Application Scenario 2: Temporary drainage or transportation pipelines in remote areas In remote areas, mountainous regions, or field projects, plastic pipes (typically PVC, PE, and PP) are often used for temporary projects, such as temporary drainage, agricultural irrigation, mine drainage, and field engineering facilities. In remote areas, the disposal of these pipes after they reach the end of their service life is often a challenge. Recycling involves cumbersome processes such as manual dismantling, sorting and collection, long-distance transportation, and reuse, and is also expensive, with a total processing cost of approximately 2800–6500 yuan / ton. Direct on-site burial in deserts, plateaus, and forests poses environmental problems due to the non-degradability of plastic pipes under natural conditions, potentially damaging the soil and landscape.

[0135] The plastic pipes of this invention, featuring a visible stabilization period and photodegradation capabilities, can be used to manufacture temporary drainage or transportation pipelines in remote areas, solving the aforementioned problems. Specifically, the service life of the pipes of this invention is defined as the stabilization period. The stabilization period can be controlled by adjusting the types of functional additives that provide both visible stabilization and photodegradation capabilities. Within the set stabilization period, the plastic pipes maintain their original physical properties such as strength, impact resistance, and watertightness, meeting the requirements for long-distance transportation, installation, and other engineering applications.

[0136] When the pipeline reaches the end of its service life (end of the stabilization period) and is discarded, it can be directly stacked on-site and degrades under sunlight, eliminating the need for recycling and transportation. Because this type of plastic pipeline possesses excellent performance and degrades under sunlight after its service life, posing no harm to the environment, the plastic pipeline of this invention, with its visible stabilization period and photodegradation function, meets the requirements of this scenario.

[0137] In summary, the plastic pipe of the present invention features a visualized stabilization period and photodegradation function. The stabilization period can be arbitrarily adjusted according to actual application needs, ranging from a few days to several years. The stabilization period status is visualized. After the stabilization period, the color change of the photocatalytic system in the pipe formulation indicates the start of the plastic degradation period, meeting the actual needs for disassembly or degradation control in the later stages. It has a wide range of applications, and is especially suitable for the use of plastic sleeves for pre-embedded holes in building construction and temporary drainage or transportation pipelines in remote areas.

[0138] The above are merely embodiments of the present invention. For example, the base resin of the pipe may specifically include any one or more of the following components: PVC type includes: PVC-SG-3, PVCSG-5, PVCSG-7, PVC-SG-8, PVC-BY1600, PVC-BY4000, PVC-LP-400, PVC-S1001, PVC-P-1000; HDPE type includes: HDPE-7600M, HDPE-GH201, HDPE-23050; LDPE type includes: LD 6524.BA, LP2306, LD 15022.BA; LLDPE type includes: DNDB7149, DGDB 2463BK-3, RELENE® LL20DS010; PP types include: PP-4420, PP-1200, PP-RP2400, PP-H5416, PP-PA14D; PS types include: PS-550P, PS-GP5000, PS-POLYREX® PG-383, PS-666H, PS-202, PS-634; PET types include: PET-CP-318, PET-YS-W01, PET-KP3755, PET-PT X174, PET-FR530. The light intensity range that causes degradation of plastic pipes after the stabilization period is 0.1-50 m / cm². 2 The mass ratio of plastic resin to functional additives with visible stability and photodegradation capabilities in the pipe material can range from 100:0.005 to 100:50. Any one or more of the above-mentioned components can realize the plastic pipe with visible stability and photodegradation capabilities, its preparation method, and its application according to the present invention.

[0139] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A plastic pipe with visible stabilization period and photodegradation function, characterized in that, It is a composite pipe structure with a visible stabilization period, an adjustable stabilization period duration, and an adjustable photodegradation function. That is, after the stabilization period, the color change of the photocatalytic system in the pipe formulation indicates the start of the plastic degradation period, thereby realizing a visible degradation process. The formulation of the composite pipe includes: matrix resin and additives. When the composite pipe structure is a multi-layer composite pipe structure, its structure includes an outer pipe layer, an inner pipe layer, and a photodegradable functional additive composite layer. The outer and inner layers are composed of a base plastic resin and additives, and have specific light transmittance. The base resin used for the outer and inner pipe layers includes PVC, PE, PP, PET, and PS, any one or more of these. The light transmittance requirements for the inner pipe layer are: PVC pipe outer and inner layers >85%; PE pipe outer and inner layers >75%; PP pipe outer and inner layers >85%; the intermediate photodegradable functional additive composite layer is opaque or has a light transmittance ≤70%. When the composite pipe structure is a single-layer composite pipe structure, its structure includes a composite region containing photodegradation function; The photodegradable functional additive composite layer or photodegradable functional composite region contains a photodegradable functional additive with a visible stabilization period. The pipeline formulation of this layer or region includes: a matrix resin, additives, and a photodegradable functional additive with a visible stabilization period, enabling it to maintain good mechanical properties of the pipeline within a preset stabilization period and to achieve rapid degradation through light irradiation after the stabilization period ends.

2. The plastic pipe with visible stabilization period and photodegradation function according to claim 1, characterized in that, When the composite pipe structure is a single-layer composite pipe structure, the photodegradation functional composite area accounts for 100%; or the composite pipe structure includes a normal area and a photodegradation functional composite area, and the two are arranged at intervals along the circumference of the pipe.

3. The plastic pipe with visible stabilization period and photodegradation function according to claim 1, characterized in that, The functional additive with visualized stabilization period and photodegradation function is composed of a photoresponsive catalyst or modified photoresponsive catalyst, a photocatalyst photogenerated electron-hole consuming agent, and a photogenerated electron-hole consuming agent complex. After the pipeline stabilization period ends, under light irradiation, the photogenerated electron-hole pairs generated by the photocatalyst in the photodegradation functional additive can exert a photocatalytic effect on substances outside the photodegradation additive. With the release of photocatalytic activity, the pipeline color changes accordingly. The color change of the photocatalytic system indicates the start of the plastic degradation period. The photoresponsive catalyst or modified photoresponsive catalyst specifically includes photoresponsive NiO, MnO, BiTiO3, TiO2, ZnO, WO3, MoO2, MoS2, Co3O4, C3N4, SiC, CdSe and NaTiO3, as well as photoresponsive modified NiO, modified MnO, modified BiTiO3, modified TiO2, modified ZnO, modified WO3, modified MoO2, modified MoS2, modified Co3O4, modified C3N4, modified SiC, modified CdSe and modified NaTiO3, any one or more of these. The photocatalyst, specifically a photogenerated electron-hole consumable, is either a reversible redox couple or a photogenerated electron-hole pair trapping agent; the reversible redox couple is specifically I3. - / I - I2 / I - Cu 2+ / Cu + and Fe 3+ / Fe 2+ Any one or more of these; the photogenerated electron-hole pair trapping agent is specifically disodium ethylenediaminetetraacetate, AgNO3-HCOOH, (NH4)2C2O4, K2S2O8, AgNO3-triethanolamine, and KBrO3-NaHCO3, any one or more of these; The photogenerated electron-hole consumable complex is specifically starch and a metal ion chelating agent, wherein the metal ion chelating agent is ethylenediamine disuccinic acid, 2,4,6-tris(2-pyridyl)triazine, 8-hydroxyquinoline and disodium erythrophenonesodium disulfonic acid, any one or more of these.

4. The plastic pipe with visible stabilization period and photodegradation function according to claim 3, characterized in that, The mass fraction of functional additives with visible stability period and photodegradation function can be adjusted from 0.005 to 50 parts relative to 100 parts of matrix resin, thereby giving plastic pipes different visible stability periods, different stability period durations and different photodegradation performance.

5. The plastic pipe with visible stabilization period and photodegradation function according to claim 3, characterized in that, The matrix resin of composite pipes specifically includes any one or more of the following components: PVC types include: PVC-SG-3, PVC-SG-5, PVC-SG-7, PVC-SG-8, PVC-BY1600, PVC-BY4000, PVC-LP-400, PVC-S1001, and PVC-P-1000. HDPE types include: HDPE-7600M, HDPE-GH201, HDPE-23050; LDPE types include LD6524.BA, LP2306, LD15022.BA; LLDPE types include: DNDB7149, DGDB 2463BK-3, RELENE® LL20DS010; PP class includes: PP-4420, PP-1200, PP-RP2400, PP-H5416, PP-PA14D; PS series includes: PS-550P, PS-GP5000, PS-POLYREX® PG-383, PS-666H, PS-202, PS-634; The PET class includes: PET-CP-318, PET-YS-W01, PET-KP3755, PET-PT X174, PET-FR530, and any one or more of these.

6. The plastic pipe with visible stabilization period and photodegradation function according to claim 3, characterized in that, The types of additives include, but are not limited to, processing aids, heat stabilizers, lubricants, fillers, antioxidants, coupling agents, and transparent nucleating agents; specific: The processing aid is ACR acrylate copolymer; The heat stabilizer is any one of Ca / Zn heat stabilizer, HSt, ZnSt, or BaSt. The lubricant is any one of stearic acid, paraffin wax, or softening oil; The filler is CaCO3; The antioxidant is antioxidant 1010 or antioxidant DLTP; The coupling agent is TTS; The transparent nucleating agent is MDBS sorbitol.

7. The plastic pipe with visible stabilization period and photodegradation function according to claim 1, characterized in that, The composite pipe has an outer diameter of 50-110 mm, a thickness of 1.8-3.2 mm, and an inner diameter of 48.2-106.8 mm. The composite pipe has a stabilization period ranging from 5 days to 2 years under natural light. After the stabilization period, it can withstand light intensities of 0.1-50 mW / cm². 2 Under ultraviolet light, it can be completely degraded in 7-30 days, or under natural light, it can be completely degraded in 1-24 months.

8. The plastic pipe with visible stabilization period and photodegradation function according to claim 1, characterized in that, The mechanical and physical performance indicators of the composite pipeline during the stabilization period include the following: (1) Tensile strength: PVC pipe ≥40 MPa, PE pipe ≥22 MPa, PP pipe ≥30 MPa; (2) Vicat softening temperature: PVC pipe ≥74 °C, PE pipe ≥120 °C, PP pipe ≥131 °C; (3) Ring stiffness: PVC pipe ≥ 6 kN / m 2 PE pipes ≥8 kN / m 2 PP pipe ≥5 kJ / m 2 ; (4) Impact strength: PP pipe ≥ 5 kJ / m 2 .

9. The method for preparing a plastic pipe with visible stabilization period and photodegradation function according to any one of claims 1-8, characterized in that, The steps include the following: S1. Ingredients and Mixing: Weigh the base resin, additives and functional auxiliaries with visible stability and photodegradation functions according to a specific ratio, and heat mix them in a high-speed mixer so that the auxiliaries are uniformly adsorbed on the surface of the resin particles. S2. Extrusion molding: The mixture is extruded in a conical twin-screw extruder. The temperature of each section of the die, neck and body, as well as the screw speed, are strictly controlled to ensure the dimensional accuracy and surface quality of the pipe. S3. Sizing and Cooling: The pipe after extrusion molding is sized in a sizing box using the internal pressure internal diameter method and then cooled in a spray cooling water tank. S4. Traction and Cutting: The cooled and shaped pipe is stably pulled by a tracked traction machine and finally cut into a specified length by a cutting machine.

10. The application method of the plastic pipe with visible stabilization period and photodegradation function according to any one of claims 1-8, characterized in that, Visual indicators: The pipeline displays a specific color during the stabilization period, and the color changes after the stabilization period ends, visually indicating that it has entered the degradation stage; details are as follows: When the mass fraction of the functional additive with visible stability and photodegradation function added is less than 0.5 parts relative to 100 parts of the matrix resin, the pipe appears white; when the mass fraction added is between 0.5 and 50 parts, the plastic pipe appears one of the following specific colors: brown, coffee, tan, gray, blue, blue-brown, dark blue, green, scarlet, or purplish-red. The mechanism of this visualization indicator is as follows: During the stable period, under sunlight irradiation, the photogenerated electron-hole consumable in the photodegradation aid inhibits the photocatalytic activity of the photocatalyst, preventing the photogenerated electron-hole pairs generated by the photocatalyst from exerting photocatalytic activity on substances outside the aid; after the stable period, the photogenerated electron-hole consumable becomes ineffective, and the photogenerated electron-hole pairs generated by the photocatalyst under light conditions can exert photocatalytic activity on substances outside the photodegradation aid. With the release of this photocatalytic activity, the pipe color changes accordingly, thus achieving a visual indication of the degradation stage; Stabilization period controllability: By adjusting the type and ratio of functional additives, the stabilization period of the pipeline can be precisely controlled according to the actual application demand cycle. Photodegradation characteristics after stabilization period: After the stabilization period, the photodegradation activity of the photodegradation functional additive will be activated, triggering the breakage and degradation reaction of the plastic polymer chain, changing the color of the pipe, and causing the pipe to degrade rapidly under light conditions; as degradation proceeds, the pipe material gradually decomposes into fragments, thus eliminating the need for complex manual dismantling or recycling transportation.

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