Pipeline trenchless repair material with thermally initiated front-end polymerization as well as preparation method and application of pipeline trenchless repair material

Abstract

The invention belongs to the technical field of pipeline trenchless repair, and particularly relates to a pipeline trenchless repair material with thermally initiated front-end polymerization as well as a preparation method and application of the pipeline trenchless repair material. The repair material comprises the following components in parts by weight: 100 parts of resin, 5-20 parts of a curing agent, 1-5 parts of an accelerant, 5-10 parts of a plasticizer, 0.1-1 part of a polymerization inhibitor and 30-40 parts of aluminum oxide. According to the resin hose prepared from the repairing material, the front-end polymerization reaction is initiated only through single-point or multi-point heating during construction, the whole pipeline can be cured by utilizing self heat release of the reaction, and compared with a traditional curing mode, the resin hose is simple and convenient to construct, low in energy consumption, free of reduction of mechanical strength and suitable for non-excavation repairing of small-size pipelines; the method has a great application prospect in the field of pipeline trenchless repair.

Description

Technical Field

[0001] The invention belongs to the technical field of pipeline trenchless repair, and in particular relates to a pipeline trenchless repair material with heat-induced front-end polymerization, and a preparation method and application thereof. Background Art

[0002] With the development of urbanization, deformation and damage of old underground drainage pipes are increasingly common. Pipeline trenchless repair technology has gradually replaced traditional excavation repair with its advantages of small impact on traffic, environmental protection and low cost, among which the in-situ solidification method (CIPP) trenchless repair technology is the most widely used.

[0003] CIPP is to place the resin-impregnated hose into the pipe to be repaired by pulling or flipping, and then use hot water, steam or ultraviolet light to cure the hose to form an inner lining, which fits tightly to the inner wall of the original pipe to complete the repair of the original pipe. However, hot water, steam and ultraviolet light curing methods all have disadvantages such as high energy consumption, complex construction methods, and high dependence on supporting equipment. In addition, for pipes with smaller diameters (below DN200), the related equipment is large in size and cannot enter the pipe, making it difficult to carry out non-excavation repair construction.

[0004] Front-end polymerization is a new method for converting monomers into polymers. Its characteristic is that after the curing reaction is initiated by heating or light, the self-exothermic reaction can maintain the reaction end face to move forward continuously until it is completely cured, without the need for continuous heating or light. Compared with traditional hot water, steam and ultraviolet light curing methods, it is simpler to construct, low-carbon and efficient. Therefore, the front-end polymerization curing method has great application prospects in the field of trenchless pipeline repair technology. Summary of the invention

[0005] The purpose of the present invention is to provide a pipeline trenchless repair material with heat-induced front-end polymerization, and its preparation method and application. The resin hose prepared by the repair material only needs single-point or multi-point heating to initiate the front-end polymerization reaction during construction, and the whole pipeline can be cured by utilizing the self-heating of the reaction. Compared with the traditional curing method, the construction is simple, the energy consumption is low, and the mechanical strength is not reduced. It is suitable for trenchless repair of small-sized pipelines, and effectively overcomes the shortcomings of the existing technology.

[0006] Specifically, the present invention provides the following technical solutions:

[0007] A heat-induced front-end polymerization trenchless pipeline repair material comprises the following components by weight: 100 parts of resin, 5-20 parts of curing agent, 1-5 parts of accelerator, 5-10 parts of plasticizer, 0.1-1 parts of inhibitor and 30-40 parts of aluminum oxide.

[0008] Preferably, the resin is selected from one or more of glycidyl ether epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, and bisphenol A epoxy vinyl resins.

[0009] Preferably, when the resin is one or more of glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, linear aliphatic epoxy resin, and alicyclic epoxy resin, the curing agent is selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine;

[0010] When the resin is bisphenol A epoxy vinyl resin, the curing agent is selected from one or more of cyclohexanone peroxide, dibenzoyl peroxide, and methyl ethyl ketone peroxide.

[0011] Preferably, when the resin is one or more of glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, linear aliphatic epoxy resin, and alicyclic epoxy resin, the accelerator is selected from one or more of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, and resorcinol;

[0012] When the resin is bisphenol A epoxy resin, the accelerator is selected from one or more of cobalt naphthenate, cobalt isooctanoate, and N,N-dimethylaniline.

[0013] In the present invention, fatty amine is selected as the curing agent of epoxy resin, and peroxide is selected as the curing agent of vinyl resin because of its high activity and strong heat release characteristics, which can ensure that the heat release in the front polymerization process is greater than the heat loss, so that the front end face moves forward by itself without external driving force. At the same time, for different resin types, the purpose of compounding specific accelerators is to further reduce the reaction energy barrier and maintain the front polymerization reaction. In addition, epoxy resin and vinyl resin have good mechanical properties after curing, and have the advantages of acid and alkali resistance, corrosion resistance, heat resistance, water resistance and durability, etc., which are suitable for urban underground pipeline construction in different environments.

[0014] Preferably, the plasticizer is selected from one or more of phthalates, sebacates, and chlorinated paraffins.

[0015] Preferably, the polymerization inhibitor is selected from one or more of hydroquinone, p-tert-butylcatechol, and p-butylphenol monobutyl ether. In the present invention, the reason for adding the polymerization inhibitor is to prevent the resin material from being cured prematurely due to bulk polymerization during storage, thereby extending its storage time. Thermosensitive polymerization inhibitors such as p-tert-butylcatechol have a high polymerization inhibition efficiency at room temperature, but can be rapidly decomposed at the reaction temperature and lose the polymerization inhibition effect. Therefore, after the front-end polymerization reaction is initiated, the high heat release in the reacted area can decompose the polymerization inhibitor in the adjacent unreacted area, release the reaction activity of the monomer and the initiator, form a chain reaction, and maintain the continuous progress of the front-end polymerization reaction.

[0016] In the present invention, the role of adding a specific amount of aluminum oxide is to increase the thermal conductivity of the resin matrix, prevent heat accumulation during the front-end polymerization reaction, improve heat transfer efficiency, and increase reaction speed. In addition, aluminum oxide has a certain reinforcing effect and can improve the mechanical strength of the pipeline after curing. If the amount of aluminum oxide is too low, the thermal conductivity of the system is poor, the heat transfer efficiency is low, and the front-end polymerization reaction is easily stopped; if the amount of aluminum oxide is too high, the viscosity of the system is large and the fluidity is poor, resulting in a slow reaction rate or even a reaction stop.

[0017] The present invention also provides a method for preparing the above-mentioned pipeline trenchless repair material by heat-induced front-end polymerization, comprising the following steps:

[0018] (1) at a certain temperature, mixing resin, curing agent, accelerator and inhibitor uniformly to obtain a resin premix;

[0019] (2) At a certain temperature, add a plasticizer and alumina to the above resin premix, adjust the viscosity to 600-800 mPa·s, and mix well to obtain.

[0020] Preferably, in step (1), the certain temperature is 20-40°C.

[0021] Preferably, in step (2), the certain temperature is 20-40°C.

[0022] Preferably, in step (2), the viscosity is adjusted to 600-800 mPa·s by adding low molecular weight (200-800) polyethylene glycol to increase fluidity and facilitate better impregnation of the glass fiber with the resin.

[0023] The present invention also provides a pipeline trenchless repair hose with heat-induced front-end polymerization, comprising a fiber layer, wherein the fiber layer is glass fiber impregnated with the above-mentioned pipeline trenchless repair material with heat-induced front-end polymerization.

[0024] Preferably, a layer of polytetrafluoroethylene film is provided on both the inner and outer sides of the fiber layer.

[0025] The present invention also provides a pipeline trenchless repair process by heat-induced front-end polymerization, comprising the following steps:

[0026] (1) According to the existing in-situ solidification trenchless repair process, the pipeline to be repaired is pretreated. After the pretreatment is completed, the above-mentioned heat-induced front-end polymerized pipeline trenchless repair hose is placed into the pipeline to be repaired by pulling and / or flipping, and then inflated to make it close to the inner side of the pipeline to be repaired;

[0027] (2) Using an infrared heater to heat both ends of the repair hose, after the polymerization reaction at the front end is initiated, the heat source is removed, and the polymerization reaction diffuses to the unreacted area by the heat released by itself until the whole is solidified, and after solidification, inspection and acceptance are carried out.

[0028] The beneficial effects of the present invention are at least:

[0029] (1) The heat-induced front-end polymerization trenchless pipe repair material provided by the present invention uses a front-end polymerization curing method to prepare a resin hose. Compared with hot water, steam and ultraviolet light curing methods, it does not require continuous heating or illumination, reduces the number of operating steps, saves construction costs, and reduces energy consumption;

[0030] (2) The heat-initiated front-end polymerization trenchless pipe repair material provided by the present invention, the resin hose prepared by the material belongs to a latent curing system, and the semi-finished hose can be prepared in the factory in advance. During construction, no professional supporting equipment is required for curing, and only a heat source needs to be provided for single-point or multi-point initiation, which is suitable for the trenchless repair of pipes with smaller diameters;

[0031] (3) The heat-induced front-end polymerization trenchless pipe repair material provided by the present invention has a resin hose prepared by the material having a mechanical strength equivalent to that of a conventional curing method after curing, a tensile strength of not less than 80 MPa after adding glass fiber, a flexural strength of not less than 125 MPa, and a short-term flexural modulus of not less than 8000 MPa, and has excellent comprehensive mechanical properties;

[0032] (4) The heat-induced front-end polymerization trenchless pipe repair material provided by the present invention avoids the front-end polymerization reaction rate being too slow or even the reaction being stopped by optimizing the amount of alumina used. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention is described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in the field or the product instructions are used.

[0034] In the following examples, information of each reagent used is shown in Table 1.

[0035] Table 1 Information of reagents used in the examples

[0036] Reagents Manufacturer / Model Glycidyl ether epoxy resin Sinopec Baling Branch / E-44 Bisphenol A epoxy vinyl resin Nan Ya Plastics Industrial Co., Ltd. / V1A01 Chlorinated paraffins Luxi Chemical Group Co., Ltd. / Chlorinated paraffin

[0037] Example 1

[0038] A heat-induced front-end polymerization pipeline trenchless repair material includes the following components by weight: 100 parts of glycidyl ether epoxy resin, 10 parts of ethylenediamine, 5 parts of N,N-dimethylbenzylamine, 6 parts of dibutyl phthalate, 0.2 parts of p-tert-butylcatechol, and 30 parts of aluminum oxide. The preparation method of the material includes the following steps:

[0039] (1) setting the stirrer temperature to 40° C., adding glycidyl ether epoxy resin, ethylenediamine, N,N-dimethylbenzylamine and p-tert-butylcatechol in proportion, and mixing them thoroughly to obtain a resin premix;

[0040] (2) Setting the stirrer temperature to 35° C., adding dibutyl phthalate and alumina to the resin premix, adjusting the viscosity to 600-800 mPa·s by adding low molecular weight polyethylene glycol, and fully mixing to obtain a heat-induced front-end polymerization trenchless pipeline repair material.

[0041] Preparation of hose: Use adhesive to bond the polytetrafluoroethylene inner film, polytetrafluoroethylene outer film and glass fiber cloth together, then put it on a DN150 pipe mold to prepare a hose, and finally use a pouring machine to evacuate the hose and pour resin into it to obtain a non-excavation repair hose with heat-induced front-end polymerization.

[0042] Hose curing: Use an infrared heater (about 150℃) to heat one end of the hose to initiate the polymerization reaction. After heating for 3 minutes, the heat source is removed and the reaction end surface is steadily pushed toward the other end of the hose under the action of self-exothermicity. The forward speed is about 5cm / min. During the reaction, the temperature of the front end surface is maintained at about 100℃ until the entire pipe is completely cured.

[0043] Performance test: Referring to DBJ43 / T 380-2021 "Technical Standard for Trenchless Repair and Renewal of Urban Drainage Pipelines in Hunan Province", the mechanical properties of the cured pipes were tested. The test results are shown in Table 2.

[0044] Table 2 Test results of mechanical properties of epoxy resin pipes

[0045] project Tensile strength / MPa Bending strength / MPa Short-term bending elastic modulus / MPa Test results 118 153 8766 standard ≥80 ≥125 ≥8000

[0046] Example 2

[0047] A heat-induced front-end polymerization trenchless pipeline repair material includes the following components by weight: 100 parts of bisphenol A epoxy vinyl resin, 5 parts of dibenzoyl peroxide, 2.5 parts of N,N-dimethylaniline, 5 parts of chlorinated paraffin, 0.5 parts of p-phenol monobutyl ether, and 40 parts of aluminum oxide. The preparation method of the material includes the following steps:

[0048] (1) setting the temperature of the stirrer to 40° C., adding vinyl resin, dibenzoyl peroxide, N,N-dimethylaniline and p-butyl phenol in proportion, and mixing them thoroughly to obtain a resin premix;

[0049] (2) Setting the temperature of the stirrer to 35° C., adding chlorinated paraffin and alumina to the resin premix, adjusting the viscosity to 600-800 mPa·s by adding low molecular weight polyethylene glycol, and fully mixing to obtain a heat-induced front-end polymerization trenchless pipeline repair material.

[0050] Preparation of hose: Use adhesive to bond the polytetrafluoroethylene inner film, polytetrafluoroethylene outer film and glass fiber cloth together, then put it on a DN200 pipe mold to prepare a hose, and finally use a pouring machine to evacuate the hose and pour resin into it to obtain a non-excavation repair hose with heat-induced front-end polymerization.

[0051] Hose curing: Use an infrared heater (about 150℃) to heat one end of the hose to initiate the polymerization reaction. After heating for 5 minutes, the heat source is then removed. The reaction end surface is steadily pushed toward the other end of the hose under the action of self-exothermicity. The forward speed is about 3cm / min. During the reaction, the temperature of the front end surface is maintained at about 80℃ until the entire pipe is completely cured.

[0052] Performance test: Referring to DBJ43 / T 380-2021 "Technical Standard for Trenchless Repair and Renewal of Urban Drainage Pipelines in Hunan Province", the mechanical properties of the cured pipes were tested. The test results are shown in Table 3.

[0053] Table 3 Mechanical properties test results of vinyl resin pipes

[0054] project Tensile strength / MPa Bending strength / MPa Short-term bending elastic modulus / MPa Test results 97 131 8234 standard ≥80 ≥125 ≥8000

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pipeline trenchless repair material with heat-induced front-end polymerization, characterized in that: The invention comprises the following components: 100 parts of resin, 5-20 parts of curing agent, 1-5 parts of accelerator, 5-10 parts of plasticizer, 0.1-1 parts of inhibitor and 30-40 parts of aluminum oxide.

2. The heat-induced front-end polymerized pipeline trenchless repair material according to claim 1, characterized in that: The resin is selected from one or more of glycidyl ether epoxy resins, glycidyl ester epoxy resins, glycidyl amine epoxy resins, linear aliphatic epoxy resins, alicyclic epoxy resins, and bisphenol A epoxy vinyl resins.

3. The heat-induced front-end polymerized pipeline trenchless repair material according to claim 1 or 2, characterized in that: When the resin is one or more of glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, linear aliphatic epoxy resin, and alicyclic epoxy resin, the curing agent is selected from one or more of ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and diethylaminopropylamine; When the resin is bisphenol A epoxy vinyl resin, the curing agent is selected from one or more of cyclohexanone peroxide, dibenzoyl peroxide, and methyl ethyl ketone peroxide.

4. The heat-induced front-end polymerized pipeline trenchless repair material according to claim 1 or 2, characterized in that: When the resin is one or more of glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, linear aliphatic epoxy resin, and alicyclic epoxy resin, the accelerator is selected from one or more of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylbenzylamine, and resorcinol; When the resin is bisphenol A epoxy resin, the accelerator is selected from one or more of cobalt naphthenate, cobalt isooctanoate, and N,N-dimethylaniline.

5. The heat-induced front-end polymerized pipeline trenchless repair material according to claim 1 or 2, characterized in that: The plasticizer is selected from one or more of phthalates, sebacates, and chlorinated paraffins.

6. The heat-induced front-end polymerized pipeline trenchless repair material according to claim 1 or 2, characterized in that: The polymerization inhibitor is selected from one or more of hydroquinone, p-tert-butylcatechol, and p-phenol monobutyl ether.

7. The method for preparing the pipeline trenchless repair material by heat-induced front-end polymerization according to any one of claims 1 to 6, characterized in that: The following steps are involved: (1) at a certain temperature, mixing resin, curing agent, accelerator and inhibitor uniformly to obtain a resin premix; (2) At a certain temperature, add a plasticizer and alumina to the above resin premix, adjust the viscosity to 600-800 mPa·s, and mix well to obtain.

8. The preparation method according to claim 7, characterized in that: In step (1), the certain temperature is 20 to 40° C.; And / or, in step (2), the certain temperature is 20 to 40° C.; Preferably, in step (2), the viscosity is adjusted to 600-800 mPa·s by adding low molecular weight polyethylene glycol.

9. A heat-induced front-end polymerized pipeline trenchless repair hose, characterized in that: The fiber layer comprises a fiber layer, wherein the fiber layer is glass fiber impregnated with the heat-induced front-end polymerized pipeline trenchless repair material according to any one of claims 1 to 6; Preferably, a layer of polytetrafluoroethylene film is provided on both the inner and outer sides of the fiber layer.

10. A pipeline trenchless repair process using heat-induced front-end polymerization, characterized in that: The following steps are involved: (1) According to the existing in-situ solidification trenchless repair process, the pipeline to be repaired is pretreated. After the pretreatment is completed, the heat-induced front-end polymerized pipeline trenchless repair hose of claim 9 is placed into the pipeline to be repaired by pulling and / or flipping, and then inflated to make it close to the inner side of the pipeline to be repaired; (2) Using a heater to heat at least one end of the repair hose, after the polymerization reaction at the front end is initiated, the heat source is removed, and the polymerization reaction diffuses to the unreacted area by the heat released by itself until the whole is solidified, and after solidification, inspection and acceptance are carried out.