阅读说明：本技术 一种耐高压防渗透的保温复合管道及其制备方法 (High-pressure-resistant anti-seepage heat-insulation composite pipeline and preparation method thereof ) 是由 侯连龙 澹台建礼 姚天姿 于 2019-03-30 设计创作，主要内容包括：本发明属于管道技术领域,提出了一种耐高压防渗透的保温复合管道及其制备方法,其中,保温复合管道包括由内到外依次设置的内层工作层、中层保温层、外层防护层,所述内层工作层包括由内到外依次设置的防渗透阻隔层、聚乙烯材料层、改性增强层、热敏微发泡黏胶层、预浸带缠绕层,聚乙烯材料层为PERT-Ⅱ型高密度聚乙烯材料层,防渗透阻隔层采用尼龙MXD6或乙烯/乙烯醇共聚物制成,改性增强层为玻璃纤维增强尼龙MXD6层,预浸带缠绕层为玻璃纤维增强聚乙烯预浸带层,改性增强层由以下重量份的组分组成：尼龙MXD6 35～50份,玻璃纤维15～50份,硅烷偶联剂0.2～1份,抗氧剂1～2份,润滑剂0.5～1份,增韧剂5～15份。本发明解决了高密度聚乙烯复合保温管道耐压程度低的问题。(The invention belongs to the technical field of pipelines and provides a high-pressure-resistant anti-seepage heat-insulation composite pipeline and a preparation method thereof, wherein the heat-insulation composite pipeline comprises an inner working layer, a middle heat-insulation layer and an outer protective layer which are sequentially arranged from inside to outside, the inner working layer comprises an anti-seepage barrier layer, a polyethylene material layer, a modified reinforcing layer, a heat-sensitive micro-foaming viscose layer and a prepreg tape winding layer which are sequentially arranged from inside to outside, the polyethylene material layer is a PERT-II type high-density polyethylene material layer, the anti-seepage barrier layer is made of nylon MXD6 or ethylene/vinyl alcohol copolymer, the modified reinforcing layer is a glass fiber reinforced nylon MXD6 layer, the prepreg tape winding layer is a glass fiber reinforced polyethylene prepreg tape layer, and the modified reinforcing layer is composed of the following components in parts by weight: 635-50 parts of nylon MXD, 15-50 parts of glass fiber, 0.2-1 part of silane coupling agent, 1-2 parts of antioxidant, 0.5-1 part of lubricant and 5-15 parts of toughening agent. The invention solves the problem of low pressure resistance of the high-density polyethylene composite heat-insulating pipeline.)

1. A high-pressure-resistant anti-seepage heat-insulation composite pipeline is characterized by comprising an inner working layer, a middle heat-insulation layer and an outer protective layer which are sequentially arranged from inside to outside, wherein the inner working layer comprises an anti-seepage barrier layer, a polyethylene material layer, a modified reinforcing layer, a heat-sensitive micro-foaming viscose layer and a prepreg tape winding layer which are sequentially arranged from inside to outside, the polyethylene material layer is a PERT-II type high-density polyethylene material layer, the anti-seepage barrier layer is made of nylon MXD6 or ethylene/vinyl alcohol copolymer, the modified reinforcing layer is a glass fiber reinforced nylon MXD6 layer, the prepreg tape winding layer is a glass fiber reinforced polyethylene prepreg tape layer,

the modified enhancement layer comprises the following components in parts by weight:

635-50 parts of nylon MXD, 15-50 parts of glass fiber, 0.2-1 part of silane coupling agent, 1-2 parts of antioxidant, 0.5-1 part of lubricant and 5-15 parts of toughening agent.

2. The high-pressure-resistant anti-seepage heat-insulation composite pipeline according to claim 1, wherein the modified reinforcing layer is composed of the following components in parts by weight:

nylon MXD 643 parts, glass fiber 33 parts, silane coupling agent 0.6 part, antioxidant 1.5 parts, lubricant 0.7 part and toughening agent 10 parts.

3. The high-pressure-resistant anti-penetration heat-insulation composite pipeline according to claim 1 or 2, wherein the length of the glass fiber is 0.4-1 mm, the silane coupling agent is a silane coupling agent KH550, the antioxidant is an antioxidant 1010, the lubricant is fatty acid amide, and the toughening agent is a polyolefin elastomer or a polyurethane elastomer.

4. The high-pressure-resistant anti-seepage heat-insulation composite pipeline according to claim 3, wherein the heat-sensitive micro-foamed adhesive layer is composed of the following components in parts by weight:

30-50 parts of epoxy resin, 10-15 parts of poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, 5-15 parts of polyethylene glycol, 3-8 parts of polyvinyl alcohol, 1-5 parts of ethyl acetate, 1-3 parts of titanium dioxide, 1-1 part of silane coupling agent KH 5500.1,

the molecular weight of the polyhedronoligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer is 15000-17000.

5. The high-pressure-resistant anti-seepage heat-insulation composite pipeline according to claim 4, wherein the heat-sensitive micro-foamed adhesive layer is composed of the following components in parts by weight:

40 parts of epoxy resin, 13 parts of poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, 5 parts of polyvinyl alcohol, 3 parts of ethyl acetate, 2 parts of titanium dioxide, and 5500.5 parts of silane coupling agent KH,

the molecular weight of the polyhedronoligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer is 15000-17000.

6. The high-pressure-resistant anti-seepage thermal insulation composite pipeline according to claim 4 or 5, wherein the epoxy resin is a mixture of epoxy resin E51 and epoxy resin 901 in a mass ratio of 8: 1.

7. The high pressure resistant and anti-seepage thermal insulation composite pipeline as claimed in claim 1, wherein the middle layer thermal insulation layer is a polyurethane foam thermal insulation layer.

8. The high pressure resistant impermeable thermal composite pipe according to claim 1, wherein the outer protective layer is made of high density polyethylene.

9. The preparation method of the high-pressure-resistant impermeable heat-insulation composite pipeline is characterized by comprising the following steps of:

s1, weighing the following raw materials in parts by weight: 635-50 parts of nylon MXD, 15-50 parts of glass fiber, 0.2-1 part of silane coupling agent, 1-2 parts of antioxidant, 0.5-1 part of lubricant and 5-15 parts of toughening agent for later use;

s2, soaking the glass fiber in an aqueous solution of a silane coupling agent with the mass ratio concentration of 1-2%, soaking for 8-12 min, drying the soaked glass fiber at the temperature of 75-90 ℃ for 30min, and heating to 120-140 ℃ for reaction for 30min to obtain the surface-treated glass fiber;

s3, mixing nylon MXD6, an antioxidant, a lubricant and a toughening agent for 10min at the rotating speed of 200r/min of a high-speed mixer, adding the surface-treated glass fiber obtained in the step S2 outside a double-screw extruder, melting, mixing, extruding and granulating to obtain glass fiber reinforced MXD6, and drying for 2h at 110 ℃ for later use;

s4, extruding and molding the anti-seepage barrier layer, the polyethylene material layer and the modified enhancement layer by adopting a multi-layer co-extrusion process;

s5, weighing the following raw materials in parts by weight: 30-50 parts of epoxy resin, 10-15 parts of poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, 3-8 parts of polyvinyl alcohol, 1-5 parts of ethyl acetate, 1-3 parts of titanium dioxide and 0.1-1 part of silane coupling agent for later use;

s6, mixing the epoxy resin, the poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer polyvinyl alcohol, ethyl acetate, titanium dioxide and the silane coupling agent for 10min at the rotating speed of 1500r/min of a high-speed mixer to obtain the thermosensitive micro-foaming adhesive for later use;

s7, coating the thermosensitive micro-foaming adhesive obtained in the step S6 on the outer surface of the modified enhancement layer by adopting an extruder annular extrusion coating method to obtain a thermosensitive micro-foaming adhesive layer;

s8, winding the glass fiber reinforced polyethylene prepreg tape outside the thermosensitive micro-foaming viscose layer for thermoplastic molding to obtain an inner working layer containing the prepreg tape winding layer;

s9, extruding and prefabricating an outer protective layer by using a high-density polyethylene material for later use;

s10, uniformly injecting rigid polyurethane foam stock solution into a cavity formed between the inner working layer and the prefabricated outer protective layer at one time by using a high-pressure foaming machine, and foaming the stock solution to obtain a polyurethane foam heat-insulating layer, thereby obtaining the high-pressure-resistant anti-seepage heat-insulating composite pipeline.

10. The method for preparing the high pressure resistant impermeable heat-insulating composite pipe according to claim 9, wherein the thickness of the winding layer of the prepreg tape in the step S8 is 0.28mm, the winding angle is 60 °, and the content of the glass fiber in the winding layer of the prepreg tape is 70%.

Technical Field

The invention belongs to the technical field of pipelines, and relates to a high-pressure-resistant anti-seepage heat-insulation composite pipeline and a preparation method thereof.

Background

With the continuous expansion of cities and the continuous exploitation of petroleum and natural gas, the demand on transportation pipelines is also increasing. The traditional pipelines are mainly steel pipelines and glass fiber reinforced plastic pipelines. For steel pipelines, due to the fact that ore mining environmental conditions are extremely severe, air is humid, and a large amount of flammable and explosive dust, gas, various corrosive gases, liquid substances and the like exist underground, the steel pipelines are easy to corrode, according to research reports, the annual corrosion rate is 0.2-1.2mm, and the service life of a steel pipe is directly shortened, and the maintenance cost is increased. In addition, when the steel pipe is used as a pipe for a coal mine, the specific gravity of the steel pipe is 7 times that of a PE pipe, so that the difficulty of underground operation is increased; and the steel pipeline easily produces the spark in the striking process, uses in the mine and has certain potential safety hazard. Meanwhile, the cost of the steel pipeline is higher, and the cost in the installation and maintenance process is correspondingly increased. Compared with a steel pipeline, the glass fiber reinforced plastic pipeline is relatively light in weight and better in corrosion resistance than the steel pipeline, but the interface of the glass fiber reinforced plastic pipeline is higher in requirement and easy to permeate in installation and use, and the glass fiber reinforced plastic pipeline belongs to a brittle material and is difficult to bear larger impact force, so that the risk of damage caused by ore impact exists.

In order to overcome the defects, technicians in the industry continuously research plastic pipelines to replace steel pipelines and glass fiber reinforced plastic pipelines, so that the aims of corrosion resistance, simple processing and low cost are fulfilled. The PERT-II type polyethylene composite heat-insulating pipeline can replace a traditional steel heat-insulating pipe with a small diameter at present, but because the pressure-resistant degree is lower compared with that of a traditional steel pipe, particularly a large-diameter pipeline, if a high-density polyethylene composite heat-insulating pipe working pipe needs a very large wall thickness, the use of materials can cause serious waste, and therefore, only part of a secondary heat-supplying pipeline can be replaced temporarily. Therefore, research and development of a high-pressure-resistant and anti-seepage large-caliber composite material pipeline are urgently needed.

Disclosure of Invention

The invention provides a high-pressure-resistant anti-seepage heat-insulation composite pipeline and a preparation method thereof, which solve the problem of low pressure resistance degree of a high-density polyethylene composite heat-insulation pipeline in the prior art and have anti-seepage industrial pipeline properties.

The technical scheme of the invention is realized as follows:

a high-pressure-resistant anti-seepage heat-insulation composite pipeline is characterized by comprising an inner working layer, a middle heat-insulation layer and an outer protective layer which are sequentially arranged from inside to outside, wherein the inner working layer comprises an anti-seepage barrier layer, a polyethylene material layer, a modified reinforcing layer, a heat-sensitive micro-foaming viscose layer and a prepreg tape winding layer which are sequentially arranged from inside to outside, the polyethylene material layer is a PERT-II type high-density polyethylene material layer, the anti-seepage barrier layer is made of nylon MXD6 or ethylene/vinyl alcohol copolymer, the modified reinforcing layer is a glass fiber reinforced nylon MXD6 layer, the prepreg tape winding layer is a glass fiber reinforced polyethylene prepreg tape layer,

the modified enhancement layer comprises the following components in parts by weight:

635-50 parts of nylon MXD, 15-50 parts of glass fiber, 0.2-1 part of silane coupling agent, 1-2 parts of antioxidant, 0.5-1 part of lubricant and 5-15 parts of toughening agent.

As a further technical scheme, the modified enhancement layer consists of the following components in parts by weight:

nylon MXD 643 parts, glass fiber 33 parts, silane coupling agent 0.6 part, antioxidant 1.5 parts, lubricant 0.7 part and toughening agent 10 parts.

According to a further technical scheme, the length of the glass fiber is 0.4-1 mm, the silane coupling agent is KH550, the antioxidant is 1010, the lubricant is fatty acid amide, and the toughening agent is polyolefin elastomer or polyurethane elastomer.

As a further technical scheme, the thermosensitive micro-foaming adhesive layer is composed of the following components in parts by weight:

30-50 parts of epoxy resin, 10-15 parts of poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, 5-15 parts of polyethylene glycol, 3-8 parts of polyvinyl alcohol, 1-5 parts of ethyl acetate, 1-3 parts of titanium dioxide, 1-1 part of silane coupling agent KH 5500.1,

the molecular weight of the polyhedronoligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer is 15000-17000.

As a further technical scheme, the thermosensitive micro-foaming adhesive layer is composed of the following components in parts by weight:

40 parts of epoxy resin, 13 parts of poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, 5 parts of polyvinyl alcohol, 3 parts of ethyl acetate, 2 parts of titanium dioxide, and 5500.5 parts of silane coupling agent KH,

the molecular weight of the polyhedronoligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer is 15000-17000.

The polyhedronal oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer comprises structural units of polyhedral oligomeric silsesquioxane and repeating structural units of dimethylaminoethyl methacrylate, wherein the number ratio of polyhedral oligomeric silsesquioxane to dimethylaminoethyl methacrylate is 1: 90 to 100 and having the following general formula:

wherein n is 90-100.

The preparation method of the polyhedronoligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer comprises the following steps: firstly, weighing 87.45g of aminopropyl isobutyl silsesquioxane, dissolving the aminopropyl isobutyl silsesquioxane in 1L of tetrahydrofuran, adding 1L of triethylamine, cooling to 0 ℃, slowly adding 27.59g of 2-bromoisobutyryl bromide, stirring at 0 ℃ for 1 hour, then moving to room temperature, stirring for 10 hours until the reaction is complete, filtering, performing rotary evaporation to obtain a white solid, cleaning with methanol, filtering to obtain a white solid, performing vacuum drying to obtain a brominated aminopropyl isobutyl silsesquioxane product, dissolving the brominated aminopropyl isobutyl silsesquioxane in 0.5L of tetrahydrofuran, adding 9.77g of 1,1,4,7,10, 10-hexamethyltriethylenetetramine and 500g of dimethylaminoethyl methacrylate, repeating the operations of freezing liquid nitrogen, vacuumizing, melting and introducing nitrogen for three times, adding 0.508g of cuprous bromide, then repeating the operations of freezing, vacuumizing, melting and introducing nitrogen for three times, reacting for 12 hours at 60 ℃, dissolving with a small amount of tetrahydrofuran after the reaction is finished, then passing through a neutral alumina column, washing with 10L of tetrahydrofuran, carrying out rotary evaporation to remove redundant solvent, precipitating in normal hexane to obtain white viscous polymer, and carrying out vacuum drying to obtain the product of the polyhedronoligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer.

As a further technical scheme, the epoxy resin is a mixture of epoxy resin E51 and epoxy resin 901 in a mass ratio of 8: 1.

As a further technical scheme, the middle-layer heat-insulating layer is a polyurethane foaming heat-insulating layer.

As a further technical scheme, the outer protective layer is made of high-density polyethylene.

A preparation method of a high-pressure-resistant anti-seepage heat-insulation composite pipeline comprises the following steps:

s1, weighing the following raw materials in parts by weight: 635-50 parts of nylon MXD, 15-50 parts of glass fiber, 0.2-1 part of silane coupling agent, 1-2 parts of antioxidant, 0.5-1 part of lubricant and 5-15 parts of toughening agent for later use;

s2, soaking the glass fiber in an aqueous solution of a silane coupling agent with the mass ratio concentration of 1-2%, soaking for 8-12 min, drying the soaked glass fiber at the temperature of 75-90 ℃ for 30min, and heating to 120-140 ℃ for reaction for 30min to obtain the surface-treated glass fiber;

s3, mixing nylon MXD6, an antioxidant, a lubricant and a toughening agent for 10min at the rotating speed of 200r/min of a high-speed mixer, adding the surface-treated glass fiber obtained in the step S2 outside a double-screw extruder, melting, mixing, extruding and granulating to obtain glass fiber reinforced MXD6, and drying for 2h at 110 ℃ for later use;

s4, extruding and molding the anti-seepage barrier layer, the polyethylene material layer and the modified enhancement layer by adopting a multi-layer co-extrusion process;

s5, weighing the following raw materials in parts by weight: 30-50 parts of epoxy resin, 10-15 parts of poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, 3-8 parts of polyvinyl alcohol, 1-5 parts of ethyl acetate, 1-3 parts of titanium dioxide and 0.1-1 part of silane coupling agent for later use;

s6, mixing epoxy resin, poly-polyhedral oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer, polyvinyl alcohol, ethyl acetate, titanium dioxide and silane coupling agent at the rotating speed of 1500r/min of a high-speed mixer for 10min to obtain the thermosensitive micro-foaming adhesive for later use;

s7, coating the thermosensitive micro-foaming adhesive obtained in the step S6 on the outer surface of the modified enhancement layer by adopting an extruder annular extrusion coating method to obtain a thermosensitive micro-foaming adhesive layer;

s8, winding the glass fiber reinforced polyethylene prepreg tape outside the thermosensitive micro-foaming viscose layer for thermoplastic molding to obtain an inner working layer containing the prepreg tape winding layer;

s9, extruding and prefabricating an outer protective layer by using a high-density polyethylene material for later use;

s10, uniformly injecting rigid polyurethane foam stock solution into a cavity formed between the inner working layer and the prefabricated outer protective layer at one time by using a high-pressure foaming machine, and foaming the stock solution to obtain a polyurethane foam heat-insulating layer, thereby obtaining the high-pressure-resistant anti-seepage heat-insulating composite pipeline.

As a further technical scheme, in the step S8, the thickness of the winding layer of the prepreg tape is 0.28mm, the winding angle is 60 °, and the content of the glass fiber in the winding layer of the prepreg tape is 70%.

The invention has the following using principle and beneficial effects:

1. compared with the PERT-II type polyethylene composite heat-insulation pipeline with the same pipeline caliber in the prior art, the composite pipeline prepared by the invention has higher short-time failure pressure, is damaged for 8760 hours at 110 ℃ and under the ring stress of 2.4MPa, still does not crack or leak, effectively solves the technical problem of low pressure resistance degree of the composite heat-insulation pipeline in the prior art, and simultaneously has better comprehensive properties such as strength, impact resistance, toughness and the like and wide application prospect.

2. In the invention, the modified enhancement layer is arranged between the polyethylene material layer and the winding layer of the prepreg tape and is compounded with the winding layer of the prepreg tape, so that the dual synergistic effect is achieved, the impact resistance of the composite pipeline is obviously improved, the modified enhancement layer adopts the nylon MDX6 as a matrix and has high strength, and the coupled glass fiber, the toughening agent, the antioxidant, the lubricant and the like are added and matched with each other, so that the comprehensive properties of the composite pipeline, such as strength, impact resistance, toughness and the like, are improved.

3. According to the invention, the thermosensitive micro-foaming viscose layer is arranged between the modified enhancement layer and the prepreg tape winding layer, so that on one hand, the modified enhancement layer and the prepreg tape winding layer made of different materials can be bonded, the interface bonding property of the modified enhancement layer and the prepreg tape winding layer is effectively enhanced, and on the other hand, the thermosensitive micro-foaming viscose layer is matched with the modified enhancement layer, so that the internal stress of an internal pipeline can be partially offset, the pressure buffering effect is achieved, the composite pipeline is high pressure resistant, and the practicability is stronger.

4. In the invention, the anti-seepage barrier layer is arranged in the polyethylene material layer and is made of nylon MXD6 or ethylene/vinyl alcohol copolymer, so that the fluid in the pipeline can be effectively prevented from permeating into the pipeline, and the anti-seepage capability of the composite pipeline is improved. The arrangement of the outer protective layer not only enables the composite pipeline to be anticorrosive and waterproof, but also can protect the middle-layer heat-insulating layer from being damaged by mechanical hard objects, and plays a role in protection. And a middle-layer heat-insulating layer is filled between the inner working layer and the outer protective layer, so that the heat-insulating capability of the composite pipeline is effectively improved.

5. According to the invention, the modified reinforcing layer is made of glass fiber reinforced nylon MXD6, the glass fiber is coupled by a silane coupling agent and then is melted and extruded with nylon MXD6, the glass fiber is added to form a net-shaped connecting structure with a nylon MXD6 matrix through intermolecular force, so that the impact strength and the tensile strength of the composite pipeline are improved, the glass fiber is pretreated by the silane coupling agent, the dispersibility of the glass fiber in a nylon MXD6 melt is effectively improved, the interface compatibility of the glass fiber and the nylon MXD6 matrix is improved, and the impact resistance of the composite pipeline is improved.

6. According to the invention, the addition of the polyhedronal oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer in the viscose layer obviously improves the impact strength, tensile strength and rigidity of the composite pipeline and reduces the longitudinal retraction rate of the composite pipeline. On one hand, the polyhedronal oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer is an amphiphilic polymer and plays a role of a foaming agent in the viscose layer, so that the viscose layer forms a compact micro-foaming layer during thermoplastic molding of the prepreg tape, and the internal stress of the pipeline can be counteracted after the glass fiber prepreg tape is coated, so that the impact strength and the ring stiffness of the composite pipeline are improved; on the other hand, the polyhedronal oligomeric silsesquioxane-dimethylaminoethyl methacrylate graft copolymer is an organic-inorganic hybrid polymer material, the material contains an inorganic structural framework of silicon-oxygen-silicon, so that the mechanical properties such as tensile strength, bending strength and the like of the composite pipeline are obviously improved, and the viscosity of the thermosensitive dimethylaminoethyl methacrylate graft copolymer is increased during thermoplastic molding, so that the winding layer of the prepreg tape is tightly wound on the outer surface of the modified enhancement layer, and the strength of the composite pipeline is increased.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.