CN-121975079-A - High-strength flame-retardant polyurea material with self-catalytic function, and preparation method and application thereof

Abstract

The invention discloses a high-strength flame-retardant polyurea material with an autocatalysis function, a preparation method and application thereof. The material takes 4,4 '-dicyclohexylmethane diisocyanate, 4' - (pentane-2, 2-diyl) diphenol, N-bis (2-hydroxyethyl) aminomethylene dimethyl phosphine oxide and N-ethyldiethanolamine as raw materials, and prepares the monocomponent polyurea prepolymer through three-step prepolymerization. The phosphorus element in the material is embedded into a molecular chain in a covalent bond form, so that stable and efficient UL 94V-0 level flame retardant performance is provided, the tensile strength and the elongation at break are synergistically improved by the benzene ring rigid structure, the reinforcement of the pipeline structure is realized, and the tertiary amine group provides an autocatalysis function, so that the tertiary amine group can be rapidly solidified on a wet base surface. The material is used for non-excavation in-situ spraying repair of underground pipelines, is convenient to construct, can synchronously realize structural reinforcement, impermeability, corrosion resistance, safety and flame retardance, and has long-term and reliable repair effect.

Inventors

• ZHANG HAICHAO
• PING YANG
• ZHANG RAN
• YANG MENG
• WANG LEI
• ZHAO PENG
• ZHANG QING
• LUO CHAO
• CHEN ZHIFENG
• SUN BAOCHENG
• WEN PENG
• WANG HANTAO

Assignees

• 中国电建集团贵阳勘测设计研究院有限公司
• 万华节能科技集团股份有限公司

Dates

Publication Date

20260505

Application Date

20260212

Claims (8)

1. 1. A high-strength flame-retardant polyurea material with an autocatalytic function is characterized by comprising the following components in parts by mass: 95-115 parts of 4,4' -dicyclohexylmethane diisocyanate; 8-14 parts of 4,4' - (pentane-2, 2-diyl) diphenol; 10-18 parts of N, N-bis (2-hydroxyethyl) aminomethylene dimethyl phosphine oxide; 10-14 parts of N-ethyldiethanolamine.
2. 2. The high-strength flame-retardant polyurea material with the self-catalytic function according to claim 1, wherein the purity of the 4,4' -dicyclohexylmethane diisocyanate is more than or equal to 99.5%.
3. 3. The high-strength flame-retardant polyurea material with the self-catalytic function according to claim 1, wherein the material is directly sprayed on a pipeline to be repaired, and the stable flame retardance of the repaired part is UL 94V-0 level, the tensile strength is more than or equal to 25MPa, and the elongation at break is more than or equal to 300%.
4. 4. A process for preparing the high-strength flame-retardant polyurea material with an autocatalytic function as claimed in any one of claims 1 to 3, which is characterized by comprising the following steps of, Step S1, raw material pretreatment, namely drying 4,4' - (pentane-2, 2-diyl) diphenol; Step S2, a first prepolymerization reaction, namely sequentially adding 4,4' -dicyclohexylmethane diisocyanate and 4,4' - (pentane-2, 2-diyl) diphenol after the drying treatment in the step S1 into a reaction kettle, stirring and mixing for 10 hours at 35-45 ℃ until the 4,4' - (pentane-2, 2-diyl) diphenol is completely dissolved to form a transparent uniform material, then gradually heating to 85-90 ℃ for holding, continuously stirring and prepolymerizing for 3 hours, and stopping the reaction when the content of-NCO reaches 22-29%, thus obtaining a first prepolymer; S3, a second prepolymerization reaction, wherein the temperature of a reaction kettle is reduced to 25-30 ℃, a certain amount of N, N-bis (2-hydroxyethyl) aminomethylene phosphine oxide is dripped, the temperature of a system is controlled to be not more than 45 ℃ in the dripping process, the dripping speed is 100-150 g/min, after the dripping is completed, the temperature is increased to 85-90 ℃ and the reaction is continued for 3-3.5 hours, when the-NCO content reaches 12-22%, the reaction is stopped, and nitrogen filling and sealing packaging are carried out, so that a second prepolymer is obtained; and S4, performing a third prepolymerization reaction, dropwise adding a certain amount of N-ethyldiethanolamine under the reaction condition of the second prepolymerization reaction, stopping the reaction when the-NCO content reaches 8.5% -11.5%, and filling nitrogen for sealing and packaging to obtain the high-strength flame-retardant polyurea material with the self-catalysis function.
5. 5. The method for preparing the high-strength flame-retardant polyurea material with the self-catalytic function according to claim 4, wherein in the step S1, the drying pretreatment is specifically that 4,4' - (pentane-2, 2-diyl) diphenol is dried for 5 hours in a 110 ℃ vacuum drying oven, ground to a particle size of less than 120 meshes, and sealed and stored for standby.
6. 6. The method for preparing a high-strength flame-retardant polyurea material with an autocatalytic function according to claim 4, wherein the chemical reaction formula of the first prepolymer is as follows, 。
7. 7. The method for preparing a high-strength flame-retardant polyurea material with an autocatalytic function according to claim 4, wherein the chemical reaction formula of the first prepolymer is as follows, Wherein, R1 molecular structural formula is: 。
8. 8. Use of the high-strength flame-retardant polyurea material with an autocatalytic function as claimed in any one of claims 1 to 3 in-situ spray repair of underground pipelines.

Description

High-strength flame-retardant polyurea material with self-catalytic function, and preparation method and application thereof Technical Field The invention relates to the technical field of high polymer materials and underground infrastructure restoration, in particular to a high-strength flame-retardant polyurea material with an autocatalysis function, a preparation method and application thereof. Background The large amount of concrete in China, underground water diversion pipelines, water conservancy culverts, drainage pipelines and other infrastructures made of reinforced concrete materials enter a long-term service stage, and part of the infrastructures run even over the age. In the long-term use process, the underground pipeline (culvert) faces multiple severe effects such as soil body loading, internal water pressure, water flow scouring, corrosive medium erosion and the like, diseases such as leakage cracking, corrosion thinning, structural strength attenuation and the like commonly occur, engineering safety accidents such as water leakage, pipe explosion, subsidence and the like are easy to cause, and serious threat is formed to the safety operation and the surrounding environment of urban infrastructure, so that the efficient restoration of the underground pipeline (culvert) is an industrial problem to be solved urgently. The non-excavation in-situ spraying repair technology has gradually replaced the traditional excavation repair mode by virtue of the remarkable advantages of high construction efficiency, small influence on ground traffic and surrounding environment, low comprehensive cost and the like, and becomes a main technical path for repairing the underground pipeline (culvert). The core of the technology is that the inner wall of the old pipeline or culvert is sprayed with the repairing material to construct the complete and excellent inner liner, so that the reinforcement and functional repairing of the pipeline structure are realized, and the advantages and disadvantages of the repairing effect directly depend on the comprehensive performance of the spraying material. The main current in-situ spraying repair materials are mainly divided into inorganic and organic materials. Inorganic materials such as cement mortar have certain strength, can improve the bearing capacity of a pipeline in a short period of time, but have the inherent defects of poor durability and weak impermeability, are easy to be secondarily damaged under the long-term scouring and erosion actions of fluid in a pipeline, and are difficult to ensure the long-term repairing effect: On one hand, the polyurea material is a flexible material, and has the condition of insufficient rigidity, but the conventional polyurea has excellent flexibility but limited flexural modulus and hardness, so that the requirement of bearing and reinforcing a damaged pipeline is difficult to meet. On the other hand, the traditional organic repairing materials (comprising conventional polyurea) generally lack flame retardant property, belong to flammable or combustible materials, and once a fire disaster occurs, the fire disaster can be accelerated to spread, a large amount of toxic and harmful gases and dense smoke can be released, so that disaster loss is greatly enlarged, and double threats are caused to personnel rescue and environmental safety. The traditional flame-retardant modification mode adopts an additive flame retardant, and although the flame-retardant effect can be improved to a certain extent, the problems of precipitation, migration and the like of the flame retardant are easy to occur, so that the flame retardant performance is attenuated, water flow and surrounding environment in a pipeline are possibly polluted, and the safety and environmental protection requirements of an underground pipeline (culvert) cannot be met. Therefore, research and development of repair materials with high-efficiency flame retardant performance and environmental protection stability have become urgent demands for guaranteeing fire safety of underground pipeline closed space. In the prior art, aiming at the modification of polyurea materials, the improvement is focused on improving the adhesive force or corrosion resistance, for example, china patent with publication number of CN107522842A discloses a polyurethane prepolymer, a polyurea material, a preparation method and application thereof, and the polyurethane prepolymer and the polyurea material react with diamine by utilizing the prepolymer containing micro-branched polyester polyol, so as to solve the problems of the adhesive force and the impact strength of the electromagnetic wave protective coating under high filling amount, and the technical purpose and the application scene are essentially different from those of the mechanical property and the flame retardant property required by the restoration of the underground pipeline. For another example, chinese patent publication No. CN109134813a d