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CN-121086519-B - Automobile nylon pipe and preparation method thereof

CN121086519BCN 121086519 BCN121086519 BCN 121086519BCN-121086519-B

Abstract

The invention relates to the technical field of nylon tube preparation, and particularly discloses an automobile nylon tube and a preparation method thereof, wherein polyamide PA66 resin, polyborosiloxane, sulfonated polyarylethersulfone, metal phosphonate, boron nitride nanosheets, maleic anhydride grafted SEBS, an antioxidant and a lubricant are used as raw materials for preparation; according to the invention, through the neutralization reaction of sulfonic acid groups of sulfonated polyarylethersulfone and ammonia, a corrosion medium is consumed and fixed, the coordination effect is formed by utilizing amide bonds in polyborosiloxane and polyamide molecular chains, the molecular structure is stabilized, the hydrolysis reaction activity is reduced, and the initiation and the expansion of microcracks are inhibited through the synergistic toughening effect of maleic anhydride grafted SEBS and boron nitride nanosheets. The synergistic effect of the components delays the mechanical property attenuation of the material in an ammonia water environment, and improves the long-term durability of the nylon tube.

Inventors

  • YANG TING

Assignees

  • 浙江铁马科技股份有限公司

Dates

Publication Date
20260508
Application Date
20250911

Claims (8)

  1. 1. The nylon pipe for the automobile is characterized by comprising the following raw materials in parts by weight: 50-70 parts of polyamide PA66 resin, 5-15 parts of polyborosiloxane, 5-12 parts of sulfonated polyarylethersulfone, 4-10 parts of metal phosphonate, 1-5 parts of boron nitride nanosheets, 8-18 parts of maleic anhydride grafted SEBS, 0.3-1 part of antioxidant and 0.5-2 parts of lubricant; The metal phosphonate is prepared by reacting diethyl aluminum phosphinate with ammonium polyphosphate; The sulfonation degree of the sulfonated polyarylethersulfone is 30-50%; the method for preparing the automobile nylon pipe comprises the following steps: S1, pretreatment, namely vacuum drying PA66 resin for 4-6 hours at 80-100 ℃, and pre-dispersing boron nitride nano-sheets and 5-10% of lubricant through a high-speed mixer to form uniform slurry; s2, segmented melt blending, namely premixing pre-dispersed boron nitride nanosheet slurry with maleic anhydride grafted SEBS for 5-10 minutes, adding dried PA66, polyborosiloxane, sulfonated polyarylethersulfone, metal phosphonate and other residual components, and melt blending through a double-screw extruder; S3, granulating, namely cooling the extruded material strips to 30-50 ℃ and then granulating to obtain composite material particles; S4, pipe molding, namely extruding the composite material particles through a single screw extruder, wherein the extrusion temperature is 240-255 ℃, the screw rotating speed is 20-40rpm, and vacuum cooling and molding are carried out by adopting a sizing sleeve, wherein the pipe wall thickness of the obtained nylon pipe is 1.0-3.0mm, and the inner diameter is 5-20mm.
  2. 2. The nylon pipe of claim 1, wherein the mass ratio of the aluminum diethylphosphinate to the ammonium polyphosphate is 1:2-1:4.
  3. 3. The nylon tube of claim 1, wherein the boron content of the polyborosiloxane is 8-12wt% and the molecular weight is 3000-8000g/mol.
  4. 4. The nylon tube of claim 1, wherein the average particle size of the boron nitride nanoplatelets is 50-150nm.
  5. 5. The nylon pipe of claim 1, wherein the mass ratio of the maleic anhydride grafted SEBS to the polyborosiloxane is 1:0.5-1.2.
  6. 6. A method of making an automotive nylon tube according to any one of claims 1-5, comprising the steps of: S1, pretreatment, namely vacuum drying PA66 resin for 4-6 hours at 80-100 ℃, and pre-dispersing boron nitride nano-sheets and 5-10% of lubricant through a high-speed mixer to form uniform slurry; s2, segmented melt blending, namely premixing pre-dispersed boron nitride nanosheet slurry with maleic anhydride grafted SEBS for 5-10 minutes, adding dried PA66, polyborosiloxane, sulfonated polyarylethersulfone, metal phosphonate and other residual components, and melt blending through a double-screw extruder; S3, granulating, namely cooling the extruded material strips to 30-50 ℃ and then granulating to obtain composite material particles; S4, pipe molding, namely extruding the composite material particles through a single screw extruder, wherein the extrusion temperature is 240-255 ℃, the screw rotating speed is 20-40rpm, and vacuum cooling and molding are carried out by adopting a sizing sleeve, wherein the pipe wall thickness of the obtained nylon pipe is 1.0-3.0mm, and the inner diameter is 5-20mm.
  7. 7. The method of claim 6, wherein in step S2, the boron nitride nanoplatelets are pre-dispersed with a portion of the lubricant to form a slurry, and then pre-mixed with the maleic anhydride grafted SEBS for 5-10 minutes.
  8. 8. The method according to claim 6, wherein the sectional temperature of the twin-screw extruder in step S2 is set to 240℃in one zone, 250℃in two zones, 255℃in three zones, and 250℃in the head.

Description

Automobile nylon pipe and preparation method thereof Technical Field The invention belongs to the technical field of nylon tube preparation, and particularly relates to an automobile nylon tube and a preparation method thereof. Background The global automobile industry is accelerating to change to low carbonization and clean, and the 'carbon neutralization' target promotes the industry to actively develop novel environment-friendly fuel for replacing traditional fuel. The traditional fuel automobile combustion process can produce pollutants such as carbon dioxide, nitrogen oxides and the like, which do not conform to the current environmental protection concept, while the hydrogen is clean fuel, but has the problems of high storage and transportation cost, severe safety requirement and the like. The ammonia gas only generates nitrogen and water when in combustion, no carbon dioxide is discharged, the storage and transportation difficulty is lower than that of hydrogen, the cost is more controllable, and the ammonia gas is gradually introduced into the automobile industry. At present, an ammonia fuel automobile enters a prototype verification and test stage, various demonstration automobile types exist at home and abroad, an ammonia power zero-emission semi-trailer truck is tested in 2023 of America Amogy company, the ignition of a liquid ammonia direct-injection internal combustion engine truck developed by the national liberation of gas is realized in the same year, and an ammonia-hydrogen fuel cell passenger car with the cooperation of Fuda Dajinyuan hydrogen and Xiamen is put into operation. In the connecting pipelines of the ammonia storage, conveying and conversion devices of the vehicle types, nylon pipes are adopted in a large number as core transmission components. The nylon pipes are mostly prepared from PA66 engineering plastics, and PA66 is a main stream material in the field because of high mechanical strength and temperature resistance, and the PA66 is suitable for the conventional working conditions of automobiles. The nylon pipe can be contacted with two types of water in the ammonia transmission process, namely, the temperature fluctuation in an engine cabin is large, water vapor in air is easy to condense into liquid water on the surface of a pipeline, and the water vapor is difficult to completely remove trace water in the actually filled ammonia fuel and enters a pipeline system together with the fuel. Ammonia itself is an alkaline gas that, upon contact with such moisture, reacts to form chemically corrosive ammonia. When the PA66 nylon tube is in an environment containing ammonia for a long time (the exposure time is usually more than 3000 hours, namely more than 4 months), ammonia water can act on amide bonds in a PA66 molecular chain gradually, so that the amide bonds are broken, the structure of the PA66 molecular chain is damaged, microcracks are gradually generated on the surface of the nylon tube along with the continuous process, the microcracks are continuously expanded along with the prolonged use time, so that the mechanical strength of the nylon tube is continuously reduced, the problem of ammonia leakage is possibly caused finally, the operation failure of an automobile power system is possibly caused, and the safety risk is possibly caused by the ammonia leakage. Disclosure of Invention The invention aims to provide an automobile nylon pipe and a preparation method thereof, which are used for solving the problems in the background technology. In order to achieve the above purpose, the present invention provides the following technical solutions: The nylon pipe for the automobile comprises, by weight, 50-70 parts of polyamide PA66 resin, 5-15 parts of polyborosiloxane, 5-12 parts of sulfonated polyarylethersulfone, 4-10 parts of metal phosphonate, 1-5 parts of boron nitride nano-sheet, 8-18 parts of maleic anhydride grafted SEBS, 0.3-1 part of antioxidant and 0.5-2 parts of lubricant. Preferably, the metal phosphonate is prepared by reacting aluminum diethylphosphinate with ammonium polyphosphate. Preferably, the mass ratio of the diethyl phosphinate aluminum to the ammonium polyphosphate is 1:2-1:4. Preferably, the boron content of the polyborosiloxane is 8-12wt% and the molecular weight is 3000-8000g/mol. Preferably, the sulfonation degree of the sulfonated polyarylethersulfone is 30-50%. Preferably, the average particle size of the boron nitride nano-sheet is 50-150nm. Preferably, the mass ratio of the maleic anhydride grafted SEBS to the polyborosiloxane is 1:0.5-1.2. The invention also provides a preparation method of the automobile nylon pipe, which comprises the following steps: S1, pretreatment, namely vacuum drying PA66 resin for 4-6 hours at 80-100 ℃, and pre-dispersing boron nitride nano-sheets and 5-10% of lubricant through a high-speed mixer to form uniform slurry; s2, segmented melt blending, namely premixing pre-dispersed boron nitride nanosheet slurry with ma