A toughened oil-absorbing bellows and a preparation method thereof
By using PA6 and maleic anhydride grafting POE in nylon corrugated pipe and adding modifiers, toughened oil-absorbing bellows were prepared, which solved the problems of insufficient toughness and poor flame retardant performance of traditional nylon corrugated pipes, and achieved high toughness, excellent mechanical properties and stable flame retardant performance.
Patent Information
- Application Number
- CN202411974618.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-04-08
AI Technical Summary
Traditional nylon corrugated pipes have poor rebound force after the opening is subjected to stress, lack of toughness, and have certain safety hazards, making it difficult to meet higher mechanical properties and flame retardant requirements.
Using PA6 as the matrix, maleic anhydride grafted POE and modifier were added, and toughened oil-absorbing corrugated pipe was prepared by melt blending, extrusion, mold setting and water cooling in a twin-screw extruder. The modifier contains polysiloxane chains, cage-shaped phosphonate structures and sulfur elements, which improves the flame retardant and mechanical properties of the material.
It significantly improves the toughness and mechanical properties of the bellows, enhances its flame retardant and corrosion resistance, and has stable performance, and is suitable for higher requirements application scenarios.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of corrugated pipes, and in particular, relates to a toughened corrugated pipe and a preparation method thereof. Background Art
[0002] The bellows is a cylindrical thin-walled corrugated shell with multiple transverse corrugations. It is a tubular elastic sensitive element, which is made of foldable corrugated sheets connected along the folding and stretching direction. The main characteristics of the bellows are that it can produce displacement under the action of pressure, axial force, transverse force or bending moment, and it has elasticity. Due to its special structure, it has been widely used in aerospace, aviation, shipbuilding, automobiles, transportation and new buildings in recent years, and has broad application prospects.
[0003] In the automotive industry, bellows are often used as wire harness protection to protect automotive wiring harnesses from damage by external environments such as wear, corrosion and impact. They are also used to protect automotive tailpipes, exhaust pipes and other components to prevent them from being eroded by high temperatures and corrosion. Bellows are made of metal or non-metallic materials, and with the development of lightweight automobiles, non-metallic bellows are receiving more and more attention. Commonly used materials are polypropylene (PP) and polyamide (PA), among which polyamide is also called nylon, which is a general term for thermoplastic resins containing repeated amide groups (-NHCO-) on the molecular chain. It has excellent mechanical properties, hydrophilicity, oil absorption, wear resistance, corrosion resistance and easy processing and molding. It has unique advantages in automotive bellows and is widely used. However, as people's needs continue to increase, the traditional nylon bellows have poor resilience after the opening is subjected to force, and it is necessary to improve the mechanical properties of the bellows, especially the toughness. For nylon materials, toughness refers to the ability of the material to absorb energy during plastic deformation and fracture. The better the toughness, the less likely it is to have brittle fracture. In addition, although nylon itself has certain flame retardant properties, there are still certain safety hazards. Therefore, it is urgent to solve the above problems to meet the higher demands in the field of bellows technology. Summary of the invention
[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a toughened corrugated oil suction pipe and a preparation method thereof.
[0005] The purpose of the present invention can be achieved through the following technical solutions:
[0006] A method for preparing a toughened oil-absorbing bellows comprises the following steps:
[0007] PA6 and maleic anhydride grafted POE are dried in an oven for 24 hours, and then mixed with a modifier, a processing aid and an antioxidant in a mixer until the mixture is uniform, and then added to a twin-screw extruder, melt blended, extruded, fixed in a mold, and water-cooled to obtain a toughened oil-absorbing bellows.
[0008] Furthermore, the raw materials are calculated in parts by weight as follows: 80-90 parts of PA6, 10-16 parts of maleic anhydride grafted POE, 5-15 parts of modifier, 4-6 parts of processing aid, and 5-9 parts of antioxidant.
[0009] Furthermore, the processing aid is one of olive oil, paraffin and zinc stearate.
[0010] Furthermore, the antioxidant is a hindered phenol antioxidant.
[0011] With PA6 as the matrix, the corrugated pipe is endowed with excellent mechanical properties, heat resistance and corrosion resistance; maleic anhydride grafted POE significantly improves the toughness of the material by introducing highly polar maleic anhydride side groups on the non-polar POE molecular main chain. Using it as a raw material can greatly enhance the toughness of the corrugated pipe.
[0012] Furthermore, the modifier is prepared by the following steps:
[0013] S1. Add pentaerythritol and trichlorothiophosphorus to a four-necked flask equipped with a thermometer and a reflux condenser, stir evenly, heat in an oil bath, and set the reaction temperature to 150°C. Reflux for 6 hours until no hydrogen chloride gas is released. Continue to heat to 170°C and heat for another hour. When the reaction is complete, wait for the device to cool to room temperature, extract with boiling water for 4 times, remove the sticky substance at the bottom of the bottle by decantation, concentrate to remove part of the water, cool and crystallize, filter with suction, and dry to obtain intermediate 1; the ratio of pentaerythritol to trichlorothiophosphorus is 16.7g:14.1g;
[0014] Pentaerythritol undergoes a nucleophilic substitution reaction with phosphorus trichloride to obtain intermediate 1; the structure of intermediate 1 is shown below:
[0015]
[0016] S2. In a three-necked flask equipped with a stirring device, nitrogen is introduced into the air in the device, and then intermediate 1, glutaryl chloride and N,N-dimethylformamide are added. After stirring and mixing, 4-dimethylaminopyridine (DMAP, catalyst) and triethylamine (acid binding agent) are added. After stirring and mixing again, the reaction temperature is controlled to 65°C, and the reaction is kept warm for 4 hours. Stirring is continued during the reaction. After the reaction is completed, the reaction is filtered, and the solvent is removed by distillation under reduced pressure. The mixture is washed with deionized water and dried in vacuo to obtain intermediate 2. The ratio of the amount of intermediate 1, glutaryl chloride, N,N-dimethylformamide, 4-dimethylaminopyridine and triethylamine is 19.6 g:18.2 g:100 mL:0.2 g:15 mL;
[0017] Under the catalysis of 4-dimethylaminopyridine and triethylamine, the acyl chloride on glutaryl chloride and the hydroxyl group on intermediate 1 undergo acylation reaction. By controlling the molar ratio of the two to be close to 1:1 and the glutaryl chloride to be slightly excessive, only one acyl chloride on glutaryl chloride participates in the reaction to obtain intermediate 2. The specific reaction process is shown below:
[0018]
[0019] S3, at room temperature, under nitrogen protection, in a three-necked flask equipped with a stirring device, the intermediate 2, 3-butene-1-ol and N,N-dimethylformamide were stirred and mixed uniformly, and then 4-dimethylaminopyridine and triethylamine were added. After stirring and mixing again, the reaction temperature was controlled to 70°C, and the reaction was kept warm for 6 hours. Stirring was continued during the reaction. After the reaction was completed, part of the solvent was distilled off under reduced pressure, and then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 4:1), the eluent was removed by rotary evaporation, and vacuum drying was performed to obtain intermediate 3; the ratio of the amount of intermediate 2, 3-butene-1-ol, N,N-dimethylformamide, 4-dimethylaminopyridine, and triethylamine was 32.7g:7.2g:100mL:0.2g:15mL;
[0020] Under the catalysis of 4-dimethylaminopyridine and triethylamine, the acyl chloride on intermediate 2 and the hydroxyl group on 3-butene-1-ol undergo acylation reaction to obtain intermediate 3; the specific reaction process is shown below:
[0021]
[0022] S4. In a four-necked flask equipped with a thermometer and a reflux condenser, add hydrogenated silicone oil, N,N-dimethylformamide and Speier catalyst, stir at 55°C for 30 min, add intermediate 3, control the reaction temperature to 80°C, keep the reaction warm for 6 h, stop heating, stir at room temperature for 5 h, filter, and rotary evaporate to obtain a modifier; the ratio of hydrogenated silicone oil, N,N-dimethylformamide, Speier catalyst, and intermediate 3 is 10g:100mL:0.5mL:4.3g; wherein the Speier catalyst is prepared by dissolving 0.1g of chloroplatinic acid in 100g of isopropanol and stirring at room temperature;
[0023] Under the catalysis of Speier catalyst, hydrogen-containing silicone oil and intermediate 3 undergo a hydrosilylation reaction to obtain a modifier; the specific reaction process is as follows:
[0024]
[0025] The modifier prepared by the present invention is mainly composed of polysiloxane chains. Due to its unique structure, the polysiloxane has very low surface energy, which can improve the corrosion resistance of the nylon matrix. In addition, the bond length of the silicon-oxygen bond is more flexible than that of the carbon-carbon bond, which can enhance the mechanical properties of the matrix to a certain extent. In addition, the modifier molecule also contains a caged phosphonate structure and sulfur elements. The caged phosphonate is a phosphorus-based flame retardant with strong stability. When burned, it can promote the formation of a carbon layer and inhibit the release of smoke. The sulfur atoms can release non-combustible gases, such as sulfur dioxide, during the combustion process. These gases can dilute the concentration of combustible gases and oxygen, and can synergize with the phosphorus element in the caged phosphonate to promote the dehydration of the substrate into carbon, enhance the condensed phase flame retardant effect, and significantly enhance the flame retardant performance of the matrix. Finally, the prepared modifier is a macromolecule, which has better migration resistance and exudation resistance and stronger stability than small molecule additives.
[0026] Beneficial effects of the present invention:
[0027] 1. The bellows prepared by the present invention uses PA6 as a matrix, which gives the bellows excellent mechanical properties and corrosion resistance;
[0028] 2. Adding maleic anhydride grafted POE into the raw materials greatly enhances the toughness of the bellows;
[0029] 3. The prepared modifier molecules contain various functional groups, which can greatly enhance the flame retardancy and mechanical properties of the bellows, and can further improve the corrosion resistance of the bellows, and the performance is stable;
[0030] Therefore, the corrugated pipe produced by the present invention has high toughness, good mechanical properties, stable and efficient flame retardancy and corrosion resistance, and has important application value in the field of corrugated pipe technology. DETAILED DESCRIPTION
[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0032] Embodiment 1
[0033] Preparation of modifier:
[0034] S1. In a four-necked flask equipped with a thermometer and a reflux condenser, add 16.7 g of pentaerythritol and 14.1 g of trichlorothiophosphorus, stir evenly, heat in an oil bath, the reaction temperature is 150°C, reflux for 6 h, until no hydrogen chloride gas is released, continue to heat to 170°C, and heat for another 1 h. After the reaction is completed, wait for the device to cool to room temperature, extract with 500 mL of boiling water 4 times, and then remove the sticky substance at the bottom of the bottle by decantation. Concentrate to remove half of the water, cool and crystallize, filter with suction, and dry to obtain intermediate 1;
[0035] S2. In a three-necked flask equipped with a stirring device, nitrogen was introduced into the air in the exhaust device, and then 19.6 g of intermediate 1, 18.2 g of glutaryl chloride and 100 mL of N,N-dimethylformamide were added, and after stirring and mixing, 0.2 g of 4-dimethylaminopyridine and 15 mL of triethylamine were added. After stirring and mixing again, the reaction temperature was controlled to 65°C, and the reaction was kept warm for 4 hours. Stirring was continued during the reaction. After the reaction was completed, the mixture was filtered, the solvent was removed by distillation under reduced pressure, the mixture was washed with deionized water, and vacuum dried to obtain intermediate 2;
[0036] S3, at room temperature, under nitrogen protection, in a three-necked flask equipped with a stirring device, 32.7g of intermediate 2, 7.2g of 3-butene-1-ol and 100mL of N,N-dimethylformamide were stirred and mixed evenly, and then 0.2g of 4-dimethylaminopyridine and 15mL of triethylamine were added. After stirring and mixing again, the reaction temperature was controlled to 70°C, and the reaction was kept warm for 6h. Stirring was continued during the reaction. After the reaction was completed, part of the solvent was distilled off under reduced pressure, and then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 4:1), the eluent was removed by rotary evaporation, and vacuum drying was performed to obtain intermediate 3;
[0037] S4. In a four-necked flask equipped with a thermometer and a reflux condenser, add 10 g of hydrogenated silicone oil, 100 mL of N,N-dimethylformamide and 0.5 mL of Speier catalyst, stir at 55 °C for 30 min, then add 4.3 g of intermediate 3, control the reaction temperature to 80 °C, keep the reaction warm for 6 h, stop heating, stir at room temperature for 5 h, filter and rotary evaporate to obtain a modifier; wherein the Speier catalyst is prepared by dissolving 0.1 g of chloroplatinic acid in 100 g of isopropanol and stirring at room temperature.
[0038] Embodiment 2
[0039] Preparation of modifier:
[0040] S1. In a four-necked flask equipped with a thermometer and a reflux condenser, add 33.4 g of pentaerythritol and 28.2 g of trichlorothiophosphorus, stir evenly, heat in an oil bath, the reaction temperature is 150°C, reflux for 6 h, until no hydrogen chloride gas is released, continue to heat to 170°C, and heat for another 1 h. After the reaction is completed, wait for the device to cool to room temperature, extract with 500 mL of boiling water 4 times, and then remove the sticky substance at the bottom of the bottle by decantation, concentrate to remove half of the water, and then cool and crystallize, filter, and dry to obtain intermediate 1;
[0041] S2. In a three-necked flask equipped with a stirring device, nitrogen was introduced into the air in the exhaust device, and then 39.2 g of intermediate 1, 36.4 g of glutaryl chloride and 200 mL of N,N-dimethylformamide were added. After stirring and mixing, 0.4 g of 4-dimethylaminopyridine and 30 mL of triethylamine were added. After stirring and mixing again, the reaction temperature was controlled to 65°C, and the reaction was kept warm for 4 hours. Stirring was continued during the reaction. After the reaction was completed, the mixture was filtered, the solvent was removed by distillation under reduced pressure, the mixture was washed with deionized water, and vacuum dried to obtain intermediate 2;
[0042] S3, at room temperature, under nitrogen protection, in a three-necked flask equipped with a stirring device, 65.4g of intermediate 2, 14.4g of 3-butene-1-ol and 200mL of N,N-dimethylformamide were stirred and mixed evenly, and then 0.4g of 4-dimethylaminopyridine and 30mL of triethylamine were added. After stirring and mixing again, the reaction temperature was controlled to 70°C, and the reaction was kept warm for 6h. Stirring was continued during the reaction. After the reaction was completed, part of the solvent was distilled off under reduced pressure, and then purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 4:1), the eluent was removed by rotary evaporation, and vacuum drying was performed to obtain intermediate 3;
[0043] S4. In a four-necked flask equipped with a thermometer and a reflux condenser, add 20 g of hydrogenated silicone oil, 200 mL of N,N-dimethylformamide and 1 mL of Speier catalyst, stir at 55 °C for 30 min, then add 8.6 g of intermediate 3, control the reaction temperature to 80 °C, keep the reaction warm for 6 h, stop heating, stir at room temperature for 5 h, filter and rotary evaporate to obtain a modifier; wherein the Speier catalyst is prepared by dissolving 0.1 g of chloroplatinic acid in 100 g of isopropanol and stirring at room temperature.
[0044] Embodiment 3
[0045] 80g PA6 and 10g maleic anhydride grafted POE were dried in an oven for 24h, and then mixed with 5g of the modifier prepared in Example 1, 4g of olive oil and 5g of antioxidant 1010 in a blender until the mixture was uniform. The mixture was added to a twin-screw extruder, melt blended and extruded to obtain a toughened oil-absorbing bellows material.
[0046] Embodiment 4
[0047] 85g PA6 and 13g maleic anhydride grafted POE were dried in an oven for 24h, and then mixed with 10g of the modifier prepared in Example 2, 5g of paraffin wax and 7g of antioxidant 1010 in a blender until the mixture was uniform. The mixture was added to a twin-screw extruder, melt blended and extruded to obtain a toughened oil-absorbing bellows material.
[0048] Embodiment 5
[0049] 90g PA6 and 16g maleic anhydride grafted POE were dried in an oven for 24h, and then mixed with 15g of the modifier prepared in Example 2, 6g of zinc stearate and 9g of antioxidant 1010 in a blender until the mixture was uniform. The mixture was added to a twin-screw extruder, melt blended and extruded to obtain a toughened oil-absorbing bellows material.
[0050] Embodiment 6
[0051] 90g PA6 and 16g maleic anhydride grafted POE were dried in an oven for 24h, and then mixed with 15g of the modifier prepared in Example 2, 6g of zinc stearate and 9g of antioxidant 1010 in a blender until the mixture was uniform. The mixture was added to a twin-screw extruder, melt blended, extruded, fixed in mold, and water-cooled to obtain a toughened oil-absorbing bellows.
[0052] Comparative Example 1
[0053] A commercially available flame retardant was used to replace the modifier in Example 5.
[0054] Comparative Example 2
[0055] Use commercially available nylon bellows material.
[0056] Embodiments 3, 4, 5, and comparative examples 1 and 2 were made into corresponding shapes according to different test standards, and the following performance tests were performed:
[0057] The tensile strength was determined using the national standard GB / T 1040-2006 "Determination of tensile properties of plastics";
[0058] Determine the tensile properties of the samples after alkali treatment and acid treatment (GB / T1040.2-2006), and calculate the tensile strength retention rate; tensile strength retention rate = tensile strength after test / tensile strength before test × 100%;
[0059] Alkali treatment: sodium hydroxide solution with a pH value of 12 in a 50°C water bath for 6 hours;
[0060] Acid treatment: hydrochloric acid solution with a pH value of 3 in a 50°C water bath for 6 hours;
[0061] The impact strength is measured using the national standard GB / T 1043.1-2008 "Determination of impact properties of simply supported plastic beams Part 1: Non-instrumented impact test";
[0062] The limiting oxygen index of the sample was measured according to the national standard GB / T 2406-2008 "Test Method for Combustion Performance of Plastics", and then the limiting oxygen index of Examples 3, 4, 5 and Comparative Example 1 was measured after being left to stand at room temperature for 300 days;
[0063] The measured results are shown in the following table:
[0064]
[0065] It can be seen from the above table that the tensile strength, impact strength, acid and alkali resistance and oxygen index of the corrugated pipe prepared in the embodiment of the present invention are higher than those of the comparative example, so the performance is better than the comparative example, and the excellent flame retardant performance can still be guaranteed after standing at room temperature for 300 days, which has important application value in the field of corrugated pipe technology.
[0066] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.
[0067] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.
Claims
1. A method for preparing a toughened oil-absorbing bellows, characterized in that: The following steps are involved: PA6 and maleic anhydride grafted POE are dried in an oven for 24 hours, and then mixed with a modifier, a processing aid and an antioxidant in a mixer until the mixture is uniform, and then added to a twin-screw extruder, melt blended, extruded, fixed in a mold, and water-cooled to obtain a toughened oil-absorbing bellows.
2. The method for preparing a toughened oil-absorbing bellows according to claim 1, characterized in that: The modifying agent is prepared by the following steps: S1. Add pentaerythritol and trichlorothiophosphorus into a four-necked bottle, stir evenly, heat in an oil bath, reflux for 6 hours at 150°C, until no hydrogen chloride gas is released, continue to heat to 170°C, heat for another hour, and the reaction is complete. Cool, extract with boiling water, remove the sticky substance at the bottom of the bottle by decantation, concentrate to remove part of the water, cool and crystallize, filter, and dry to obtain intermediate 1; S2, nitrogen was introduced into a three-necked flask, and intermediate 1, glutaryl chloride and N,N-dimethylformamide were added, and after stirring and mixing, 4-dimethylaminopyridine and triethylamine were added, and after stirring and mixing again, the mixture was reacted at 65° C. for 4 h, with continuous stirring during the reaction. After the reaction was completed, the mixture was filtered, distilled under reduced pressure, washed, and dried in vacuo to obtain intermediate 2; S3, at room temperature, under nitrogen protection, the intermediates 2, 3-butene-1-ol and N,N-dimethylformamide were stirred and mixed uniformly, and then 4-dimethylaminopyridine and triethylamine were added, and the mixture was stirred and mixed again, and the mixture was kept at 70°C for 6 hours, with continuous stirring during the reaction. After the reaction was completed, the mixture was distilled under reduced pressure, purified by column chromatography, rotary evaporated, and dried in vacuo to obtain the intermediate 3; S4. In a four-necked bottle, add hydrogenated silicone oil, N,N-dimethylformamide and Speier catalyst, stir at 55°C for 30 min, then add intermediate 3, keep warm at 80°C for 6 h, stop heating, stir at room temperature for 5 h, filter and rotary evaporate to obtain the modifier.
3. The method for preparing a toughened oil-absorbing bellows according to claim 2, characterized in that: In step S1, the ratio of pentaerythritol to phosphorus thiochloride is 16.7 g:14.1 g.
4. The method for preparing a toughened oil-absorbing bellows according to claim 2, characterized in that: In step S2, the ratio of the amount of intermediate 1, glutaryl chloride, N,N-dimethylformamide, 4-dimethylaminopyridine and triethylamine is 19.6 g:18.2 g:100 mL:0.2 g:15 mL.
5. The method for preparing a toughened oil-absorbing bellows according to claim 2, characterized in that: In step S3, the ratio of the amount of intermediate 2, 3-butene-1-ol, N,N-dimethylformamide, 4-dimethylaminopyridine and triethylamine used is 32.7 g:7.2 g:100 mL:0.2 g:15 mL.
6. The method for preparing a toughened oil-absorbing bellows according to claim 2, characterized in that: In step S4, the ratio of the amount of hydrogen-containing silicone oil, N,N-dimethylformamide, Speier catalyst, and intermediate 3 is 10 g: 100 mL: 0.5 mL: 4.3 g.
7. The method for preparing a toughened oil-absorbing bellows according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 80-90 parts of PA6, 10-16 parts of maleic anhydride grafted POE, 5-15 parts of modifier, 4-6 parts of processing aid, and 5-9 parts of antioxidant.
8. The method for preparing a toughened oil-absorbing bellows according to claim 1, characterized in that: The processing aid is one of olive oil, paraffin and zinc stearate.
9. The method for preparing a toughened oil-absorbing bellows according to claim 1, characterized in that: The antioxidant is a hindered phenol antioxidant.
10. A toughened oil-absorbing bellows, characterized in that: Prepared according to the method according to any one of claims 1 to 9.