Sound-insulation and pressure-resistant PE pipe and preparation method thereof

Abstract

The invention discloses a sound-proof and pressure-resistant PE pipe and a preparation method thereof, and belongs to the technical field of PE pipes. Comprising the following raw materials in parts by weight: 70-80 parts of high-density polyethylene, 12-18 parts of thermoplastic elastomer SBS, 20-25 parts of asbestos fibers, 6-12 parts of a modifier, 0.1-0.3 part of an initiator and 3-5 parts of a processing aid. The prepared PE pipe takes high-density polyethylene as a matrix, so that the pipe is endowed with excellent mechanical properties; wherein the thermoplastic elastomer SBS can enhance the toughness of the pipe and improve the pressure resistance of the pipe; wherein the asbestos fiber can enhance the sound insulation property of the pipe; wherein the modifier can improve the waterproof, anti-aging and mechanical properties of the PE pipe, and the performance is long-term and stable, and the PE pipe is not easy to fall off; therefore, the prepared PE pipe is excellent in mechanical property, good in pressure resistance and strong in sound insulation, also has stable and efficient water resistance and aging resistance, and has important application value in the technical field of PE pipes.

Description

Technical Field

[0001] The present invention belongs to the technical field of PE pipes, and in particular, relates to a sound-insulating and pressure-resistant PE pipe and a preparation method thereof. Background Art

[0002] With the development of society and the construction industry, the use of pipes has increased year by year, and the development of pipes with excellent performance has great market potential. Common pipes on the market are plastic pipes and steel pipes. Steel pipes are heavy, inconvenient to transport and install, and easy to rust in a humid environment. These defects hinder the further development of steel pipes. Plastic pipes are generally made of synthetic resin as raw material, stabilizers, lubricants, plasticizers, etc., and are extruded in a pipe making machine by the "plastic" method. Because it has the characteristics of light weight, corrosion resistance, beautiful appearance, no bad smell, easy processing, and convenient construction, it is widely used in building drainage, buried drainage pipes, building heating, gas transmission and distribution, gas pipelines, electrical and telecommunications protective casings, industrial pipes, agricultural pipes and other fields.

[0003] Common plastic pipes are divided into polyvinyl chloride pipes, polyethylene pipes and polypropylene pipes according to the materials. The raw material of polyethylene pipes is polyethylene, which is a thermoplastic resin made from ethylene monomers through polymerization. It has good comprehensive properties, is non-toxic, easy to shape and process, and is cheap. It is the most widely used general plastic in the world. Polyethylene material is a non-inert material, resistant to corrosion by a variety of chemicals, and not easy to breed bacteria. It is widely used due to its excellent performance. However, the existing polyethylene pipes have poor pressure resistance and buffering capacity, insufficient mechanical properties, and poor aging resistance. In addition, polyethylene cannot be used for a long time, and it is easy to generate noise in pipe drainage, which has a great impact on people's lives. Therefore, it is urgent to solve the above problems to meet the higher demands in the field of PE pipe technology. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a sound-insulating and pressure-resistant PE 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 sound-insulating and pressure-resistant PE pipe comprises the following steps:

[0007] After high-density polyethylene and thermoplastic elastomer SBS are dried in an oven, they are added into a mixer with asbestos fiber, modifier, initiator and processing aid, and after being mixed evenly, they are put into a twin-screw extruder, melt-blended, extruded, fixed molded and water-cooled to obtain a sound-insulating and pressure-resistant PE pipe.

[0008] Furthermore, the raw materials are calculated in parts by weight as follows: 70-80 parts of high-density polyethylene, 12-18 parts of thermoplastic elastomer SBS, 20-25 parts of asbestos fiber, 6-12 parts of modifier, 0.1-0.3 parts of initiator, and 3-5 parts of processing aid.

[0009] Furthermore, the initiator is one of benzoyl peroxide, dicumyl peroxide, and tert-butyl perbenzoate.

[0010] Furthermore, the processing aid is one of olive oil, beeswax and zinc stearate.

[0011] With high-density polyethylene as the matrix, it has better mechanical properties than ordinary polyethylene; the addition of thermoplastic elastomer SBS can enhance the toughness of the pipe and improve the pressure resistance of the pipe; the added asbestos fiber is an inorganic sound-absorbing material that can absorb noise inside the pipe, thereby enhancing the sound insulation of the pipe.

[0012] Furthermore, the modifier is prepared by the following steps:

[0013] S1. Add pentaerythritol and toluene to a four-necked flask equipped with a thermometer, an electromagnetic stirrer, a spherical condenser, a drying tube and a tail gas absorption device. After stirring, slowly drop phosphorus trichloride, and control the dropwise addition temperature not to exceed 35° C. After the dropwise addition is completed, heat the device to 75° C. and reflux for 4 hours. After the reaction is completed, distill off the solvent toluene and excess phosphorus trichloride to obtain intermediate 1; the ratio of pentaerythritol, toluene and phosphorus trichloride is 13.6 g:100 mL:28.6 g;

[0014] Pentaerythritol reacts with phosphorus trichloride to obtain intermediate 1; the specific reaction is as follows:

[0015]

[0016] S2. In a three-necked flask equipped with a stirring device, the intermediate 1, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, triethylamine (acid binding agent) and toluene were mixed and stirred uniformly, the reaction temperature was controlled to 75°C, and the reaction was kept warm for 8 hours. After the reaction was completed, the intermediate 1 was filtered, and the solvent was removed by distillation under reduced pressure. The mixture was washed with anhydrous ethanol for 2-3 times and dried in vacuo to obtain the intermediate 2. The ratio of the amount of the intermediate 1, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, triethylamine and toluene was 28.7 g:23.6 g:15 mL:100 mL.

[0017] Under the catalysis of triethylamine, intermediate 1 and 3,5-di-tert-butyl-4-hydroxybenzyl alcohol react, and by controlling the molar ratio of the two to be close to 1:1 and a slight excess of intermediate 1, only one chlorine group on intermediate 1 participates in the reaction to obtain intermediate 2; the specific reaction process is as follows:

[0018]

[0019] S3. In a three-necked flask equipped with a thermometer and a stirring device, 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, 9-decenoic acid and N,N-dimethylformamide (DMF) were mixed and stirred evenly, and then dibutyltin oxide (catalyst) and dicyclohexylcarbodiimide (DCC, dehydrating agent) were added. The temperature of the device was raised to 85°C and the reaction was carried out for 6 hours, and stirring was continued during the reaction. After the reaction was completed, the mixture was filtered and some solvents were removed by rotary evaporation. The mixture was purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 4:1), and the eluent was removed by rotary evaporation to obtain intermediate 3; the ratio of 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, 9-decenoic acid, N,N-dimethylformamide, dibutyltin oxide, and dicyclohexylcarbodiimide was 27.1 g:16.9 g:150 mL:0.4 g:20.6 g;

[0020] Under the catalysis of dibutyltin oxide and DCC, the hydroxyl group on 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane and the carboxyl group on 9-decenoic acid undergo esterification reaction. By controlling the molar ratio of the two to be close to 1:1 and a slight excess of 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, only one hydroxyl group on 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane participates in the reaction to obtain intermediate 3. The specific reaction process is shown below:

[0021]

[0022] S4. In a three-necked flask equipped with a stirring device, the intermediate 2, the intermediate 3, potassium carbonate (acid binding agent) and N, N-dimethylformamide (DMF) were mixed and stirred uniformly, the reaction temperature was controlled to 80°C, and the reaction was kept warm for 8 hours. After the reaction was completed, the mixture was filtered, and part of the solvent was removed by rotary evaporation. The mixture was purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate in a volume ratio of 5:1), and the eluent was removed by rotary evaporation to obtain a modifier; the ratio of the amount of intermediate 2, intermediate 3, potassium carbonate and N, N-dimethylformamide was 46.4 g:40.2 g:15 mL:150 mL;

[0023] Under the catalysis of potassium carbonate, intermediate 2 and intermediate 3 react to obtain a modifier; the structure of the modifier is shown below:

[0024]

[0025] The prepared modifier molecules contain phosphite, hindered phenol, silicon-oxygen bond, long carbon chain and carbon-carbon double bond structure. Phosphite can be used as a kind of auxiliary antioxidant to decompose the hydroperoxide generated in the polymer due to oxidative aging, making it inactive, thereby achieving the purpose of terminating or delaying the oxidative degradation of the polymer; in addition, hindered phenol is used as a main antioxidant. The structure of this type of antioxidant contains -OH functional group, which can provide active hydrogen atoms, capture peroxy free radicals, and can play a synergistic role with phosphite, greatly enhancing the aging resistance of the polyethylene matrix; the introduced silicon-oxygen bond, bond energy The bond length of the silicon-oxygen bond is higher than that of the carbon-carbon bond, which can enhance the mechanical properties of the matrix to a certain extent, reduce the surface energy of the matrix, and improve the waterproof performance of the matrix; in addition, the introduced long carbon chain is a methylene chain segment, which is a flexible chain segment and can be interspersed in the cross-linked structure of the matrix, which not only improves the mechanical properties of the matrix, but also improves the stability of the modifier performance, and can further enhance the waterproof performance of the matrix; finally, the carbon-carbon double bond at one end of the modifier molecule can be cross-linked with the polyethylene matrix under the action of the initiator, further enhancing the stability of the small molecule modifier.

[0026] Beneficial effects of the present invention:

[0027] 1. The PE pipe prepared by the present invention uses high-density polyethylene as a matrix, which gives the pipe excellent mechanical properties;

[0028] 2. Adding thermoplastic elastomer SBS can enhance the toughness of the pipe and improve its pressure resistance;

[0029] 3. Adding asbestos fiber can absorb the noise inside the pipe, thereby enhancing the sound insulation of the pipe;

[0030] 4. The prepared modifier molecules contain various functional groups that can improve the waterproof, aging resistance and mechanical properties of PE pipes, and the performance is long-lasting and stable and not easy to fall off;

[0031] Therefore, the PE pipe prepared by the present invention has excellent mechanical properties, good pressure resistance, strong sound insulation, stable and efficient waterproofness and aging resistance, and has important application value in the field of PE pipe technology. DETAILED DESCRIPTION

[0032] 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.

[0033] Embodiment 1

[0034] Preparation of modifier:

[0035] S1. In a four-necked flask equipped with a thermometer, an electromagnetic stirrer, a spherical condenser, a drying tube and a tail gas absorption device, 13.6 g of pentaerythritol and 100 mL of toluene were added, and after stirring, 28.6 g of phosphorus trichloride was slowly added dropwise, and the dropping temperature was controlled not to exceed 35° C. After the dropping was completed, the device was heated to 75° C. and refluxed for 4 hours. After the reaction was completed, the solvent toluene and excess phosphorus trichloride were distilled off to obtain intermediate 1;

[0036] S2. In a three-necked flask equipped with a stirring device, 28.7 g of intermediate 1, 23.6 g of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, 15 mL of triethylamine and 100 mL of toluene were mixed and stirred evenly, the reaction temperature was controlled to 75° C., and the reaction was kept warm for 8 hours. After the reaction was completed, the mixture was filtered, and the solvent was removed by vacuum distillation. The mixture was washed with anhydrous ethanol for 2-3 times, and vacuum dried to obtain intermediate 2.

[0037] S3, in a three-necked flask equipped with a thermometer and a stirring device, 27.1g 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, 16.9g 9-decenoic acid and 150mL N,N-dimethylformamide were mixed and stirred evenly, and then 0.4g dibutyltin oxide and 20.6g dicyclohexylcarbodiimide were added, and the temperature of the device was raised to 85°C for 6h, and stirring was continued during the reaction. After the reaction was completed, the mixture was filtered, and part of the solvent was removed by rotary evaporation. Then, the mixture was 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), and the eluent was removed by rotary evaporation to obtain intermediate 3;

[0038] S4. In a three-necked flask equipped with a stirring device, 46.4 g of intermediate 2, 40.2 g of intermediate 3, 15 mL of potassium carbonate and 150 mL of N,N-dimethylformamide were mixed and stirred evenly, the reaction temperature was controlled to 80°C, and the reaction was kept warm for 8 hours. After the reaction was completed, it was filtered, and part of the solvent was removed by rotary evaporation. Then it was purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 5:1), and the eluent was removed by rotary evaporation to obtain a modifier.

[0039] Embodiment 2

[0040] Preparation of modifier:

[0041] S1. In a four-necked flask equipped with a thermometer, an electromagnetic stirrer, a spherical condenser, a drying tube and a tail gas absorption device, 27.2 g of pentaerythritol and 200 mL of toluene were added, and after stirring, 57.2 g of phosphorus trichloride was slowly added dropwise, and the dropping temperature was controlled not to exceed 35° C. After the dropping was completed, the device was heated to 75° C. and refluxed for 4 hours. After the reaction was completed, the solvent toluene and excess phosphorus trichloride were distilled off to obtain intermediate 1;

[0042] S2. In a three-necked flask equipped with a stirring device, 57.4 g of intermediate 1, 47.2 g of 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, 30 mL of triethylamine and 200 mL of toluene were mixed and stirred evenly, the reaction temperature was controlled to 75° C., and the reaction was kept warm for 8 hours. After the reaction was completed, the mixture was filtered, the solvent was removed by vacuum distillation, the mixture was washed twice with anhydrous ethanol, and vacuum dried to obtain intermediate 2;

[0043] S3, in a three-necked flask equipped with a thermometer and a stirring device, 54.2g of 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, 33.8g of 9-decenoic acid and 300mL of N,N-dimethylformamide were mixed and stirred uniformly, and then 0.8g of dibutyltin oxide and 41.2g of dicyclohexylcarbodiimide were added, and the temperature of the device was raised to 85°C for 6h, and stirring was continued during the reaction. After the reaction was completed, the mixture was filtered, and part of the solvent was removed by rotary evaporation. The mixture was 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), and the eluent was removed by rotary evaporation to obtain intermediate 3;

[0044] S4. In a three-necked flask equipped with a stirring device, 92.8 g of intermediate 2, 80.4 g of intermediate 3, 30 mL of potassium carbonate and 300 mL of N,N-dimethylformamide were mixed and stirred evenly, the reaction temperature was controlled to 80°C, and the reaction was kept warm for 8 hours. After the reaction was completed, it was filtered, and part of the solvent was removed by rotary evaporation. Then it was purified by column chromatography (the eluent was a mixed solvent of petroleum ether / ethyl acetate, and the volume ratio of the two was 5:1), and the eluent was removed by rotary evaporation to obtain a modifier.

[0045] Embodiment 3

[0046] 70 g of high-density polyethylene and 12 g of thermoplastic elastomer SBS were dried in an oven, and then added to a mixer with 20 g of asbestos fiber, 6 g of the modifier prepared in Example 1, 0.1 g of benzoyl peroxide and 3 g of olive oil. After mixing evenly, the mixture was put into a twin-screw extruder, melt-blended, extruded, fixed in mold, and water-cooled to obtain a PE material.

[0047] Embodiment 4

[0048] 75g of high-density polyethylene and 15g of thermoplastic elastomer SBS were dried in an oven, and then added to a mixer with 23g of asbestos fiber, 9g of the modifier prepared in Example 2, 0.2g of diisopropylbenzene peroxide and 4g of beeswax. After mixing evenly, the mixture was put into a twin-screw extruder, melt-blended, extruded, fixed in mold, and water-cooled to obtain a PE material.

[0049] Embodiment 5

[0050] 80g of high-density polyethylene and 18g of thermoplastic elastomer SBS were dried in an oven, and then added to a mixer with 25g of asbestos fiber, 12g of the modifier prepared in Example 2, 0.3g of tert-butyl perbenzoate and 5g of zinc stearate. After mixing evenly, the mixture was put into a twin-screw extruder for melt blending and extrusion to obtain a PE material.

[0051] Embodiment 6

[0052] 80g of high-density polyethylene and 18g of thermoplastic elastomer SBS were dried in an oven, and then added to a mixer with 25g of asbestos fiber, 12g of the modifier prepared in Example 2, 0.3g of tert-butyl perbenzoate and 5g of zinc stearate. After mixing evenly, the mixture was put into a twin-screw extruder, melt-blended, extruded, fixed in mold, and water-cooled to obtain a sound-insulating and pressure-resistant PE pipe.

[0053] Comparative Example 1

[0054] The modifier in Example 5 was replaced by a commercially available antioxidant of equal quality, and the remaining steps were the same as those in Example 5 to obtain a PE material.

[0055] Comparative Example 2

[0056] Use commercially available high-strength PE masterbatch.

[0057] Comparative Example 3

[0058] Use commercially available PE pipes.

[0059] Embodiments 3, 4, 5 and comparative examples 1 and 2 were made into corresponding shapes according to different test standards and subjected to the following performance tests:

[0060] 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";

[0061] The national standard GB / T 1040.2-2006 "Determination of tensile properties of plastics Part 2: Test conditions for molded and extruded plastics" was used to measure the tensile properties of the sample before and after water treatment, and the tensile strength retention rate was calculated; tensile strength retention rate = tensile strength after test / tensile strength before test × 100%; Water treatment: immerse the sample in water, 55℃ water bath for 12h;

[0062] The national standard GB / T 19466.6-2009 "Plastic Differential Scanning Calorimetry" was used to measure the induction time of the sample before and after hot air oxidation for 48 hours at 75°C.

[0063] The measured results are shown in Table 1:

[0064] Table 1

[0065]

[0066] Take 10m of the pipes prepared in Example 6 and Comparative Example 3 and perform pressure resistance tests under the same conditions.

[0067] Table 2

[0068] Test items Embodiment 6 Comparative Example 3 Compressive strength / MPa 53.6 47.4

[0069] It can be seen from the above table that the PE material prepared in the embodiment of the present invention has higher aging resistance, waterproofness and mechanical properties than the comparative example, and the pipe made from it has a higher compressive strength than the comparative example three. Therefore, the present invention has important application value in the field of PE pipe technology.

[0070] 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.

[0071] 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 sound-insulating and pressure-resistant PE pipe, characterized in that: The following steps are involved: After high-density polyethylene and thermoplastic elastomer SBS are dried in an oven, they are added into a mixer with asbestos fiber, modifier, initiator and processing aid, and after being mixed evenly, they are put into a twin-screw extruder, melt-blended, extruded, fixed molded and water-cooled to obtain a sound-insulating and pressure-resistant PE pipe.

2. The method for preparing a sound-insulating and pressure-resistant PE pipe according to claim 1, characterized in that: The modifying agent is prepared by the following steps: S1. After pentaerythritol and toluene are mixed and stirred, phosphorus trichloride is slowly added dropwise, and the temperature of the addition is controlled not to exceed 35° C. After the addition is completed, reflux reaction is carried out at 75° C. for 4 hours. After the reaction is completed, distillation is performed to obtain intermediate 1; S2, mixing intermediate 1, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, triethylamine and toluene, stirring evenly, keeping warm at 75° C. for 8 h, filtering, distilling under reduced pressure, washing, and vacuum drying to obtain intermediate 2; S3, 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, 9-decenoic acid and N,N-dimethylformamide were mixed and stirred evenly, and then dibutyltin oxide and dicyclohexylcarbodiimide were added, and the mixture was reacted at 85° C. for 6 h, with continuous stirring during the reaction. After the reaction was completed, the mixture was filtered, rotary evaporated, purified by column chromatography, and rotary evaporated to obtain intermediate 3; S4. Mix and stir intermediate 2, intermediate 3, potassium carbonate and N,N-dimethylformamide evenly, and heat-retain at 80°C for 8 hours. After the reaction is completed, filter, rotary evaporate, purify by column chromatography, and rotary evaporate to obtain a modifier.

3. The method for preparing a sound-insulating and pressure-resistant PE pipe according to claim 2, characterized in that: In step S1, the ratio of pentaerythritol, toluene and phosphorus trichloride is 13.6 g:100 mL:28.6 g.

4. The method for preparing a sound-insulating and pressure-resistant PE pipe according to claim 2, characterized in that: In step S2, the ratio of the amount of intermediate 1, 3,5-di-tert-butyl-4-hydroxybenzyl alcohol, triethylamine and toluene is 28.7 g:23.6 g:15 mL:100 mL.

5. The method for preparing a sound-insulating and pressure-resistant PE pipe according to claim 2, characterized in that: In step S3, the ratio of the amount of 1,3-bis(3-hydroxypropyl)-1,1,3,3-tetramethyldisiloxane, 9-decenoic acid, N,N-dimethylformamide, dibutyltin oxide, and dicyclohexylcarbodiimide is 27.1 g:16.9 g:150 mL:0.4 g:20.6 g.

6. The method for preparing a sound-insulating and pressure-resistant PE pipe according to claim 2, characterized in that: In step S4, the ratio of the amount of intermediate 2, intermediate 3, potassium carbonate and N,N-dimethylformamide is 46.4 g:40.2 g:15 mL:150 mL.

7. The method for preparing a sound-insulating and pressure-resistant PE pipe according to claim 1, characterized in that: The raw materials are calculated in parts by weight as follows: 70-80 parts of high-density polyethylene, 12-18 parts of thermoplastic elastomer SBS, 20-25 parts of asbestos fiber, 6-12 parts of modifier, 0.1-0.3 parts of initiator, and 3-5 parts of processing aid.

8. A sound-insulating and pressure-resistant PE pipe, characterized in that: Prepared according to the method according to any one of claims 1 to 7.

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