Preparation method of impact-resistant polyethylene composite pipe

Abstract

The invention relates to a preparation method of an impact-resistant polyethylene composite pipe, and discloses a preparation method of an impact-resistant polyethylene composite pipe, which comprises the following steps: adding polyethylene, nylon 6, polyamide grafted POE (Polyolefin Elastomer), an antioxidant and an assistant into a high-speed mixer for mixing, and then carrying out melt extrusion and molding through a twin-screw extruder. The impact-resistant polyethylene composite pipe is obtained. The main chain of the polyamide grafted POE is an ethylene-octylene copolymer, and the side chain is grafted with a polyamide molecular chain, so that the polyamide grafted POE can be used as a compatilizer of polyethylene and nylon 6, the compatibility between polyethylene and nylon 6 is improved, the polyethylene and nylon 6 form an alloy phase, the mechanical property of the material is improved, and the POE can be used as an elastomer material with high toughness and good mechanical property, so that the mechanical property of the material is improved. The material has a good toughening effect on polyethylene, and the tensile property, the bending strength and the impact strength of the material are remarkably improved.

Description

Technical Field

[0001] The present invention relates to a preparation method of a polyethylene composite pipe with impact resistance, specifically a preparation method of a polyethylene composite pipe with impact resistance. Background Art

[0002] Polyethylene is non-toxic, odorless, has good low-temperature resistance, excellent electrical insulation, is easy to process, and has low cost. It is widely used in pipe materials, wires and cables, packaging materials, agricultural films, etc. Traditional polyethylene and its pipes have low mechanical strength and poor impact resistance and other properties, which limit the practical application of polyethylene materials.

[0003] Combining polyethylene with nylon, polystyrene, ethylene propylene diene monomer rubber, ethylene-octene copolymer POE, etc. can obtain alloy materials with better mechanical properties. Patent CN115960409B discloses a continuous glass fiber-reinforced high-density polyethylene / nylon 12 alloy prepreg tape and its preparation method. Using polyethylene, nylon 12, glass fiber, polyethylene-grafted maleic anhydride compatibilizer, toughening agent, etc. as raw materials, the obtained alloy prepreg tape material has good tensile strength, flexural strength and other properties. However, this patent requires adding additional compatibilizer and toughening agent, and continuous glass fiber needs to be added to achieve the strengthening effect. Summary of the Invention

[0004] (1) Technical problems to be solved: The present invention solves the problem of poor compatibility between polyethylene and nylon 6, and at the same time improves the toughness, impact resistance and other properties of polyethylene and its pipes.

[0005] (2) Technical solution: A preparation method of a polyethylene composite pipe with impact resistance:

[0006] (1) Add xylene and N-(3-aminopropyl) methacrylamide salt-grafted POE to the reaction flask, heat and stir to dissolve, cool to 20-35 °C, and add diacyl chloride compound Diamine compound (H2N-R-NH2), triethylamine, stir and react for 6-8 h, pour the solution into acetone, filter, and wash successively with N,N-dimethylformamide, chloroform, and ethanol, and dry to obtain polyamide-grafted POE. The reaction formula is:

[0007]

[0008] (2) Add polyethylene, nylon 6, polyamide-grafted POE, antioxidant, and additive to a high-speed mixer for mixing, and then melt and extrude through a twin-screw extruder. The temperature of 1-6 sections is 170 °C - 220 °C, and the screw speed is 30-50 r / min; form to obtain a polyethylene composite pipe with impact resistance.

[0009] Preferably, the mass ratio of N-(3-aminopropyl) methacrylamide salt grafted POE, diacyl chloride compound, diamine compound, and triethylamine in (1) is 100:(6-20):(3.4-12.7):(4-11).

[0010] Preferably, the diacyl chloride compound is succinyl chloride, glutaroyl chloride, or adipoyl chloride.

[0011] Preferably, the diamine compound is butanediamine, pentanediamine, or hexanediamine.

[0012] Preferably, the auxiliary agent is zinc stearate or calcium stearate.

[0013] Preferably, the mass ratio of polyethylene, nylon 6, polyamide grafted POE, antioxidant, and auxiliary agent in (2) is (60-80):(20-40):(4-10):(0.3-0.5):(0.07-0.1).

[0014] Preferably, the preparation method of N-(3-aminopropyl) methacrylamide salt grafted POE is as follows: Add ethylene-octene copolymer POE, N-(3-aminopropyl) methacrylamide hydrochloride, and dicumyl peroxide with a mass ratio of 100:(2-5):(0.16-0.4) into a rheometer, carry out melt grafting at 150-160 °C for 6-8 min, add the product into xylene, heat and stir to dissolve, then pour the solution into acetone, filter, wash with acetone, and dry to obtain N-(3-aminopropyl) methacrylamide salt grafted POE.

[0015] (III) Beneficial technical effects: The present invention uses N-(3-aminopropyl) methacrylamide salt to carry out melt grafting on ethylene-octene copolymer POE elastomer, introduces amino groups into the side chains of POE elastomer, and then uses the amino groups as polymerization sites to carry out in-situ polymerization grafting reaction with diacyl chloride compounds and diamine compounds to obtain polyamide grafted POE, thereby introducing polyamide molecular chains into the side chains of POE elastomer.

[0016] The present invention melts and blends polyethylene, nylon 6, polyamide grafted POE, etc., and forms them into polyethylene composite pipes. The main chain of polyamide grafted POE is ethylene-octene copolymer, which has good compatibility with polyethylene resin. At the same time, polyamide molecular chains similar to nylon 6 are grafted on the side chains of POE, so that polyamide grafted POE can be used as a compatibilizer between polyethylene and nylon 6, improve the compatibility between polyethylene and nylon 6, and form an alloy phase between the two, which is beneficial to improving the mechanical properties of the material. And POE, as an elastomer material with high toughness and good mechanical properties, has a good toughening effect on polyethylene, significantly improving the tensile properties, flexural strength, and impact strength of the material. Detailed implementation methods

[0017] The following polyethylene, model Petrochemical 2911, was purchased from Ningbo Keming Plasticizing Co., Ltd. Maleic anhydride grafted POE, model MA8510, from Ningbo Keming Plasticizing Co., Ltd. Ethylene-octene copolymer POE, model PN0040, was purchased from Ningbo Keming Plasticizing Co., Ltd. Nylon 6, model 1030, was purchased from Dongguan Putian Plastic Co., Ltd.

[0018] Example 1

[0019] (1) Add 500 g of ethylene-octene copolymer POE, 18 g of N-(3-aminopropyl) methacrylamide hydrochloride, and 1.4 g of diisopropylbenzene peroxide to a rheometer, and conduct melt grafting at 160 °C for 6 min. Add the product to xylene, heat to 140 °C, condense and reflux while stirring to dissolve, then pour the solution into acetone, wash with acetone after filtration, and dry to obtain N-(3-aminopropyl) methacrylamide salt grafted POE.

[0020] (2) Add 1.2 L of xylene and 100 g of N-(3-aminopropyl) methacrylamide salt grafted POE to a reaction flask, heat to 140 °C, condense and reflux while stirring to dissolve, cool to 35 °C, add 6 g of succinyl chloride, 3.4 g of butanediamine, and 4 g of triethylamine, stir and react for 6 h, pour the solution into acetone, wash successively with N,N-dimethylformamide, chloroform, and ethanol after filtration, and dry to obtain polyamide grafted POE.

[0021] (3) Add 8 kg of polyethylene, 2 kg of nylon 6, 0.4 kg of polyamide grafted POE, 42 g of antioxidant 168, and 10 g of auxiliary agent calcium stearate to a high-speed mixer for mixing, and then melt extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, 220 °C, and the screw speed is 50 r / min; form to obtain an impact-resistant polyethylene composite pipe.

[0022] Comparative Example 1

[0023] (1) Add 8 kg of polyethylene, 2 kg of nylon 6, 42 g of antioxidant 168, and 10 g of auxiliary agent calcium stearate to a high-speed mixer for mixing, and then melt extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, 220 °C, and the screw speed is 50 r / min; form to obtain a polyethylene composite pipe.

[0024] Comparative Example 2

[0025] (1) Add 8 kg of polyethylene, 2 kg of nylon 6, 0.4 kg of ethylene-octene copolymer POE, 42 g of antioxidant 168, and 10 g of auxiliary agent calcium stearate to a high-speed mixer for mixing, and then melt and extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 50 r / min; form to obtain a polyethylene composite pipe.

[0026] Comparative Example 3

[0027] (1) Add 8 kg of polyethylene, 2 kg of nylon 6, 0.4 kg of maleic anhydride POE, 42 g of antioxidant 168, and 10 g of auxiliary agent calcium stearate to a high-speed mixer for mixing, and then melt and extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 50 r / min; form to obtain a polyethylene composite pipe.

[0028] Example 2

[0029] (1) Add 500 g of ethylene-octene copolymer POE, 10 g of N-(3-aminopropyl)methacrylamide hydrochloride, and 0.8 g of diisopropylbenzene peroxide to a rheometer, and perform melt grafting at 155 °C for 6 min. Add the product to xylene, heat to 140 °C, condense and reflux while stirring to dissolve, then pour the solution into acetone, filter, wash with acetone, and dry to obtain N-(3-aminopropyl)methacrylamide salt grafted POE.

[0030] (2) Add 1.5 L of xylene and 100 g of N-(3-aminopropyl)methacrylamide salt grafted POE to a reaction flask, heat to 140 °C, condense and reflux while stirring to dissolve, cool to 25 °C, add 20 g of adipoyl chloride, 12.7 g of hexamethylenediamine, and 11 g of triethylamine, stir and react for 8 h, pour the solution into acetone, filter, and wash successively with N,N-dimethylformamide, chloroform, and ethanol, and dry to obtain polyamide grafted POE.

[0031] (3) Add 7 kg of polyethylene, 3 kg of nylon 6, 0.4 kg of polyamide grafted POE, 50 g of antioxidant 168, and 10 g of auxiliary agent calcium stearate to a high-speed mixer for mixing, and then melt and extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 30 r / min; form to obtain an impact-resistant polyethylene composite pipe.

[0032] Example 3

[0033] (1) Add 500 g of ethylene-octene copolymer POE, 25 g of N-(3-aminopropyl)methacrylamide hydrochloride, and 2 g of dicumyl peroxide into a rheometer, and conduct melt grafting at 150 °C for 8 min. Add the product into xylene, heat to 140 °C, condense and reflux while stirring to dissolve, then pour the solution into acetone, wash with acetone after filtration, and dry to obtain N-(3-aminopropyl)methacrylamide salt grafted POE.

[0034] (2) Add 1.5 L of xylene and 100 g of N-(3-aminopropyl)methacrylamide salt grafted POE into a reaction flask, heat to 140 °C, condense and reflux while stirring to dissolve, cool to 20 °C, add 12 g of glutaroyl chloride, 7.3 g of pentamethylenediamine, and 7.2 g of triethylamine, stir and react for 8 h, pour the solution into acetone, wash successively with N,N-dimethylformamide, chloroform, and ethanol after filtration, and dry to obtain polyamide grafted POE.

[0035] (3) Add 6 kg of polyethylene, 4 kg of nylon 6, 0.4 kg of polyamide grafted POE, 30 g of antioxidant 168, and 7 g of zinc stearate as an additive into a high-speed mixer for mixing, and then conduct melt extrusion through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 50 r / min; carry out molding to obtain an impact-resistant polyethylene composite pipe.

[0036] Example 4

[0037] (1) Add 7 kg of polyethylene, 3 kg of nylon 6, 0.6 kg of polyamide grafted POE (prepared in the same way as in Example 2), 50 g of antioxidant 168, and 10 g of calcium stearate as an additive into a high-speed mixer for mixing, and then conduct melt extrusion through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 30 r / min; carry out molding to obtain an impact-resistant polyethylene composite pipe.

[0038] Example 5

[0039] (1) Add 7 kg of polyethylene, 3 kg of nylon 6, 0.8 kg of polyamide grafted POE (prepared in the same way as in Example 2), 50 g of antioxidant 168, and 10 g of calcium stearate as an additive into a high-speed mixer for mixing, and then conduct melt extrusion through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 30 r / min; carry out molding to obtain an impact-resistant polyethylene composite pipe.

[0040] Example 6

[0041] (1) Add 7 kg of polyethylene, 3 kg of nylon 6, 1 kg of polyamide-grafted POE (prepared in the same way as in Example 2), 50 g of antioxidant 168, and 10 g of stearic acid calcium as an additive to a high-speed mixer and mix them. Then, melt and extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 30 r / min; form the product to obtain an impact-resistant polyethylene composite pipe.

[0042] Mechanical property test: Taking Example 1 as an example, add 8 kg of polyethylene, 2 kg of nylon 6, 0.4 kg of polyamide-grafted POE, 42 g of antioxidant 168, and 10 g of stearic acid calcium as an additive to a high-speed mixer and mix them. Then, melt and extrude through a twin-screw extruder. The temperatures of the 1st - 6th sections are 170 °C, 220 °C, 225 °C, 230 °C, 230 °C, and 220 °C, and the screw speed is 50 r / min; granulate, and then inject and form into specimens through an injection molding machine. The injection molding temperature is 260 °C. The tensile properties of the specimens are tested according to the standard of GB / T 1040.1 - 2018. The flexural strength is tested according to the standard of GB / T 9341 - 2000. The impact strength is tested according to the standard of GB / T 1043.1 - 2008.

[0043] Table 1 Polyethylene Property Test

[0044]

[0045]

[0046] After testing, compared with Comparative Example 1, polyamide-grafted POE is added in Example 1. Its main chain is an ethylene-octene copolymer, which has good compatibility with the polyethylene resin. At the same time, the POE side chain is grafted with a polyamide molecular chain similar to nylon 6. Therefore, polyamide-grafted POE can be used as a compatibilizer for polyethylene and nylon 6, improving the compatibility between polyethylene and nylon 6. The two form an alloy phase, which is beneficial to improving the mechanical properties of the material. And POE, as an elastomer material with high toughness and good mechanical properties, has a good toughening effect on polyethylene, significantly improving the tensile properties, flexural strength, and impact strength of the material.

[0047] In Comparative Example 2, only ethylene-octene copolymer POE is added. Its compatibility with nylon 6 is poor, and it cannot act as a compatibilizer well, so it cannot improve the compatibility between polyethylene and nylon 6, resulting in lower mechanical properties of the material.

[0048] In Comparative Example 3, conventional maleic anhydride POE is used as a compatibilizer. The compatibility between polyethylene and nylon 6 becomes better, and the mechanical properties are improved. However, the tensile strength, flexural strength, and impact strength are significantly lower than those in Example 1.

[0049] In Examples 2-6, the polyethylene materials prepared from polyethylene, nylon 6, and polyamide-grafted POE with different ratios still have good mechanical properties such as tensile strength.

[0050] It should be noted that the above-mentioned embodiments are only some of the preferred embodiments for implementing the present invention, rather than all embodiments. Obviously, all other embodiments obtained by those of ordinary skill in the art without creative efforts based on the above embodiments of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A preparation method of an impact-resistant polyethylene composite pipe, characterized in that, The preparation method is as follows: (1) Add xylene and N-(3-aminopropyl)methacrylamide salt-grafted POE into a reaction flask, heat and stir to dissolve, add a diacyl chloride compound, a diamine compound, and triethylamine. After stirring and reacting, pour the solution into acetone, filter, wash, and dry to obtain polyamide-grafted POE; (2) Add polyethylene, nylon 6, polyamide-grafted POE, an antioxidant, and an auxiliary agent into a high-speed mixer for mixing, and then melt-extrude and mold through a twin-screw extruder to obtain an impact-resistant polyethylene composite pipe.

2. The preparation method of the impact-resistant polyethylene composite pipe according to claim 1, characterized in that, In the above (1), the mass ratio of N-(3-aminopropyl)methacrylamide salt-grafted POE, diacyl chloride compound, diamine compound, and triethylamine is 100:(6-20):(3.4-12.7):(4-11).

3. The preparation method of the impact-resistant polyethylene composite pipe according to claim 1, characterized in that, The diacyl chloride compound is succinyl chloride, glutaroyl chloride, or adipoyl chloride.

4. The preparation method of the impact-resistant polyethylene composite pipe according to claim 1, characterized in that, The diamine compound is butanediamine, pentanediamine, or hexanediamine.

5. The preparation method of the impact-resistant polyethylene composite pipe according to claim 1, characterized in that, In the above (1), the reaction temperature is 20-35°C, and the reaction time is 6-8 h.

6. The preparation method of the impact-resistant polyethylene composite pipe according to claim 1, characterized in that, In the above (2), the mass ratio of polyethylene, nylon 6, polyamide-grafted POE, antioxidant, and auxiliary agent is (60-80):(20-40):(4-10):(0.3-0.5):(0.07-0.1).

7. The preparation method of the impact-resistant polyethylene composite pipe according to claim 6, characterized in that, The auxiliary agent is zinc stearate or calcium stearate.

8. The preparation method of the impact-resistant polyethylene composite pipe according to claim 1, characterized in that, In the above (2), the temperatures of the 1st to 6th sections of the twin-screw extruder are 170-230°C and 220°C, and the screw speed is 30-50 r / min.

9. The preparation method of the impact-resistant polyethylene composite pipe according to claim 2, characterized in that, The preparation method of the N-(3-aminopropyl)methacrylamide salt-grafted POE is as follows: Add an ethylene-octene copolymer, N-(3-aminopropyl)methacrylamide hydrochloride, and dicumyl peroxide into a rheometer, conduct melt grafting at 150-160°C for 6-8 min, add the product into xylene, heat and stir to dissolve, then pour the solution into acetone, filter, wash, and dry to obtain N-(3-aminopropyl)methacrylamide salt-grafted POE.

10. The preparation method of the impact-resistant polyethylene composite pipe according to claim 9, characterized in that, The mass ratio of the ethylene-octene copolymer, N-(3-aminopropyl)methacrylamide hydrochloride, and dicumyl peroxide is 100:(2-5):(0.16-0.4).

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