Method for preparing PPO / HDPE alloy through reactive extrusion

Abstract

The invention belongs to the technical field of molecular material modification, and particularly relates to a method for preparing PPO / HDPE alloy through reactive extrusion, which comprises the following steps: dissolving styrene, a second functional monomer, an initiator and an antioxidant by adopting a solvent, and then mixing and stirring with HDPE in a high-speed stirrer to obtain a mixture; carrying out reactive extrusion granulation on the obtained mixture by adopting a double-screw extruder to obtain modified HDPE; uniformly mixing PPO, the modified HDPE, a catalyst, a cocatalyst and an antioxidant in a high-speed mixer, and carrying out reactive extrusion granulation by virtue of a double-screw extruder, so as to obtain PPO-g-HDPE; the preparation method comprises the following steps: uniformly mixing PPO, HDPE and PPO-g-HDPE according to a ratio in a high-speed mixer, and carrying out melt blending granulation through a twin-screw extruder to obtain the PPO / HDPE alloy. The PPO-g-HDPE copolymer is added into a PPO / HDPE blending system, so that the strength, toughness, processability, heat resistance, solvent resistance and stress cracking resistance of the alloy can be effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of molecular material modification technology, specifically relating to a method for preparing PPO / HDPE alloy by reactive extrusion. Background Technology

[0002] Polyphenylene oxide (PPO) is a high-performance engineering plastic with high heat distortion temperature and strength, excellent dimensional stability, and flame retardancy. However, unmodified PPO has a very high melt viscosity and poor processability. Therefore, most PPO products on the market are modified, with PPO / PS or PPO / HIPS blends being the most common. The introduction of PS (polystyrene) polymers can significantly improve its processability.

[0003] However, since both PPO and PS are amorphous polymers, these blends exhibit poor solvent resistance; the inherent brittleness of PS results in poor stress cracking resistance; furthermore, the plasticizing effect of PS on PPO leads to a significant decrease in the heat distortion temperature of the blends. HIPS, while possessing better toughness than PS, also suffers from poor solvent resistance, and the presence of unsaturated components reduces its weather resistance. Therefore, the use of these blends in the production and application of high-performance pipes is limited.

[0004] To overcome these drawbacks, there have been many reports of blending PPO with other polymers such as polyamides and polyesters to maintain heat resistance. However, the compatibility of such blends is very poor, and polarized modified SBS or SEBS are usually used as compatibilizers, which reduces the strength of the system to some extent.

[0005] Polyolefins are a common type of general-purpose plastic, known for their high cost-effectiveness, excellent processing performance, and strong solvent resistance. However, research reports on the preparation of PPO / polyolefin blends are extremely rare. PPO also has very poor compatibility with polyolefins (polyethylene, polypropylene). A common method is to prepare polyolefins grafted with polystyrene as a compatibility agent, but this method is essentially similar to PPO / PS blends, resulting in a significant decrease in heat resistance and a reduction in the solvent resistance of PPO itself. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing PPO / HDPE alloy by reactive extrusion. This method can effectively improve the strength, toughness, processing performance, heat resistance, solvent resistance and stress cracking resistance of the alloy by adding PPO-g-HDPE copolymer to the PPO / HDPE blend system.

[0007] Technical solution to achieve the purpose of this invention: A method for preparing PPO / HDPE alloy by reactive extrusion, the method comprising: Step (1) Styrene, secondary functional monomer, initiator and antioxidant are dissolved in solvent, and then mixed and stirred with HDPE in a high-speed mixer to obtain a mixture; the mixture is then subjected to reactive extrusion granulation using a twin-screw extruder to obtain modified HDPE; Step (2) PPO, modified HDPE, catalyst, co-catalyst and antioxidant are mixed evenly in a high-speed mixer and then granulated by reactive extrusion through a twin-screw extruder to obtain PPO-g-HDPE. Step (3) PPO, HDPE and PPO-g-HDPE are mixed evenly in a high-speed mixer in proportion, and then PPO / HDPE alloy is obtained by melt blending and granulation in a twin-screw extruder.

[0008] Further, the second functional monomer is one of maleic anhydride, acrylic acid, methacrylic acid, methyl acrylate, and methyl methacrylate; the initiator is one of benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and di-tert-butyl peroxide; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168, with a mass ratio of antioxidant 1010 to antioxidant 168 of 1:1; and the solvent is acetone.

[0009] Further, in step (1), the mass ratio of styrene to the second functional monomer is 0.5:1-1.5:1; the total amount of styrene and the second functional monomer is defined as the total monomer amount; the mass ratio of solvent to total monomer amount is 2:1; the mass ratio of total monomer amount to HDPE is 1.5:100-2.5:100; the amount of initiator is 0.1-0.6 wt% of HDPE; and the amount of antioxidant is 0.1-0.3 wt% of HDPE.

[0010] Further, in step (1), the mixing temperature in the high-speed mixer is 60-80℃, the mixing speed is 400-800 r / min, and the mixing time is 10 min; the reaction extrusion temperature in the twin-screw extruder is 185-200℃, and the reaction extrusion time is 1-2 min.

[0011] Further, the catalyst is one of aluminum trichloride, cerium trichloride, zinc dichloride, phosphotungstic acid, phosphomolybdic acid, germanotungstic acid, arsostungstic acid, and antimonytungstic acid; the co-catalyst is one of styrene and α-methylstyrene; the antioxidant is a mixture of antioxidant 1076 and antioxidant 168, wherein the mass ratio of antioxidant 1076 to antioxidant 168 is 1:1.

[0012] Further, in step (2), the mass ratio of PPO to modified HDPE is 40:60-60:40, the amount of catalyst is 0.2-1wt% of the total mass of PPO and modified HDPE; the amount of co-catalyst is 0.2-0.8wt% of the total mass of PPO and modified HDPE, and the amount of antioxidant is 0.1-0.3wt% of the total mass of PPO and modified HDPE.

[0013] Further, in step (2), the mixing temperature in the high-speed mixer is room temperature, the stirring speed is 400-800 r / min, and the mixing time is 3-5 min; in the twin-screw extruder, the reaction extrusion temperature is 285-300℃; and the reaction extrusion time is 2-3 min.

[0014] Further, in step (3), the mass ratio of PPO to HDPE is 80:20-60:40; the amount of PPO-g-HDPE added is 5-15 wt% of the total mass of PPO and HDPE.

[0015] Furthermore, in step (3), the mixing temperature in the high-speed mixer is room temperature, the stirring speed is 400-800 r / min, and the mixing time is 2-5 min; in the twin-screw extruder, the reaction extrusion temperature is 265-285℃; and the reaction extrusion time is 1-3 min.

[0016] The beneficial technical effects of this invention are as follows: 1. This invention prepares HDPE-grafted styrene / functional monomer copolymers through a first reactive extrusion, and then PPO and modified HDPE are reactively extruded under the action of a main catalyst and a co-catalyst. PPO-g-HDPE copolymers are prepared through Friedel-Crafts acylation reaction. These copolymers are easy to process.

[0017] 2. The PPO-g-HDPE prepared by this invention exhibits good compatibilizing effect. Adding 5-15% of the PPO-g-HDPE copolymer to a PPO / HDPE blend system with a mass ratio of 20:80-40:60 improves the alloy's strength, toughness, processing performance, heat resistance, solvent resistance, and stress cracking resistance. Compared to ordinary PPO / PS blends and PPO / PE-g-PS systems, the copolymer prepared by this invention forms chemical bonds between PPO and HDPE after being added to the blend system, effectively enhancing interfacial interactions and solvent resistance. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to the embodiments.

[0019] This invention provides a method for preparing PPO / HDPE alloy by reactive extrusion, specifically including the following steps: Step (1) Styrene, secondary functional monomer, initiator and antioxidant are dissolved in solvent, and then mixed and stirred with HDPE (high density polyethylene) in a high-speed mixer to obtain a mixture; the mixture is then subjected to reactive extrusion granulation using a twin-screw extruder to obtain modified HDPE; In step (1), the second functional monomer is one of maleic anhydride, acrylic acid, methacrylic acid, methyl acrylate, and methyl methacrylate; the initiator is one of benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and di-tert-butyl peroxide; the antioxidant is a mixture of antioxidant 1010 (pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and antioxidant 168 (tris(2,4-di-tert-butylphenyl)phosphite), with a mass ratio of antioxidant 1010 to antioxidant 168 of 1:1; and the solvent is acetone.

[0020] In step (1), the mass ratio of styrene to the second functional monomer is 0.5:1-1.5:1, the total amount of styrene and the second functional monomer is defined as the total amount of monomer, the mass ratio of solvent to total amount of monomer is 2:1, the mass ratio of total amount of monomer to HDPE is 1.5:100-2.5:100, the amount of initiator is 0.1-0.6 wt% of HDPE, and the amount of antioxidant is 0.1-0.3 wt% of HDPE.

[0021] In step (1), the mixing temperature in the high-speed mixer is 60-80℃, the mixing speed is 400-800 r / min, and the mixing time is 10 min; the reaction extrusion temperature in the twin-screw extruder is 185-200℃, and the reaction extrusion time is 1-2 min.

[0022] Step (2) PPO (polyphenylene oxide), modified HDPE, catalyst, co-catalyst and antioxidant are mixed evenly in a high-speed mixer and then granulated by reactive extrusion through a twin-screw extruder to obtain PPO-g-HDPE; In step (2), the catalyst is one of aluminum trichloride, cerium trichloride, zinc dichloride, phosphotungstic acid, phosphomolybdic acid, germanic tungstic acid, arsenotungstic acid, and antimony tungstic acid; the co-catalyst is one of styrene and α-methylstyrene; the antioxidant is a mixture of antioxidant 1076 (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate octadecyl alcohol ester) and antioxidant 168 (tris(2,4-di-tert-butylphenyl)phosphite), with a mass ratio of antioxidant 1076 to antioxidant 168 of 1:1.

[0023] In step (2), the mass ratio of PPO to modified HDPE is 40:60-60:40, the amount of catalyst is 0.2-1wt% of the total mass of PPO and modified HDPE, the amount of co-catalyst is 0.2-0.8wt% of the total mass of PPO and modified HDPE, and the amount of antioxidant is 0.1-0.3wt% of the total mass of PPO and modified HDPE.

[0024] In step (2), the mixing temperature in the high-speed mixer is room temperature, the stirring speed is 400-800 r / min, and the mixing time is 3-5 min; in the twin-screw extruder, the reaction extrusion temperature is 285-300℃; and the reaction extrusion time is 2-3 min. The PPO-g-HDPE copolymer is used to compatibilize the PPO / HDPE alloy.

[0025] Step (3) PPO, HDPE and PPO-g-HDPE are mixed evenly in a high-speed mixer in proportion, and then PPO / HDPE alloy is obtained by melt blending and granulation in a twin-screw extruder.

[0026] In step (3), the mass ratio of PPO to HDPE is 80:20-60:40; the amount of PPO-g-HDPE added is 5-15 wt% of the total mass of PPO and HDPE. In step (3), the mixing temperature in the high-speed mixer is room temperature, the stirring speed is 400-800 r / min, and the mixing time is 2-5 min; in the twin-screw extruder, the reaction extrusion temperature is 265-285℃; and the reaction extrusion time is 1-3 min.

[0027] Example 1 This embodiment provides a method for preparing PPO / HDPE alloy by reactive extrusion, specifically including the following steps: Step (1) Dissolve 0.5 parts styrene, 1 part maleic anhydride, 0.3 parts benzoyl peroxide, 0.3 parts antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio using 3 parts acetone, then mix with 100 parts HDPE in a high-speed mixer at 70°C and 400 r / min for 10 min to obtain a mixture; extrude the mixture using a twin-screw extruder at 185-200°C for 2 min to obtain modified HDPE; Step (2) Mix 50 parts of polyphenylene ether, 50 parts of modified HDPE, 0.8 parts of aluminum trichloride, 0.8 parts of styrene, 0.3 parts of antioxidant 1076 and antioxidant 168 in a 1:1 mass ratio in a high-speed mixer until homogeneous. The mixing temperature is room temperature, the stirring speed is 400 r / min, and the mixing time is 3 min. Then, extrude the mixture using a twin-screw extruder at 285-300℃ for reactive extrusion granulation. The reactive extrusion time is 2 min to obtain PPO-g-HDPE. Step (3) Mix 60 parts PPO, 40 parts HDPE and 5 parts PPO-g-HDPE in a high-speed mixer in proportion, mix at room temperature, stir at 400 r / min and mix for 2 min; melt blend and granulate in a twin-screw extruder at 265-285℃, react and extrude for 1 min to obtain PPO / HDPE alloy.

[0028] Example 2 This embodiment provides a method for preparing PPO / HDPE alloy by reactive extrusion, specifically including the following steps: Step (1) Dissolve 1 part styrene, 1 part methyl methacrylate, 0.5 part dicumyl peroxide, 0.2 parts antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio using 4 parts acetone, then mix with 100 parts HDPE in a high-speed mixer at 70 ℃ and 600 r / min for 10 min to obtain a mixture; extrude the mixture using a twin-screw extruder at 185-200℃ for 1.5 min to obtain modified HDPE; Step (2) Mix 40 parts of polyphenylene ether, 60 parts of modified HDPE, 0.2 parts of cerium trichloride, 0.2 parts of styrene, 0.1 parts of antioxidant 1076 and antioxidant 168 in a 1:1 mass ratio in a high-speed mixer until homogeneous. The mixing temperature is room temperature, the stirring speed is 500 r / min, and the mixing time is 3 min. Then, granulate the mixture by reactive extrusion at 285-300℃ using a twin-screw extruder for 2.5 min to obtain PPO-g-HDPE. Step (3) Mix 70 parts PPO, 30 parts HDPE and 10 parts PPO-g-HDPE in a high-speed mixer in proportion, mix at room temperature, stir at 500 r / min and mix for 2 min; melt blend and granulate in a twin-screw extruder at 265-285℃, react and extrude for 1.5 min to obtain PPO / HDPE alloy.

[0029] Example 3 This embodiment provides a method for preparing PPO / HDPE alloy by reactive extrusion, specifically including the following steps: Step (1) Dissolve 1.5 parts styrene, 1 part maleic anhydride, 0.1 parts 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, 0.3 parts antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio in 5 parts acetone, then mix with 100 parts HDPE in a high-speed mixer at 80°C and 600 r / min for 10 min to obtain a mixture; extrude the mixture using a twin-screw extruder at 185-200°C for 2 min to obtain modified HDPE; Step (2) Mix 60 parts of polyphenylene ether, 40 parts of modified HDPE, 0.8 parts of zinc dichloride, 0.8 parts of styrene, 0.3 parts of antioxidant 1076 and antioxidant 168 in a 1:1 mass ratio in a high-speed mixer until homogeneous. The mixing temperature is room temperature, the stirring speed is 600 r / min, and the mixing time is 3 min. Then, granulate the mixture by reactive extrusion at 285-300℃ using a twin-screw extruder for 3 min to obtain PPO-g-HDPE. Step (3) Mix 70 parts PPO, 30 parts HDPE and 10 parts PPO-g-HDPE in a high-speed mixer in proportion, mix at room temperature, stir at 600 r / min and mix for 3 min; melt blend and granulate in a twin-screw extruder at 265-285℃, react and extrude for 2 min to obtain PPO / HDPE alloy.

[0030] Example 4 This embodiment provides a method for preparing PPO / HDPE alloy by reactive extrusion, specifically including the following steps: Step (1) Dissolve 1 part styrene, 1 part maleic anhydride, 0.5 part dicumyl peroxide, 0.3 part antioxidant 1010 and antioxidant 168 in a 1:1 mass ratio using 4 parts acetone, then mix with 100 parts HDPE in a high-speed mixer at 70 ℃ and 800 r / min for 10 min to obtain a mixture; use a twin-screw extruder to perform reactive extrusion granulation at 185-200℃ for 2 min to obtain modified HDPE; Step (2) Mix 60 parts of polyphenylene ether, 40 parts of modified HDPE, 0.5 parts of aluminum trichloride, 0.5 parts of styrene, 0.3 parts of antioxidant 1076 and antioxidant compound antioxidant in a 1:1 mass ratio in a high-speed mixer. The mixing temperature is room temperature, the stirring speed is 800 r / min, and the mixing time is 4 min. Then, granulate by reaction extrusion at 285-300℃ using a twin-screw extruder for 3 min to obtain PPO-g-HDPE. Step (3) Mix 80 parts PPO, 20 parts HDPE and 15 parts PPO-g-HDPE in a high-speed mixer in proportion, mix at room temperature, stir at 800 r / min and mix for 5 min; melt blend and granulate in a twin-screw extruder at 265-285℃, react and extrude for 3 min to obtain PPO / HDPE alloy.

[0031] Compare with Example 1 Modified MPPO was injection molded into standard specimens for testing. The modified MPPO grade was Sabiq SE1X.

[0032] Compare with Example 2 PPO and HDPE-g-PS were melt-blended and extruded at a mass ratio of 80:20, and then injection-molded into standard test specimens.

[0033] Compare with Example 3 PPO and HDPE-g-PS were melt-blended and extruded at a mass ratio of 60:40, and then injection-molded into standard test specimens.

[0034] The performance of the PPO / HDPE alloy prepared in the examples and the standard specimens prepared in the comparative examples were tested, and the test data are shown in Table 1.

[0035] Table 1 Performance test data of the examples and comparative examples Table 1 shows that in Comparative Example 1, MPPO is a PS-modified PPO alloy with high strength. However, due to the poor ductility of both PPO and PS, the alloy has poor ductility. Comparative Example 2 is an HDPE-g-PS-modified PPO alloy, which improves ductility to some extent, but significantly reduces impact and tensile strength. In Comparative Example 3, reducing the PPO ratio increases the tensile strength and ductility of the system, but significantly reduces impact strength. In Examples 1-4 of this invention, the PPO-g-HDPE prepared by the Friedel-Crafts reaction has a good compatibilizing effect on alloys with PPO:HDPE = 80:20-60:40. The toughness, strength, and ductility of the alloys are superior to those of Comparative Examples 1, 2, and 3, and can be used for the production of high-performance equipment.

[0036] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. All contents not described in detail in the present invention can be derived from existing technologies.

Claims

1. A method for preparing PPO / HDPE alloy by reactive extrusion, characterized in that, The method includes: Step (1) Styrene, secondary functional monomer, initiator and antioxidant are dissolved in solvent, and then mixed and stirred with HDPE in a high-speed mixer to obtain a mixture; the mixture is then subjected to reactive extrusion granulation using a twin-screw extruder to obtain modified HDPE; Step (2) PPO, modified HDPE, catalyst, co-catalyst and antioxidant are mixed evenly in a high-speed mixer and then granulated by reactive extrusion through a twin-screw extruder to obtain PPO-g-HDPE. Step (3) PPO, HDPE and PPO-g-HDPE are mixed evenly in a high-speed mixer in proportion, and then PPO / HDPE alloy is obtained by melt blending and granulation in a twin-screw extruder.

2. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, The second functional monomer is one of maleic anhydride, acrylic acid, methacrylic acid, methyl acrylate, and methyl methacrylate; the initiator is one of benzoyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and di-tert-butyl peroxide; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168, with a mass ratio of antioxidant 1010 to antioxidant 168 of 1:1; the solvent is acetone.

3. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, In step (1), the mass ratio of styrene to the second functional monomer is 0.5:1-1.5:1; the total amount of styrene and the second functional monomer is defined as the total amount of monomer; the mass ratio of solvent to total amount of monomer is 2:1; the mass ratio of total amount of monomer to HDPE is 1.5:100-2.5:100; the amount of initiator is 0.1-0.6 wt% of HDPE; and the amount of antioxidant is 0.1-0.3 wt% of HDPE.

4. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, In step (1), the mixing temperature in the high-speed mixer is 60-80℃, the mixing speed is 400-800 r / min, and the mixing time is 10 min; the reaction extrusion temperature in the twin-screw extruder is 185-200℃, and the reaction extrusion time is 1-2 min.

5. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, The catalyst is one of aluminum trichloride, cerium trichloride, zinc dichloride, phosphotungstic acid, phosphomolybdic acid, germanotungstic acid, arsostungstic acid, and antimonytungstic acid; the co-catalyst is one of styrene and α-methylstyrene; the antioxidant is a mixture of antioxidant 1076 and antioxidant 168, with a mass ratio of antioxidant 1076 to antioxidant 168 of 1:

1.

6. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, In step (2), the mass ratio of PPO to modified HDPE is 40:60-60:40, the amount of catalyst is 0.2-1wt% of the total mass of PPO and modified HDPE, the amount of co-catalyst is 0.2-0.8wt% of the total mass of PPO and modified HDPE, and the amount of antioxidant is 0.1-0.3wt% of the total mass of PPO and modified HDPE.

7. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, In step (2), the mixing temperature in the high-speed mixer is room temperature, the stirring speed is 400-800 r / min, and the mixing time is 3-5 min; in the twin-screw extruder, the reaction extrusion temperature is 285-300℃; and the reaction extrusion time is 2-3 min.

8. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, In step (3), the mass ratio of PPO to HDPE is 80:20-60:40; the amount of PPO-g-HDPE added is 5-15 wt% of the total mass of PPO and HDPE.

9. The method for preparing PPO / HDPE alloy by reactive extrusion according to claim 1, characterized in that, In step (3), the mixing temperature in the high-speed mixer is room temperature, the stirring speed is 400-800 r / min, and the mixing time is 2-5 min; in the twin-screw extruder, the reaction extrusion temperature is 265-285℃; and the reaction extrusion time is 1-3 min.

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