A modified PPO material, its preparation method, a PPO foamed material and its preparation method

Abstract

The present invention provides a modified PPO material, a preparation method thereof, a PPO foaming material and a preparation method thereof, belonging to the technical field of modification. The modified PPO material of the present invention comprises modified PPO, high impact polystyrene and an antioxidant; the modified PPO comprises PPO and side chains grafted onto the PPO through ether bonds; the side chains are formed by ring-opening of a polyepoxy functional group modifier and etherification with the PPO. The side chains of the modified PPO will become entangled under the action of force during the foaming process, thereby improving its strength. The improvement in strength, on the one hand, makes the bubbles not easily break during the growth process, so that they can grow continuously and the foaming ratio is increased; on the other hand, it also makes the prepared foaming material have good strength. The results of the examples show that the density of the foaming material prepared from the modified PPO of the present invention is 17-21 kg / m<supgt;3< / supgt;, and the flexural strength of the modified PPO material is 75.42-97.52 MPa.

Description

Technical Field

[0001] The invention belongs to the technical field of modification, and specifically relates to a modified PPO material and a preparation method thereof, a PPO foaming material and a preparation method thereof. Background Art

[0002] 2,6-Dimethyl-1,4-phenylene oxide (PPO) is one of the cheapest and lightest high-temperature resistant engineering plastics, with excellent mechanical strength, stress relaxation resistance, creep resistance, heat resistance, water resistance, water vapor resistance, and dimensional stability. At the same time, PPO also has good flame retardancy and extremely low dielectric properties, and is almost unaffected by temperature and humidity, and can be used in the field of high-frequency communications.

[0003] Supercritical fluid foaming is an effective way to achieve lightweight polymer materials, and it is green and environmentally friendly. After foaming, polyphenylene ether can be lightweight and endowed with unique functionality, such as heat insulation, sound insulation, cushioning performance and low dielectric properties. Polyphenylene ether foamed materials have excellent heat resistance and dimensional stability, and have broad application prospects in the fields of automobiles, new energy batteries, precision instruments, etc.

[0004] CN202210428833.2 discloses a foaming method for PPO / polypropylene (PP) composite beads, which is prepared by autoclave foaming with a material density of 25kg / m 3 PPO / PP foam beads.

[0005] CN202111674095.1 discloses a method for preparing a modified polyphenylene ether foamed bead molded body, wherein PPO, PS and a flame retardant are blended and modified, extruded and granulated, and then placed in a molding mold, filled with CO 2 , quickly release pressure and foam to obtain polyphenylene ether foam beads with a density of 100-200 kg / m 3 .

[0006] It can be found from the above-mentioned published reports that the density of PPO foam materials prepared by the prior art is relatively high, all greater than 25kg / m 3 ; and most of them are physical blending systems, and their strength needs to be further improved. Summary of the invention

[0007] The object of the present invention is to provide a modified PPO material and a preparation method thereof, a PPO foam material and a preparation method thereof. The PPO foam material prepared from the modified PPO material of the present invention has the advantages of low density and high strength.

[0008] The present invention provides a modified PPO material, characterized in that it comprises modified PPO, high impact polystyrene and an antioxidant; the modified PPO comprises PPO and a branched chain grafted onto the PPO through an ether bond;

[0009] The side chains are formed by ring-opening of a polyepoxy functional group modifier and etherification with the PPO.

[0010] Preferably, the polyepoxy functional group modifier includes TGIC or BASF chain extender ADR.

[0011] Preferably, when the polyepoxy functional group modifier is BASF chain extender ADR, the BASF chain extender ADR is 2.0-6.0 wt% of PPO; when the polyepoxy functional group modifier is TGIC, the TGIC is 0.6-2.0 wt% of PPO.

[0012] The present invention also provides a method for preparing the modified PPO material described in the above scheme, comprising the following steps:

[0013] The PPO, high impact polystyrene and antioxidant are first co-extruded to obtain a physically modified product;

[0014] The physical modified substance and the multi-epoxy functional group modifier are subjected to a second co-extrusion to cause ring opening and etherification to obtain the modified PPO material.

[0015] Preferably, the temperatures of the first co-extrusion and the second co-extrusion are independently 240-285°C.

[0016] Preferably, the mass ratio of the PPO to high impact polystyrene is 1:0.05-13.

[0017] Preferably, the mass ratio of the PPO to the antioxidant is 0.3 to 30:1.

[0018] The present invention also provides a PPO foam material, which is obtained by foaming the modified PPO material described in the above scheme or the modified PPO material obtained by the preparation method described in the above scheme; the density of the PPO foam material is 17-21 kg / m 3 The flexural strength of the modified PPO material is 75.42~97.52MPa.

[0019] The present invention also provides a method for preparing the PPO foam material described in the above scheme, comprising the following steps:

[0020] Processing the modified PPO material to obtain a sheet-like foamed body;

[0021] Saturating the sheet-like body to be foamed in a gas foaming agent and then releasing the pressure to obtain the PPO foaming material;

[0022] The saturated temperature is 100-250°C, the pressure is 10-20Mpa, and the time is ≥a×(d / 2) 1.75 , where a = 0.2762h / mm 1.75 , the d is the thickness of the foam to be formed, in mm.

[0023] Preferably, the pressure relief rate is 100-1000 MPa / s.

[0024] The present invention provides a modified PPO material, including modified PPO, high impact polystyrene and an antioxidant; the modified PPO includes PPO and a side chain grafted onto the PPO through an ether bond; the side chain is formed by ring-opening a multi-epoxy functional group modifier and etherifying with the PPO. The side chains of the modified PPO will become entangled under the action of force during the foaming process, so that its strength is improved. On the one hand, the improvement in strength will make it less likely for bubbles to break during the growth process, so that they can grow continuously and improve the foaming ratio; on the other hand, it will also make the prepared foamed material have good strength. The results of the embodiment show that the density of the foamed material prepared by the modified PPO material of the present invention is 17 to 21 kg / m 3 The pore size is 8.91~12.53μm, and the bending strength of the modified PPO material is 75.42~97.52MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a cross-sectional electron microscope scan of the PPO foam material of Application Example 1;

[0026] Figure 2 This is a cross-sectional electron microscope scan of the PPO foam material of Application Example 2;

[0027] Figure 3 This is a cross-sectional electron microscope scan of the PPO foam material of comparative application example 1. DETAILED DESCRIPTION

[0028] The present invention provides a modified PPO material, comprising modified PPO, high-impact polystyrene and an antioxidant; the modified PPO comprises PPO and a branched chain grafted onto the PPO via an ether bond;

[0029] The side chains are formed by ring-opening of a polyepoxy functional group modifier and etherification with the PPO.

[0030] In the present invention, the polyepoxy functional group modifier preferably includes TGIC or BASF chain extender ADR.

[0031] In the present invention, when the polyepoxy functional modifier is BASF chain extender ADR, the BASF chain extender ADR is preferably 2-6wt% of PPO, more preferably 4-5wt%; when the polyepoxy functional modifier is TGIC, the TGIC is preferably 0.6-2wt% of PPO, more preferably 1-1.5wt%. Controlling the amount of the polyepoxy functional modifier within the above range allows PPO to fully react with the polyepoxy functional modifier to form a branched chain. If the content of the polyepoxy functional modifier is low, the amount of PPO involved in the reaction is small, and the modification effect is not obvious; if the content of the polyepoxy functional modifier is high, self-polymerization is likely to occur, affecting the material properties.

[0032] In the present invention, unless otherwise specified, the raw materials used are commercially available products well known in the art.

[0033] The present invention also provides a method for preparing the modified PPO material described in the above scheme, comprising the following steps:

[0034] The PPO, high impact polystyrene and antioxidant are first co-extruded to obtain a physically modified product;

[0035] The physical modified substance and the multi-epoxy functional group modifier are subjected to a second co-extrusion to cause ring opening and etherification to obtain the modified PPO material.

[0036] The present invention performs a first co-extrusion of PPO, high impact polystyrene and an antioxidant to obtain a physical modified product. In the present invention, the mass ratio of the PPO to the high impact polystyrene is preferably 1:0.05-13, more preferably 1:2-10, and further preferably 1:5-8. The addition of high impact polystyrene can improve the processing properties of PPO. In the present invention, the mass ratio of the PPO to the antioxidant is preferably 0.3-30:1, more preferably 5-20:1, and further preferably 10-15:1. In the present invention, the antioxidant preferably includes antioxidant 1010 and antioxidant 168, and the mass ratio of the antioxidant 1010 to the antioxidant 168 is preferably 1:2. In the present invention, the temperature of the first co-extrusion is preferably 240-285°C. In the present invention, the first co-extrusion is preferably carried out in a twin-screw extruder. In the present invention, the screw speed of the twin-screw extruder is preferably 40-200 rpm, more preferably 80-150 rpm, and further preferably 100-120 rpm. In the present invention, the temperature zone of the twin-screw extruder is preferably divided into six zones, and the temperatures of the temperature zones from the feeding zone to the die head are preferably: 240°C, 260°C, 280°C, 280°C, 285°C and 285°C.

[0037] After the first coextrusion, the first coextrudate is preferably granulated to obtain the physically modified product. In the present invention, the particle size of the physically modified product is preferably 0.1 to 2 mm, more preferably 0.5 to 1.5 mm.

[0038] After obtaining the physical modified product, the present invention performs a second co-extrusion on the physical modified product and a multi-epoxy functional group modifier to cause ring opening and etherification to obtain the modified PPO material.

[0039] In the present invention, the temperature of the second co-extrusion is preferably 240 to 285°C. In the present invention, the second co-extrusion is preferably carried out in a twin-screw extruder. In the present invention, the screw speed of the twin-screw extruder is preferably 40 to 200 rpm, more preferably 80 to 150 rpm, and further preferably 100 to 120 rpm. In the present invention, the temperature zone of the twin-screw extruder is preferably divided into six zones, and the temperature of ethylene in the temperature zone from the feeding zone to the die head is preferably: 240°C, 260°C, 280°C, 280°C, 285°C and 285°C.

[0040] After the second coextrusion, the present invention preferably granulates the obtained second coextrudate to obtain the modified PPO material. In the present invention, the particle size of the modified PPO material is preferably 0.1 to 2 mm, more preferably 0.5 to 1.5 mm. During the second coextrusion, the epoxy group of the multi-epoxy functional group modifier undergoes a ring-opening reaction, etherifies with the terminal hydroxyl group of PPO to form an ether bond, and is thereby grafted onto PPO.

[0041] When the polyepoxy functional group modifier is TGIC, the equations for the ring-opening and etherification reactions are:

[0042]

[0043] The present invention also provides a PPO foam material, which is obtained by foaming the modified PPO material described in the above scheme or the modified PPO material obtained by the preparation method described in the above scheme; the density of the PPO foam material is 17-21 kg / m 3 The flexural strength of the modified PPO material is 75.42~97.52MPa.

[0044] The present invention also provides a method for preparing the PPO foam material described in the above scheme, comprising the following steps:

[0045] Processing the modified PPO material to obtain a sheet-like foamed body;

[0046] The sheet-like body to be foamed is saturated in a gas foaming agent and then the pressure is released to obtain the PPO foaming material.

[0047] The present invention processes the modified PPO material to obtain a sheet-like body to be foamed. In the present invention, the thickness of the sheet-like body to be foamed is preferably 1 to 20 mm, more preferably 5 to 15 mm, and further preferably 8 to 12 mm; the length is preferably 10 to 1000 mm, more preferably 200 to 800 mm, and further preferably 400 to 600 mm; the width is preferably 10 to 1000 mm, more preferably 200 to 800 mm, and further preferably 400 to 600 mm. The present invention does not specifically limit the processing method, and a method well known to those skilled in the art can be used, such as hot pressing, injection molding, and extrusion.

[0048] After obtaining the sheet-like foamed body, the present invention saturates the sheet-like foamed body in a gas foaming agent and then releases the pressure to obtain the PPO foaming material. In the present invention, the gas foaming agent preferably includes CO 2 、N 2 , methanol and butane. In the present invention, the saturation temperature is 100-250°C, preferably 120-200°C, and more preferably 150-180°C. In the present invention, the saturation pressure is 10-20Mpa, preferably 12-18Mpa, and more preferably 15-16Mpa. In the present invention, the saturation pressure is preferably provided by a gas foaming agent. The saturation time ≥ a×(d / 2) 1.75 , where a = 0.2762h / mm 1.75 , d is the thickness of the foamed body, in mm. For example, when d is 3 mm, the saturation time is 0.57 hours. After saturation, the gas foaming agent reaches a dissolution equilibrium in the foamed body.

[0049] In the present invention, the pressure relief rate of the pressure relief foaming is 100-1000 MPa / s, preferably 200-700 MPa / s, and more preferably 400-600 MPa / s. The pressure relief rate within the above range can provide sufficient driving force for cell nucleation and growth.

[0050] In order to further illustrate the present invention, the modified PPO material and its preparation method, the PPO foam material and its preparation method provided by the present invention are described in detail below in conjunction with the accompanying drawings and examples, but they should not be understood as limiting the scope of protection of the present invention.

[0051] Example 1

[0052] PPO (Nantong Xingchen Synthetic Materials Co., Ltd., LXN040), high-impact polystyrene particles (Chimei Chemical, PH-60), antioxidant 1010, and antioxidant 168 were mixed in a mass ratio of 90:7:2:1 and extruded into granules in a twin-screw extruder. The extruder was divided into six zones for temperature control. The temperatures from the feeding zone to the die head were 240°C, 260°C, 280°C, 280°C, 285°C, and 285°C, respectively. The screw speed was 150rpm, and a 1.5mm physical modified product was formed.

[0053] Subsequently, the physical modifier and multi-epoxy functional modifier TGIC were reacted and chemically modified in a twin-screw extruder at a mass ratio of 100:1.093. The extruder was divided into six zones for temperature control. The temperatures from the feeding zone to the die head were 240°C, 260°C, 280°C, 280°C, 285°C, and 285°C, respectively. The screw speed was 120rpm, and then granulated by a pelletizer to form a 1.5mm modified PPO material.

[0054] Application Example 1

[0055] The modified PPO material of Example 1 was made into a foamed body with a thickness of 5 mm, a length of 50 mm, and a width of 50 mm by injection molding. The foamed body was placed in a high-pressure mold cavity at a temperature of 225°C. The high-pressure mold cavity was closed by a hydraulic system at the bottom of the mold cavity, and then CO was injected into the mold cavity. 2 To 15MPa, saturated for 1.5h, CO 2 The dissolution equilibrium is reached in the material matrix. Finally, the pressure is quickly released through the high-pressure ball valve connected to the high-pressure mold cavity at a rate of 400 MPa / s, and the high-pressure mold cavity is quickly opened to take out the foamed sample.

[0056] Example 2

[0057] The only difference from Example 1 is that the polyepoxy functional group modifier is BASF chain extender ADR, and the mass ratio of the physical modifier to the polyepoxy functional group modifier is 100:1.837.

[0058] Application Example 2

[0059] The only difference from Application Example 1 is that the modified PPO material of Example 2 is used.

[0060] Example 3

[0061] The only difference from Example 1 is that the mass ratio of PPO raw powder (Nantong Xingchen Synthetic Materials Co., Ltd., LXN040), high impact polystyrene particles (Chimei Chemical, PH-60), antioxidant 1010, and antioxidant 168 is 10:87:2:1, and the mass ratio of the physical modifier to the multi-epoxy functional group modifier is 100:0.121.

[0062] Application Example 3

[0063] The only difference from Application Example 1 is that the modified PPO material of Example 3 is used and the saturation temperature is 110°C.

[0064] Comparative Example 1

[0065] The only difference from Example 1 is that no polyepoxy functional group modifier is added during the chemical modification.

[0066] Comparative application example 1

[0067] The only difference from Application Example 1 is that the modified PPO material of Comparative Example 1 is used.

[0068] Comparative Example 2

[0069] The only difference from Example 3 is that no polyepoxy functional group modifier is added during the secondary modification.

[0070] Comparative Application Example 2

[0071] The only difference from Application Example 1 is that the modified PPO material of Comparative Example 2 is used.

[0072] Comparative Example 3

[0073] The only difference from Example 1 is that the mass ratio of PPO raw powder (Nantong Xingchen Synthetic Materials Co., Ltd., LXN040), high-impact polystyrene particles (Chimei Chemical, PH-60), antioxidant 1010, and antioxidant 168 is 90:10:0:0.

[0074] Comparative Application Example 3

[0075] The only difference from Application Example 1 is that the modified PPO material of Comparative Example 3 is used.

[0076] Comparative Example 4

[0077] The only difference from Example 1 is that the mass ratio of PPO raw powder (Nantong Xingchen Synthetic Materials Co., Ltd., LXN040), high impact polystyrene particles (Chimei Chemical, PH-60), antioxidant 1010, and antioxidant 168 is 97:0:2:1.

[0078] Comparative Application Example 4

[0079] The only difference from Application Example 1 is that the modified PPO material of Comparative Example 4 is used.

[0080] Comparative Application Example 5

[0081] The only difference from Application Example 1 is that the saturation temperature is 255°C.

[0082] Comparative Application Example 6

[0083] The only difference from Application Example 3 is that the saturation temperature is 90°C.

[0084] The molecular weight of the modified PPO of Examples 1 to 3 and Comparative Examples 1 to 6 and the flexural strength of the modified PPO materials were measured. The results are shown in Table 1.

[0085] Table 1 Molecular weight of modified PPO and flexural strength of modified PPO materials of Examples 1 to 3 and Comparative Examples 1 to 6

[0086]

[0087] As can be seen from Table 1, the molecular weight of the modified PPO has been improved. This proves that the multi-epoxy functional modifier reacts with PPO, otherwise the molecular weight should not change much.

[0088] The density and average pore size of the foamed materials finally prepared in Examples 1 to 3 and Comparative Examples 1 to 3, 5 to 6 were measured, and the results are shown in Table 2.

[0089] Table 2 Foam material density and average pore size

[0090]

[0091]

[0092] As shown in Table 2, the modified PPO material prepared by the present invention has a density of less than 25 kg / m 3 , PPO foaming material with an average pore diameter of less than 15μm has good foamability.

[0093] At the same time, by comparing Application Examples 1 to 2 with Comparative Application Example 1, and Application Example 3 with Comparative Application Example 2, it can be found that the long-chain branching modification based on the epoxy functional group modifier can increase the molecular weight and the bending strength of the material. The modified PPO materials in Comparative Application Example 1 and Comparative Application Example 2 do not use epoxy functional group modifiers, so the polymer segments are linear segments and cannot provide heterogeneous nucleation sites. At the same time, the low melt strength of the linear segments cannot support the pore structure, so the pores undergo more aggregation, the pore size is larger, and the material density is higher.

[0094] The modified PPO material in comparative application example 3 has no added antioxidant, so the material is severely degraded during processing, the molecular weight and bending strength are low, and the melt strength cannot support the pores, resulting in huge pores and high material density.

[0095] The modified PPO material in comparative application example 4 does not have high-impact polystyrene added, and PPO is difficult to process. During twin-screw processing, the die head pressure is too high and the alarm stops, making subsequent operations impossible.

[0096] The foaming temperature of comparative application example 5 is relatively high, and a large number of pores collapse, so the material density is high and the pores can no longer be observed.

[0097] The foaming temperature of comparative application example 6 is relatively low. At this time, the matrix melt strength is too high and the cells are difficult to grow. Therefore, the material density is high and the cell size is small.

[0098] The cross-section electron microscope scanning analysis of the PPO foam material corresponding to Example 1 shows the following results: Figure 1 As shown. Figure 1 It can be seen that the average pore size of the foamed material is relatively small, only 8.91 μm.

[0099] The cross-section electron microscope scanning analysis of the PPO foam material corresponding to Example 2 shows the following results: Figure 2 As shown. Figure 2 It can be seen that the average pore size of the foamed material is relatively small, only 9.72 μm.

[0100] The cross-section electron microscope scanning analysis of the PPO foam material of comparative application example 1 shows the following results: Figure 3 As shown. Figure 3 It can be seen that the average pore size of the foamed material is relatively large, exceeding 20 μm.

[0101] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A modified PPO material, characterized in that, it comprises modified PPO, high impact polystyrene and an antioxidant; the modified PPO comprises PPO and branches grafted onto the PPO through ether bonds; the branches are formed by ring-opening of a polyepoxy functional group modifier and etherification with the PPO; the polyepoxy functional group modifier comprises TGIC or BASF chain extender ADR; when the polyepoxy functional group modifier is BASF chain extender ADR, the BASF chain extender ADR is 2.0 - 6.0 wt% of the PPO; when the polyepoxy functional group modifier is TGIC, the TGIC is 0.6 - 2.0 wt% of the PPO.

2. A preparation method of the modified PPO material according to claim 1, characterized in that, it comprises the following steps: Performing a first co-extrusion on PPO, high impact polystyrene and an antioxidant to obtain a physical modification; Performing a second co-extrusion on the physical modification and a polyepoxy functional group modifier to undergo ring-opening and etherification to obtain the modified PPO material.

3. According to the preparation method of claim 2, characterized in that, the temperature of the first co-extrusion and the second co-extrusion is independently 240 - 285 °C.

4. According to the preparation method of claim 2, characterized in that, the mass ratio of the PPO to the high impact polystyrene is 1:0.05 - 13.

5. According to the preparation method of claim 2 or 4, characterized in that, the mass ratio of the PPO to the antioxidant is 0.3 - 30:

1.

6. A PPO foam material, characterized in that, Obtained by foaming the modified PPO material according to claim 1 or the modified PPO material obtained by the preparation method according to any one of claims 2 to 5; the density of the PPO foamed material is 17 to 21 kg / m 3 .

7. A preparation method of the PPO foam material according to claim 6, characterized in that, it comprises the following steps: Processing the modified PPO material to obtain a sheet-like body to be foamed; Saturating the sheet-like body to be foamed in a gas foaming agent and then depressurizing to obtain the PPO foam material; The temperature of the saturation is 100 to 250 °C, the pressure is 10 to 20 Mpa, and the time ≥ a×(d / 2) 1.75 , where a = 0.2762 h / mm 1.75 , and the d is the thickness of the to-be-foamed body, with the unit of mm.

8. According to the preparation method of claim 7, characterized in that, the depressurization rate is 100 - 1000 MPa / s.

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