A PS / PP composite material and its preparation method and application

Abstract

The present invention relates to a PS / PP composite material and a preparation method and application thereof. The composite material components include, by weight: 40-70 parts of PS resin; 10-60 parts of PP resin; 3-21 parts of a compatibilizer 1; 1-7 parts of a compatibilizer 2; 1-10 parts of a filler; and 0.5-3 parts of a nucleating agent. The composite material has good mechanical properties and vacuum forming efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of general plastics, and in particular relates to a PS / PP composite material and a preparation method and application thereof. Background Art

[0002] PS has good processing fluidity, high modulus, high surface hardness, low shrinkage and excellent printing performance, and is widely used in home appliances, office equipment, furniture and other industries, but its environmental cracking and chemical resistance are poor; at the same time, polypropylene is a semi-crystalline polymer with good chemical resistance; the prepared PP / PS alloy has excellent processing performance and environmental cracking and chemical resistance, and has wide application potential in the home appliance industry.

[0003] Because PP is a semi-crystalline polymer and PS is an amorphous polymer, the two are typical incompatible systems and cannot form a stable phase structure. The mechanical properties of the prepared PS / PP alloy are extremely poor. At present, the compatibilizer and preparation process of PS / PP alloy are studied, but the prepared PS / PP alloy plate material has many problems such as blister cracking, low blister efficiency, deformation and folding when blister molding. The main reason for blister cracking is: due to the low notch impact strength of the material, the processing ductility is poor, and cracking will occur during the blow molding process due to poor ductility; however, when the material toughness is too good and the rigidity is insufficient, it is very easy to have poor dimensional stability and deformation, folding and other problems. Therefore, it is very important for the PS / PP alloy to have good mechanical properties and blister efficiency. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a PS / PP composite material and a preparation method and application thereof, so as to overcome the defects of poor mechanical properties and poor blister efficiency of PS / PP alloy materials in the prior art.

[0005] The present invention provides a PS / PP composite material, wherein the composite material components include, by weight:

[0006]

[0007] The compatibilizer 1 is SBS or SEBS, the S / B mass ratio in the SBS is 30 / 70 to 35 / 65, and the styrene mass fraction in the SEBS is 30 to 35%;

[0008] The compatibilizer 2 is maleic anhydride grafted polypropylene or a random copolymer of styrene and maleic anhydride, the mass fraction of maleic anhydride in the maleic anhydride grafted polypropylene is 0.6-1%, and the mass fraction of maleic anhydride in the random copolymer of styrene and maleic anhydride is 15-20%.

[0009] The test method for the S / B mass ratio is as follows: using tetrahydrofuran as the mobile phase, separating by a Wondasil-C18 column, detecting the peak area at a wavelength of 260 nm by ultraviolet light, using a standard curve for quantification based on the linear relationship between the peak areas of S and SBS components, and then calculating the S / B ratio; the test method for the styrene mass fraction in SEBS is as follows: using tetrahydrofuran as the mobile phase, separating by a Wondasil-C18 column, detecting the peak area at a wavelength of 260 nm by ultraviolet light, using a standard curve for quantification based on the linear relationship between the peak areas of S and SEBS components, and then calculating the styrene mass fraction; the test method for the maleic anhydride mass fraction in maleic anhydride grafted polypropylene or a random copolymer of styrene and maleic anhydride is a titration test, dissolving the maleic anhydride grafted polypropylene or the random copolymer of styrene and maleic anhydride in a KOH-ethanol standard solution, and calculating the anhydride content using a neutralization reaction.

[0010] Preferably, the composite material components include, by weight:

[0011]

[0012] Preferably, the PS resin is HIPS.

[0013] Preferably, the PP resin is a copolymer of propylene and ethylene.

[0014] More preferably, the notched impact strength of the PP resin is 10-40 KJ / m 2 The ethylene content in copolymer PP resin with higher impact strength will be relatively higher, so its crystallinity will be relatively low and its melting temperature will be relatively low, which is beneficial to the efficiency of blister molding. Notched impact strength is tested according to GB / T 1843-2008, A-type notch, 23℃, 50% humidity.

[0015] Preferably, the SBS has a linear molecular structure.

[0016] Preferably, the mass ratio of the compatibilizer 1 to the compatibilizer 2 is 2:1 to 4:1.

[0017] Preferably, the filler includes one or more of wollastonite, talc and calcium carbonate.

[0018] Preferably, the nucleating agent includes one or more of amide compounds, phosphate compounds, and hydrazide compounds.

[0019] Preferably, the composite material further comprises 0-3 parts of other additives.

[0020] Preferably, the other auxiliary agents include antioxidants and / or lubricants.

[0021] Preferably, the antioxidant is present in an amount of 0.1-0.3 parts by weight.

[0022] Preferably, the antioxidant includes one or more of hindered phenol antioxidants, phosphite antioxidants, and thiodipropionic acid diester antioxidants.

[0023] Preferably, the lubricant is present in an amount of 0.5-2 parts by weight.

[0024] Preferably, the lubricant includes one or more of polysiloxane, calcium stearate, magnesium stearate, zinc stearate, and PE wax.

[0025] The present invention also provides a method for preparing a PS / PP composite material, comprising:

[0026] (1) PS resin and compatibilizer 1 are mixed, added into a twin-screw extruder for melt blending, and extruded into granules to obtain a premixed masterbatch;

[0027] (2) adding the premixed masterbatch in step (1) and other components into a twin-screw extruder for melt blending, extrusion granulation, and obtaining a PS / PP composite material.

[0028] Preferably, in step (1), the melt blending temperature is 180-230° C., the feed rate is 800-1200 kg / h, the screw speed is 400-600 rpm, and the screw aspect ratio is 38 / 1-48 / 1.

[0029] Preferably, in step (2), the melt blending temperature is 180-230° C., the feed rate is 600-1000 kg / h, the screw speed is 500-700 rpm, and the screw aspect ratio is 38 / 1-48 / 1.

[0030] The present invention also provides an application of a PS / PP composite material in household appliances, automobiles or medical consumables, such as refrigerator liner, automobile door panel, etc.

[0031] The compatibilizer 1 of the present invention is SBS or SEBS, wherein the styrene segment can be well entangled with the PS phase, and the S segment can be well entangled with the PP phase. At this time, the SEBS or SBS is dispersed at the interface between the PP phase and the PS phase to improve the interface strength; the compatibilizer 2 is a random copolymer of styrene and maleic anhydride or maleic anhydride grafted polypropylene, wherein the maleic anhydride group can be physically adsorbed or chemically reacted with the filler, so that the filler is dispersed in the PS / PP alloy together with the compatibilizer 2; because the S / B ratio in the SBS in the compatibilizer 1 or the styrene content in the SEBS is within the selected range, the SBS or SEBS will be dispersed at the interface of the PS and PP, and the interface compatibility of the PS and PP will be enhanced; if the S / B ratio in the SBS or the styrene content in the SEBS is not within the selected range, the compatibilizer 1 will form micelles in the system and will not play a role in increasing the volume; the compatibilizer 2 Only when compatibilizer 1 and compatibilizer 2 are within the selected range, compatibilizer 2 will have good compatibility with compatibilizer 1, so that compatibilizer 2 is dispersed at the interface of PS and PP together with compatibilizer 1, and the filler is also dispersed at the interface of PS and PP, which greatly increases the viscosity and strength of the system; inhibits the movement of PP molecular chains, reduces its crystallinity, and makes it have good suction molding efficiency; if only compatibilizer 1 is added, the filler system will be randomly dispersed in the system, at this time the crystallinity of PP in the system is high, and the power and time required for suction molding will be greatly extended; if only compatibilizer 2 is added, the interface compatibility of PS and PP is poor, and the mechanical properties of PS and PP alloy materials are poor; only when compatibilizer 1 and compatibilizer 2 are within the selected range, they have good compatibility, at this time compatibilizer 1, compatibilizer 2 and filler are all dispersed at the interface of PS and PP, which improves the mechanical properties of PS / PP, enhances viscosity and inhibits PP crystallization.

[0032] Beneficial Effects

[0033] The present invention adopts the compounding of compatibilizer 1 and compatibilizer 2, so that the PS / PP composite material has good mechanical properties and plastic absorption efficiency, and overcomes the defects of poor mechanical properties of general PS / PP alloys and the problem of thermal plastic absorption efficiency caused by PP crystallization. The selection of copolymer PP resin with high impact strength can further improve the plastic absorption efficiency of the composite material, while ensuring the mechanical properties of the composite material. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0035] Source of reagents:

[0036] PS resin: HIPS, HIPS 8265, Total Petrochemical Co., Ltd.;

[0037] PP resin 1: Copolymer of propylene and ethylene, notched impact strength of 10KJ / m 2 , PP EP548R, Wanhua Chemical Group Co., Ltd.;

[0038] PP resin 2: Copolymer of propylene and ethylene, notched impact strength of 40KJ / m 2 , PP K8009, Sinopec;

[0039] PP resin 3: Copolymer of propylene and ethylene, notched impact strength of 5.2KJ / m 2 , PP EP648U(V), CNOOC and Shell Petrochemical Co., Ltd.;

[0040] PP resin 4: copolymer of propylene and ethylene, notched impact strength of 53KJ / m 2 , PP K8003, Donghua Energy (Ningbo) New Materials Co., Ltd.;

[0041] Compatibility enhancer 1:

[0042] Compatibilizer 1-1: SBS, linear molecular structure, SBS 188, S / B=34 / 66, Sinopec Baling Petrochemical Company;

[0043] Compatibilizer 1-2: SEBS, styrene mass fraction is 32%, SEBS 6151, Taiwan Rubber Corporation;

[0044] Compatibilizer 2:

[0045] Compatibilizer 2-1: maleic anhydride grafted polypropylene, maleic anhydride mass fraction is 0.8%, PC-1, Foshan Nanhai Bochen Polymer New Materials Co., Ltd.;

[0046] Compatibilizer 2-2: random copolymer of styrene and maleic anhydride, with a maleic anhydride mass fraction of 18%, SMA-700, Jiaxing Huawen Chemical Co., Ltd.;

[0047] Compatibilizer 3:

[0048] Compatibilizer 3-1: SBS, linear molecular structure, S / B is 2 / 8, SBS 796, Sinopec Baling Petrochemical Company;

[0049] Compatibilizer 3-2: SBS, linear molecular structure, S / B is 4 / 6, SBS 815, Sinopec Baling Petrochemical Company;

[0050] Compatibilizer 3-3: SEBS, styrene mass fraction 13%, SEBS G1657 MS, Kraton Polymers Co., Ltd.

[0051] Compatibilizer 3-4: SEBS, styrene mass fraction 36%, SEBS MD6958 HU, Kraton Polymers Co., Ltd.

[0052] Compatibility agent 4:

[0053] Compatibilizer 4-1: maleic anhydride grafted polypropylene, maleic anhydride mass fraction is 0.5%, PC-3, Foshan Nanhai Bochen Polymer New Materials Co., Ltd.;

[0054] Compatibilizer 4-2: maleic anhydride grafted polypropylene, maleic anhydride mass fraction is 1.2%, AD-105, Foshan Nanhai Bochen Polymer New Materials Co., Ltd.;

[0055] Compatibilizer 4-3: random copolymer of styrene and maleic anhydride, with a maleic anhydride mass fraction of 10%, SMA-700-R50, Shanghai Huawen New Materials Co., Ltd.;

[0056] Compatibilizer 4-4: random copolymer of styrene and maleic anhydride, maleic anhydride mass fraction is 23%, SZ23110,

[0057] Polyscope Polymers BV;

[0058] Filler: talc, TYT-777AY, commercially available;

[0059] Nucleating agent: phosphate compound, NP-509, commercially available;

[0060] Antioxidant: hindered phenol antioxidant (Antioxidant 1098), commercially available;

[0061] Lubricant: calcium stearate, commercially available;

[0062] Unless otherwise specified, a certain component (such as antioxidant, lubricant) in the parallel embodiments and comparative examples of the present invention is the same commercially available product.

[0063] A method for preparing a PS / PP composite material comprises the following steps:

[0064] (1) PS resin, PP resin, compatibilizer 1, compatibilizer 2, filler, and nucleating agent are dried, and PS resin and compatibilizer 1 are mixed uniformly according to the proportions in Table 1-3, and added into a twin-screw extruder for melt blending at 220° C., with a feed rate of 1000 kg / h, a screw speed of 500 rpm, and a screw length-diameter ratio of 48:1, and extruded and granulated to obtain a premixed masterbatch;

[0065] (2) The premixed masterbatch obtained in step (1) and other components were added into a twin-screw extruder according to the proportions in Table 1-3, melt blended at 220°C, with a feed rate of 800 kg / h, a screw speed of 600 rpm, a screw length-diameter ratio of 48 / 1, and extruded and granulated to obtain a PS / PP composite material.

[0066] Performance Testing:

[0067] (1) Tensile strength:

[0068] According to GB / T 1040-2006 test, tensile rate 50mm / min, dumbbell-shaped specimen, 5A-type specimen: the width of the narrow part is 4mm and the thickness is 3mm; the tensile strength ≥20MPa can meet the requirements;

[0069] (2) Notched impact strength:

[0070] Tested according to GB / T 1843-2008, A-type notch, 23°C, 50% humidity; notched impact strength ≥10KJ / m 2 The problem of blister cracking can be solved;

[0071] (3) Blistering time:

[0072] The prepared PS / PP composite material was extruded at 170-220°C in a single screw extruder with a length-to-diameter ratio of 38:1-48:1 and cut into square plates of 2000*1000*2.0mm, and then vacuum-formed into qualified parts in a mold with a set temperature of 100°C; the minimum vacuum-forming cycle time was recorded as the vacuum-forming time.

[0073] Table 1 Example 1-11 ratio (weight parts)

[0074]

[0075] Table 2 Proportions of Examples 12-14 (parts by weight)

[0076] Example 12 Example 13 Embodiment 14 PS resin 50 50 50 PP resin 1 40 40 40 Compatibility enhancer 1-1 12 Compatibilizer 1-2 12 12 Compatibilizer 2-1 4 Compatibilizer 2-2 4 4 filler 6 6 6 Nucleating Agent 1.8 1.8 1.8 Antioxidants 0.3 0.3 0.3 Lubricants 0.5 0.5 0.5 Tensile strength(MPa) 29.3 29.2 29.5 <![CDATA[Notched impact strength (KJ / m 2 )]]> 13.3 14.1 14.5 Blistering time(S) 5.4 5.6 5.2

[0077] Table 3 Comparative Example Proportions (parts by weight)

[0078]

[0079]

[0080] As can be seen from Tables 1-3, the PS / PP composite material of the present invention has good mechanical properties and vacuum forming efficiency. Comparative Examples 9-12 only add one compatibilizer, and the tensile strength and notched impact strength of the composite material are lower than those of Example 1 or 14, and the vacuum forming time is longer than that of Example 1 or 14. The S / B in the SBS used in Comparative Examples 3-4 is not within the scope of the present invention, the mass fraction of styrene in the SEBS used in Comparative Examples 7-8 is not within the scope of the present invention, the tensile strength and notched impact strength of the PS / PP composite material of Comparative Examples 3-4 or Comparative Examples 7-8 are lower than those of Example 1 or 14, and the vacuum forming time is longer than that of Example 1 or 14. The mass fraction of MAH in the PP-g-MAH used in Comparative Examples 1-2 is not within the scope of the present invention, the mass fraction of MAH in the PS-g-MAH used in Comparative Examples 5-6 is not within the scope of the present invention, the tensile strength and notched impact strength of the PS / PP composite material of Comparative Examples 1-2 or Comparative Examples 5-6 are lower than those of Example 1 or 14, and the vacuum forming time is longer than that of Example 1 or 14. It is shown that the compounding of the compatibilizer 1 and the compatibilizer 2 of the present invention can improve the mechanical properties and the suction efficiency of the composite material.

[0081] Example 1-2 uses PP resin with a notched impact strength of 10-40 KJ / m 2 In the range of Example 3-4, the notched impact strength is not within the range of 10-40 KJ / m 2 The blister time of the composite material of Example 3 is longer than that of Examples 1-2, and the blister time of the composite material of Example 4 is similar to that of Example 2, but its tensile strength and notched impact strength are lower than those of Examples 1-2. It can be seen that the notched impact strength of the PP resin selected by the present invention is 10-40KJ / m 2 Within this range, the plastic absorption efficiency of the composite material can be further improved while ensuring the mechanical properties of the composite material.

Claims

1. A PS / PP composite material, characterized in that: The composite material components include, by weight: The compatibilizer 1 is SBS or SEBS, the S / B mass ratio in the SBS is 30 / 70 to 35 / 65, and the styrene mass fraction in the SEBS is 30-35%; The compatibilizer 2 is maleic anhydride grafted polypropylene or a random copolymer of styrene and maleic anhydride, the mass fraction of maleic anhydride in the maleic anhydride grafted polypropylene is 0.6-1%, and the mass fraction of maleic anhydride in the random copolymer of styrene and maleic anhydride is 15-20%; The PS resin is HIPS; the PP resin is a copolymer of propylene and ethylene.

2. The composite material according to claim 1, characterized in that The composite material components include, by weight:

3. The composite material according to claim 1, characterized in that The SBS has a linear molecular structure.

4. The composite material according to claim 1, characterized in that The notched impact strength of the PP resin is 10-40KJ / m 2 .

5. The composite material according to claim 1, characterized in that The mass ratio of the compatibilizer 1 to the compatibilizer 2 is 2:1 to 4:1; the filler includes one or more of wollastonite, talc and calcium carbonate.

6. The composite material according to claim 1, characterized in that The nucleating agent includes one or more of amide compounds, phosphate compounds, and hydrazide compounds.

7. The composite material according to claim 1, characterized in that The composite material further comprises 0-3 parts of other additives; the other additives comprise antioxidants and / or lubricants.

8. A method for preparing the PS / PP composite material according to any one of claims 1 to 7, comprising: (1) PS resin and compatibilizer 1 are mixed, added into a twin-screw extruder for melt blending, and extruded into granules to obtain a premixed masterbatch; (2) adding the premixed masterbatch in step (1) and other components into a twin-screw extruder for melt blending, extrusion granulation, and obtaining a PS / PP composite material.

9. The preparation method according to claim 8, characterized in that: The melt blending temperature in steps (1) and (2) is 180-230°C.

10. Use of the PS / PP composite material as claimed in any one of claims 1 to 7 in household appliances, automobiles or medical consumables.

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