CN115850783B - Low-density toughened polypropylene foaming material composition, low-density toughened polypropylene foaming material and preparation method thereof - Google Patents
Low-density toughened polypropylene foaming material composition, low-density toughened polypropylene foaming material and preparation method thereof Download PDFInfo
- Publication number
- CN115850783B CN115850783B CN202111121436.2A CN202111121436A CN115850783B CN 115850783 B CN115850783 B CN 115850783B CN 202111121436 A CN202111121436 A CN 202111121436A CN 115850783 B CN115850783 B CN 115850783B
- Authority
- CN
- China
- Prior art keywords
- polypropylene
- foaming
- density
- pressure
- elastomer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000005187 foaming Methods 0.000 title claims abstract description 109
- 239000004743 Polypropylene Substances 0.000 title claims abstract description 102
- -1 polypropylene Polymers 0.000 title claims abstract description 102
- 229920001155 polypropylene Polymers 0.000 title claims abstract description 102
- 239000000463 material Substances 0.000 title claims abstract description 37
- 239000000203 mixture Substances 0.000 title claims abstract description 35
- 238000002360 preparation method Methods 0.000 title abstract description 11
- 229920001971 elastomer Polymers 0.000 claims abstract description 29
- 239000000806 elastomer Substances 0.000 claims abstract description 29
- 229920002223 polystyrene Polymers 0.000 claims abstract description 23
- 239000004793 Polystyrene Substances 0.000 claims abstract description 22
- 229920005604 random copolymer Polymers 0.000 claims abstract description 9
- 150000001336 alkenes Chemical class 0.000 claims abstract description 8
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 claims abstract description 7
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims abstract description 6
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims abstract description 6
- 239000011324 bead Substances 0.000 claims description 34
- 238000000034 method Methods 0.000 claims description 30
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 24
- 239000002245 particle Substances 0.000 claims description 24
- 238000001035 drying Methods 0.000 claims description 22
- 238000000465 moulding Methods 0.000 claims description 18
- 238000002156 mixing Methods 0.000 claims description 13
- 239000001569 carbon dioxide Substances 0.000 claims description 12
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 12
- 238000010438 heat treatment Methods 0.000 claims description 12
- 239000006261 foam material Substances 0.000 claims description 9
- 238000011068 loading method Methods 0.000 claims description 9
- 239000012752 auxiliary agent Substances 0.000 claims description 8
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 6
- 210000000497 foam cell Anatomy 0.000 claims description 6
- 239000000155 melt Substances 0.000 claims description 6
- 239000003381 stabilizer Substances 0.000 claims description 6
- 229920002943 EPDM rubber Polymers 0.000 claims description 5
- 239000003963 antioxidant agent Substances 0.000 claims description 5
- 230000018044 dehydration Effects 0.000 claims description 5
- 238000006297 dehydration reaction Methods 0.000 claims description 5
- 239000002667 nucleating agent Substances 0.000 claims description 5
- 229920006124 polyolefin elastomer Polymers 0.000 claims description 5
- 229920000468 styrene butadiene styrene block copolymer Polymers 0.000 claims description 5
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 claims description 4
- 230000003078 antioxidant effect Effects 0.000 claims description 4
- 229920001577 copolymer Polymers 0.000 claims description 4
- BXOUVIIITJXIKB-UHFFFAOYSA-N ethene;styrene Chemical group C=C.C=CC1=CC=CC=C1 BXOUVIIITJXIKB-UHFFFAOYSA-N 0.000 claims description 4
- 229920006132 styrene block copolymer Polymers 0.000 claims description 4
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 3
- 239000005977 Ethylene Substances 0.000 claims description 3
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-UHFFFAOYSA-N 0.000 claims description 3
- 238000004321 preservation Methods 0.000 claims description 3
- 229920005653 propylene-ethylene copolymer Polymers 0.000 claims description 3
- 239000004711 α-olefin Substances 0.000 claims description 3
- PSGCQDPCAWOCSH-UHFFFAOYSA-N (4,7,7-trimethyl-3-bicyclo[2.2.1]heptanyl) prop-2-enoate Chemical compound C1CC2(C)C(OC(=O)C=C)CC1C2(C)C PSGCQDPCAWOCSH-UHFFFAOYSA-N 0.000 claims description 2
- HQTRGFZLVRBFPT-UHFFFAOYSA-N 2,2-bis(hydroxymethyl)-3-octadecylhenicosane-1,3-diol Chemical compound CCCCCCCCCCCCCCCCCCC(O)(C(CO)(CO)CO)CCCCCCCCCCCCCCCCCC HQTRGFZLVRBFPT-UHFFFAOYSA-N 0.000 claims description 2
- SJIXRGNQPBQWMK-UHFFFAOYSA-N 2-(diethylamino)ethyl 2-methylprop-2-enoate Chemical compound CCN(CC)CCOC(=O)C(C)=C SJIXRGNQPBQWMK-UHFFFAOYSA-N 0.000 claims description 2
- BEWCNXNIQCLWHP-UHFFFAOYSA-N 2-(tert-butylamino)ethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCNC(C)(C)C BEWCNXNIQCLWHP-UHFFFAOYSA-N 0.000 claims description 2
- VKJLYEDTHCTCOH-UHFFFAOYSA-N 3-(3-octadecoxy-3-oxopropyl)sulfanylpropanoic acid Chemical compound CCCCCCCCCCCCCCCCCCOC(=O)CCSCCC(O)=O VKJLYEDTHCTCOH-UHFFFAOYSA-N 0.000 claims description 2
- 238000009826 distribution Methods 0.000 claims description 2
- VOZRXNHHFUQHIL-UHFFFAOYSA-N glycidyl methacrylate Chemical compound CC(=C)C(=O)OCC1CO1 VOZRXNHHFUQHIL-UHFFFAOYSA-N 0.000 claims description 2
- LIGACIXOYTUXAW-UHFFFAOYSA-N phenacyl bromide Chemical compound BrCC(=O)C1=CC=CC=C1 LIGACIXOYTUXAW-UHFFFAOYSA-N 0.000 claims description 2
- 125000000383 tetramethylene group Chemical group [H]C([H])([*:1])C([H])([H])C([H])([H])C([H])([H])[*:2] 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 229920000642 polymer Polymers 0.000 abstract description 5
- 238000011031 large-scale manufacturing process Methods 0.000 abstract 1
- 210000004027 cell Anatomy 0.000 description 18
- 230000000052 comparative effect Effects 0.000 description 10
- 239000006260 foam Substances 0.000 description 10
- 239000011159 matrix material Substances 0.000 description 8
- 238000001125 extrusion Methods 0.000 description 6
- 238000009472 formulation Methods 0.000 description 6
- 239000011347 resin Substances 0.000 description 5
- 229920005989 resin Polymers 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000007906 compression Methods 0.000 description 4
- 230000006835 compression Effects 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 239000010419 fine particle Substances 0.000 description 4
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000004088 foaming agent Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 239000004604 Blowing Agent Substances 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical class [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229920000181 Ethylene propylene rubber Polymers 0.000 description 1
- JKIJEFPNVSHHEI-UHFFFAOYSA-N Phenol, 2,4-bis(1,1-dimethylethyl)-, phosphite (3:1) Chemical compound CC(C)(C)C1=CC(C(C)(C)C)=CC=C1OP(OC=1C(=CC(=CC=1)C(C)(C)C)C(C)(C)C)OC1=CC=C(C(C)(C)C)C=C1C(C)(C)C JKIJEFPNVSHHEI-UHFFFAOYSA-N 0.000 description 1
- BGYHLZZASRKEJE-UHFFFAOYSA-N [3-[3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoyloxy]-2,2-bis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoyloxymethyl]propyl] 3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate Chemical compound CC(C)(C)C1=C(O)C(C(C)(C)C)=CC(CCC(=O)OCC(COC(=O)CCC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)(COC(=O)CCC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)COC(=O)CCC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)=C1 BGYHLZZASRKEJE-UHFFFAOYSA-N 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 230000003712 anti-aging effect Effects 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 230000010261 cell growth Effects 0.000 description 1
- 230000001413 cellular effect Effects 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000012669 compression test Methods 0.000 description 1
- 239000012792 core layer Substances 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- FPAFDBFIGPHWGO-UHFFFAOYSA-N dioxosilane;oxomagnesium;hydrate Chemical compound O.[Mg]=O.[Mg]=O.[Mg]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O FPAFDBFIGPHWGO-UHFFFAOYSA-N 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000004620 low density foam Substances 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- 239000012802 nanoclay Substances 0.000 description 1
- SSDSCDGVMJFTEQ-UHFFFAOYSA-N octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate Chemical compound CCCCCCCCCCCCCCCCCCOC(=O)CCC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 SSDSCDGVMJFTEQ-UHFFFAOYSA-N 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- BIKXLKXABVUSMH-UHFFFAOYSA-N trizinc;diborate Chemical compound [Zn+2].[Zn+2].[Zn+2].[O-]B([O-])[O-].[O-]B([O-])[O-] BIKXLKXABVUSMH-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
The invention relates to the technical field of high polymer foaming materials, and discloses a low-density toughened polypropylene foaming material composition, a low-density toughened polypropylene foaming material and a preparation method thereof. The composition comprises polypropylene, polystyrene and an elastomer, wherein the polystyrene is 5-15 parts by weight and the elastomer is 5-25 parts by weight based on 100 parts by weight of the polypropylene; wherein the polypropylene is random copolymer polypropylene obtained by copolymerizing C2-C4 olefin and propylene, and the content of the C2-C4 olefin is 1-8 wt%. In addition, the preparation method is simple, low in production cost and suitable for large-scale production, and the low-density foaming polypropylene material with uniform cells and excellent mechanical properties can be prepared.
Description
Technical Field
The invention relates to the technical field of high molecular foaming materials, in particular to a low-density toughened polypropylene foaming material composition, a low-density toughened polypropylene foaming material and a preparation method thereof.
Background
The foaming polypropylene is a polypropylene/gas two-phase composite material which takes polypropylene as a continuous phase and gas as a disperse phase, and has the characteristics of light weight, heat resistance, excellent mechanical property, sound insulation and the like. In recent years, the novel foaming material is developed rapidly and gradually becomes a novel foaming material for replacing the foaming polystyrene, and is widely applied to industries such as automobiles, packaging, toys, home furnishings, buildings and the like. However, since polypropylene has high crystallinity, resin hardly flows at a temperature lower than the melting point, its melt strength drastically decreases at a temperature higher than the melting point, and it is difficult for a thin and visco-elastic polypropylene melt to hold the blowing agent gas molecules, a low density (. Ltoreq.0.045 g/cm) cannot be achieved at a time during the foaming process 3 ) Uniformly cellular expanded beads.
Currently, to obtain a polypropylene foam material with high strength and low density, researchers have improved its performance by a variety of approaches:
CN104974368A discloses an antistatic polypropylene foaming bead, which is prepared by using polypropylene as matrix resin, adding modified carbon nano tube as antistatic agent and adopting physical foaming agent to foam; in addition, the foaming temperature and the foaming pressure are high.
CN101805481a discloses a high-magnification cross-linked foaming polypropylene sheet and a preparation method thereof, wherein the high-magnification cross-linked foaming polypropylene sheet comprises polypropylene resin, a cross-linking agent, an anti-aging agent and foaming agent master batches, and the high-magnification polypropylene foaming material is obtained through irradiation cross-linking.
CN105885242a discloses a high-rigidity polypropylene foaming bead and an energy-saving preparation method thereof, wherein a double-layer coextrusion mode is adopted, the surface layer is low-forming-pressure polypropylene, and the core layer is high-rigidity polypropylene, so that the high-rigidity low-forming-pressure foaming polypropylene bead is obtained.
The foaming polypropylene material prepared by the method has a complex production process, and the density of the foaming material obtained by foaming is generally higher than 0.045g/cm 3 The low density foam material is required to be obtained by secondary foaming with pressurized steam, thereby increasing energy and time costs during the production process.
Therefore, the development of the low-density toughened foaming polypropylene material and the preparation method thereof have very important significance.
Disclosure of Invention
The invention aims to overcome the defects that the density of the foaming material prepared by a one-step method in the prior art is lower than 0.045g/cm 3 However, the defect of poor mechanical properties is overcome, the density of the foaming material prepared by adopting the two-step method needs to be secondarily foamed by pressurized steam to obtain a low-density foaming material, so that the defect of energy and time cost increase in the production process is overcome.
In order to achieve the above object, a first aspect of the present invention provides a low-density toughened polypropylene foam composition, wherein the composition comprises polypropylene, polystyrene and an elastomer, and the polystyrene is 5 to 15 parts by weight and the elastomer is 5 to 25 parts by weight based on 100 parts by weight of the polypropylene; wherein the polypropylene is random copolymer polypropylene obtained by copolymerizing C2-C4 olefin and propylene, and the content of the C2-C4 olefin is 1-8 wt%.
The invention provides a method for preparing a low-density toughened polypropylene foaming material by adopting the composition, wherein the method comprises the following steps of:
(1) Mixing polypropylene, polystyrene, an elastomer, an optional compatilizer and an optional foaming auxiliary agent, and then performing melt coextrusion, cooling, bracing and granulating to obtain blend particles;
(2) Placing the blend particles and carbon dioxide in a high-pressure closed container, carrying out heat preservation treatment under a first temperature condition, then carrying out heating treatment under a second temperature condition at a heating rate of 0.1-1 ℃/min, and then carrying out pressure relief treatment, dehydration and first drying on the high-pressure closed container to obtain foaming beads;
(3) And standing the foaming beads, and carrying out pressure loading, steam molding and second drying treatment to obtain the low-density toughened polypropylene foaming material.
The third aspect of the invention provides a low-density toughened polypropylene foam material prepared by the method.
According to the technical scheme, the preparation method of the toughened polypropylene foaming material provided by the invention has the advantages that the polystyrene is added into the polypropylene matrix to improve the solubility of carbon dioxide in the polymer matrix, so that the primary foaming multiplying power of the polypropylene foaming beads is improved, and the density of the foaming beads is reduced; the elastomer is added into the polypropylene matrix, so that the toughness of the foaming beads is increased, the forming pressure of the foaming beads can be reduced, and the polypropylene foaming material with excellent mechanical properties, wider application range and more suitability for industrial application is obtained.
Drawings
FIG. 1 is a scanning electron microscope photograph of a low-density toughened polypropylene foam material prepared in example 1 of the present invention;
FIG. 2 is a scanning electron micrograph of the expanded beads obtained by one-time foaming in comparative example 1.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
In the present invention, it is to be noted that the data ranges given are selected from any value in the ranges, and include the end points of the ranges.
The invention provides a low-density toughened polypropylene foaming material composition, which comprises polypropylene, polystyrene and an elastomer, wherein the polystyrene is 5-15 parts by weight and the elastomer is 5-25 parts by weight based on 100 parts by weight of the polypropylene; wherein the polypropylene is random copolymer polypropylene obtained by copolymerizing C2-C4 olefin and propylene, and the content of the C2-C4 olefin is 1-8 wt%.
The inventors of the present invention unexpectedly found that: the density of the low-density foaming polypropylene prepared by the prior art is lower than 0.045g/cm by a one-step method 3 However, the low-density expanded polypropylene beads obtained by one-time foaming generally have the defects of shrinkage of cells, poor mechanical properties and the like. The two-step method is adopted: one-time kettle pressure foaming reaches 0.045g/cm 3 The secondary foaming by the water vapor under the overload pressure is required to reach the concentration of less than 0.045g/cm 3 Polypropylene expanded beads of (a).
Based on this, the inventors of the present invention unexpectedly found that, in order to be able to foam once to obtain low-density high-magnification expanded polypropylene beads: the polystyrene is added into the polypropylene matrix to improve the solubility of carbon dioxide in the polymer matrix, and the elastomer is added for blending, so that the mechanical property of the polypropylene matrix is improved, the forming pressure of the foaming material can be effectively reduced, and the energy conservation and emission reduction are realized. In addition, the preparation method of the invention can prepare the foam with the density lower than 0.045g/cm 3 And the polypropylene foaming material with excellent mechanical properties can reduce the production cost.
According to the present invention, it is preferable that the polystyrene is 5 to 10 parts by weight and the elastomer is 10 to 20 parts by weight based on 100 parts by weight of the polypropylene.
According to the invention, the polypropylene is propylene and 1-butene random copolymer and/or ethylene propylene copolymer polypropylene; preferably, the polypropylene is ethylene propylene copolymer polypropylene; more preferably, the polypropylene has a melt index of 1-20g/10min, more preferably 5-12g/10min at 230℃under 2.16 kg. In the invention, specifically, the polypropylene is obtained from China petrochemical Co., ltd, which is named E07ES, and has a melt index of 10g/10min; purchased from singapore TPC petrochemical company under the trade name W331 with a melt index of 7g/10min; purchased from Taiwan plast Co., ltd., trade name 5050, melt index 6.5g/10min.
According to the invention, the elastomer is a polyolefin elastomer and/or a styrenic elastomer.
In the present invention, preferably, the polyolefin elastomer is selected from one or more of ethylene propylene diene monomer, metallocene ethylene propylene diene monomer, ethylene/α -olefin random copolymer elastomer and metallocene catalyzed propylene ethylene copolymer elastomer; wherein ethylene propylene rubber is purchased from Italian Erni corporation with the trade name of 059; ethylene propylene diene monomer is purchased from Mitsui chemical under the brand 3072EP; ethylene/alpha-olefin random copolymer elastomer (POE) was purchased from dow chemical under the trade designation 8200; metallocene-catalyzed propylene ethylene copolymer elastomer (POP) was purchased from Exxon Mobil chemical company under the designation VM3588FL.
In the present invention, preferably, the styrenic elastomer is selected from one or more of styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene/butylene/propylene-styrene block copolymer, styrene-ethylene/propylene-styrene block copolymer. Among them, styrene-butadiene-styrene block copolymer (SBS) is purchased from China petrochemical Baling petrochemical division, brand YH-1401.
According to the invention, the polystyrene has a weight average molecular weight of 1.5X10 5 Up to 4X 10 5 The molecular weight distribution index Mw/Mn is less than or equal to 4; preferably, in the present inventionThe polystyrene is selected from polystyrene 1 (trademark GPPS251 of Shanghai Seisaceae petrochemical Co., ltd.) or polystyrene (trademark GPPS535N of polystyrene Co., ltd.).
According to the invention, the composition further comprises a compatilizer and a foaming auxiliary agent, wherein the compatilizer is 0.5-5 parts by weight based on 100 parts by weight of the polypropylene, and the foaming auxiliary agent is 1-10 parts by weight; preferably, the compatilizer is 1-3 parts by weight and the foaming auxiliary is 1-5 parts by weight based on 100 parts by weight of the polypropylene.
According to the invention, the compatilizer is selected from one or more of maleic anhydride, t-butylaminoethyl methacrylate, glycidyl methacrylate, diethylaminoethyl methacrylate and isobornyl acrylate; preferably, the compatibilizing agent is selected from maleic anhydride.
According to the invention, the foaming auxiliary is selected from one or more of antioxidants, nucleating agents and stabilizers; preferably, the foaming auxiliary agent is a mixture of an antioxidant, a nucleating agent and a stabilizer, and the weight ratio of the dosages of the antioxidant, the nucleating agent and the stabilizer is 1: (1-5): (1-5).
According to the present invention, the antioxidant is selected from one or more of antioxidant 168, antioxidant 1010 and antioxidant 1076; the nucleating agent is selected from one or more of zinc borate, montmorillonite, talcum powder, nano clay and kaolin; the stabilizer is one or more selected from stearyl thio-dipropionate, diethyl 3, 5-di-tert-butyl-4-hydroxybenzyl phosphate, distearyl pentaerythritol and bisphosphite.
The invention provides a method for preparing a low-density toughened polypropylene foaming material by adopting the composition, wherein the method comprises the following steps of:
(1) Mixing polypropylene, polystyrene, an elastomer, an optional compatilizer and an optional foaming auxiliary agent, and then performing melt coextrusion, cooling, bracing and granulating to obtain blend particles;
(2) Placing the blend particles and carbon dioxide in a high-pressure closed container, carrying out heat preservation treatment under a first temperature condition, then carrying out heating treatment under a second temperature condition at a heating rate of 0.1-1 ℃/min, and then carrying out pressure relief treatment, dehydration and first drying on the high-pressure closed container to obtain foaming beads;
(3) And standing the foaming beads, and carrying out pressure loading, steam molding and second drying treatment to obtain the low-density toughened polypropylene foaming material.
According to the present invention, in step (1), the conditions of melt coextrusion include: the heating temperature of each section of the twin-screw is 170-200 ℃. In addition, the melt coextrusion can be melt extruded in twin-screw extrusion, and then cooled, bracing and granulating to obtain the blend particles with the length of 1.5-3mm, the diameter of 1-2mm and the length-diameter ratio of (1.5-2): 1. The conditions for cooling, drawing and granulating are not particularly limited in the present application, and may be conditions for twin-screw extrusion granulation known to those skilled in the art.
According to the invention, in step (2), the pressure of the carbon dioxide is 1-3.5MPa, the first temperature is 125-155 ℃, the second temperature is 130-160 ℃, and the first temperature is 3-10 ℃ lower than the second temperature; preferably, the pressure of the carbon dioxide is 1.5-2.5MPa, the first temperature is 125-150 ℃, the second temperature is 130-155 ℃, and the first temperature is 5-8 ℃ lower than the second temperature. In the present invention, the temperature conditions defined above are employed in order to sufficiently dissolve carbon dioxide in the polymer matrix.
According to the present invention, the high-pressure closed vessel may be a high-pressure reaction vessel having an internal pressure of 1.5 to 5MPa, preferably 2 to 3MPa.
According to the invention, the conditions of the pressure relief treatment include: the pressure release rate is 0.1-1MPa/min, preferably 0.2-0.8MPa/min. In the present invention, the purpose of the depressurization is to allow uniform growth of cells in the polymer.
According to the present invention, the conditions for dehydration drying include: dewatering by a dewatering machine, and drying by an oven. In the invention, dehydration can be performed by adopting a dehydrator mode; in addition, the drying can be performed by adopting an oven, wherein the temperature of the first drying is 50-80 ℃ and the time is 3-10h.
According to the present invention, in step (3), the conditions for standing include: the temperature is 10-40deg.C, and the time is 3-7 days. In the present invention, the purpose of the standing is to allow the pressure difference in the EPP particle network to reach an equilibrium state.
According to the invention, the conditions of the load pressure include: the pressure is 0.2-0.8MPa, preferably 0.3-0.6MPa; in the present invention, the purpose of the pressure loading is to fill the interior of the EPP particles with internal pressure, and to expand and bond the particles under the action of hot air.
According to the present invention, the conditions for steam molding include: the pressure is 0.10-0.40MPa, preferably 0.15-0.25MPa; in the present invention, the purpose of the steam molding is to bond between EPP particles.
According to the present invention, drying may be performed using an oven, wherein the conditions for the second drying include: the temperature is 60-90 ℃ and the time is 3-10h.
According to a particularly preferred embodiment of the present invention, the method for preparing the low density toughened polypropylene foam material of the present invention comprises the steps of:
(S1): mixing 100 parts by weight of polypropylene, 5-10 parts by weight of polystyrene, 10-20 parts by weight of polyolefin elastomer or styrene elastomer, 1-3 parts by weight of compatilizer and 1-5 parts by weight of foaming auxiliary agent by a high-speed mixer, adding into twin-screw extrusion for melt extrusion, cooling, bracing and granulating to prepare blend particles with the length of 1.5-3mm, the diameter of 1-1.5mm and the length-diameter ratio of (1.5-2): 1;
(S2): placing the particles prepared in the step (S1) into a high-pressure reaction kettle, introducing carbon dioxide, heating, maintaining the pressure for 30-60 minutes after reaching a first temperature, heating to a second temperature at a speed of 0.1-1 ℃/min, placing the particles in the high-pressure kettle into atmospheric pressure at a certain pressure release speed, and dehydrating and drying to obtain foaming beads; wherein the pressure of the carbon dioxide is 1.5-2.5MPa, the first temperature is 125-150 ℃, the second temperature is 130-155 ℃, and the first temperature is 5-8 ℃ lower than the second temperature; the pressure in the high-pressure reaction kettle is 2-3MPa; the conditions of the pressure release treatment include: the pressure release rate is 0.2-0.8MPa/min; the first drying temperature is 50-80 ℃ and the time is 3-10h;
(S3): standing the foaming beads prepared in the step (S2) for one week, carrying out pressure loading, and drying through steam molding; wherein the conditions of the standing include: the temperature is 10-40 ℃ and the time is 3-7 days; the conditions for steam molding include: the pressure is 0.15-0.25MPa; the second drying conditions include: the temperature is 60-90 ℃ and the time is 3-10h; and preparing the low-density toughened polypropylene foaming material.
The third aspect of the invention provides a low-density toughened polypropylene foam material prepared by the method.
According to the invention, the density of the low-density toughened polypropylene foaming material is 0.020-0.10g/cm 3 The foaming multiplying power is 9-45 times, the average diameter of the foam cells is 50-200 mu m, and the density of the foam cells is 1 multiplied by 10 4 Individual/cm 3 Up to 1X 10 9 Individual/cm 3 The 50% compression strength is 0.1-0.8Mpa, and the tensile strength is 0.1-1.2Mpa; preferably, the density is 0.025-0.09g/cm 3 The foaming multiplying power is 10-36 times, the average diameter of the foam cells is 60-180 mu m, and the density of the foam cells is 1 multiplied by 10 5 Individual/cm 3 Up to 1X 10 9 Individual/cm 3 The 50% compression strength is 0.1-0.5Mpa, and the tensile strength is 0.2-0.9Mpa; more preferably, the density is from 0.025 to 0.045g/cm 3 The foaming multiplying power is 20-36 times, the average diameter of the cells is 80-140 mu m, and the density of the cells is 3.7X10 5 Individual/cm 3 To 7.8X10 7 Individual/cm 3 The 50% compressive strength is 0.2-0.3Mpa, and the tensile strength is 0.39-0.8Mpa.
The present invention will be described in detail by examples.
In the following examples and comparative examples:
primary device
Twin screw extruder: nanjing Hai extrusion equipment Co., ltd., SHL-52;
kettle pressure foaming equipment: ningbo materials technology and engineering institute of China academy of sciences: self-grinding;
and (3) forming equipment: suzhou Xinshun mechanical Co Ltd
Density testing device: METTLER-TOLEDO, switzerland: a ME104e+ density component;
cell structure: hitachi high technology Co Ltd: TM1000 scanning electron microscope;
mechanical properties: instron Co., USA: 5567 universal mechanical testing machine;
(II) test method
Density: the density of the polypropylene base resin and the density of the foaming beads are obtained by using a density balance and a drainage method, and the foaming multiplying power formula of the foaming beads is as followsWherein->For the foaming multiplying power ρ 1 As the base resin density ρ 2 Is the density of the foaming beads;
cell structure: observing the section of the foaming bead by using a scanning electron microscope, selecting a certain area to obtain information such as cell diameter, cell number and the like, and obtaining the cell density of the foaming bead by the following formula:
N 0 ＝[nM 2 /A] 3/2 φ
wherein n is the number of cells in the scanning electron microscope photograph, M is a multiple of the method, A is the area (in cm) of the selected region on the scanning electron microscope photograph 2 ) Phi is the expansion ratio of the expanded beads.
Compressive strength: A50X 50mm specimen was cut out from the foam molded body, and a compression test was performed at a compression rate of 5mm/min by a universal tester to obtain a compression strength at which the specimen was compressed by 50%.
Tensile strength: sample bars were prepared according to GB/T6344-2008 and tensile tested using a universal tester at a tensile rate of 50mm/min to obtain the tensile strength of the sample.
Example 1
This example is intended to illustrate a polypropylene foam prepared by the method of the present invention.
(S1): mixing polypropylene, polystyrene, elastomer, compatilizer and foaming auxiliary agent by a high-speed mixer, adding into twin-screw extrusion, melting and extruding, cooling, bracing and granulating to obtain blend particles with the length of 1.5-3mm, the diameter of 1-2mm and the length-diameter ratio of (1.5-2): 1;
(S2): placing the particles prepared in the step (S1) into a high-pressure reaction kettle, introducing carbon dioxide, heating to a first temperature, maintaining the pressure, heating to a second temperature at a heating rate, placing the particles in the high-pressure kettle into atmospheric pressure at a certain pressure release rate, dehydrating, and performing first drying to obtain foaming beads;
(S3): and (3) standing the foaming beads prepared in the step (S2) for a week, carrying out pressure loading, and carrying out steam molding and secondary drying to prepare the polypropylene foaming material.
Wherein, the blending particle formula combination is shown in table 1; the parameters of the kettle pressure foaming and molding process are shown in Table 2; the density and properties of the foamed fine particles are shown in Table 3.
In addition, fig. 1 is a scanning electron microscope photograph of the low-density toughened polypropylene foaming material prepared in example 1 of the present invention; from fig. 1, it can be derived that: the cells were uniform in size, the cell diameters were between 80 and 120. Mu.m, the average cell diameter was directly 100. Mu.m, and the cell density was 4.5X10 6 Individual/cm 3 。
Examples 2 to 8
This example is intended to illustrate a polypropylene foam prepared by the method of the present invention.
A polypropylene foam was produced in the same manner as in example 1 except that: the blending particle formulation and the autoclave foaming and molding process parameters, specifically, the blending particle formulation combinations are shown in table 1; the parameters of the kettle pressure foaming and molding process are shown in Table 2; the density and properties of the foamed fine particles are shown in Table 3.
Comparative example 1
A polypropylene foam was produced in the same manner as in example 1 except that: the blending particle formulation and the autoclave foaming and molding process parameters, specifically, the blending particle formulation combinations are shown in table 1; the parameters of the kettle pressure foaming and molding process are shown in Table 2; and the expanded beads of comparative example 1 were subjected to a secondary foaming and molding operation, as follows:
and (2) placing the foaming beads obtained in the step (S2) into a pressure-carrying tank, carrying out pressure carrying for 12 hours under the air pressure of 0.5MPa, and then performing secondary foaming by using an EPP secondary foaming machine to obtain the foaming beads.
And carrying out pressure loading on the foaming beads in a pressure loading tank of 0.5MPa for 12 hours, and then carrying out steam molding to prepare a foaming product, drying and measuring the mechanical properties of the foaming product. The density and properties of the foamed fine particles are shown in Table 3.
FIG. 2 is a scanning electron micrograph of the expanded beads obtained by one-time foaming of comparative example 1; from fig. 2, it can be derived that: the cell diameter is 30-80 μm, the average cell diameter is 70 μm, the cell size is small, and the cell density is 6.7X10 9 Individual/cm 3 。
Comparative examples 2 to 5
A polypropylene foam was produced in the same manner as in example 1 except that: the blending particle formulation and the autoclave foaming and molding process parameters, specifically, the blending particle formulation combinations are shown in table 1; the parameters of the kettle pressure foaming and molding process are shown in Table 2; the density and properties of the foamed fine particles are shown in Table 3.
TABLE 1
TABLE 2
Remarks: in this table, in the examples and comparative examples of the present invention, the temperatures of the first drying and the second drying are the same.
TABLE 3 Table 3
As can be seen from the results of tables 1 to 3, the foamed beads prepared by the preparation method of the present invention and under the conditions specifically defined in the present invention have significantly better effects of high foaming ratio, excellent mechanical properties, etc. Comparative examples 1 to 5 have poor results due to the absence of the technical solutions or conditions according to the present invention, and in addition, comparative example 4 focuses on the non-added elastomer, so that the stretching thereof should have an effect; comparative example 5 focused on high pressure release rate, small cells formed, high density, and thus affecting mechanical properties.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.
Claims (12)
1. A low-density toughened polypropylene foaming material composition, which is characterized by comprising polypropylene, polystyrene and an elastomer, wherein the polystyrene is 5-15 parts by weight and the elastomer is 5-25 parts by weight based on 100 parts by weight of the polypropylene; wherein the polypropylene is C 2 -C 4 Random copolymer polypropylene obtained by copolymerizing olefin and propylene, and C 2 -C 4 The content of olefins is 1-8 wt%;
the elastomer is polyolefin elastomer and/or styrene elastomer;
the polyolefin elastomer is selected from one or more of ethylene propylene diene monomer, metallocene ethylene propylene diene monomer, ethylene/alpha-olefin random copolymer elastomer and metallocene catalyzed propylene ethylene copolymer elastomer;
the styrene elastomer is selected from one or more of styrene-butadiene-styrene block copolymer, styrene-ethylene/butylene/propylene-styrene block copolymer and styrene-ethylene/propylene-styrene block copolymer.
2. The composition of claim 1, wherein the polypropylene is a propylene and 1-butene random copolymer and/or an ethylene propylene copolymer polypropylene;
and/or the polypropylene has a melt index of 1-20g/10min at 230 ℃ under 2.16 kg.
3. The composition of claim 2, wherein the polypropylene is ethylene propylene copolymer polypropylene;
and/or the polypropylene has a melt index of 5-12g/10min at 230 ℃ under 2.16 kg.
4. The composition of claim 1, wherein the polystyrene has a weight average molecular weight of 1.5 x 10 5 Up to 4X 10 5 The molecular weight distribution index Mw/Mn is less than or equal to 4.
5. The composition according to any one of claims 1 to 4, wherein the composition further comprises a compatibilizer and a foaming aid, and the compatibilizer is 0.5 to 5 parts by weight and the foaming aid is 1 to 10 parts by weight based on 100 parts by weight of the polypropylene;
and/or the compatilizer is selected from one or more of maleic anhydride, tert-butylaminoethyl methacrylate, glycidyl methacrylate, diethylaminoethyl methacrylate and isobornyl acrylate;
and/or the foaming auxiliary is selected from one or more of an antioxidant, a nucleating agent and a stabilizer.
6. The composition of claim 5, wherein the stabilizer is selected from one or more of stearyl thiodipropionate, diethyl 3, 5-di-tert-butyl-4-hydroxybenzyl phosphate, distearyl pentaerythritol, and bisphosphites.
7. A method of preparing a low density toughened polypropylene foam material using the composition of any of claims 1 to 6, said method comprising:
(1) Mixing polypropylene, polystyrene, an elastomer, an optional compatilizer and an optional foaming auxiliary agent, and then performing melt coextrusion, cooling, bracing and granulating to obtain blend particles;
(2) Placing the blend particles and carbon dioxide in a high-pressure closed container, carrying out heat preservation treatment under a first temperature condition, then carrying out heating treatment under a second temperature condition at a heating rate of 0.1-1 ℃/min, and then carrying out pressure relief treatment, dehydration and first drying on the high-pressure closed container to obtain foaming beads; wherein, the pressure release treatment conditions include: the pressure release rate is 0.1-1MPa/min;
(3) And standing the foaming beads, and carrying out pressure loading, steam molding and second drying treatment to obtain the low-density toughened polypropylene foaming material.
8. The method of claim 7, wherein in step (2), the pressure of the carbon dioxide is 1-3.5MPa and the first temperature is 125-155 ℃; the second temperature is 130-160 ℃;
and/or the pressure inside the high-pressure closed container is 1.0-5MPa.
9. The method of claim 8, wherein the first temperature is 3-10 ℃ lower than the second temperature.
10. The method of claim 7, wherein in step (3), the conditions of rest include: the temperature is 10-40 ℃ and the time is 3-7 days;
and/or, the loading conditions include: the pressure is 0.2-0.8MPa;
and/or, the conditions of the steam molding include: the pressure is 0.10-0.40MPa;
and/or, the second drying conditions include: the temperature is 60-90 ℃.
11. A low density toughened polypropylene foam material prepared by the method of any of claims 7-10.
12. The low density toughened polypropylene foam material of claim 11 wherein the low density toughened polypropylene foam material has a density of 0.02 to 0.1g/cm 3 The foaming multiplying power is 9-45 times, the average diameter of the foam cells is 50-200 mu m, and the density of the foam cells is 1 multiplied by 10 4 Individual/cm 3 Up to 1X 10 9 Individual/cm 3 The 50% compressive strength is 0.1-0.8MPa, and the tensile strength is 0.1-1.2MPa.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111121436.2A CN115850783B (en) | 2021-09-24 | 2021-09-24 | Low-density toughened polypropylene foaming material composition, low-density toughened polypropylene foaming material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111121436.2A CN115850783B (en) | 2021-09-24 | 2021-09-24 | Low-density toughened polypropylene foaming material composition, low-density toughened polypropylene foaming material and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115850783A CN115850783A (en) | 2023-03-28 |
| CN115850783B true CN115850783B (en) | 2024-03-22 |
Family
ID=85652521
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111121436.2A Active CN115850783B (en) | 2021-09-24 | 2021-09-24 | Low-density toughened polypropylene foaming material composition, low-density toughened polypropylene foaming material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115850783B (en) |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014136933A1 (en) * | 2013-03-08 | 2014-09-12 | 株式会社カネカ | Method for manufacturing foamed polypropylene-resin particles |
| CN106633360A (en) * | 2016-11-21 | 2017-05-10 | 广东炜林纳新材料科技股份有限公司 | Low-temperature-impact resistant polypropylene foaming bead forming body and preparation method thereof |
| CN107200929A (en) * | 2016-03-16 | 2017-09-26 | 青岛科技大学 | A kind of propylene copolymer microcellular foam material and preparation method thereof |
| CN111234373A (en) * | 2018-11-28 | 2020-06-05 | 中国科学院宁波材料技术与工程研究所 | Preparation method of halogen-free flame-retardant polypropylene foam material |
| CN111534001A (en) * | 2020-06-03 | 2020-08-14 | 星贝达（上海）化工材料有限公司 | High oil absorption polypropylene material and preparation method thereof |
| CN112442250A (en) * | 2019-08-30 | 2021-03-05 | 中国石油化工股份有限公司 | Composition for preparing glass fiber reinforced polypropylene material, material prepared from composition and application of material |
| CN112831127A (en) * | 2020-12-31 | 2021-05-25 | 新子元(上海)科技发展有限公司 | Expandable polypropylene particles, modified polypropylene expanded beads and preparation thereof |
| EP3872121A1 (en) * | 2020-02-28 | 2021-09-01 | Borealis AG | Expanded polypropylene beads, a process for producing expanding polypropylene beads, molded articles formed from expanded polypropylene beads, and a process for forming such molded articles |
-
2021
- 2021-09-24 CN CN202111121436.2A patent/CN115850783B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014136933A1 (en) * | 2013-03-08 | 2014-09-12 | 株式会社カネカ | Method for manufacturing foamed polypropylene-resin particles |
| CN107200929A (en) * | 2016-03-16 | 2017-09-26 | 青岛科技大学 | A kind of propylene copolymer microcellular foam material and preparation method thereof |
| CN106633360A (en) * | 2016-11-21 | 2017-05-10 | 广东炜林纳新材料科技股份有限公司 | Low-temperature-impact resistant polypropylene foaming bead forming body and preparation method thereof |
| CN111234373A (en) * | 2018-11-28 | 2020-06-05 | 中国科学院宁波材料技术与工程研究所 | Preparation method of halogen-free flame-retardant polypropylene foam material |
| CN112442250A (en) * | 2019-08-30 | 2021-03-05 | 中国石油化工股份有限公司 | Composition for preparing glass fiber reinforced polypropylene material, material prepared from composition and application of material |
| EP3872121A1 (en) * | 2020-02-28 | 2021-09-01 | Borealis AG | Expanded polypropylene beads, a process for producing expanding polypropylene beads, molded articles formed from expanded polypropylene beads, and a process for forming such molded articles |
| CN111534001A (en) * | 2020-06-03 | 2020-08-14 | 星贝达（上海）化工材料有限公司 | High oil absorption polypropylene material and preparation method thereof |
| CN112831127A (en) * | 2020-12-31 | 2021-05-25 | 新子元(上海)科技发展有限公司 | Expandable polypropylene particles, modified polypropylene expanded beads and preparation thereof |
Non-Patent Citations (1)
| Title |
|---|
| 徐同考.塑料改性实用技术.中国轻工业出版社,2012,(第1版),57. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115850783A (en) | 2023-03-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112457596B (en) | Energy-saving foaming polypropylene bead and preparation method thereof | |
| CN108409985B (en) | Method for improving foaming ratio of polylactic acid through pre-isothermal cold crystallization treatment | |
| CN113956530A (en) | Energy-saving expanded polypropylene bead and molded part thereof | |
| CN111087705B (en) | Foaming composition, foaming material, preparation method and application thereof | |
| CN102702561A (en) | Preparation method of low-density thermoplastic polyimide micro-foamed material | |
| CN111978585A (en) | Preparation method and application of polymer foam material with trimodal cellular structure | |
| CN114230916B (en) | Polypropylene composite material and preparation method and application thereof | |
| CN115850783B (en) | Low-density toughened polypropylene foaming material composition, low-density toughened polypropylene foaming material and preparation method thereof | |
| US12017395B2 (en) | In-situ microfibrillated reinforced polymer composite heat-insulating foam material as well as preparation method and application thereof | |
| CN112852056B (en) | Polypropylene master batch for foaming and preparation method and application thereof | |
| WO2024066971A1 (en) | Polypropylene micro-foaming material, and preparation method therefor and use thereof | |
| CN109265825B (en) | Polypropylene or polypropylene compound foamed product and preparation method thereof | |
| CN111777817A (en) | Phase-change energy storage material and preparation method and application thereof | |
| CN114605694B (en) | Reinforced polybutene foam material and preparation method thereof | |
| CN115073854A (en) | High-temperature-resistant flame-retardant polypropylene foam material and preparation method and application thereof | |
| CN113603977A (en) | High-hardness micro-foaming material and preparation method thereof | |
| JP7471423B2 (en) | A method for preparing highly efficient, low-cost and environmentally friendly physical foamed materials | |
| CN112341724A (en) | Composition for preparing microcellular foam material, microcellular foam material and preparation method thereof | |
| CN113444315B (en) | Low-forming-pressure polypropylene foamed product and preparation method thereof | |
| CN113563670A (en) | High-melt-strength polybutylene bead as well as preparation method and application thereof | |
| CN110551339A (en) | Polypropylene resin particles, polypropylene resin expanded particles, process for producing the same, and molded article | |
| CN109624184B (en) | Polycarbonate micro-foaming product prepared by processing through common injection molding machine and processing method thereof | |
| JP5527153B2 (en) | Polyphenylene sulfide resin composition for foaming and foamed molded article | |
| CN115636971A (en) | Preparation method and application of polybutylene foam beads | |
| CN115073855A (en) | Modified polypropylene heat-resistant foam material and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |