Highly-modified polystyrene blending foaming material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of foam materials and preparation thereof, and relates to a highly modified polystyrene blended foam material and a preparation method and application thereof, the highly modified polystyrene blended foam material comprises the following raw materials by mass: 91%-94% of polystyrene, 1%-2% of a nucleating agent, 2%-5.5% of pentane and 1%-3% of citric acid; the nucleating agent is calcium carbonate or calcium oxide. The high-modified polystyrene blending foaming material is synthesized from polystyrene, the nucleating agent, pentane and citric acid by adopting an extrusion one-step process, the cost is low, the emission of three wastes is reduced, the material performance is good, and the high-modified polystyrene blending foaming material can be well applied to the field of high-end packaging.

Description

Technical Field

[0001] The invention belongs to the technical field of foaming materials and preparation thereof, and relates to a highly modified polystyrene blended foaming material, a preparation method thereof and an application thereof. Background Art

[0002] A foaming agent is a substance that vaporizes and produces bubbles within a substance, making it porous. These substances are used in the manufacture of foam materials such as foam plastics, foam rubber, and foam resin. These foam materials are widely used in construction, home appliances, packaging, transportation, and other fields due to their thermal insulation, insulation, and waterproof properties.

[0003] Commonly used materials in the packaging industry include EPS (expanded polystyrene) and non-crosslinked closed-cell EPE (polyethylene foam). However, EPS suffers from poor resistance to repeated impacts, brittleness, and low tensile strength. EPE, on the other hand, is difficult to form into films and is expensive. Therefore, researchers have proposed EPO foam, made by expanding polyolefin and vinyl aromatic monomer interpolymer resin particles. The interpolymer resin particles consist of uncrosslinked polyolefins (polyethylene, polypropylene) and vinyl aromatic monomers (styrene). The vinyl aromatic monomers are polymerized using a suspension process to form an interpenetrating network of polyolefin and polymerized vinyl aromatic monomer particles. However, EPO is mostly imported. For example, the EPO produced by Nufa, called Arcel, is composed of 30% polyethylene and 70% polystyrene. Air bubbles are then chemically formed within the foam, creating a lightweight, sound-insulating, heat-insulating, and energy-absorbing material. However, the high cost of EPO synthesis leads to high costs. Furthermore, traditional chemical processes for foaming materials generate significant amounts of waste, waste gas, and other environmentally friendly materials.

[0004] In summary, how to provide a new foaming material with low cost, less three wastes and better performance is a technical problem that needs to be solved at present. Summary of the Invention

[0005] In view of the technical problems of high cost, high waste, high waste and poor performance of foam materials in the background technology, the present invention provides a highly modified polystyrene blended foam material and a preparation method and application thereof.

[0006] The invention adopts polystyrene, a nucleating agent, pentane and citric acid, and adopts a one-step extrusion process to synthesize a high-modified polystyrene blended foam material, which has low cost, reduces the emission of three wastes, and has excellent material properties, and can be well used in the field of high-end packaging.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A highly modified polystyrene blended foam material comprises the following raw materials in the following mass fractions:

[0009]

[0010] The nucleating agent is calcium carbonate or calcium oxide.

[0011] It is further defined that the mass fraction of the pentane is 5% to 5.5%; the mass fraction of the pentane is 5% to 5.5%; and the mass fraction of the polystyrene is 91% to 93%.

[0012] It is further defined that the high-modified polystyrene blended foam material has a density of 24.5g / L to 50g / L, an average particle size of 1.22mm, and a water vapor permeability of 1.2g / m 2 / h~1.6g / m 2 / h.

[0013] The preparation method of the highly modified polystyrene blended foam material comprises the following steps:

[0014] S1. Raw material preparation

[0015] Prepare the raw materials according to the mass fractions;

[0016] S2, mixed

[0017] mixing polystyrene and a nucleating agent in a closed environment to obtain a mixture;

[0018] S3, Extrusion

[0019] The mixed material, pentane and citric acid are added to a twin-screw extruder and melt-mixed at a temperature of 130°C to 200°C; the material is instantly cooled and pelletized after being extruded;

[0020] S4, coating

[0021] The coating agent is mixed with the pelletized material to obtain a highly modified polystyrene foam material.

[0022] It is further defined that in step S3, the feeding speed of the twin-screw extruder is 15r / min~25r / min, the main engine speed is 150r / min~260r / min, the melt mixer speed is 10r / min~25r / min, the die head temperature is 240℃~300℃, and the water tank temperature is controlled at 40℃~50℃.

[0023] It is further defined that in step S3, instantaneous cooling is achieved by cooling water at a pressure of 0.48 MPa to 0.65 MPa.

[0024] It is further defined that in step S4, the mass of the coating agent added is 1‰-2‰ of the total mass of the pelletized material.

[0025] It is further defined that the coating agent is zinc stearate or tristearic acid.

[0026] Application of the highly modified polystyrene blended foaming material in electronic product packaging.

[0027] The highly modified polystyrene blended foam material is used in the packaging of liquid crystals, mobile phones, tablets or silicon chips.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention uses polystyrene, a nucleating agent, pentane and citric acid as raw materials and adopts a one-step extrusion process to produce a highly modified polystyrene blended foaming material, so that the performance of the formed blended foaming material is modified and improved; and the preparation cost is low, and it can be well used in the field of high-end packaging, such as the packaging of liquid crystals (panels, glass, televisions), mobile phones, tablets, silicon chips and other electronic products.

[0030] 2. Compared with the traditional EPO process, the high-modified polystyrene blended foam material adopts physical principles for mixing, extrusion and granulation, which is more environmentally friendly and energy-saving. It reduces the emission of three wastes compared with the traditional process (chemical reaction), and complies with the national policy guidelines on safe and environmentally friendly production. It actively responds to the country's call for carbon neutrality and carbon peak development, and is included in the international foam waste recycling category 6, reducing the odor of the product while improving the stability and corrosion resistance of the product.

[0031] 3. The high-modified polystyrene foam material prepared by the present invention is close to EPO in terms of material properties, usage functions and fields when used, and has higher physical strength than imported EPO materials. However, it adopts low-pressure and low-temperature foaming, with the temperature not exceeding 88°C, and the curing time is within 4 to 6 hours. The molding time is relatively short, while the curing time of imported EPO is 2-3 days, and the production efficiency is improved. Under normal circumstances, the foaming loss of high-modified polystyrene is only 4% to 5%, which can meet the use of more occasions. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] The present invention provides a highly modified polystyrene blended foam material, comprising the following raw materials in the following mass fractions:

[0034]

[0035] The nucleating agent is calcium carbonate or calcium oxide.

[0036] Preferably, the mass fraction of polystyrene is 91%, 92%, 93% or 94%; the mass fraction of the nucleating agent is 1%, 1.5% or 2%; the mass fraction of pentane is 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% or 5.5%; and the mass fraction of citric acid is 1%, 1.5%, 2%, 2.5% or 3%.

[0037] Preferably, the mass fraction of pentane is 5% to 5.5%.

[0038] The high-modified polystyrene foam material provided by the present invention has a density of 24.5g / L to 50g / L, an average particle size of 1.22mm, and a water vapor permeability of 1.2g / m 2 / h~1.6g / m 2 / h.

[0039] The present invention also provides a method for preparing a highly modified polystyrene blended foam material, comprising the following steps:

[0040] S1. Raw material preparation

[0041] Prepare the raw materials according to the mass fractions;

[0042] S2, mixed

[0043] mixing polystyrene and a nucleating agent in a closed environment to obtain a mixture;

[0044] S3, Extrusion

[0045] The mixed material, pentane and citric acid are added to a twin-screw extruder and melt-mixed at a temperature of 130°C to 200°C; the material is instantly cooled and pelletized after being extruded;

[0046] In step S3 of the present invention, the feeding speed of the twin-screw extruder is 15 r / min to 25 r / min, the main engine speed is 150 r / min to 260 r / min, the melt mixer speed is 10 r / min to 25 r / min, the die head temperature is 240°C to 300°C, and the water tank temperature is controlled at 40°C to 50°C.

[0047] In step S3 of the present invention, instant cooling is achieved by cooling water at a pressure of 0.48 MPa to 0.65 MPa.

[0048] S4, coating

[0049] The coating agent is mixed with the pelletized material to obtain a highly modified polystyrene foam material.

[0050] In step S4 of the present invention, the mass of the coating agent added is 1‰-2‰ of the total mass of the pelletized material.

[0051] Preferably, the coating agent is zinc stearate or tristearic acid.

[0052] The highly modified polystyrene blended foam material prepared by the present invention adopts a one-step extrusion method, has little three-waste, is environmentally friendly, and has readily available raw materials. It has extremely strong performance and can be well used in high-end electronic product packaging, especially in the packaging of liquid crystals, mobile phone tablets or silicon chips.

[0053] The highly modified polystyrene blended foam material and its preparation method provided by the present invention are described in detail below with reference to several groups of embodiments.

[0054] It should be noted that, unless otherwise specified, the chemical raw materials used in the following examples are all conventional commercial products in the art.

[0055] Example 1

[0056] This embodiment provides a highly modified polystyrene blended foaming material, comprising the following raw materials in the following mass fractions: 91% polystyrene, 2% nucleating agent, 4% pentane, and 3% citric acid; the nucleating agent is calcium carbonate.

[0057] The preparation method of the highly modified polystyrene blended foam material provided in this embodiment comprises the following steps:

[0058] S1. Raw material preparation

[0059] Prepare each raw material according to the mass fraction; if the total mass of the high-modified polystyrene blended foam material is 100 parts, the mass ratio of polystyrene, nucleating agent, pentane and citric acid is 91:2:4:3.

[0060] S2, mixed

[0061] The polystyrene and the nucleating agent are mixed in a closed environment to obtain a mixture.

[0062] S3, Extrusion

[0063] The mixed material is continuously added into a twin-screw extruder, and pentane and citric acid are added into the twin-screw extruder at the same time. At a temperature of 130° C., the mixed material, pentane and citric acid are melted, mixed and plasticized, and the formed material is extruded, instantly cooled and pelletized.

[0064] Preferably, in step S3, the feeding speed of the twin-screw extruder is 15 r / min, the main engine speed is 260 r / min, the melt mixer speed is 25 r / min, the die temperature is 300° C., and the water tank temperature is controlled at 50° C. Instant cooling is achieved by cooling water at 0.48 MPa.

[0065] S4, coating

[0066] The coating agent is mixed with the pelletized material to obtain a high-modified polystyrene foam material. The added mass of the coating agent is 2‰ of the total mass of the pelletized material. The coating agent is zinc stearate.

[0067] Example 2

[0068] This embodiment provides a highly modified polystyrene blended foaming material, comprising the following raw materials in the following mass fractions: 92% polystyrene, 1.5% nucleating agent, 5.5% pentane, and 1% citric acid; the nucleating agent is calcium carbonate.

[0069] The preparation method of the highly modified polystyrene blended foam material provided in this embodiment comprises the following steps:

[0070] S1. Raw material preparation

[0071] Prepare each raw material according to the mass fraction; the total mass of the high-modified polystyrene blended foam material is 100 parts, and the mass ratio of polystyrene, nucleating agent, pentane and citric acid is 92:1.5:5.5:1.

[0072] S2, mixed

[0073] The polystyrene and the nucleating agent are mixed in a closed environment to obtain a mixture.

[0074] S3, Extrusion

[0075] The mixed material is continuously added into a twin-screw extruder, and pentane and citric acid are added into the twin-screw extruder at the same time. At a temperature of 150° C., the mixed material, pentane and citric acid are melted, mixed and plasticized, and the formed material is extruded, instantly cooled and pelletized.

[0076] Preferably, in step S3, the feeding speed of the twin-screw extruder is 25 r / min, the main engine speed is 150 r / min, the melt mixer speed is 10 r / min, the die temperature is 240° C., and the water tank temperature is controlled at 40° C. Instant cooling is achieved by cooling water at 0.65 MPa.

[0077] S4, coating

[0078] The coating agent is mixed with the pelletized material to obtain a high-modified polystyrene foam material. The added mass of the coating agent is 1‰ of the total mass of the pelletized material. The coating agent is zinc stearate.

[0079] Example 3

[0080] This embodiment provides a highly modified polystyrene blended foaming material, comprising the following raw materials in the following mass fractions: 92% polystyrene, 1.5% nucleating agent, 5% pentane, and 1.5% citric acid; the nucleating agent is calcium carbonate.

[0081] The preparation method of the highly modified polystyrene blended foam material provided in this embodiment comprises the following steps:

[0082] S1. Raw material preparation

[0083] Prepare each raw material according to the mass fraction; the total mass of the high-modified polystyrene blended foam material is 100 parts, and the mass ratio of polystyrene, nucleating agent, pentane and citric acid is 92:1.5:5:1.5.

[0084] S2, mixed

[0085] The polystyrene and the nucleating agent are mixed in a closed environment to obtain a mixture.

[0086] S3, Extrusion

[0087] The mixed material is continuously added into a twin-screw extruder, and pentane and citric acid are added into the twin-screw extruder at the same time. At a temperature of 160° C., the mixed material, pentane and citric acid are melted, mixed and plasticized, and the formed material is extruded, instantly cooled and pelletized.

[0088] Preferably, in step S3, the feeding speed of the twin-screw extruder is 20 r / min, the main engine speed is 200 r / min, the melt mixer speed is 15 r / min, the die temperature is 260° C., and the water tank temperature is controlled at 45° C. Instant cooling is achieved by cooling water at 0.55 MPa.

[0089] S4, coating

[0090] The coating agent is mixed with the pelletized material to obtain a high-modified polystyrene foam material. The added mass of the coating agent is 1‰ of the total mass of the pelletized material. The coating agent is zinc stearate.

[0091] Example 4

[0092] This embodiment provides a highly modified polystyrene blended foaming material, comprising the following raw materials in the following mass fractions: 94% polystyrene, 1% nucleating agent, 2% pentane, and 3% citric acid; the nucleating agent is calcium carbonate.

[0093] The preparation method of the highly modified polystyrene blended foam material provided in this embodiment comprises the following steps:

[0094] S1. Raw material preparation

[0095] Prepare each raw material according to the mass fraction; the total mass of the high-modified polystyrene blended foam material is 100 parts, and the mass ratio of polystyrene, nucleating agent, pentane and citric acid is 94:1:2:3.

[0096] S2, mixed

[0097] The polystyrene and the nucleating agent are mixed in a closed environment to obtain a mixture.

[0098] S3, Extrusion

[0099] The mixed material is continuously added into a twin-screw extruder, and pentane and citric acid are added into the twin-screw extruder at the same time. At a temperature of 200° C., the mixed material, pentane and citric acid are melted, mixed and plasticized, and the formed material is extruded, instantly cooled and pelletized.

[0100] Preferably, in step S3, the feeding speed of the twin-screw extruder is 25 r / min, the main engine speed is 240 r / min, the melt mixer speed is 20 r / min, the die temperature is 280° C., and the water tank temperature is controlled at 45° C. Instant cooling is achieved by cooling water at 0.6 MPa.

[0101] S4, coating

[0102] The coating agent is mixed with the pelletized material to obtain a high-modified polystyrene foam material. The added mass of the coating agent is 1‰ of the total mass of the pelletized material. The coating agent is zinc stearate.

[0103] The above embodiments are several groups of preferred implementations of the present invention, wherein the nucleating agent can be replaced by calcium oxide, and the coating agent can be replaced by tristearic acid.

[0104] Furthermore, the performance of the foamed material prepared by the present invention was verified through experiments.

[0105] The purpose of the test is to compare the performance of the highly modified polystyrene blended foam material provided in Example 2 with the EPO foam material imported from Nufa Company.

[0106] Performance testing: The density, compressive strength, tensile strength at break, and puncture strength of high-modified polystyrene foam materials were compared with those of imported EPO foam materials at expansion ratios of 20, 25, 30, and 35 times. Density was measured using GB / T 6343-2009, compressive strength using GB / T 8813-2008, tensile strength using GB / T 1040-2006, and puncture strength using ASTM-F1306-16.

[0107] Table 1 Comparison of properties of two foaming materials

[0108]

[0109] As can be seen from Table 1, the high-modified polystyrene blended foam material prepared by the present invention is compared with import EPO, and the compressive strength, tensile strength at break and puncture strength of the high-modified polystyrene blended foam material are all higher than EPO.Therefore, the present invention adopts calcium carbonate or calcium oxide as nucleating agent, mixes with polystyrene, pentane and citric acid, and the polystyrene blended foam material performance obtained by physical extrusion is greatly improved, is a kind of high-modified polystyrene blended foam material.In addition, no matter from raw materials and preparation method, compared to import EPO, the high-modified polystyrene blended foam material prepared by the present invention, cost is much lower than the preparation cost of import EPO, and the three wastes produce less, more environmentally friendly.

[0110] In addition, when the foaming rate is 20 times, 25 times, 30 times and 40 times, the flexural strength, maximum bending force, breaking deflection, breaking elongation, dimensional stability, Poisson's ratio, compressive elastic modulus, tensile elastic modulus, vapor permeability and particle diameter of the high-modified polystyrene blended foam material prepared in Example 2 of the present invention are respectively measured.

[0111] The test methods for performance indicators are based on the following standards: flexural strength, maximum bending force and deflection at break are based on GB / T 8812-2007; elongation at break is based on GB / T 1040-2006, dimensional stability is based on JIS K6767 and ASTM-D3575 respectively, Poisson's ratio is based on ISO 527-1-2019; compressive elastic modulus is based on ASTM-D1612; tensile elastic modulus is based on ISO527-1-2019; water vapor transmission rate is based on ASTM-E96; particle diameter is based on GB / T 4009-2010.

[0112] The performance test results are shown in Table 2.

[0113] Table 2 Performance results of blended foaming materials in Example 2

[0114]

[0115] It can be seen from Table 1 and Table 2 that the average particle size of the prepared high-modified polystyrene foam material is 1.22 mm, and the water vapor transmission rate is 1.2 g / m 2 / h~1.6g / m 2 / h, and a density of 24.5g / L to 50g / L; at the same time, after testing, it was found that the high-modified polystyrene blended foaming material prepared in Example 2 has high bending resistance, compressive strength, tensile properties and fracture resistance. Therefore, the high-modified polystyrene blended foaming material prepared by the present invention can be well used in the field of high-end packaging, especially in the packaging of electronic products such as liquid crystals (panels, glass, TVs), mobile phone tablets, silicon chips, etc. In addition, the high-modified polystyrene blended foaming material prepared by the present invention adopts low-pressure and low-temperature foaming during use, the temperature does not exceed 88°C, and the curing time is within 4 hours for molding (the curing time of imported EPO is 2-3 days), the molding time is relatively short, and the molding efficiency is high; and under normal circumstances, the foaming loss of high-modified polystyrene is only 4% to 5%, which is energy-saving and environmentally friendly.

[0116] The above performance test was conducted on the highly modified polystyrene blended foam material prepared in Example 2. When the highly modified polystyrene blended foam material prepared in other examples was used for performance research, it showed the same or similar performance as that in Example 2.

[0117] It can be seen that the highly modified polystyrene blended foam material prepared by the present invention has higher performance than the new material of imported EPO, and its cost is lower than the current market price of imported EPO, thus realizing localized production and having excellent performance in high-end packaging materials; especially in the application of liquid crystal, mobile phone tablet or silicon chip packaging.

[0118] Obviously, the above embodiments are merely examples to clearly illustrate the technical solutions of the present invention and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications can be made based on the above descriptions, and it is not necessary or possible to enumerate all implementation methods here. Obvious variations or modifications derived therefrom remain within the scope of protection of the present invention.

Claims

1. A highly modified polystyrene blended foam material, characterized in that: Including the following mass fractions of each raw material: 91%~94% polystyrene 1% to 2% nucleating agent 2% to 5.5% pentane 1% to 3% citric acid; The nucleating agent is calcium carbonate or calcium oxide.

2. The highly modified polystyrene blended foam material according to claim 1, characterized in that: The mass fraction of the pentane is 5% to 5.5%; the mass fraction of the polystyrene is 91% to 93%.

3. The highly modified polystyrene blended foam material according to claim 1, characterized in that: The high-modified polystyrene blended foam material has a density of 24.5g / L to 50g / L, an average particle size of 1.22mm, and a water vapor permeability of 1.2g / m 2 / h~1.6g / m 2 / h.

4. The method for preparing the highly modified polystyrene blended foam material according to claim 1, wherein: The preparation method comprises the following steps: S1. Raw material preparation Prepare the raw materials according to the mass fractions; S2, mixed mixing polystyrene and a nucleating agent in a closed environment to obtain a mixture; S3, Extrusion The mixed material, pentane and citric acid are added to a twin-screw extruder and melt-mixed at a temperature of 130°C to 200°C; the material is instantly cooled and pelletized after being extruded; S4, coating The coating agent is mixed with the pelletized material to obtain a highly modified polystyrene foam material.

5. The preparation method according to claim 4, characterized in that In step S3, the feeding speed of the twin-screw extruder is 15 rpm to 25 rpm, the main engine speed is 150 rpm to 260 rpm, the melt mixer speed is 10 rpm to 25 rpm, the die head temperature is 240° C. to 300° C., and the water tank temperature is controlled at 40° C. to 50° C.

6. The preparation method according to claim 4, characterized in that In step S3, instant cooling is achieved by using cooling water at a pressure of 0.48 MPa to 0.65 MPa.

7. The preparation method according to claim 4, characterized in that In step S4, the mass of the coating agent added is 1‰-2‰ of the total mass of the pelletized material.

8. The preparation method according to claim 7, characterized in that The coating agent is zinc stearate or tristearic acid.

9. Use of the highly modified polystyrene blended foam material according to claim 1 in electronic product packaging.

10. Use of the highly modified polystyrene blended foam material according to claim 1 in packaging of liquid crystals, mobile phones, tablets or silicon chips.

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