High-barrier compatibilization-free all-polypropylene film product and preparation method thereof

Abstract

The invention discloses a high-barrier compatibilization-free all-polypropylene film product and a preparation method thereof. The preparation method comprises the following steps: (1) preparing cross-linked polypropylene by utilizing ultraviolet irradiation; (2) carrying out melt blending on polypropylene and cross-linked polypropylene at a certain temperature to construct a gradient cross-linked structure; and (3) regulating and controlling the morphology of the dispersed phase by using high pressure, and carrying out hot press molding on the blend to obtain the polypropylene film product. According to the invention, preparation of the high-barrier compatibilization-free all-polypropylene film product is realized, high performance and high value of general-purpose plastic are realized, and a brand new thought and method are provided for preparation of high-barrier products.

Description

Technical Field

[0001] The present invention belongs to the field of high-performance polymer materials, and particularly relates to a high-barrier and compatibilizer-free all-polypropylene product and a preparation method thereof. Background Art

[0002] The high-performance and high-value transformation of general plastics has always been the common goal pursued by the polymer science community and the industrial community. Polypropylene is one of the general plastics with the second-largest usage volume after polyethylene, and has excellent chemical resistance, electrical insulation, etc., and is widely used in fields such as clothing, automobiles, medical devices, food, and drug packaging. However, the insufficient gas barrier performance of polypropylene is an important factor restricting its application in the packaging field.

[0003] Molecular chain crosslinking can modify linear polymers into network-structured polymers, which can not only improve their mechanical properties, heat resistance, and dimensional stability, but also increase the diffusion resistance of gas small molecules inside the material, thereby improving the barrier performance. However, crosslinking makes PP products unable to be recycled, which does not conform to the national dual-carbon development strategy. Industrially, polymer alloying and compounding are important means to improve the barrier performance. However, the effect of improving the barrier performance of materials by alloying or compounding methods is not good, and at the same time, the mechanical properties deteriorate, mainly because of the poor compatibility between different polymers or between the matrix and the filler, and there are a large number of interfacial defects between the two phases. Although interfacial compatibilization can improve the compatibility or interaction between the two to a certain extent, there are still a large number of interfacial defects between the two phases, resulting in poor improvement of the barrier performance.

[0004] Therefore, it is still necessary to optimize the gas barrier performance of polypropylene films through the innovation of material design and processing technology, further broaden the application of polypropylene in the packaging field, and achieve the high-performance and high-value transformation of general plastics. Summary of the Invention

[0005] To improve the barrier performance of materials, the present invention aims to provide a preparation method for a high-barrier and compatibilizer-free all-polypropylene film product, aiming to solve the problems of a large number of interfacial defects between two phases and difficult-to-control dispersed phase morphology during the polymer alloying process, and ultimately improve the barrier performance. The present invention constructs a gradient crosslinked structure to enhance the interaction between the matrix and the dispersed phase, thereby regulating the dispersed phase morphology, extending the diffusion path of small molecules inside the product, and increasing the diffusion resistance, so as to achieve the purpose of improving its gas barrier performance. This method has the advantages of no need to add compatibilizers, simple process, small pollution, low cost, and recyclability.

[0006] Another object of the present invention is to provide a high-barrier and compatibilizer-free all-polypropylene film product prepared by this preparation method.

[0007] To achieve the above invention purposes, the present invention adopts the following technical solutions:

[0008] A preparation method of a high-barrier and non-capacity-increasing all-polypropylene product, comprising the following steps:

[0009] (1) Melting and mixing polypropylene, a sensitizer and a UV initiator to prepare a polypropylene masterbatch, and then crosslinking by UV irradiation to obtain modified polypropylene;

[0010] (2) Melting and blending the modified polypropylene and unmodified polypropylene to construct a gradient crosslinked structure;

[0011] (3) Using high pressure, preferably ultra-high pressure, to regulate the morphology of the dispersed phase, and hot pressing the melt blend to obtain a polypropylene film product.

[0012] In some specific embodiments, the polypropylene in step (1) is selected from at least one of isotactic polypropylene and syndiotactic polypropylene.

[0013] In some specific embodiments, the sensitizer in step (1) is trimethylolpropane triacrylate or triallyl cyanurate, and the UV initiator is benzophenone or 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-propanone.

[0014] In some specific embodiments, in step (1), based on the total mass of the polypropylene, sensitizer and UV initiator, the content of the sensitizer is 0.1-1.0 wt%, such as 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, etc., and the content of the photoinitiator is 0.1-1.0 wt%, such as 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, etc., and the balance is polypropylene.

[0015] In some specific embodiments, in step (1), the melting temperature of the melting and mixing is 190-230 °C, such as 200 °C, 210 °C, 220 °C, etc., and the mixing time is 7-12 min, such as 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, etc.

[0016] In some specific embodiments, the UV irradiation in step (1) is carried out under a nitrogen atmosphere and at 20-30 °C, such as 20 °C, 25 °C, 30 °C, etc.;

[0017] Preferably, the irradiation source is a 1-3 kW high-pressure mercury lamp, such as 2 kW, the irradiation time is 1-5 min, such as 1 min, 2 min, 3 min, 4 min, etc., and the distance between the light source and the polypropylene masterbatch is 10-20 cm, such as 10 cm, 15 cm, 20 cm, etc.

[0018] In some specific embodiments, the modified polypropylene described in step (2) accounts for 10-30 wt% of the total mass of the modified polypropylene and unmodified polypropylene, that is, 10 wt%, 13 wt%, 15 wt%, 18 wt%, 20 wt%, 25 wt%, 30 wt% of modified polypropylene and unmodified polypropylene are blended, and the total mass of the two is counted as 100%.

[0019] In some specific embodiments, for the melt blending in step (2), the melting temperature is 190-230 °C, such as 190 °C, 200 °C, 210 °C, 220 °C, 230 °C, etc., and the mixing time is 7-12 min, such as 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, etc.

[0020] In step (3), the ultra-high pressure technology is used to regulate the morphology of the dispersed phase. The ultra-high pressure technology refers to a technology that applies a pressure higher than 100 MPa, preferably 100-500 MPa, to the substance to be treated, causing changes in its structure. The ultra-high pressure technology can cause the interaction between hydrogen bonds and hydrophilic structures in the three-dimensional structure of macromolecules in organisms, thereby generating a non-covalent bond structure, and is widely used in food processing, but there are few reports in the processing of polymer materials. In the present invention, the ultra-high pressure is 100-500 MPa, such as 100 MPa, 150 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, etc.

[0021] In some specific embodiments, for the hot pressing and forming in step (3), the pressure is 100-500 MPa, such as 100 MPa, 150 MPa, 200 MPa, 300 MPa, 400 MPa, 500 MPa, etc., the hot pressing temperature is 190-230 °C, such as 190 °C, 200 °C, 210 °C, 220 °C, 230 °C, etc., and the mixing time is 7-12 min;

[0022] Preferably, the thickness of the polypropylene film is 35-65 μm, such as 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, etc.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] The present invention enhances the interaction between the matrix and the dispersed phase through material formulation design, reduces interfacial defects under the condition of no compatibilizer, and increases the diffusion resistance of small molecules inside the material.

[0025] The present invention constructs a gradient cross-linked structure, uses the component with a high degree of cross-linking to construct a gas diffusion barrier, and prolongs the diffusion path of gas molecules inside the material.

[0026] The present invention regulates the morphology of cross-linked polypropylene by ultra-high pressure. Under the action of ultra-high pressure, the cross-linked polypropylene transforms from zero-dimensional spherical particles into two-dimensional sheet-like particles, further prolonging the diffusion path of gas molecules inside the material. Description of the Drawings

[0027] Figure 1 It is a preparation flow chart for high-barrier and compatibilizer-free all-polypropylene.

[0028] Figure 2 It is a data graph of the cross-linking degree of the modified polypropylene in the examples of the present invention. Detailed Description of the Invention

[0029] The purpose of the present invention will be further described in detail through specific examples below. The examples cannot be elaborated one by one here, but the implementation modes of the present invention are not limited to the following examples.

[0030] As Figure 1 shown, the present invention uses polypropylene, a sensitizer, and a photoinitiator as raw materials, obtains a polypropylene masterbatch through melt blending, obtains modified polypropylene through ultraviolet irradiation, then melts and blends a certain amount of modified polypropylene and unmodified polypropylene to form a polypropylene mixture, and obtains a polypropylene film through hot pressing or ultra-high pressure treatment.

[0031] The main raw material sources used in the following examples are as follows:

[0032] 1100N: Homopolypropylene, Shenhua Ningmei;

[0033] EP548R: Copolypropylene, CNOOC and Shell;

[0034] EM231: Photosensitizer (trimethylolpropane triacrylate, TMPTA), Changxing;

[0035] TAC: Photosensitizer (triallyl cyanurate), Pulesi;

[0036] IRGACURE 907: Photoinitiator (2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-one, MMMP), BASF;

[0037] MIASORB: Photoinitiator (benzophenone), Nanjing Milan.

[0038] The test methods involved in the following examples are as follows:

[0039] The gas permeability was tested using a gas permeability tester: BSG-33-E, resolution: 0.01 cm 3 / m 2 .24h.0.1MPa; test area: 50 cm 2 , and the execution standard is ASTM D134.

[0040] For the convenience of data analysis, the present invention defines the ratio of the permeability of each example to the permeability of Comparative Example 1 as the normalized permeability coefficient.

[0041] The crosslinking degree test was carried out according to the standard of ASTM DZ765-2016.

[0042] Comparative Example 1

[0043] Using compression molding, 1100N was hot-pressed into a polypropylene film, the molding pressure was 20 MPa, the hot-pressing temperature was 200 °C, and the hot-pressing time was 10 min. The prepared sample was named PP-00.

[0044] Example 1

[0045] (1) 0.1 wt% of benzophenone, 0.1 wt% of trimethylolpropane triacrylate and 99.8 wt% of 1100N were placed in a mixer to be melt-blended to prepare a polypropylene masterbatch. The temperature of the mixer was 190 °C and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene, the power was 1 kW, the irradiation time was 5 min, the temperature was 25 °C, and the irradiation distance was 15 cm;

[0046] (2) The modified polypropylene obtained after irradiation and the unmodified polypropylene were melt-blended under the processing conditions of 200 °C and a processing time of 7 min. The contents of the modified polypropylene were 10, 20 and 30 wt% respectively. Finally, the obtained mixture was hot-pressed into a polypropylene film by compression molding. The molding pressure was 20 MPa, the hot-pressing temperature was 200 °C, and the hot-pressing time was 10 min. The prepared samples were named PP-110, PP-120 and PP-130 respectively.

[0047] The gas permeability of the samples of Example 1 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0048] Table 1 Barrier properties of different specimens

[0049]

[0050] Example 2

[0051] (1) A polypropylene masterbatch was prepared by melt blending 1 wt% benzophenone, 1 wt% trimethylolpropane triacrylate, and 98 wt% 1100N in a Banbury mixer. The temperature of the Banbury mixer was 200 °C, and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene. The power was 1 kW, the irradiation time was 5 min, the temperature was 25 °C, and the irradiation distance was 15 cm;

[0052] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under processing conditions of 200 °C and a processing time of 7 min. The contents of the modified polypropylene were 10, 20, and 30 wt%, respectively. Finally, the obtained mixture was hot pressed into a polypropylene film by compression molding. The molding pressure was 20 MPa, the hot pressing temperature was 200 °C, and the hot pressing time was 10 min. The prepared samples were named PP-210, PP-220, and PP-230, respectively.

[0053] The gas permeability of the samples of Example 2 and Comparative Example 1 was tested, and the results are shown in Table 2.

[0054] Table 2 Barrier properties of different specimens

[0055]

[0056] Example 3

[0057] (1) A polypropylene masterbatch was prepared by melt blending 0.5 wt% benzophenone, 0.5 wt% trimethylolpropane triacrylate, and 99.0 wt% 1100N in a Banbury mixer. The temperature of the Banbury mixer was 190 °C, and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene. The power was 1 kW, the irradiation time was 5 min, the temperature was 25 °C, and the irradiation distance was 15 cm;

[0058] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under processing conditions of 200 °C and a processing time of 7 min. The contents of the modified polypropylene were 10, 20, and 30 wt%, respectively. Finally, the obtained mixture was hot pressed into a polypropylene film by compression molding. The molding pressure was 20 MPa, the hot pressing temperature was 200 °C, and the hot pressing time was 10 min. The prepared samples were named PP-310, PP-320, and PP-330, respectively.

[0059] The gas permeability of the samples of Example 3 and Comparative Example 1 was tested, and the results are shown in Table 3.

[0060] Table 3 Barrier properties of different specimens

[0061]

[0062] Example 4

[0063] (1) 1 wt% of 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-one, 1 wt% of triallyl cyanurate, and 98 wt% of 1100N were placed in a mixer and melt-blended to prepare a polypropylene masterbatch. The temperature of the mixer was 220 °C and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene. The power was 1 kW, the irradiation time was 5 min, the temperature was 20 °C, and the irradiation distance was 10 cm;

[0064] (2) The modified polypropylene obtained after irradiation was melt-blended with 1100N under the processing conditions of 200 °C and a processing time of 7 min. The content of the modified polypropylene was 10 wt%. Finally, the obtained mixture was hot-pressed into a polypropylene film by compression molding. The molding pressure was 20 MPa, the hot-pressing temperature was 200 °C, and the hot-pressing time was 10 min. The prepared samples were named PP-10 respectively.

[0065] Example 5

[0066] (1) 1 wt% of 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-one, 1 wt% of triallyl cyanurate, and 98 wt% of 1100N were placed in a mixer and melt-blended to prepare a polypropylene masterbatch. The temperature of the mixer was 220 °C and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene. The power was 1 kW, the irradiation time was 5 min, the temperature was 20 °C, and the irradiation distance was 10 cm;

[0067] (2) The modified polypropylene obtained after irradiation was melt-blended with unmodified polypropylene under the processing conditions of 200 °C and a processing time of 7 min. The content of the modified polypropylene was 10 wt%. Finally, the obtained mixture was hot-pressed into a polypropylene film by ultra-high pressure compression molding. The molding pressures were 100, 300, and 500 MPa respectively, the hot-pressing temperature was 190 °C, and the hot-pressing time was 10 min. The prepared samples were named PP-10-100, PP-10-300, and PP-10-500 respectively.

[0068] The gas permeability of the samples of Example 4, 5 and Comparative Example 1 was tested, and the results are shown in Table 4.

[0069] Table 4 Barrier properties of different specimens

[0070]

[0071] Example 6

[0072] (1) A polypropylene masterbatch was prepared by melt blending 1 wt% benzophenone, 1 wt% trimethylolpropane triacrylate, and 98 wt% EP548R in a Banbury mixer. The temperature of the Banbury mixer was 190 °C and the mixing time was 9 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene, with a power of 3 kW, an irradiation time of 5 min, a temperature of 20 °C, and an irradiation distance of 10 cm;

[0073] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under processing conditions of 200 °C and a processing time of 7 min. The content of the modified polypropylene was 20 wt%. Finally, the obtained mixture was hot pressed into a polypropylene film by compression molding, with a molding pressure of 20 MPa, a hot pressing temperature of 230 °C, and a hot pressing time of 10 min. The prepared samples were named PP-20 respectively.

[0074] Example 7

[0075] (1) A polypropylene masterbatch was prepared by melt blending 1 wt% benzophenone, 1 wt% trimethylolpropane triacrylate, and 98 wt% EP548R in a Banbury mixer. The temperature of the Banbury mixer was 190 °C and the mixing time was 9 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene, with a power of 3 kW, an irradiation time of 5 min, a temperature of 30 °C, and an irradiation distance of 20 cm;

[0076] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under processing conditions of 200 °C and a processing time of 7 min. The content of the modified polypropylene was 20 wt%. Finally, the obtained mixture was hot pressed into a polypropylene film by ultra-high pressure compression molding, with molding pressures of 100, 300, and 500 MPa respectively, a hot pressing temperature of 230 °C, and a hot pressing time of 10 min. The prepared samples were named PP-20-100, PP-20-300, and PP-20-500 respectively.

[0077] The gas permeability of the samples of Example 6, 7 and Comparative Example 1 was tested, and the results are shown in Table 5.

[0078] Table 5 Barrier properties of different specimens

[0079]

[0080] Example 8

[0081] (1) A polypropylene masterbatch was prepared by melt blending 1 wt% benzophenone, 1 wt% trimethylolpropane triacrylate, and 98 wt% 1100N in a mixer. The temperature of the mixer was 190 °C and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene, with a power of 1 kW, an irradiation time of 7 min, a temperature of 30 °C, and an irradiation distance of 20 cm;

[0082] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under processing conditions of 220 °C and a processing time of 9 min. The content of the modified polypropylene was 30 wt%. Finally, the obtained mixture was hot pressed into a polypropylene film by compression molding, with a molding pressure of 20 MPa, a hot pressing temperature of 200 °C, and a hot pressing time of 10 min. The prepared samples were named PP-30.

[0083] Example 9

[0084] (1) A polypropylene masterbatch was prepared by melt blending 1 wt% benzophenone, 1 wt% trimethylolpropane triacrylate, and 98 wt% 1100N in a mixer. The temperature of the mixer was 190 °C and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene, with a power of 1 kW, an irradiation time of 7 min, a temperature of 30 °C, and an irradiation distance of 20 cm;

[0085] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under processing conditions of 220 °C and a processing time of 9 min. The content of the modified polypropylene was 30 wt%. Finally, the obtained mixture was hot pressed into a polypropylene film by ultra-high pressure compression molding, with molding pressures of 100, 300, and 500 MPa respectively, a hot pressing temperature of 200 °C, and a hot pressing time of 10 min. The prepared samples were named PP-30-100, PP-30-300, and PP-30-500.

[0086] The gas permeability of the samples of Example 8, 9, and Comparative Example 1 was tested, and the results are shown in Table 6.

[0087] Table 6 Barrier properties of different specimens

[0088]

[0089] Comparative Example 2

[0090] (1) A polypropylene masterbatch was prepared by melt blending 1 wt% of 2-methyl-1-(4-methylthiophenyl)-2-morpholin-1-propanone, 1 wt% of triallyl cyanurate, and 98 wt% of 1100N in a mixer. The temperature of the mixer was 220 °C and the mixing time was 7 min. The polypropylene masterbatch was irradiated with ultraviolet light to obtain modified polypropylene. The power was 1 kW, the irradiation time was 5 min, the temperature was 20 °C, and the irradiation distance was 10 cm;

[0091] (2) The modified polypropylene obtained after irradiation and unmodified polypropylene were melt blended under the processing conditions of 200 °C and a processing time of 7 min. The content of the modified polypropylene was 10 wt%. Finally, the obtained mixture was hot pressed into a polypropylene film by low-pressure pressing. The forming pressure was 10 MPa, the hot pressing temperature was 190 °C, and the hot pressing time was 10 min. The prepared samples were named PP-10-10.

[0092] Comparative Example 3

[0093] Unmodified polypropylene 1100N and unmodified polypropylene EP548R were melt blended under the processing conditions of 200 °C and a processing time of 7 min. The content of unmodified polypropylene 1100N was 10 wt%. Finally, the obtained mixture was hot pressed into a polypropylene film by ultra-high pressure pressing. The forming pressure was 100 MPa, the hot pressing temperature was 190 °C, and the hot pressing time was 10 min. The prepared samples were named PP-100-10.

[0094] The gas permeability of the samples of Comparative Example 2, 3 and Comparative Example 1 was tested, and the results are shown in Table 6.

[0095] Table 7 Barrier properties of different specimens

[0096]

[0097] The crosslinking degrees of the modified polypropylene samples of Comparative Examples 1-2 and Examples 1-9 were further tested, and the results are as Figure 2 shown.

[0098] It is Figure 2 shown that with the increase of the content of photoinitiator, sensitizer and irradiation time, the crosslinking degree in the modified PP is also improved. The barrier property results of the comparative examples show that adding modified PP with a high crosslinking degree or increasing the proportion of modified PP can improve the gas barrier rate of the polypropylene separator. At the same time, the examples also well prove the improvement of the ultra-high pressure on the gas barrier of the separator, and the greater the pressure, the better the gas barrier property.

[0099] As described above, the present invention can be preferably implemented. The above embodiments are only preferred embodiments of the present invention and are not used to limit the scope of implementation of the present invention; that is, all equivalent changes and modifications made according to the content of the present invention are covered by the scope protected by the claims of the present invention.

Claims

1. A method for preparing a high barrier and non-compatibilized all-polypropylene film product. It is characterized in that The following steps are involved: (1) melt-mixing polypropylene, a sensitizer and an ultraviolet light initiator to prepare a polypropylene masterbatch, and then cross-linking the masterbatch by ultraviolet light irradiation to obtain a modified polypropylene; (2) melt-blending the modified polypropylene and unmodified polypropylene to construct a gradient cross-linking structure; (3) The molten blend is hot-pressed under high pressure to obtain a polypropylene film product.

2. The preparation method according to claim 1, It is characterized in that The polypropylene in step (1) is selected from at least one of isotactic polypropylene and syndiotactic polypropylene.

3. The preparation method according to claim 1, It is characterized in that The sensitizer in step (1) is at least one of trimethylolpropane triacrylate, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane triallyl ether, pentaerythritol tetraallyl ether, and triethylene glycol methacrylate; The ultraviolet photoinitiator is at least one of an intramolecular cleavage type photoinitiator or an intermolecular hydrogen abstraction type photoinitiator; Preferably, the intramolecular cleavage type photoinitiator is an aromatic aliphatic ketone photoinitiator, and the intermolecular hydrogen abstraction type photoinitiator is an aromatic ketone photoinitiator; More preferably, the ultraviolet light initiator is benzophenone or 2-methyl-1-(4-methylthiophenyl)-2-morpholine-1-propanone.

4. The preparation method according to any one of claims 1 to 3, It is characterized in that Based on the total weight of the polypropylene, the sensitizer and the ultraviolet light initiator, the content of the sensitizer is 0.1-1.0 wt %, the content of the light initiator is 0.1-1.0 wt %, and the balance is polypropylene.

5. The preparation method according to any one of claims 1 to 4, It is characterized in that The melting temperature of the melt mixing in step (1) is 190-230° C., and the mixing time is 7-12 min.

6. The preparation method according to any one of claims 1 to 5, It is characterized in that The ultraviolet light irradiation in step (1) is carried out in a nitrogen atmosphere at 20-30° C.; Preferably, the irradiation source is a 1-3 kW high-pressure mercury lamp, the irradiation time is 0.5-5 min, and the distance between the light source and the polypropylene masterbatch is 10-20 cm.

7. The preparation method according to claim 1, It is characterized in that In step (2), the modified polypropylene accounts for 10-30 wt% of the total mass of the modified polypropylene and the unmodified polypropylene.

8. The preparation method according to claim 1 or 7, It is characterized in that The melt blending in step (2) has a melting temperature of 190-230° C. and a mixing time of 7-12 min.

9. The preparation method according to claim 1, It is characterized in that The hot pressing molding in step (3) has a pressure of 20-500 MPa, preferably 100-500 MPa, a hot pressing temperature of 190-230° C., and a mixing time of 7-12 min; Preferably, the polypropylene film has a thickness of 30-70 μm.

10. A high barrier, non-compatibilized all-polypropylene film product obtained by the preparation method according to any one of claims 1 to 9.

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