A puncture-resistant nylon film and its preparation method and application

Abstract

The present application relates to the technical field of thin films, and particularly relates to an anti-puncture nylon film, a preparation method and application thereof.The anti-puncture nylon film comprises, by weight fraction, 75-92 parts of nylon, 1-5 parts of a slip agent, 0.5-1.5 parts of an anti-adhesion agent, 2-5 parts of modified MXene nanosheets and 4-10 parts of a toughening agent.The anti-puncture nylon film of the present application "softens" the nylon matrix through the toughening agent and forms a hydrogen bond network with the nylon matrix, and a "rigidity-hydrophobic" barrier is constructed by introducing fluorinated modified MXene, and the two achieve "high strength-high barrier" integration in cooperation; in addition, the toughening agent also endows the nylon film with excellent flame retardant performance, so that the nylon film has a wide application prospect in the field of packaging materials.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thin films, in particular to an anti-puncture nylon film and a preparation method and application thereof. BACKGROUND

[0002] Nylon film has been widely used in the packaging field of food, medicine, cosmetics and mechanical and electronic products due to its excellent heat resistance, chemical stability, light weight, economy and environmental friendliness. In recent years, with the rapid development of the packaging industry, especially the rapid growth of the pharmaceutical blister packaging market, higher requirements have been put forward for the performance of packaging materials. Not only should they have good barrier properties to effectively isolate external factors such as water vapor, but they should also have excellent anti-puncture ability to meet the stringent requirements of packaging strength in different application scenarios.

[0003] In addition, nylon film has obvious shortcomings in terms of flame retardance. In order to improve its flame retardance, it is usually necessary to add flame retardant additives such as aluminum hydroxide, magnesium hydroxide, ammonium phosphate or triethyl phosphate. However, the use amount of traditional flame retardants is large, generally accounting for 10% to 40% of the weight of the resin, which not only increases the production cost, but also easily causes problems such as film breakage and film rupture during the production of nylon film, and also has an adverse effect on the mechanical properties of the film. Therefore, it is necessary to improve the material formula to solve the above problems. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, one of the purposes of the present application is to provide an anti-puncture nylon film. The toughening agent "softens" the nylon matrix and forms a hydrogen bond network with it, and a fluorinated modified MXene is introduced to construct a "rigid-hydrophobic" barrier, and the two achieve "high strength-high barrier" integration in cooperation. In addition, the toughening agent also endows the nylon film with excellent flame retardance.

[0005] The second purpose of the present application is to provide a preparation method of an anti-puncture nylon film. The method is simple, efficient and easy to operate, and is suitable for large-scale production.

[0006] The third purpose of the present application is to provide an application of an anti-puncture nylon film. It has a broad application prospect in the field of packaging materials.

[0007] The purposes of the present application are achieved by the following technical solutions:

[0008] An anti-puncture nylon film, comprising, by weight fraction: 75-92 parts of nylon, 1-5 parts of a slip agent, 0.5-1.5 parts of an anti-adhesion agent, 2-5 parts of modified MXene nanosheets and 4-9 parts of a toughening agent.

[0009] The preparation method of the toughening agent is as follows:

[0010] (1) under the protection of N2, 2-carboxyphenyl phosphate is dissolved in DMF, sodium hydroxide and compound 1 are added for reaction, the reaction is washed, extracted, concentrated, recrystallized to obtain intermediate 1;

[0011] (2) under the protection of N2, intermediate 1 and tetrabutyl titanate are added in DMSO for stirring reaction to obtain a reaction liquid; the reaction liquid is subjected to hydrothermal reaction at normal pressure, then subjected to polycondensation reaction under reduced pressure and heating, and the product is washed and dried to obtain a toughening agent.

[0012] Further, in step (1), the amount ratio of 2-carboxyphenyl phosphate, compound 1, sodium hydroxide and DMF is 2.8-3.5 g:4 g:0.04-0.08 g:100-120 mL; the reaction temperature is 110-125℃, and the reaction time is 36-48 h; the chemical structural formula of compound 1 is

[0013] .

[0014] Further, in step (2), the amount ratio of intermediate 1, tetrabutyl titanate and DMSO is 1.12 g:0.27-0.41 g:8-15 mL; the stirring reaction temperature is 110-120℃, and the stirring reaction time is 2-3 h; the hydrothermal reaction temperature is 140-150℃, and the hydrothermal reaction time is 3-5 h; the reduced pressure is reduced to 50-60 kPa, and the temperature is raised to 250-270℃, and the polycondensation reaction time is 20-24 h.

[0015] Further, the molecular weight of the toughening agent is 9000-15000 g / mol.

[0016] Further, the preparation method of the modified MXene nanosheet is as follows:

[0017] a. LiF is added into hydrochloric acid solution, then Ti3AlC2 is added, after stirring reaction, centrifugation and washing to neutral, multi-layer Mxene is obtained, then the multi-layer Mxene is added into water for ultrasonic stripping, centrifugation and drying to obtain few-layer MXene nanosheet;

[0018] b. the few-layer MXene nanosheet is dispersed in DMF, 2-(perfluoropropoxy) perfluoropropionyl fluoride and triethylamine are added for reaction, after the reaction is completed, the reaction liquid is filtered, washed and dried to obtain the modified MXene nanosheet.

[0019] Further, in step a, the amount of the LiF, Ti3AlC2 and hydrochloric acid solution is 1-2 g: 1 g: 25-30 mL; the concentration of the hydrochloric acid solution is 9 mol / L; the stirring reaction temperature is 45-55 DEG C, and the time is 1.5-2 days; the ultrasonic stripping power is 300-500 W, and the time is 45-75 min; the Ti3AlC2 is MAX phase Ti3AlC2, and the average particle size is 200 mesh.

[0020] Further, in step b, the amount of the few-layer MXene nanosheet, 2-(perfluoropropoxy) perfluoropropyl fluoride, triethylamine and DMF is 1 g: 3-5 g: 0.5-1 g: 45-60 mL; the reaction temperature is 35-45 DEG C, and the time is 24-36 h.

[0021] Further, the nylon is at least one of nylon 6, nylon 66 and nylon 12; the slip agent is oleic acid amide; and the anti-adhesion agent is nano-silicon dioxide with a particle size of 25-35 nm.

[0022] The preparation method of the anti-puncture nylon film provided by the application comprises the following steps:

[0023] The nylon, the slip agent, the anti-adhesion agent, the modified MXene nanosheet and the toughening agent are mixed and then melt-extruded into a cast sheet, and then the cast sheet is synchronously bidirectionally stretched, and the anti-puncture nylon film is obtained.

[0024] Further, the stretching temperature is 150-180 DEG C, the transverse stretching ratio is 1.5-1.8, and the longitudinal stretching ratio is 1.6-2.5.

[0025] The application further provides the use of the anti-puncture nylon film in the preparation of packaging materials.

[0026] Compared with the prior art, the anti-puncture nylon film provided by the application has the following beneficial effects:

[0027] 1. The anti-puncture nylon film provided by the application is obtained by "softening" the nylon matrix through a toughening agent and forming a hydrogen bond network with the nylon matrix, and introducing a fluorinated modified MXene to construct a "rigidity-hydrophobic" barrier, so that the two achieve "high strength-high barrier" integration.

[0028] (1) The present application utilizes 2-carboxyphenyl phosphate and compound 1 to synthesize a monomer containing carboxyl and hydroxyl groups through substitution reaction, and further obtains a toughening agent through solution polymerization. The long alkyl chain structure in the molecule of the toughening agent can effectively improve the flexibility of the nylon film; moreover, the introduced phenyl phosphate group can significantly enhance the flame retardant performance of the nylon film through the condensed phase flame retardant mechanism. In addition, the polyester structure of the toughening agent and the hydroxyl group in the phosphate can form hydrogen bond interaction with the nylon molecules, thereby significantly improving the compatibility and dispersion stability of the toughening agent and the nylon matrix.

[0029] (2) The present application also adds modified MXene nanosheets as reinforcing agents, and the ultra-high intrinsic strength of the two-dimensional MXene nanosheets and the toughening effect of the toughening agent are synergistic, which significantly improves the puncture resistance of the nylon film, and the modified MXene nanosheets also endow the nylon film with excellent barrier properties.

[0030] (3) The MXene nanosheets are branched modified by the reaction of the hydroxyl groups on the surface of the MXene nanosheets and 2-(perfluoropropoxy) perfluoropropionyl fluoride, and the introduction of perfluoroalkyl chain can significantly reduce the surface energy of the nylon film, so that water molecules are difficult to spread and penetrate on the film surface; at the same time, the dense layered structure of the MXene nanosheets can prolong the diffusion path of water, oxygen molecules and the like, and further enhance the barrier effect.

[0031] 2、The present application also provides a preparation method of the puncture-resistant nylon film, which is simple and efficient, easy to operate, and convenient for large-scale production.

[0032] 3、The present application also provides an application of the puncture-resistant nylon film in the preparation of packaging materials, so that it has a broad application prospect in the field of packaging materials. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 The nuclear magnetic resonance hydrogen spectrum of the toughening agent obtained in Example 1 of the present application;

[0034] Figure 2 The infrared spectrum of the modified MXene nanosheet obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0035] In the following, the present application will be further described in conjunction with the drawings and specific embodiments, and it should be noted that the following described embodiments or technical features can be combined in any manner to form new embodiments without conflict. The specific conditions in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used, such as those without special instructions, are conventional products obtained through market channels.

[0036] Example 1

[0037] A puncture-resistant nylon film, wherein the puncture-resistant nylon film comprises, by weight, 85 parts nylon 66, 3 parts slip agent (oleamide), 1 part anti-adhesion agent (nano silica with a particle size of 25-35 nm), 4 parts modified MXene nanosheets and 7 parts toughening agent.

[0038] The toughening agent is prepared as follows:

[0039]

[0040] (1) Under nitrogen protection, 2-carboxyphenyl phosphate was dissolved in DMF, and sodium hydroxide and compound 1 (CAS No.: 1470071-08-9; Chinese name: 1-chloro-3-hydroxypropyl-2-yl(9z,12z)-octadec-9,12-dienoate) were added. The ratio of 2-carboxyphenyl phosphate, compound 1, sodium hydroxide and DMF was 3.2 g: 4 g: 0.06 g: 110 mL. After reacting at 120 °C for 42 h, the reactants were washed successively with deionized water, 5 wt% sulfuric acid and 5 wt% NaHCO3, extracted with dichloromethane, concentrated by rotary evaporation, and recrystallized with ethanol to obtain intermediate 1.

[0041] Intermediate 1 1 HNMR: (C 28 H 43 O9P, 400MHz, DMSO-d6) δ: 0.86-0.90 (m, 3H), 1.24-1.35 (m, 14H), 1.64-1.68 (m, 2H), 2. 14-2.18 (m, 4H), 2.33-2.37 (m, 2H), 2.78-2.82 (m, 2H), 3.61-3.69 (m, 2H), 3.94 (s, H), 4 .11-4.15 (m, H), 4.20 (s, H), 4.36-4.40 (m, H), 4.65-4.69 (m, H), 5.27-5.31 (m, 2H), 5. 41-5.45 (m, 2H), 7.47-7.51 (dd, H), 7.73-7.80 (m, 2H), 8.23-8.27 (dd, H), 12.04 (s, H). MS (ESI) m / z=554.26 [M].

[0042] (2) under N2 atmosphere, intermediate 1, tetrabutyl titanate were added into DMSO, the amount ratio of intermediate 1, tetrabutyl titanate and DMSO was 1.12 g:0.35 g:12 mL; after stirring at 115℃ for 2.5 h, the reaction solution was obtained; the reaction solution was added into a high-pressure reaction kettle, the air in the kettle was replaced by nitrogen, the reaction was carried out at normal pressure and 145℃ for 4 h, the pressure was reduced to 55 kPa, the temperature was increased to 260℃, the reaction was continued for 22 h, then the product was obtained by natural cooling to room temperature, deionized water was used to precipitate the product, ethanol was used for washing, and vacuum drying was carried out, to obtain the toughening agent.

[0043] The toughening agent has the following properties: 1 HNMR: (400MHz, DMSO-d6) δ: 0.86-0.90 (m, 6H), 1.24-1.35 (m, 28H), 1.64-1.68 (m, 4H), 2.14-2.18 (m, 8H), 2.33-2.37 (m, 4H), 2.78-2.82 (m, 4H), 3.44-3.48 (m, H), 3.69-3.73 (m, H), 4.11-4.15 (m, 2H), 4.2 (s, 2H), 4.36-4.40 (m, 3H), 4.57-4.61 (m, H), 5.24-5.28 (m, 2H), 5.27-5.31 (m, 4H), 5.41-5.45 (m, 4H), 7.37-7.41 (m, 2H), 7.60-7.70 (m, 4H), 8.07-8.11 (m, 2H). The nuclear magnetic resonance hydrogen spectrum of the toughening agent is shown in Figure 1. The molecular weight of the toughening agent was tested by gel permeation chromatography (GPC) using DMF eluent: Mn (number average molecular weight) = 12000 g / mol. Figure 1

[0044] The preparation method of the modified MXene nanosheet is as follows:

[0045]

[0046] a. LiF was added into a concentrated hydrochloric acid solution with a concentration of 9 mol / L, and then MAX phase Ti3AlC2 powder (average particle size of 200 mesh) was slowly added, the amount ratio of LiF, Ti3AlC2 powder and hydrochloric acid solution was 1.5 g:1 g:28 mL; after stirring at 50℃ for 1.5 d, centrifugation was carried out at 4000 rpm for 5 min, deionized water was used for washing until the pH of the supernatant was neutral, then the obtained multi-layer Mxene was added into deionized water and ultrasonic exfoliation was carried out for 60 min, the power of ultrasonic exfoliation was 400 W; then centrifugation was carried out at 4000 rpm for 5 min, freeze-drying was carried out at -50℃ for 1.5 d, to obtain few-layer MXene nanosheet;

[0047] ​b. Disperse few-layer MXene nanosheets in DMF, add 2-(perfluoropropoxy)perfluoropropionyl fluoride and triethylamine, the ratio of few-layer MXene nanosheets, 2-(perfluoropropoxy)perfluoropropionyl fluoride, triethylamine and DMF is 1g:4g:0.8g:50mL; react at 40℃ for 30h, filter, wash with DMF and deionized water, and vacuum dry to obtain modified MXene nanosheets.

[0048] Infrared spectrum of modified MXene nanosheets as follows Figure 2 As shown, observe Figure 2 It can be seen that, compared to MXene, modified MXene nanosheets have a higher content of 1748 cm⁻¹. -1 1129 cm -1 The presence of characteristic peaks for C=O and CF bonds at the site proves that the MXene modification was successful.

[0049] The present invention also provides a method for preparing a puncture-resistant nylon film, comprising the following steps:

[0050] According to the stated weight proportions, nylon 66, slip agent (oleamide), anti-adhesion agent (nano silica), modified MXene nanosheets and toughening agent are mixed and melt-extruded into a casting. Then, the casting is subjected to simultaneous biaxial stretching at a stretching temperature of 170°C, with a transverse stretching ratio of 1.6 and a longitudinal stretching ratio of 2.3, thus obtaining the final product.

[0051] Example 2

[0052] A puncture-resistant nylon film, comprising, by weight: 75 parts nylon 66, 1 part slip agent (oleamide), 0.5 parts anti-adhesion agent (nano silica), 2 parts modified MXene nanosheets, and 4 parts toughening agent.

[0053] The toughening agent is prepared as follows:

[0054] (1) Under nitrogen protection, 2-carboxyphenyl phosphate was dissolved in DMF, and sodium hydroxide and compound 1 (CAS No.: 1470071-08-9; Chinese name: 1-chloro-3-hydroxypropyl-2-yl(9z,12z)-octadec-9,12-dienoate) were added. The ratio of 2-carboxyphenyl phosphate, compound 1, sodium hydroxide and DMF was 2.8 g: 4 g: 0.04 g: 100 mL. After reacting at 110 °C for 48 h, the reactants were washed successively with deionized water, 5 wt% sulfuric acid and 5 wt% NaHCO3, extracted with dichloromethane, concentrated by rotary evaporation, and recrystallized from ethanol to obtain intermediate 1; intermediate 1 1 HNMR and MS (ESI) are the same as in Example 1.

[0055] (2) under N2 atmosphere, intermediate 1, tetrabutyl titanate were added into DMSO, the amount ratio of intermediate 1, tetrabutyl titanate and DMSO was 1.12 g:0.27 g:8 mL; after being fully stirred at 110℃ for 3 h, a reaction solution was obtained; the reaction solution was added into a high-pressure reaction kettle, the air in the kettle was replaced by nitrogen, the reaction was carried out at normal pressure and 140℃ for 5 h, the pressure was reduced to 50 kPa, the temperature was increased to 270℃, the reaction was continued for 20 h, and then the reaction was naturally cooled to room temperature; the product was precipitated by deionized water, washed by ethanol, and dried in vacuum to obtain the toughening agent.

[0056] The toughening agent of the application has the following characteristics: 1 HNMR was the same as that in Example 1. The molecular weight of the toughening agent was tested by gel permeation chromatography (GPC) using DMF eluent: Mn (number average molecular weight) = 11562 g / mol.

[0057] The preparation method of the modified MXene nanosheet is as follows:

[0058] a. LiF was added into a 9 mol / L hydrochloric acid solution, and then MAX phase Ti3AlC2 powder was slowly added, the amount ratio of LiF, Ti3AlC2 powder and hydrochloric acid solution was 1 g:1 g:25 mL; after being stirred at 45℃ for 1.5 d, centrifugation was carried out at 3500 r / min for 10 min, deionized water was used for washing until the pH of the supernatant was neutral, then the obtained multi-layer Mxene was added into deionized water and ultrasonic stripping was carried out for 45 min, the power of ultrasonic stripping was 500 W; then centrifugation was carried out at 500 r / min for 10 min, and freeze-drying was carried out at-40℃ for 2 d to obtain a few-layer MXene nanosheet;

[0059] b. the few-layer MXene nanosheet was dispersed in DMF, 2-(perfluoropropoxy) perfluoropropionyl fluoride and triethylamine were added, the amount ratio of the few-layer MXene nanosheet, 2-(perfluoropropoxy) perfluoropropionyl fluoride, triethylamine and DMF was 1 g:3 g:0.5 g:45 mL; after being reacted at 35℃ for 36 h, filtration was carried out, DMF and deionized water were used for washing, and vacuum drying was carried out to obtain the modified MXene nanosheet.

[0060] The application further provides a preparation method of the anti-puncture nylon film, which comprises the following steps:

[0061] According to the weight fractions, the nylon 66, the slip agent (oleamide), the anti-adhesion agent (nano silicon dioxide), the modified MXene nanosheet and the toughening agent were mixed and then melt-extruded into a cast sheet, and then the cast sheet was subjected to synchronous bidirectional stretching, and the stretching temperature was 150℃, the transverse stretching ratio was 1.5, and the longitudinal stretching ratio was 1.6, so that the anti-puncture nylon film was obtained.

[0062] Example 3

[0063] An anti-puncture nylon film, which comprises, in parts by weight: 92 parts of nylon 66, 5 parts of a slip agent (oleic acid amide), 1.5 parts of an anti-adhesion agent (nano-silicon dioxide), 5 parts of modified MXene nanosheets, and 9 parts of a toughening agent.

[0064] The preparation method of the toughening agent is as follows:

[0065] (1) Under the protection of nitrogen, 2-carboxyphenyl phosphate was dissolved in DMF, sodium hydroxide and compound 1 (CAS No.: 1470071-08-9; Chinese name: 1-chloro-3-hydroxyprop-2-yl (9z, 12z)-octadeca-9, 12-dienoate) were added, and the amount ratio of 2-carboxyphenyl phosphate, compound 1, sodium hydroxide and DMF was 3.5g:4g:0.08g:120mL; after reacting at 125℃ for 36h, the reaction was washed with deionized water, 5wt% sulfuric acid and 5wt% NaHCO3 in turn, extracted with dichloromethane, concentrated by rotary evaporation, recrystallized with ethanol to obtain intermediate 1; the yield of intermediate 1 was 1.12g. 1 HNMR and MS (ESI) are the same as Example 1.

[0066] (2) Under N2 atmosphere, intermediate 1 and tetrabutyl titanate were added to DMSO, and the amount ratio of intermediate 1, tetrabutyl titanate and DMSO was 1.12g:0.41g:15mL; after stirring at 120℃ for 2h, a reaction solution was obtained; the reaction solution was added to a high-pressure reaction kettle, the air in the kettle was replaced with nitrogen, and the reaction was carried out at normal pressure and 150℃ for 3h, then the pressure was reduced to 60kPa, the temperature was increased to 250℃, and the reaction was continued for 24h, then the reaction was naturally cooled to room temperature, the product was precipitated with deionized water, washed with ethanol, and vacuum dried to obtain the toughening agent.

[0067] The preparation method of the toughening agent is as follows: 1 HNMR is the same as Example 1. The molecular weight of the toughening agent was tested by gel permeation chromatograph (GPC) using DMF eluent: Mn (number average molecular weight) = 14890g / mol.

[0068] The preparation method of the modified MXene nanosheet is as follows:

[0069] a. LiF was added to a 9mol / L hydrochloric acid solution, and then MAX phase Ti3AlC2 powder was slowly added, and the amount ratio of LiF, Ti3AlC2 powder and hydrochloric acid solution was 2g:1g:30mL; after stirring at 55℃ for 2 days, centrifugation was carried out at 4000rpm for 10min, deionized water was washed until the supernatant pH was neutral, then the obtained multi-layer Mxene was added to deionized water and ultrasonically exfoliated for 75min, the ultrasonic exfoliation power was 300W, then centrifugation was carried out at 4000rpm for 10min, and freeze-drying was carried out at-60℃ for 2d to obtain few-layer MXene nanosheets;

[0070] b. The few-layer MXene nanosheets were dispersed in DMF, 2-(perfluoropropoxy)perfluoropropionyl fluoride and triethylamine were added, the amount ratio of few-layer MXene nanosheets, 2-(perfluoropropoxy)perfluoropropionyl fluoride, triethylamine and DMF was 1 g:5 g:1 g:60 mL; after reaction at 45℃ for 24 h, filtration, DMF, deionized water washing, vacuum drying, modified MXene nanosheets were obtained.

[0071] The application also provides a preparation method of the anti-puncture nylon film, comprising the following steps:

[0072] According to the weight fraction, the nylon 66, the slip agent (oleamide), the anti-adhesion agent (nano-silicon dioxide), the modified MXene nanosheets and the toughening agent were mixed and then melt-extruded into a casting sheet, and then the casting sheet was synchronously bidirectionally stretched, the stretching temperature was 180℃, the transverse stretching ratio was 1.8, and the longitudinal stretching ratio was 2.5, thereby obtaining the product.

[0073] Comparative Example 1

[0074] The comparative example 1 and the example 1 are basically the same, except that the toughening agent is omitted.

[0075] Comparative Example 2

[0076] The comparative example 2 and the example 1 are basically the same, except that the modified MXene nanosheets are replaced by the few-layer MXene nanosheets prepared in the example 1.

[0077] Test Example

[0078] 1. The flame retardancy of the products of the examples 1-3 and the comparative examples 1-2 was tested according to the standard of UL-94.

[0079] 2. The tensile strength, elongation at break and surface wetting tension of the products were tested according to the test standard of GB / T 20218-2021.

[0080] 3. Anti-puncture: the puncture strength of the products was tested according to the test standard of GB / T 10004-2008.

[0081] 4. Barrier ability of the nylon film to water vapor: the water and oxygen transmission amount of the products was tested according to the test standard of GB / T 1307-2021. The test results are shown in Table 1.

[0082] Table 1

[0083]

[0084] As can be seen from Table 1, the products obtained in Examples 1-3 have higher flexibility and tensile strength, stronger puncture resistance, more excellent water molecule barrier ability and good flame retardation.

[0085] Compared with Example 1, the flame retardation of Comparative Example 1 is obviously reduced and the elongation at break is poor, which is mainly due to the fact that the phenyl phosphate groups in the toughening agent can enhance the flame retardation of the nylon film and the long alkyl chain structure in the toughening agent molecule can improve the flexibility of the nylon film.

[0086] Compared with Example 1, the tensile strength, puncture strength, surface wetting tension and water vapor transmission of the nylon film of Comparative Example 2 are all reduced, which shows that the ultra-high intrinsic strength of the modified MXene nanosheet and the toughening effect of the toughening agent synergistically improve the puncture resistance and improve the barrier effect of the film to water vapor.

[0087] In summary, by introducing the modified MXene nanosheet and the toughening agent into the nylon film, the toughening agent “softens” the nylon matrix and forms a hydrogen bond network with it, while the fluorinated modified MXene constructs a “rigidity-hydrophobic” barrier, and the two synergistically realize the integration of “high strength-high barrier”, improve the puncture resistance of the film; in addition, the toughening agent also endows the nylon film with excellent flame retardation, so that it has a broad application prospect in the field of packaging materials.

[0088] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application, and any non-essential changes and substitutions made by those skilled in the art on the basis of the present application are within the scope of protection of the present application.

Claims

1. A puncture-resistant nylon film, characterized in that, The puncture-resistant nylon film comprises, by weight, 75-92 parts nylon, 1-5 parts slip agent, 0.5-1.5 parts anti-adhesion agent, 2-5 parts modified MXene nanosheets, and 4-9 parts toughening agent; The toughening agent is prepared as follows: (1) Under N2 protection, 2-carboxyphenyl phosphate was dissolved in DMF, sodium hydroxide and compound 1 were added to react, and the reactants were washed, extracted, concentrated and recrystallized to obtain intermediate 1. (2) Under N2 protection, intermediate 1 and tetrabutyl titanate were added to DMSO and stirred to obtain a reaction solution; the reaction solution was subjected to hydrothermal reaction under normal pressure, and then polycondensation reaction was carried out under reduced pressure and increased temperature. The product was washed and dried to obtain toughening agent. The chemical structural formula of compound 1 is as follows: 。 2. The puncture-resistant nylon film according to claim 1, characterized in that, In step (1), the ratio of 2-carboxyphenyl phosphate, compound 1, sodium hydroxide and DMF is 2.8-3.5g:4g:0.04-0.08g:100-120mL; the reaction temperature is 110-125℃ and the time is 36-48h.

3. The puncture-resistant nylon film according to claim 1, characterized in that, In step (2), the ratio of intermediate 1, tetrabutyl titanate and DMSO is 1.12g:0.27-0.41g:8-15mL; the stirring reaction temperature is 110-120℃ and the time is 2-3h; the hydrothermal reaction temperature is 140-150℃ and the time is 3-5h; the reduced pressure conditions are reduced to 50-60kPa and heated to 250-270℃; the polycondensation reaction time is 20-24h.

4. The puncture-resistant nylon film according to claim 1, characterized in that, The toughening agent has a number-average molecular weight of 9000-15000 g / mol.

5. The puncture-resistant nylon film according to claim 1, characterized in that, The modified MXene nanosheets are prepared as follows: a. LiF was added to hydrochloric acid solution, and then Ti3AlC2 was added. After stirring and reacting, the mixture was centrifuged and washed until neutral to obtain multilayer Mxene. Then, the multilayer Mxene was added to water, ultrasonically exfoliated, centrifuged, and dried to obtain few-layer MXene nanosheets. b. Disperse few-layer MXene nanosheets in DMF, add 2-(perfluoropropoxy)perfluoropropionyl fluoride and triethylamine to react. After the reaction is completed, filter, wash and dry the reaction solution to obtain modified MXene nanosheets.

6. The puncture-resistant nylon film according to claim 5, characterized in that, In step a, the ratio of LiF, Ti3AlC2, and hydrochloric acid solution is 1-2g:1g:25-30mL; the concentration of the hydrochloric acid solution is 9mol / L; the stirring reaction temperature is 45-55℃ and the time is 1.5-2d; the ultrasonic exfoliation power is 300-500W and the time is 45-75min; the Ti3AlC2 is MAX phase Ti3AlC2 with an average particle size of 200 mesh.

7. The puncture-resistant nylon film according to claim 5, characterized in that, In step b, the ratio of the few-layer MXene nanosheets, 2-(perfluoropropoxy)perfluoropropionyl fluoride, triethylamine and DMF is 1g:3-5g:0.5-1g:45-60mL; the reaction temperature is 35-45℃ and the reaction time is 24-36h.

8. The puncture-resistant nylon film according to claim 1, characterized in that, The nylon is at least one of nylon 6, nylon 66 and nylon 12; the slip agent is oleic acid amide; the anti-adhesion agent is nano-silica with a particle size of 25-35nm.

9. The method for preparing the puncture-resistant nylon film according to any one of claims 1-8, characterized in that, Includes the following steps: Nylon, slip agent, anti-adhesion agent, modified MXene nanosheets and toughening agent are mixed and melt-extruded into a casting, and then the casting is simultaneously biaxially stretched to obtain the final product.

10. The use of the puncture-resistant nylon film as described in any one of claims 1-8 in the preparation of packaging materials.

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