Degradable material, film and application thereof

Abstract

The invention provides a degradable material, a film and application thereof, the degradable material comprises PHA and an anti-ultraviolet absorbent, the anti-ultraviolet absorbent is modified carbonitride, and the mass ratio of the PHA to the modified carbonitride is (70-130): (3-30). According to the degradable material, the modified carbonitride is adopted as the anti-ultraviolet absorbent and has a remarkable ultraviolet absorption effect, so that the anti-ultraviolet performance of the degradable material is effectively improved, PHA and the modified carbonitride have better interfacial compatibility, and good processing performance and mechanical performance of the degradable material can be guaranteed; the degradable material provided by the invention has excellent anti-ultraviolet performance, long service life and good processability and stability, and the degradable material is environment-friendly, easy to degrade and low in production cost.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and particularly relates to a degradable material, a film and their applications. Background Art

[0002] Due to the problem of white pollution, traditional blown film materials such as PE are being prohibited, and are replaced by biodegradable materials such as PBAT, PLA, PBS, etc. The above-mentioned biodegradable materials need to be biodegradable under specific composting conditions, so they are restricted by conditions.

[0003] Polyhydroxyalkanoates (PHA) are a new type of bio-based and renewable biodegradable material. Compared with traditional non-recyclable plastics such as petroleum, the biggest advantage of PHA is that its production substrates are all recyclable carbon sources (such as starch sugar, food waste treatment products, straw hydrolysis sugar, etc.). Moreover, the entire polymerization process of PHA is biological polymerization rather than chemical polymerization, which significantly reduces carbon emissions during the production process. In addition, PHA has good biodegradability. Generally, biodegradable materials need to be degraded under composting conditions, while PHA has spontaneous biodegradability and can be degraded in the natural environment without composting, and the degradation time is controllable, and finally generates carbon dioxide and water without polluting the environment, which is very beneficial to environmental protection and is a recognized environmentally friendly material.

[0004] However, PHA materials are prone to degradation under ultraviolet (UV) irradiation, which affects their service life and performance. Existing studies have tried to improve the UV resistance of PHA cast films by adding UV absorbers (such as titanium dioxide, zinc oxide, etc.). However, using traditional UV absorbers to improve the UV resistance of PHA materials has the following disadvantages: First, the preparation process of some traditional UV absorbers is complex, the cost is high, and many are difficult to degrade in the environment. For example, some benzophenone compounds are considered toxic to aquatic organisms; Second, the added UV absorber may migrate out of the PHA cast film during long-term use or high-temperature conditions, resulting in a decrease in UV resistance; Third, certain UV absorbers may have poor compatibility with PHA materials, affecting the mechanical properties and processing properties of the cast film. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems in the prior art to some extent. To this end, an object of the present invention is to provide a degradable material, a film and their applications.

[0006] In the first aspect of the present invention, a degradable material is provided, which includes: PHA and an anti-UV absorber, the anti-UV absorber is modified carbon nitride, and the mass ratio of the PHA to the modified carbon nitride is (70-130):(3-30).

[0007] Preferably, the mass ratio of the PHA to the modified carbonitride is 100:(3-20). For example, the mass ratio of the PHA to the modified carbonitride is 70:3, 100:3, 130:3, 70:15, 100:15, 130:15, 70:30, 100:30, 130:30, etc., or the range between any two of the above values.

[0008] According to the above-mentioned degradable material provided by the present invention, which includes PHA and modified carbonitride, on the one hand, the modified carbonitride, as an ultraviolet absorption agent, has a significant ultraviolet absorption effect, thus effectively improving the ultraviolet resistance of the degradable material. Even under long-term ultraviolet irradiation, the material is not easily degraded, ensuring the service life and performance of the material. On the other hand, compared with the unmodified carbonitride, the PHA and the modified carbonitride have better interfacial compatibility and will not migrate out of the material even under long-term ultraviolet irradiation, which can ensure good processing performance and mechanical properties of the degradable material. Moreover, the modified carbonitride is a natural compound, environmentally friendly, with easily available raw materials and low production costs. Therefore, the degradable material has excellent ultraviolet resistance, a long service life, good processing performance and stability, is environmentally friendly, easy to degrade, and has low production costs.

[0009] According to the above-mentioned degradable material provided by the present invention, the PHA is selected from one or more of PHB, P34HB, PHBV, and PHBHHx. Preferably, the PHA is selected from at least one of PHB and P34HB, and more preferably a mixture of PHB and P34HB. PHB and P34HB have good biocompatibility, biodegradability and mechanical properties, so they can improve the compatibility, stability and processing performance of the degradable material.

[0010] In some embodiments of the present invention, when the PHA is selected from the mixture of PHB and P34HB, the mass ratio of the PHB to the P34HB is (60-90):(10-40), for example, the mass ratio is 60:10, 80:10, 90:10, 60:40, 80:40, 90:40, etc., or the range between any two of the above values. Controlling the mass ratio of PHB and P34HB within the above range can improve the comprehensive performance of the mixture, and further improve the overall performance of the degradable material.

[0011] Preferably, the molecular weight of the PHB is 300,000-1,000,000.

[0012] Preferably, the molecular weight of the P34HB is 100,000-600,000.

[0013] In some embodiments of the present invention, the degradable material comprises a mixture of PHB and P34HB and modified carbon nitride, and the mass ratio of the total mass of PHB and P34HB to the mass of the modified carbon nitride is (70 - 130):(3 - 30).

[0014] Preferably, the mass ratio of the total mass of PHB and P34HB to the mass of the modified carbon nitride is (70 - 130):(3 - 30), and the mass ratio of PHB to P34HB is (60 - 90):(10 - 40).

[0015] According to the above-mentioned degradable material provided by the present invention, the modified carbon nitride is obtained by grafting reaction of graphite-phase carbon nitride with a silanol compound. The inventors found that when graphite-phase carbon nitride (g-C 3 N 4 ) is mixed with a silanol compound, because the silanol compound contains -OH and the graphite-phase carbon nitride contains oxygen-containing groups such as carboxyl and hydroxyl groups, the hydroxyl group in the silanol compound and the carboxyl group in the graphite-phase carbon nitride will undergo a chemical reaction, so that the silanol compound is grafted onto the graphite-phase carbon nitride to obtain the modified carbon nitride. For example, the specific process of the grafting reaction is as follows: , The obtained modified carbon nitride has a significant ultraviolet absorption effect, which can significantly improve the ultraviolet resistance of the degradable material and ensure better performance of the degradable material.

[0016] Preferably, the silanol compound is selected from hydrolyzed silane coupling agent KH550.

[0017] In some embodiments of the present invention, the mass ratio of the graphite-phase carbon nitride to the silanol compound is (10~20):(5~10). For example, the mass ratio is 10:5, 15:5, 20:5, 10:10, 15:10, etc., or the range between any two of the above numerical values. By controlling the mass ratio of the graphite-phase carbon nitride to the silanol compound within the above range, the graphite-phase carbon nitride can be effectively modified, thereby improving the ultraviolet absorption ability of the modified carbon nitride.

[0018] In some embodiments of the present invention, the temperature of the grafting reaction is 50°C - 70°C and the time is 3h - 5h.

[0019] Preferably, the hydrolyzed silane coupling agent KH550 is obtained by mixing and reacting silane coupling agent KH550 with an aqueous solution of alcohol at room temperature. The silane coupling agent KH550 and the aqueous solution of alcohol can undergo the following hydrolysis reaction at room temperature: , Thus, the silane coupling agent KH550 has hydroxyl groups in its structure, and a silanol compound is obtained.

[0020] Furthermore, the volume ratio of the silane coupling agent KH550 to the aqueous solution of alcohol can be controlled to be 1:1, and the alcohol includes but is not limited to ethanol. Preferably, the mass concentration of the alcohol in the aqueous solution of alcohol is 60% - 90%.

[0021] According to the above biodegradable material provided by the present invention, it further includes at least one of a nucleating agent, an antioxidant, a hydrolysis inhibitor, a plasticizer, a compatibilizer, a chain extender, and a heat stabilizer.

[0022] It should be noted that nucleating agents, antioxidants, hydrolysis inhibitors, plasticizers, compatibilizers, chain extenders, and heat stabilizers are conventional materials in the art, and those skilled in the art can select specific types of additives according to the actual situation.

[0023] As an example, the nucleating agent includes but is not limited to talcum powder, magnesium silicate, bentonite, calcined kaolin, calcium carbonate, silicon dioxide, alum, titanium dioxide, calcium oxide, magnesium oxide, carbon black, mica, dibenzylidene sorbitol, sodium succinate, sodium glutarate, sodium caproate, sodium 4-methylpentanoate, adipic acid, aluminum adipate, aluminum tert-butylbenzoate, aluminum benzoate, potassium benzoate, lithium benzoate, sodium cinnamate, sodium β-naphthoate, etc.

[0024] As an example, the antioxidant includes but is not limited to phosphite antioxidants (168), phenolic antioxidants (1010), thioether compounds, etc.

[0025] As an example, the hydrolysis inhibitor includes but is not limited to carbodiimide, polycarbodiimide, etc.

[0026] As an example, the plasticizer includes but is not limited to bio-based plasticizers, epoxidized soybean oil, triethyl citrate, tributyl citrate, tributyl acetylcitrate, etc.

[0027] As an example, the compatibilizer includes but is not limited to ethylene-acrylic acid copolymer, hexamethylene diisocyanate, etc.

[0028] As an example, the chain extender includes but is not limited to glycidyl methacrylate, oligomeric epoxy chain extenders, ethanolamine, tetrabutyl titanate, trimethylolpropane, etc.

[0029] As an example, the heat stabilizer includes but is not limited to calcium stearate, zinc stearate, calcium laurate, magnesium laurate, zinc 2-ethylhexanoate, magnesium 2-ethylhexanoate, etc.

[0030] Preferably, the degradable material comprises: 70-130 parts by weight of the PHA, 3-30 parts by weight of the modified carbonitride, 0.5-1 part by weight of the nucleating agent, 0.1-0.5 part by weight of the antioxidant, 0.1-1 part by weight of the hydrolysis inhibitor, 1-20 parts by weight of the plasticizer, 0.2-1 part by weight of the compatibilizer, 0.2-1 part by weight of the chain extender, and 0.2-1 part by weight of the heat stabilizer.

[0031] Preferably, the degradable material comprises: 60-90 parts by weight of the PHB, 10-40 parts by weight of the P34HB, and 3-30 parts by weight of the modified carbonitride.

[0032] More preferably, the degradable material comprises: 60-90 parts by weight of the PHB, 10-40 parts by weight of the P34HB, 3-30 parts by weight of the modified carbonitride, 0.5-1 part by weight of the nucleating agent, 0.1-0.5 part by weight of the antioxidant, 0.1-1 part by weight of the hydrolysis inhibitor, 1-20 parts by weight of the plasticizer, 0.2-1 part by weight of the compatibilizer, 0.2-1 part by weight of the chain extender, and 0.2-1 part by weight of the heat stabilizer.

[0033] In the second aspect of the present invention, the present invention provides a film, which is prepared from a raw material comprising the above-mentioned degradable material. Thus, the film has excellent ultraviolet resistance, and thus has excellent weather resistance and service life. At the same time, the film has good mechanical properties and processing properties, and the overall comprehensive performance of the film is good, which can reduce the subsequent treatment and maintenance costs and improve the overall economic benefits.

[0034] In some embodiments of the present invention, the film comprises a cast film.

[0035] Specifically, the cast film is obtained by melt-extruding and casting the above-mentioned degradable material. Processes such as melt-extruding and casting are conventional operations in the art, and those skilled in the art can select specific process parameters according to actual situations.

[0036] In the third aspect of the present invention, the present invention proposes an application of the above-mentioned film in the fields of packaging, printing, building materials decoration or catering. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0038] Figure 1It is the physical pictures before and after the ultraviolet accelerated aging test of the sample strips of the cast films provided in Embodiments 1-4 and Comparative Examples 1-2 of the present invention. Detailed implementation manners

[0039] Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention. The present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are only illustrative and do not limit the present invention in any way.

[0040] Embodiment 1 (1) The preparation process of the modified carbonitride in this embodiment is as follows: a) Dissolve KH550 in 50 ml of an ethanol aqueous solution (the volume ratio of KH550 to the ethanol aqueous solution is 1:1, and the mass concentration of ethanol in the ethanol aqueous solution is 60%), and stir and react at room temperature for 2 hours to obtain a hydrolyzed KH550 solution.

[0041] b) Add carbon nitride (g-C 3 N 4 ) into the above KH550 solution, where the mass ratio of carbon nitride to KH550 is 2:1, ultrasonically disperse for 30 minutes, and then stir and react at 60 °C for 4 hours to obtain KH550-modified carbon nitride, denoted as CNO-KH550.

[0042] (2) The composition of the degradable material in this embodiment is as follows: 70 parts by mass of PHB, 30 parts by mass of P34HB-15% 4HB, 0.5 part by mass of antioxidant 1010, 1 part by mass of anti-hydrolysis agent (carbodiimide), 0.5 part by mass of nucleating agent (talc powder), 0.5 part by mass of compatibilizer (hexamethylene diisocyanate), 10 parts by mass of plasticizer (tributyl citrate), 0.5 part by mass of chain extender (tetrabutyl titanate), 0.5 part by mass of heat stabilizer (zinc stearate), 3 parts by mass of CNO-KH550.

[0043] (3) The preparation process of the cast film in this embodiment is as follows: Mix the materials in step (2) evenly, add the dried raw materials after mixing into a screw extruder, and melt it by heating. The processing temperature is between 150-200 °C, cast it onto a casting roll through a die head, the roll temperature is designed to be 60 °C, and then obtain a cast film through cooling and shaping and winding. The thickness of the obtained cast film is 50 μm.

[0044] Embodiment 2 The difference between the preparation process of the cast film in Embodiment 2 and the preparation process of the cast film in Embodiment 1 is: In step (2), the mass portion of the modified carbonitride CNO-KH550 added is 5, and the other materials are the same as those in Example 1.

[0045] Example 3 The difference between the preparation process of the cast film in Example 3 and that in Example 1 is as follows: In step (2), the mass portion of the modified carbonitride CNO-KH550 added is 10, and the other materials are the same as those in Example 1.

[0046] Example 4 The difference between the preparation process of the cast film in Example 4 and that in Example 1 is as follows: In step (2), the mass portion of the modified carbonitride CNO-KH550 added is 15, and the other materials are the same as those in Example 1.

[0047] Comparative Example 1 (1) The degradable material of Comparative Example 1 is as follows: 70 parts by mass of PHB, 30 parts by mass of P34HB-15% 4HB, 0.5 part by mass of antioxidant 1010, 1 part by mass of anti-hydrolysis agent (carbodiimide), 0.5 part by mass of nucleating agent (talc powder), 0.5 part by mass of compatibilizer (hexamethylene diisocyanate), 10 parts by mass of plasticizer (tributyl citrate), 0.5 part by mass of chain extender (tetrabutyl titanate), 0.5 part by mass of heat stabilizer (zinc stearate).

[0048] (2) The preparation process of the cast film in Comparative Example 1 is the same as that in Example 1.

[0049] Comparative Example 2 (1) The composition of the degradable material of Comparative Example 1 is as follows: 70 parts by mass of PHB, 30 parts by mass of P34HB-15% 4HB, 0.5 part by mass of antioxidant 1010, 1 part by mass of anti-hydrolysis agent (carbodiimide), 0.5 part by mass of nucleating agent (talc powder), 0.5 part by mass of compatibilizer (hexamethylene diisocyanate), 10 parts by mass of plasticizer (tributyl citrate), 0.5 part by mass of chain extender (tetrabutyl titanate), 0.5 part by mass of heat stabilizer (zinc stearate), 3 parts by mass of carbon nitride (commercially available unmodified carbon nitride in Example 1).

[0050] (2) The preparation process of the cast film in Comparative Example 2 is the same as that in Example 1.

[0051] The properties of the cast films provided in the examples and comparative examples were tested, as follows: Determination of tensile strength and nominal strain at break: The mechanical properties before and after 50 hours of ultraviolet accelerated aging test (PCT) were determined in accordance with Part 3 of the national standard B / T 1040.3-2006 "Determination of Tensile Properties of Plastics". Test conditions for the film: The dumbbell-shaped specimen had a length of 150 mm, a narrow parallel width of 10 mm, a tensile speed of 50 mm / min, and a room temperature of 25 °C. PCT: The test samples were placed in an ultraviolet lamp aging test chamber (model UVZN-320), and the ultraviolet accelerated aging test (PCT) was carried out on the test samples according to the method described in ISO 4892.3 "Plastics - Methods of Exposure to Laboratory Light Sources - Part 3: Fluorescent Ultraviolet Lamps". The test conditions were as follows: light source, UVA-340; radiation energy, 0.83 W / (m 2 ﹒nm); test temperature, 70 °C; for every 4 hours of illumination, the lamp was turned off for an intermittent period of 1 hour, and the cycle was tested for 50 hours.

[0052] The performance test results of the cast films of the examples and comparative examples are shown in Table 1.

[0053] Table 1

[0054] Combined with Figure 1 , it can be seen from Table 1 that the cast film of the present application has more excellent anti-ultraviolet aging effect and toughness. In Comparative Example 1, no ultraviolet absorber was added, and the anti-ultraviolet aging effect of the cast film in Comparative Example 1 was poor, and both the tensile strength and the nominal strain at break were low. In Comparative Example 2, unmodified carbonitride was used as the ultraviolet absorber. Although the anti-ultraviolet ability of the cast film was improved to a certain extent, there was still a large difference compared with the anti-ultraviolet ability of the cast film in Example 1. In particular, the nominal strain at break of the cast film in Comparative Example 2 decreased significantly after ultraviolet aging. For the cast films of Examples 1-4 of the present invention, not only the change in tensile strength was small before and after the ultraviolet aging test, but also the nominal strain at break did not change much, indicating that the modified carbonitride and PHA were used to prepare the cast film in the present application, and the modified carbonitride could achieve better dispersibility and interfacial bonding, thereby improving the anti-ultraviolet performance of the overall cast film.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A degradable material, characterized in that: include: PHA and an anti-ultraviolet absorber, wherein the anti-ultraviolet absorber is a modified carbonitride, and the mass ratio of the PHA to the modified carbonitride is (70-130): (3-30).

2. The degradable material according to claim 1, characterized in that: The mass ratio of the PHA to the modified carbonitride is 100:(3-20).

3. The degradable material according to claim 1, characterized in that: The PHA is selected from one or more of PHB, P34HB, PHBV, and PHBHHx; Preferably, the PHA is selected from at least one of PHB and P34HB, more preferably a mixture of PHB and P34HB.

4. The degradable material according to claim 3, characterized in that: When the PHA is selected from a mixture of PHB and P34HB, the mass ratio of the PHB to the P34HB is (60-90): (10-40); And / or, the molecular weight of the PHB is 300,000-1,000,000; And / or, the molecular weight of the P34HB is 100,000-600,000.

5. The degradable material according to any one of claims 1 to 4, characterized in that: The modified carbonitride is obtained by a grafting reaction between a graphite phase carbonitride and a silanol-containing compound; Preferably, the silanol-containing compound is selected from hydrolyzed silane coupling agent KH550.

6. The degradable material according to claim 5, characterized in that: The mass ratio of the graphite phase carbonitride to the silanol-containing compound is (10-20): (5-10); And / or, the grafting reaction temperature is 50°C-70°C, and the time is 3h-5h; And / or, the hydrolyzed silane coupling agent KH550 is obtained by mixing and reacting the silane coupling agent KH550 with an aqueous solution of alcohol at room temperature.

7. The degradable material according to any one of claims 1 to 4, characterized in that: It also includes at least one of a nucleating agent, an antioxidant, an anti-hydrolysis agent, a plasticizer, a compatibilizer, a chain extender, and a thermal stabilizer; Preferably, the degradable material comprises: 70-130 parts by weight of the PHA, 3-30 parts by weight of the modified carbon nitride, 0.5-1 parts by weight of the nucleating agent, 0.1-0.5 parts by weight of the antioxidant, 0.1-1 parts by weight of the anti-hydrolysis agent, 1-20 parts by weight of the plasticizer, 0.2-1 parts by weight of the compatibilizer, 0.2-1 parts by weight of the chain extender and 0.2-1 parts by weight of the thermal stabilizer.

8. The degradable material according to claim 7, comprising: 60-90 parts by weight of PHB, 10-40 parts by weight of P34HB and 3-30 parts by weight of the modified carbonitride; Preferably, the degradable material comprises: 60-90 parts by weight of the PHB, 10-40 parts by weight of the P34HB, 3-30 parts by weight of the modified carbon nitride, 0.5-1 parts by weight of the nucleating agent, 0.1-0.5 parts by weight of the antioxidant, 0.1-1 parts by weight of the anti-hydrolysis agent, 1-20 parts by weight of the plasticizer, 0.2-1 parts by weight of the compatibilizer, 0.2-1 parts by weight of the chain extender and 0.2-1 parts by weight of the thermal stabilizer.

9. A film, characterized in that: Prepared by using raw materials including the degradable material according to any one of claims 1 to 8; Preferably, the film comprises a cast film.

10. Use of the film according to claim 9 in the fields of packaging, printing, building material decoration or catering.

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