Fruit net and method for manufacturing the same

Abstract

The application discloses a fruit net and a preparation method thereof, and belongs to the technical field of polymer materials.The fruit net is characterized by the following raw material weight proportion: PPCP 50-90 parts, PBAT 10-50 parts, foaming agent 1-20 parts, and compatibilizing chain-extending agent 1-10 parts.The preparation steps are as follows: the preparation raw materials except the foaming agent are mixed and granulated, the granulation temperature is 100-160 DEG C, and a master batch is obtained;the master batch and the foaming agent are added into a foaming machine for extrusion foaming, the extrusion foaming temperature is 100-140 DEG C, and the fruit net is obtained.The fruit net is prepared from degradable PPCP and PBAT, the PPCP and the PBAT are mixed and combined with each other by using the compatibilizing chain-extending agent, the degradation performance is relatively strong, the foaming performance and the toughness of the material are adjusted, and the fruit net is more suitable.The fruit net can be degraded by forced composting for 6 months.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a fruit netting sleeve and its preparation method. Background Technology

[0002] With the development of the times, people have increasingly higher requirements for the appearance of fruit. Damage to fruit during transportation, leading to poor appearance or even rotting, can severely impact its value. Fruit netting effectively solves this problem and is therefore often sold alongside the fruit. However, since most fruit netting is currently made of polyethylene foam, its disposal generates significant amounts of white pollution. Furthermore, as the fresh fruit sales industry continues to develop and fruit packaging becomes increasingly sophisticated, the amount of packaging waste such as preservation bags and fruit netting is constantly increasing, exacerbating the environmental burden. Therefore, the complete replacement of fruit packaging with biodegradable materials is an inevitable trend.

[0003] Chinese patent CN114031904A discloses a biodegradable fruit netting with antibacterial modified atmosphere packaging, consisting of a biodegradable netting masterbatch and an antibacterial modified atmosphere packaging masterbatch. The biodegradable netting masterbatch is made of polyglycolic acid, polybutylene adipate terephthalate, crosslinking agent, antistatic agent, filler, and antioxidant. The antibacterial modified atmosphere packaging masterbatch is made of antibacterial preservative, lubricant, release agent, polyglycolic acid, polybutylene adipate terephthalate, and crosslinking agent. Although this fruit netting is biodegradable, its foaming ratio is low, limiting its protective effect on fruit. Furthermore, its high production cost increases the sales cost of fruit, making it unsuitable for large-scale promotion. Summary of the Invention

[0004] The purpose of this invention is to provide a biodegradable fruit netting with good water resistance and high toughness, and a method for preparing the same. The fruit netting prepared by this invention has good water resistance, is less affected by the moisture content in the air, and meets the toughness requirements for use as a fruit netting. It can be degraded after 6 months of forced composting.

[0005] The technical solution adopted by the present invention to solve its technical problem is a fruit netting sleeve, characterized in that the raw materials by weight include: 50-90 parts of PPCP, 10-50 parts of PBAT, 1-20 parts of foaming agent, and 1-10 parts of compatibilizer and chain extender.

[0006] Propylene oxide-phthalic anhydride-carbon dioxide terpolymer (PPCP) is biodegradable, but its tensile strength is poor. When mixed with biodegradable material PBAT and bonded together using compatibilizers and chain extenders, it becomes a raw material for fruit netting. This results in stronger degradation performance, and the adjusted foaming properties and toughness of the material are more suitable for fruit netting. This invention provides a fruit netting material mainly made of carbon dioxide-based biodegradable plastic. It can be degraded through biodegradation, and due to its good water resistance, controllable degradation rate, and good toughness, it can adapt to certain humid transportation environments. Its good toughness allows it to accommodate fruits of different sizes and provide a tight wrap. This invention uses PPCP and PBAT as the main raw materials to produce fruit netting material, which meets the degradation requirements after use. The addition of regulators further improves the toughness and dimensional stability of the propylene oxide-phthalic anhydride-carbon dioxide terpolymer, which is beneficial for fruit storage and transportation, effectively reducing fruit damage caused by external forces. The CO2-based biodegradable copolymer composition used in this invention can be degraded in 6 months by forced composting.

[0007] Preferably, the raw materials in the above-mentioned fruit netting include, by weight: 60-70 parts PPCP, 20-30 parts PBAT, 4-15 parts foaming agent, and 3-6 parts compatibilizer and chain extender. The fruit netting obtained with the preferred raw material composition has both a larger foaming ratio, resulting in a lighter netting, and sufficient toughness to prevent easy damage.

[0008] Preferably, in the above-mentioned fruit netting, the compatibilizer and chain extender includes epoxy chain extenders and / or oxazoline chain extenders. Adding appropriate compatibilizers and chain extenders can bind the molecular chains of PPCP and PBAT together, thereby better ensuring the material's toughness and promoting uniform foaming.

[0009] Preferably, in the above-mentioned fruit netting, the compatibilizer and chain extender are BASF chain extender ADR-4368C and BASF chain extender ADR-4385, and the mass ratio of BASF chain extender ADR-4368C to BASF chain extender ADR-4385 is 2~5:1. This invention provides a compatibilizer and chain extender with the best component adjustment properties. After use, PPCP and PBAT are mixed more evenly, and their properties are better combined. At the same dosage, the resulting fruit netting exhibits better toughness and strength, better resilience, better fruit wrapping, and is less prone to falling off.

[0010] Preferably, in the above-mentioned fruit netting, the preparation method of the PPCP includes the following steps: copolymerizing propylene oxide, phthalic anhydride, a non-metallic catalyst, and carbon dioxide to obtain the propylene oxide-phthalic anhydride-carbon dioxide terpolymer; the molar ratio of propylene oxide to phthalic anhydride is 1~2:1; and the pressure of the carbon dioxide is 0.1MPa~0.8MPa.

[0011] Fruit netting is used in large quantities, and the cycle from packaging to waste gas is short, often generating a large amount of waste in a short period. The PPCP prepared by the preferred process of this invention, although it cannot produce a high molecular weight polymer, has a relatively high content of phthalic anhydride in its molecular chain, resulting in good gas encapsulation during foaming and a high foaming ratio. When combined with PBAT using the aforementioned preferred compatibilizer and chain extender and foamed, it exhibits better elasticity and can complete biodegradation in a shorter time. This better protects the fruit while rapidly completing biodegradation, reducing environmental pollution.

[0012] Preferably, in the above-mentioned fruit netting, the non-metallic catalyst is a composite catalyst of tetra-n-butylammonium halide and / or tetra-n-propylammonium halide with triethylboron or tributylboron. The preferred catalyst, when used, can accelerate the reaction efficiency and obtain the above-mentioned PPCP with a suitable molecular weight.

[0013] Preferably, in the above-mentioned fruit netting, the foaming agent includes a gaseous foaming agent and / or a volatile liquid foaming agent.

[0014] Preferably, in the above-mentioned fruit netting, the gaseous foaming agent includes one or more of air, nitrogen, helium, hydrogen, and carbon dioxide; the volatile liquid foaming agent includes one or more of butane, pentane, hexane, heptane, fluorinated hydrocarbons, chlorinated hydrocarbons, liquid carbon dioxide, liquid water, alcohols, ethers, ketones, and aromatic hydrocarbons. This invention does not have high requirements for the foaming agent and can adapt to most foaming agents, all of which can achieve high foaming ratios.

[0015] Preferably, the above-mentioned fruit netting further comprises one or more of the following raw materials by weight: 0.1-5 parts antioxidant, 0.1-5 parts light stabilizer, 0.1-2 parts pigment, 1-2 parts foaming nucleating agent, and 0.5-2 parts foam stabilizer. Each regulator is hydrolyzable, and the preferred regulator ratio better modifies the propylene oxide-phthalic anhydride-carbon dioxide terpolymer and PBAT, improving toughness and antioxidant properties while maintaining the material's resistance to hydrolysis, thus achieving better performance.

[0016] More preferably, the above-mentioned fruit netting further includes at least 1-2 parts by weight of a foaming nucleating agent and 0.5-2 parts by weight of an active polyether-modified silicone oil; the foaming nucleating agent is nano-sized talc or nano-sized calcium carbonate. The preferred foaming nucleating agent and foam stabilizer, the active polyether-modified silicone oil, are more evenly distributed in the PPCP, resulting in a fruit netting with dense and uniform bubbles after foaming, exhibiting better foaming ratio and toughness.

[0017] The method for preparing the above-mentioned fruit netting is characterized by comprising the following steps:

[0018] 1) Mix the raw materials except for the foaming agent and then granulate them at a temperature of 100℃~160℃ to obtain masterbatch;

[0019] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming. The extrusion foaming temperature is 100℃~140℃ to obtain the fruit netting.

[0020] The material of the present invention can be adapted to the extrusion foaming process of fruit netting. Preferably, the granulation temperature is 130℃~140℃ and the extrusion foaming temperature is 110℃~120℃. Under the preferred processing temperature, the flow state or softening state of the material can better maintain the material's performance, the material is mixed more evenly, the molecular chain bonding points are more uniform, and the foaming ratio and material toughness can reach the optimal state of the present invention.

[0021] Compared with the prior art, the fruit netting and its preparation method of the present invention have the following beneficial effects: The present invention uses PPCP and PBAT as fruit netting materials, both of which are biodegradable and will not cause white pollution to the environment; they also have good resistance to hydrolysis and will not be decomposed prematurely due to changes in moisture in the transportation environment. They can achieve good toughness and protection with a lighter amount of material, thus avoiding damage to the fruit.

[0022] This invention provides a fruit netting material primarily made of carbon dioxide-based biodegradable plastic. It degrades through biodegradation and exhibits good water resistance, controllable degradation rate, and good toughness, making it suitable for certain humid transportation environments. The controllable degradation rate prevents excessively rapid decomposition during use, and its good toughness allows it to accommodate fruits of different sizes while providing a tight wrap. This invention uses PPCP and PBAT as the main raw materials to produce the fruit netting material, meeting the degradation requirements after use. The addition of regulators further improves the toughness and dimensional stability of the propylene oxide-phthalic anhydride-carbon dioxide terpolymer, which is beneficial for fruit storage and transportation, effectively reducing fruit damage caused by external forces.

[0023] This invention uses biodegradable propylene oxide-phthalic anhydride-carbon dioxide terpolymer and polyadipate as raw materials to make the fruit netting biodegradable. Example results show that the fruit netting of this invention completes degradation in 6 months through forced composting. Detailed Implementation

[0024] In this invention, the copolymerization reaction of propylene oxide, phthalic anhydride, non-metallic catalyst, and carbon dioxide preferably includes: mixing propylene oxide, phthalic anhydride, and non-metallic catalyst in a sealed container, then introducing CO2 into the sealed container until the pressure of the carbon dioxide is reached, and then raising the temperature to the copolymerization temperature. This invention does not have a specific limitation on the sealed container; any sealed container well-known to those skilled in the art can be used. Specifically, in this embodiment, a 50L high-pressure reactor is used. This invention does not have a specific limitation on the mixing process; any method well-known to those skilled in the art can be used to achieve uniform mixing. Specifically, in this embodiment, mixing is performed under stirring conditions at a stirring speed of 100 r / min.

[0025] In this invention, the copolymerization reaction is preferably carried out under anaerobic conditions. The temperature of the copolymerization reaction is preferably 40~100℃, more preferably 60~80℃. In this invention, the copolymerization reaction is preferably carried out under stirring conditions.

[0026] In this invention, the molar ratio of tetrabutylammonium halide to triethylboron in the preparation of PPCP is 1:1 to 5, more preferably 1:2 to 4, and even more preferably 1:2.5 to 3. The tetrabutylammonium halide is preferably tetrabutylammonium chloride and / or tetrabutylammonium bromide. In this invention, triethylboron and tributylboron preferably participate in the reaction in the form of a triethylboron solution and a tributylboron solution, respectively, and the concentration of the triethylboron solution and the tributylboron solution is preferably 1 mol / L. In this invention, the solvent in the triethylboron solution is tetrahydrofuran, diethyl ether, or n-butyl ether.

[0027] After the copolymerization reaction is completed, the present invention preferably involves depressurizing and depressurizing the obtained copolymerization product, dissolving it in dichloroethane, and then adding ethanol to obtain a precipitate. The precipitate is then subjected to devolatilization, granulation, and drying to obtain the PPCP. The present invention does not have a specific limitation on the amount of dichloroethane used, as long as the obtained copolymerization product is completely dissolved. The present invention also does not have a specific limitation on the amount of ethanol used, as long as the precipitate is completely precipitated. The present invention does not have specific limitations on the devolatilization, granulation, and drying processes; conventional techniques in the art can be used.

[0028] In this invention, the foaming agent preferably comprises a gaseous foaming agent and / or a volatile liquid foaming agent; the gaseous foaming agent preferably comprises one or more of air, nitrogen, helium, hydrogen, and carbon dioxide; the volatile liquid foaming agent preferably comprises one or more of butane, pentane, hexane, heptane, fluorinated hydrocarbons, chlorinated hydrocarbons, liquid carbon dioxide, liquid water, alcohols, ethers and ketones, and aromatic hydrocarbons. In this invention, the fluorinated hydrocarbons preferably comprise one or more of CFC-11, CFC-12, CFC-113, CFC-142b, and HCFC-141b; the chlorinated hydrocarbons preferably comprise one or more of chloroform, tetrachloromethane, and dichloroethane; the alcohols preferably comprise one or more of methanol, ethanol, and butanol; the ethers and ketones preferably comprise 2-acetoneoxy-3,4-difluoronitrobenzene; and the aromatic hydrocarbons preferably comprise one or more of benzene, toluene, ethylbenzene, xylene, and cumene.

[0029] In this invention, the compatibilizing chain extender preferably includes epoxy chain extenders and / or oxazoline chain extenders. In this invention, the oxazoline chain extender preferably includes bis(oxazoline) (BOZ) chain extender.

[0030] Based on the mass fractions of the PPCP, the raw materials for preparing the fruit netting of the present invention preferably include 0.1 to 5 parts of antioxidant, more preferably 1 to 4 parts, and even more preferably 2 to 3 parts. In the present invention, the antioxidant preferably includes antioxidant 1010 and / or antioxidant 168.

[0031] Based on the mass fraction of the PPCP, the raw materials for preparing the fruit netting of the present invention preferably include 0.1 to 5 parts of light stabilizer, more preferably 1 to 4 parts, and even more preferably 2 to 3 parts. In the present invention, the light stabilizer preferably includes UV-531 and / or UV-9.

[0032] Based on the mass fraction of the PPCP, the raw materials for preparing the fruit netting of the present invention preferably include 0.1 to 2 parts of pigment, more preferably 0.5 to 1.5 parts, and even more preferably 0.8 to 1.2 parts. In the present invention, the pigment preferably includes organic pigments and / or inorganic pigments.

[0033] Based on the mass fraction of the PPCP, the raw materials for preparing the fruit netting of the present invention preferably include 1-2 parts of foaming and nucleating agent, more preferably 1.2-1.8 parts, and even more preferably 1.5-1.6 parts.

[0034] Based on the mass fraction of the PPCP, the raw materials for preparing the fruit netting of the present invention preferably include 0.5 to 2 parts of foam stabilizer, more preferably 0.8 to 1.5 parts, and even more preferably 1 to 1.2 parts. In the present invention, the foam stabilizer preferably includes one or more of organosilicon, polyol, and sulfonated fatty alcohol, more preferably active polyether modified silicone oil.

[0035] This invention uses biodegradable PPCP and PBAT as raw materials, making fruit netting also biodegradable.

[0036] The present invention also provides a method for preparing the fruit netting described above, comprising the following steps:

[0037] The raw materials, excluding the foaming agent, are mixed and granulated to obtain masterbatch.

[0038] The masterbatch and foaming agent are added to a foaming machine for extrusion foaming to obtain the fruit netting.

[0039] In this invention, PPCP and PBAT are preferably dried before mixing the raw materials other than the foaming agent. This invention does not have specific limitations on the drying temperature and time; drying to constant weight can be achieved using methods well-known to those skilled in the art. Specifically, in this embodiment, drying is performed at 60°C for 4 hours.

[0040] This invention does not impose any particular limitation on the mixing process; any method well-known to those skilled in the art can be used to achieve uniform mixing. In this invention, the granulation temperature is preferably 100~160℃, more preferably 110~150℃, and even more preferably 130~140℃.

[0041] After obtaining the masterbatch, the present invention adds the masterbatch and foaming agent into a foaming machine for extrusion foaming to obtain the fruit net sleeve. In the present invention, the extrusion foaming temperature is preferably 100℃~140℃, more preferably 110~120℃.

[0042] To further illustrate the present invention, the following detailed description of a fruit netting and its preparation method provided by the present invention is provided in conjunction with embodiments, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0043] Example 1

[0044] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 1.5:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1000:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 0.4 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0045] Prepare the raw materials according to the following weight parts: 65 parts PPCP, 25 parts PBAT, 8 parts pentane, 4.5 parts chain extender and compatibilizer, 1.5 parts nano-grade talc, 1.2 parts active polyether modified silicone oil, and 1 part antioxidant 1010. The chain extender and compatibilizer is a composite chain extender of ADR-4368C and ADR-4385 in a mass ratio of 3.5:1.

[0046] Preparation of fruit netting:

[0047] 1) PPCP and PBAT are pre-dried at 60℃ for 4 hours. The raw materials except for the foaming agent are mixed and granulated at 135℃ to obtain masterbatch.

[0048] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 115°C to obtain the fruit netting sample.

[0049] Example 2

[0050] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 1:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1200:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 0.1 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0051] Prepare the raw materials according to the following weight parts: 70 parts PPCP, 20 parts PBAT, 15 parts carbon dioxide, 3 parts chain extender and compatibilizer, 1 part nano calcium carbonate, 2 parts active polyether modified silicone oil, 0.1 parts antioxidant 168, 5 parts UV-531, and 0.1 parts pigment. The chain extender and compatibilizer is a composite chain extender of ADR-4368C and ADR-4385 in a mass ratio of 2:1.

[0052] Preparation of fruit netting:

[0053] 1) PPCP and PBAT are pre-dried at 60°C for 4 hours. The raw materials, except for the foaming agent, are mixed and granulated at 140°C to obtain masterbatch.

[0054] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 120°C to obtain the fruit netting sample.

[0055] Example 3

[0056] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 2:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1000:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 0.8 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0057] Prepare the raw materials according to the following weight parts: 60 parts PPCP, 30 parts PBAT, 4 parts pentane, 6 parts chain extender and compatibilizer, 2 parts nano-grade talc, 0.5 parts active polyether modified silicone oil, 5 parts antioxidant 1010, 0.1 parts UV-531, and 2 parts pigment. The chain extender and compatibilizer is a composite chain extender of ADR-4368C and ADR-4385 in a mass ratio of 5:1.

[0058] Preparation of fruit netting:

[0059] 1) PPCP and PBAT are pre-dried at 60°C for 4 hours. The raw materials, except for the foaming agent, are mixed and granulated at 130°C to obtain masterbatch.

[0060] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 110°C to obtain the fruit netting sample.

[0061] Example 4

[0062] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 6:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1000:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 2 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0063] Prepare the raw materials according to the following weight parts: 65 parts PPCP, 25 parts PBAT, 8 parts pentane, 4.5 parts chain extender and compatibilizer, 1.5 parts nano-grade talc, 1.2 parts active polyether modified silicone oil, and 1 part antioxidant 1010. The chain extender and compatibilizer is a composite chain extender of ADR-4368C and ADR-4385 in a mass ratio of 3.5:1.

[0064] Preparation of fruit netting:

[0065] 1) PPCP and PBAT are pre-dried at 60℃ for 4 hours. The raw materials except for the foaming agent are mixed and granulated at 135℃ to obtain masterbatch.

[0066] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 115°C to obtain the fruit netting sample.

[0067] Example 5

[0068] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 1.5:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1000:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 0.4 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0069] Prepare the raw materials according to the following weight proportions: 65 parts PPCP, 25 parts PBAT, 8 parts pentane, 4.5 parts ADR-4468, 1.5 parts nano-grade talc, 1.2 parts active polyether modified silicone oil, and 1 part antioxidant 1010.

[0070] Preparation of fruit netting:

[0071] 1) PPCP and PBAT are pre-dried at 60℃ for 4 hours. The raw materials except for the foaming agent are mixed and granulated at 135℃ to obtain masterbatch.

[0072] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 115°C to obtain the fruit netting sample.

[0073] Example 6

[0074] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 1.5:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1000:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 0.3 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0075] The raw materials are: 90 parts PPCP, 10 parts PBAT, 8 parts pentane, 1 part ADR-4368C, 2 parts nano-grade talc, and 0.5 parts active polyether modified silicone oil by weight.

[0076] Preparation of fruit netting:

[0077] 1) PPCP and PBAT are pre-dried at 60°C for 4 hours. The raw materials, except for the foaming agent, are mixed and granulated at 100°C to obtain masterbatch.

[0078] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 100°C to obtain the fruit netting sample.

[0079] Example 7

[0080] Preparation of PPCP: Propylene oxide, phthalic anhydride, and a non-metallic catalyst were added to a closed reactor with a stirring speed of 100 r / min. The molar ratio of propylene oxide to phthalic anhydride was 1.5:1, and the molar ratio of propylene oxide to the non-metallic catalyst was 1200:1. The molar ratio of tetrabutylammonium bromide to triethylborane to tetrabutylammonium bromide in the non-metallic catalyst was 2.2:1. Triethylborane was added in the form of a 1 mol / L tetrahydrofuran solution of triethylborane. CO2 was introduced into the closed container to a pressure of 0.4 MPa, and the temperature was then raised to the copolymerization temperature of 70°C. After the copolymerization reaction was completed, the obtained copolymer product was depressurized and dissolved in dichloroethane, followed by the addition of ethanol to obtain a precipitate. The precipitate was then devolatilized, granulated, and dried to obtain PPCP.

[0081] The raw materials are as follows (by weight): 50 parts PPCP, 50 parts PBAT, 8 parts pentane, 10 parts ADR-4385, 1 part nano-calcium carbonate, 2 parts active polyether modified silicone oil, and 2 parts antioxidant.

[0082] Preparation of fruit netting:

[0083] 1) PPCP and PBAT are pre-dried at 60°C for 4 hours. The raw materials, except for the foaming agent, are mixed and granulated at 160°C to obtain masterbatch.

[0084] 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming at a temperature of 140°C to obtain the fruit netting sample.

[0085] Performance testing:

[0086] 1. Biodegradation rate: Analyzed and tested according to GB / T19277.1 and GB / T19277.2.

[0087] Table 1 compares the properties of the foamed materials prepared in Examples 1 to 7 of this invention:

[0088] Table 1 Thermal properties of the samples

[0089] Example Tensile strength Foaming ratio Biodegradation rate rebound rate Compression deformation Compressive strength Example 1 1016 kPa 52 times 92.1% 86% 14% 308kPa Example 2 979 kPa 54 times 92.5% 87% 13% 314kPa Example 3 1002 kPa 49 times 91.9% 84% 15% 297kPa Example 4 897 kPa 51 times 93.2% 80% 16% 281kPa Example 5 764 kPa 50 times 91.4% 74% 19% 271kPa Example 6 708 kPa 64 times 92.4% 71% 20% 267kPa Example 7 923 kPa 49 times 91.7% 72% 22% 259kPa

[0090] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A fruit netting sleeve, characterized in that, The raw material composition by weight includes: 50-90 parts PPCP, 10-50 parts PBAT, 1-20 parts foaming agent, and 1-10 parts compatibilizer and chain extender; The compatibilizing chain extender is a compound chain extender solubilizer consisting of BASF chain extender ADR-4368C and BASF chain extender ADR-4385 in a mass ratio of 3.5:

1. The preparation method of the PPCP includes the following steps: copolymerizing propylene oxide, phthalic anhydride, a non-metallic catalyst, and carbon dioxide to obtain the propylene oxide-phthalic anhydride-carbon dioxide terpolymer; the molar ratio of propylene oxide and phthalic anhydride is 1~2:1; the pressure of carbon dioxide is 0.1MPa~0.8MPa; The preparation method includes the following steps: 1) Mix the raw materials except for the foaming agent and then granulate them at a temperature of 100℃~160℃ to obtain masterbatch; 2) The masterbatch and foaming agent are added to a foaming machine for extrusion foaming. The extrusion foaming temperature is 100℃~140℃ to obtain the fruit netting.

2. The fruit netting sleeve according to claim 1, characterized in that, The raw materials consist of the following components by weight: 60-70 parts PPCP, 20-30 parts PBAT, 4-15 parts foaming agent, and 3-6 parts compatibilizer and chain extender.

3. The fruit netting sleeve according to claim 1, characterized in that, The non-metallic catalyst is a composite catalyst of tetra-n-butylammonium halide and / or tetra-n-propylammonium halide with triethylboron or tributylboron.

4. The fruit netting sleeve according to claim 1 or 2, characterized in that, The foaming agent includes gaseous foaming agents and / or volatile liquid foaming agents.

5. The fruit netting sleeve according to claim 4, characterized in that, The gaseous foaming agent includes one or more of air, nitrogen, helium, hydrogen, and carbon dioxide; the volatile liquid foaming agent includes one or more of butane, pentane, hexane, heptane, fluorinated hydrocarbons, chlorinated hydrocarbons, liquid carbon dioxide, liquid water, alcohols, ethers, ketones, and aromatic hydrocarbons.

6. The fruit netting sleeve according to claim 1, characterized in that, The raw material composition by weight also includes one or more of the following preparation raw materials: Antioxidant 0.1-5 parts, light stabilizer 0.1-5 parts, pigment 0.1-2 parts, foaming nucleating agent 1-2 parts, foam stabilizer 0.5-2 parts.