Degradable high molecular material, preparation method and degradable high molecular film

Abstract

The application relates to the technical field of polymer films, and specifically discloses a degradable polymer material, a preparation method thereof and a degradable polymer film. The degradable polymer material is mainly made of the following raw materials in parts by weight: 35-45 parts of polybutylene adipate terephthalate, 20-30 parts of modified starch, 10-20 parts of polydimethylsiloxane, 5-15 parts of trimethylolpropane trimethacrylate, 2-8 parts of a plasticizer and 2-8 parts of an antibacterial agent; the polydimethylsiloxane is vinyl-terminated polydimethylsiloxane; the modified starch is obtained by treating starch with 1-chlorohex-5-ene-2-ol and 1,2-epoxy chlorobutane. The degradable polymer film obtained from the degradable polymer material not only has good hydrophobicity and degradability, meets environmental protection requirements, but also has the advantages of high tensile strength, high right-angle tear strength and good light transmittance, meets market demands, has commercial application prospects and economic value.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of high-molecular thin films, in particular to a degradable high-molecular material, a preparation method thereof and a degradable high-molecular thin film. BACKGROUND

[0002] Plastic thin films have been widely used due to their light weight, corrosion resistance and chemical stability. The plastic thin films are generally prepared from high-molecular materials. Some researchers have begun to study degradable high-molecular materials in order to realize the degradation of plastic thin films and reduce the influence of white pollution on the environment, so that the degradable high-molecular thin films obtained have degradability, the environmental pollution is reduced, and the purpose of environmental protection is achieved.

[0003] At present, the degradable high-molecular materials on the market often use polybutylene terephthalate, starch and plasticizers. Since polybutylene terephthalate is a hydrophobic polymer and the starch contains a large number of hydrogen bonds, when the polybutylene terephthalate and the starch are blended, the mixing is poor, the intermolecular forces and the bonding strength between the raw materials are reduced, and the tensile strength of the degradable high-molecular thin film is affected. SUMMARY

[0004] In order to improve the tensile strength of the degradable high-molecular thin film, the application provides a degradable high-molecular material, a preparation method thereof and a degradable high-molecular thin film.

[0005] In the first aspect, the application provides a degradable high-molecular material, which adopts the following technical scheme:

[0006] A degradable high-molecular material is prepared from the following raw materials by weight: polybutylene terephthalate 35-45 parts, modified starch 20-30 parts, polydimethylsiloxane 10-20 parts, trimethylolpropane trimethacrylate 5-15 parts, plasticizer 2-8 parts and antibacterial agent 2-8 parts.

[0007] The polydimethylsiloxane is vinyl-terminated polydimethylsiloxane; and the modified starch is obtained by treating starch with 1-chlorohex-5-ene-2-ol and 1,2-epoxy chlorobutane.

[0008] The degradable high-molecular material has good hydrophobicity and degradability, and the degradable high-molecular thin film prepared therefrom has a transverse tensile strength of >21 MPa, a longitudinal tensile strength of >20 MPa, a transverse right-angle tear strength of >7 MPa, a longitudinal right-angle tear strength of >7 MPa and a light transmittance of >91%, which has the advantages of high tensile strength, high right-angle tear strength and good light transmittance, meets the market demand, has commercial application prospects and economic value.

[0009] Adding starch to the raw materials of a biodegradable polymer significantly increases its degradability. The starch is then treated with 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane. The chlorine groups in the 1-chlorohex-5-en-2-ol and the epoxy and chlorine groups in the 1,2-epoxychlorobutane react with the hydroxyl groups in the starch, achieving grafting and crosslinking. This introduces carbon-carbon double bonds and reactive groups onto the starch surface, significantly increasing the intermolecular forces and bonding strength between the starch and the raw materials. The interaction between the carbon-carbon double bonds and siloxy groups in polydimethylsiloxane and the three carbon-carbon double bonds and three ester groups in trimethylolpropane trimethacrylate creates a compact three-dimensional network structure in the biodegradable polymer. This significantly improves the mechanical properties of the biodegradable polymer without compromising light transmittance, and enhances the tensile strength and right-angle tear strength of the biodegradable polymer film.

[0010] Optionally, the modified starch is prepared by the following method: heating water to 40-60° C., then adding starch and mixing, adjusting the pH value to 13-14 with alkali, then adding 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane, stirring for 7-9 hours, adjusting the pH value to 6-7 with acid, cooling to room temperature, filtering, and drying to obtain modified starch.

[0011] Optionally, the weight ratio of the starch, water, 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane is 100:(120-150):(4-6):1-3).

[0012] By adopting the above technical solution, water is first heated, then starch is dispersed, and then the pH value is adjusted to alkaline, and 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane are added. The chlorine groups in the 1-chlorohex-5-en-2-ol react with the hydroxyl groups in the starch to achieve grafting, and the epoxy groups and chlorine groups in the 1,2-epoxychlorobutane can also react with the hydroxyl groups in the starch to achieve cross-linking. Then, the pH value is adjusted to 6-7, and filtration is performed to obtain modified starch. 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane are used to not only achieve cross-linking of the starch, but also introduce active groups on the starch surface, thereby increasing the interaction between the modified starch and polybutylene terephthalate-adipate, and also increasing the interaction between the modified starch and polydimethylsiloxane and trimethylolpropane trimethacrylate, thereby improving the tensile strength and right-angle tear strength of the degradable polymer film.

[0013] Optionally, the starch is one or more of corn starch, sweet potato starch, and wheat starch.

[0014] By adopting the above technical solution, starch is limited, which facilitates the selection of starch.

[0015] Furthermore, in the method for preparing modified starch, the alkali is a sodium hydroxide solution, and the mass concentration of the sodium hydroxide solution is 10-30%. Preferably, the mass concentration of the sodium hydroxide solution is 15%.

[0016] In the modified starch preparation method, the acid is a hydrochloric acid solution, and the mass concentration of the hydrochloric acid solution is 10-30%. Preferably, the mass concentration of the hydrochloric acid solution is 15%.

[0017] Optionally, the polybutylene terephthalate-adipate has a melt index of 2-5 g / min at 190° C. and 2.16 kg; the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.01-0.15% and the molecular weight is 500,000-800,000 Daltons.

[0018] By adopting the above technical solution, the melt index of polybutylene terephthalate-adipate is limited, and the vinyl content and molecular weight of vinyl-terminated polydimethylsiloxane are also limited, which facilitates the selection of polybutylene terephthalate-adipate and polydimethylsiloxane, while reducing the stability of the performance of the degradable polymer material due to excessive fluctuations in their parameters.

[0019] In multiple embodiments, the melt index of polybutylene terephthalate-adipate at 190°C and 2.16 kg is 3.4 g / min, and the melt index can also be set to 2 g / min, 2.5 g / min, 3 g / min, 3.5 g / min, 4 g / min, 4.5 g / min, 5 g / min, etc. as needed.

[0020] In various embodiments, the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.05% and the molecular weight is 600,000 Daltons. The vinyl content can also be set to 0.01%, 0.03%, 0.1%, 0.12%, 0.15%, etc. as needed. The molecular weight can also be set to 500,000 Daltons, 700,000 Daltons, 800,000 Daltons, etc. as needed.

[0021] Optionally, the plasticizer is one or more of acetyl tributyl citrate, triethanolamine, and sorbitol. Preferably, the plasticizer is one or both of acetyl tributyl citrate and triethanolamine. More preferably, the plasticizer is acetyl tributyl citrate.

[0022] By adopting the above technical solution, the plasticizer is limited, making the selection of the plasticizer easier. Moreover, acetyl tributyl citrate not only has good compatibility, but also can increase the mobility between raw materials, enhance the plasticity of raw materials, and make the degradable polymer material exhibit good flexibility and toughness.

[0023] Optionally, the antimicrobial agent is one or more of chitosan, carboxymethyl chitosan, and chitosan quaternary ammonium salt. Preferably, the plasticizer is one or both of carboxymethyl chitosan and chitosan quaternary ammonium salt. More preferably, the plasticizer is carboxymethyl chitosan.

[0024] By adopting the above technical solution, the antimicrobial agent is limited, which facilitates the selection of the antimicrobial agent. In addition, the introduction of carboxymethyl groups into carboxymethyl chitosan enhances the stability of the chitosan, making the degradable polymer material exhibit excellent antimicrobial activity.

[0025] In a second aspect, the present application provides a method for preparing the above-mentioned degradable polymer material, which adopts the following technical solution:

[0026] A method for preparing the above-mentioned degradable polymer material comprises the following steps: mixing polybutylene terephthalate-adipate, modified starch, polydimethylsiloxane, trimethylolpropane trimethacrylate, a plasticizer, and an antibacterial agent, melt-extruding, cooling and granulating to obtain the degradable polymer material.

[0027] Optionally, the temperature of the melt extrusion is 160-200°C.

[0028] By adopting the above technical solution, the raw materials are directly mixed, then melt-extruded, and cooled to granulate, which facilitates the preparation and control of the degradable polymer material.

[0029] In a third aspect, the present application provides a degradable polymer film, which adopts the following technical solution:

[0030] A degradable polymer film is prepared using the above-mentioned degradable polymer material. Preferably, the degradable polymer film is prepared using the degradable polymer material through film blowing.

[0031] By adopting the above technical solution, the degradable polymer material is directly blown into film, which facilitates the preparation and control of the degradable polymer film.

[0032] In summary, this application has at least the following beneficial effects:

[0033] The degradable polymer material of the present application has good hydrophobicity and degradability, meeting environmental protection requirements. Moreover, through the mutual cooperation of modified starch, polydimethylsiloxane and trimethylolpropane trimethacrylate, the degradable polymer material forms a tight three-dimensional spatial network structure, which greatly improves the performance of the degradable polymer material, and makes the transverse tensile strength of the degradable polymer film greater than 21MPa, the longitudinal tensile strength greater than 20.MPa, the transverse right-angle tear strength greater than 7MPa, the longitudinal right-angle tear strength greater than 7MPa, and the transmittance greater than 91%. Without affecting the transmittance, the tensile strength and right-angle tear strength of the degradable polymer film are significantly enhanced, so that the degradable polymer film has the advantages of high tensile strength, high right-angle tear strength and good transmittance, meets market demand, and has commercial application prospects and economic value. DETAILED DESCRIPTION

[0034] To make this application easier to understand, the following examples will be used to further illustrate this application. These examples are for illustrative purposes only and are not intended to limit the scope of application of this application. Unless otherwise specified, the raw materials or components used in this application can be obtained through commercial channels or conventional methods.

[0035] Preparation Example

[0036] Preparation Example 1

[0037] A modified starch is prepared by the following method:

[0038] Heat 140g of water to 50°C, then add 100g of starch and stir for 40 minutes. Adjust the pH to 13.5 with 15% sodium hydroxide solution. Then add 5g of 1-chlorohex-5-en-2-ol and 2g of 1,2-epoxychlorobutane and stir for 8 hours. Adjust the pH to 6.5 with 15% hydrochloric acid solution. Cool to 25°C and filter. Dry at 70°C to obtain modified starch.

[0039] Among them, starch is corn starch, and is selected from Shandong Gushuo Biotechnology Co., Ltd.

[0040] Preparation Example 2

[0041] A modified starch, which differs from Preparation Example 1 in that, in the preparation method, the added amounts of water, 1-chlorohex-5-en-2-ol, and 1,2-epoxychlorobutane are different, and the added amount of water is 150 g, the added amount of 1-chlorohex-5-en-2-ol is 4 g, and the added amount of 1,2-epoxychlorobutane is 3 g.

[0042] Preparation Example 3

[0043] A modified starch, which differs from Preparation Example 1 in that, in the preparation method, the added amounts of water, 1-chlorohex-5-en-2-ol, and 1,2-epoxychlorobutane are different, and the added amount of water is 120 g, the added amount of 1-chlorohex-5-en-2-ol is 6 g, and the added amount of 1,2-epoxychlorobutane is 1 g.

[0044] Example

[0045] Table 1 Raw materials and raw material ratios of biodegradable polymer materials (unit: kg)

[0046] Example Example 1 Example 2 Example 3 Polybutylene adipate terephthalate 40 35 45 Modified starch 25 30 20 Dimethicone 15 10 20 Trimethylolpropane trimethacrylate 10 15 5 Plasticizer 5 2 8 Antibacterial agent 5 8 2 Total 100 100 100

[0047] Example 1

[0048] A degradable polymer film is prepared by film blowing using a degradable polymer material. The raw materials and the raw material ratios of the degradable polymer material are shown in Table 1.

[0049] Among them, the melt index of polybutylene terephthalate-adipate at 190°C and 2.16 kg is 3.4 g / min; the polydimethylsiloxane is vinyl-terminated polydimethylsiloxane, the vinyl content of the vinyl-terminated polydimethylsiloxane is 0.05%, and the molecular weight is 600,000 Daltons; the plasticizer is acetyl tributyl citrate; the antibacterial agent is carboxymethyl chitosan; and the modified starch is prepared by the method of Preparation Example 1.

[0050] A method for preparing a degradable polymer film comprises the following steps:

[0051] S1. Add modified starch, polydimethylsiloxane, trimethylolpropane trimethacrylate, a plasticizer, and an antibacterial agent to polybutylene terephthalate-adipate, stir for 10 minutes, then place in a twin-screw extruder, melt-extrude, cool and granulate to obtain a biodegradable polymer material.

[0052] The screw speed of the twin-screw extruder is 200 r / min and the melting temperature is 180°C.

[0053] S2. Put the degradable polymer material into a film blowing machine and blow the film to obtain a degradable polymer film.

[0054] Among them, the screw speed of the film blowing machine is 50r / min, the film blowing temperature is 170℃, and the pulling speed is 7m / min.

[0055] Example 2

[0056] A degradable polymer film is different from Example 1 in that the raw material ratio of the degradable polymer material is different. The raw material ratio of the degradable polymer material is shown in Table 1.

[0057] Example 3

[0058] A degradable polymer film is different from Example 1 in that the raw material ratio of the degradable polymer material is different. The raw material ratio of the degradable polymer material is shown in Table 1.

[0059] Example 4

[0060] A degradable polymer film is provided, which differs from Example 1 in that the source of the modified starch in the raw materials of the degradable polymer material is different, and the modified starch is prepared by the method of Preparation Example 2.

[0061] Example 5

[0062] A degradable polymer film is provided, which differs from Example 1 in that the source of the modified starch in the raw materials of the degradable polymer material is different, and the modified starch is prepared by the method of Preparation Example 3.

[0063] Comparative Example

[0064] Comparative Example 1

[0065] A degradable polymer film is different from Example 1 in that an equal amount of starch is used to replace modified starch in the raw material of the degradable polymer material.

[0066] Comparative Example 2

[0067] A degradable polymer film is different from Example 1 in that, in the raw materials of the degradable polymer material, in the preparation method of the modified starch, an equal amount of 1-chlorohex-5-en-2-ol is used to replace 1,2-epoxychlorobutane.

[0068] Comparative Example 3

[0069] A degradable polymer film is different from Example 1 in that, in the raw materials of the degradable polymer material, in the preparation method of the modified starch, an equal amount of 1,2-epoxychlorobutane is used to replace 1-chlorohex-5-en-2-ol.

[0070] Comparative Example 4

[0071] A degradable polymer film is provided, which differs from Example 1 in that polydimethylsiloxane and trimethylolpropane trimethacrylate are replaced by an equal amount of modified starch in the raw materials of the degradable polymer material.

[0072] Comparative Example 5

[0073] A degradable polymer film is different from Example 1 in that trimethylolpropane trimethacrylate is replaced by an equal amount of polydimethylsiloxane in the raw material of the degradable polymer material.

[0074] Comparative Example 6

[0075] A degradable polymer film is different from Example 1 in that an equal amount of trimethylolpropane trimethacrylate is used to replace polydimethylsiloxane in the raw material of the degradable polymer material.

[0076] Performance testing

[0077] The degradable polymer films obtained in Examples 1-5 and Comparative Examples 1-6 were taken as samples, respectively. The thickness of the degradable polymer films was 30 μm. The following performance tests were performed on the samples. The test results are shown in Table 2.

[0078] Among them, the tensile strength of the sample is tested in accordance with GB / T1040-2018 "Determination of Tensile Properties of Plastics".

[0079] According to GB / T16578-2008 “Plastic film and sheeting - Determination of tear resistance”, the right-angle tear strength of the test is tested.

[0080] According to GB / T16578-2008 “Determination of light transmittance and haze of transparent plastics”, the light transmittance of the sample is tested.

[0081] Table 2 Test results

[0082]

[0083] As can be seen from Table 2, the degradable polymer film obtained in the present application has a high tensile strength, with a transverse tensile strength of 21.2-23.3 MPa and a longitudinal tensile strength of 20.7-22.8 MPa. It also has a high right-angle tear strength, with a transverse right-angle tear strength of 7.34-7.88 MPa and a longitudinal right-angle tear strength of 7.15-7.69 MPa. At the same time, it also has good light transmittance, with a light transmittance of 91.4-93.1%, which makes the degradable polymer film have the advantages of high tensile strength, high right-angle tear strength and good light transmittance, which meets market demand.

[0084] Comparative Examples 1-3 are compared. In Comparative Example 1, starch is added to the raw materials of the degradable polymer material; in Comparative Example 2, compared to Comparative Example 1, modified starch treated with 1-chlorohex-5-en-2-ol is added to the raw materials of the degradable polymer material; in Comparative Example 3, compared to Comparative Example 1, modified starch treated with 1,2-epoxychlorobutane is added to the raw materials of the degradable polymer material. This shows that modifying starch can increase the effectiveness of starch. In conjunction with Example 1, in Example 1, compared to Comparative Example 1, modified starch treated with 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane is added to the raw materials of the degradable polymer material. This shows that the synergistic effect between 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane can introduce a large number of active groups on the starch surface and increase the crosslinking degree of the modified starch, greatly improving the tensile strength and right-angle tear strength of the degradable polymer film.

[0085] Compare Example 1 with Comparative Examples 4-6. In Comparative Example 4, polydimethylsiloxane and trimethylolpropane trimethacrylate were not added to the raw materials of the degradable polymer material; in Comparative Example 5, polydimethylsiloxane was added to the raw materials of the degradable polymer material compared to Comparative Example 4; in Comparative Example 6, trimethylolpropane trimethacrylate was added to the raw materials of the degradable polymer material compared to Comparative Example 4; in Example 1, polydimethylsiloxane and trimethylolpropane trimethacrylate were added to the raw materials of the degradable polymer material compared to Comparative Example 4. It can be seen from this that by adding polydimethylsiloxane and trimethylolpropane trimethacrylate to the raw materials of the degradable polymer material at the same time and utilizing the synergistic effect between them, the intermolecular force and bonding strength between the raw materials are significantly increased, the density of the degradable polymer material is increased, and the degradable polymer film exhibits better performance.

[0086] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same function.

Claims

1. A degradable polymer material, characterized by: It is mainly made of the following raw materials in parts by weight: 35-45 parts of polybutylene terephthalate-adipate, 20-30 parts of modified starch, 10-20 parts of polydimethylsiloxane, 5-15 parts of trimethylolpropane trimethacrylate, 2-8 parts of plasticizer, and 2-8 parts of antibacterial agent; The polydimethylsiloxane is vinyl-terminated polydimethylsiloxane; the modified starch is obtained by treating starch with 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane; The polybutylene terephthalate-adipate has a melt index of 2-5 g / min at 190° C. and 2.16 kg; the vinyl terminated polydimethylsiloxane has a vinyl content of 0.01-0.15% and a molecular weight of 500,000-800,000 Daltons; The modified starch is prepared by the following method: heating water to 40-60° C., then adding starch and mixing, adjusting the pH value to 13-14 with alkali, then adding 1-chlorohex-5-en-2-ol and 1,2-epoxychlorobutane, stirring for 7-9 hours, adjusting the pH value to 6-7 with acid, cooling to room temperature, filtering, and drying to obtain the modified starch; The weight ratio of the starch, water, 1-chlorohex-5-ene-2-ol and 1,2-epoxychlorobutane is 100:(120-150):(4-6):(1-3).

2. The degradable polymer material according to claim 1, characterized in that: The starch is one or more of corn starch, sweet potato starch and wheat starch.

3. The degradable polymer material according to claim 1, characterized in that: The plasticizer is one or more of acetyl tributyl citrate, triethanolamine, and sorbitol.

4. The degradable polymer material according to claim 1, characterized in that: The antibacterial agent is one or more of chitosan, carboxymethyl chitosan and chitosan quaternary ammonium salt.

5. A method for preparing a degradable polymer material according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: mixing polybutylene terephthalate-adipate, modified starch, polydimethylsiloxane, trimethylolpropane trimethacrylate, a plasticizer and an antibacterial agent, melting and extruding, cooling and granulating to obtain a degradable polymer material.

6. A degradable polymer film, characterized in that: The biodegradable polymer is prepared from the biodegradable polymer material according to any one of claims 1 to 4.

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