A biodegradable polylactic acid composite material with antibacterial properties and its application in the preparation of packaging materials.

Abstract

This invention relates to the field of biodegradable material preparation technology, specifically disclosing a biodegradable polylactic acid (PLA) composite material with antibacterial properties and its application in the preparation of packaging materials. The biodegradable PLA composite material with antibacterial properties comprises the following raw material components in parts by weight: 50-80 parts of polylactic acid resin; 40-60 parts of poly(butylene adipate / terephthalate); 20-30 parts of filler; and 1-3 parts of dispersant; wherein the filler comprises nano-silver oxide and mica powder. This invention, by adding a filler composed of nano-silver oxide and mica powder to the biodegradable PLA composite material, enables the composite material to possess good antibacterial properties; simultaneously, it also enhances the impact resistance of the biodegradable PLA composite material.

Description

Technical Field

[0001] This invention relates to the field of biodegradable material preparation technology, and specifically discloses a biodegradable polylactic acid composite material with antibacterial properties and its application in the preparation of packaging materials. Background Technology

[0002] Polylactic acid (PLA) is a novel biodegradable material, a polyester polymer obtained by polymerizing lactic acid as the main raw material. In addition to its biodegradability, PLA products also possess advantages such as biocompatibility, transparency, and heat resistance; therefore, they are widely used in plastic products, packaged food, fast food containers, non-woven fabrics, and industrial and civilian textiles.

[0003] However, because polylactic acid (PLA) does not possess antibacterial properties, it is difficult to use it in the preparation of packaging materials that require antibacterial effects. Therefore, providing a biodegradable PLA composite material with antibacterial properties has significant application value. Summary of the Invention

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present invention provides a biodegradable polylactic acid composite material with antibacterial properties.

[0005] The technical solution described in this invention is as follows:

[0006] This invention first provides a biodegradable polylactic acid composite material with antibacterial properties, which comprises the following raw material components in parts by weight:

[0007] 50-80 parts of polylactic acid resin; 40-60 parts of polybutylene adipate / terephthalate; 20-30 parts of filler; 1-3 parts of dispersant;

[0008] The filler comprises nano-silver oxide and mica powder.

[0009] This invention, by adding fillers composed of nano-silver oxide and mica powder to a biodegradable polylactic acid composite material, enables the biodegradable polylactic acid composite material to have good antibacterial properties; at the same time, it also enables the biodegradable polylactic acid composite material to have good impact resistance.

[0010] Preferably, the biodegradable polylactic acid composite material with antibacterial properties comprises the following raw material components in parts by weight:

[0011] 60-70 parts of polylactic acid resin; 50-60 parts of poly(butylene adipate / terephthalate); 20-25 parts of filler; 1-2 parts of dispersant.

[0012] Most preferably, the biodegradable polylactic acid composite material with antibacterial properties comprises the following raw material components in parts by weight:

[0013] 65 parts polylactic acid resin; 50 parts polybutylene adipate / terephthalate; 25 parts filler; 2 parts dispersant.

[0014] Preferably, in the filler, the weight ratio of nano-silver oxide to mica powder is 1:6 to 12.

[0015] Most preferably, in the filler, the weight ratio of nano-silver oxide to mica powder is 1:9.

[0016] Preferably, the filler is a modified filler;

[0017] The modified filler was prepared by the following method:

[0018] (1) Take mica powder and add it to water and stir for 10-20 minutes to obtain dispersion A;

[0019] (2) Add cocamidopropylamine oxide to dispersion A, stir for 20-40 min, then add dodecyl dimethyl betaine and continue stirring for 10-20 min to obtain dispersion B;

[0020] (3) Add nano silver oxide to dispersion B, stir for 2-4 hours, separate the solid, and dry the solid to obtain the modified filler.

[0021] The inventors made a surprising discovery during their research: adding modified fillers obtained by modifying nano-silver oxide and mica powder using the methods described above in this invention to biodegradable polylactic acid composite materials can significantly improve the impact strength of biodegradable polylactic acid composite materials compared to adding unmodified fillers composed of nano-silver oxide and mica powder.

[0022] Preferably, the weight ratio of mica powder to water is 1:10 to 15.

[0023] The most preferred ratio is 1:12 in weight of mica powder to water.

[0024] Preferably, the weight ratio of dispersion A to cocamidopropylamine oxide and dodecyl dimethyl betaine is 100:3-6:4-8.

[0025] Most preferably, the weight ratio of dispersion A to cocamidopropylamine oxide and dodecyl dimethyl betaine is 100:4:6.

[0026] Preferably, the weight ratio of nano-silver oxide to mica powder is 1:6 to 12.

[0027] Most preferably, in the filler, the weight ratio of nano-silver oxide to mica powder is 1:9.

[0028] Preferably, the dispersant is magnesium stearate.

[0029] The present invention also provides an application of the above-mentioned biodegradable polylactic acid composite material with antibacterial properties in the preparation of packaging materials.

[0030] Beneficial effects: This invention provides a novel biodegradable polylactic acid composite material with antibacterial properties; by adding a filler composed of nano-silver oxide and mica powder to the biodegradable polylactic acid composite material, this invention can give the biodegradable polylactic acid composite material good antibacterial properties; at the same time, it can also give the biodegradable polylactic acid composite material good impact resistance. Detailed Implementation

[0031] The present invention will be further explained below with reference to specific embodiments, but the embodiments do not limit the present invention in any way.

[0032] The polylactic acid resin used in the following examples is polylactic acid resin with the grade 2002D from NatureWorks, USA; the polybutylene adipate / terephthalate is PBAT resin with the grade TH801T from Xinjiang Lanshan Tunhe Company; the remaining raw materials are all conventional raw materials that can be purchased by those skilled in the art through conventional purchasing channels.

[0033] Example 1: Preparation of a biodegradable polylactic acid composite material with antibacterial properties

[0034] Raw material composition by weight: 65 parts polylactic acid resin; 50 parts polybutylene adipate / terephthalate; 25 parts filler; 2 parts magnesium stearate dispersant;

[0035] The filler is composed of nano silver oxide and mica powder in a weight ratio of 1:9.

[0036] Preparation method: Polylactic acid resin, polybutylene adipate / terephthalate, filler, and dispersion are mixed.

[0037] Agent

[0038] After being mixed evenly, the mixture is then extruded and granulated using a twin-screw extruder to obtain the aforementioned biodegradable polylactic acid composite material with antibacterial properties.

[0039] Example 2: Preparation of a biodegradable polylactic acid composite material with antibacterial properties

[0040] Raw material composition by weight: 65 parts polylactic acid resin; 50 parts polybutylene adipate / terephthalate; 25 parts modified filler; 2 parts magnesium stearate dispersant;

[0041] The modified filler was prepared by the following method:

[0042] (1) Take mica powder and add it to water and stir for 15 minutes to obtain dispersion A; wherein the weight ratio of mica powder to water is 1:12;

[0043] (2) Add cocamidopropylamine oxide to dispersion A, stir for 30 min, then add dodecyl dimethyl betaine, and continue stirring for 15 min to obtain dispersion B; wherein, the weight ratio of dispersion A to cocamidopropylamine oxide and dodecyl dimethyl betaine is 100:4:6.

[0044] (3) Add nano silver oxide to dispersion B, stir for 3 hours, separate the solid, and dry the solid to obtain the modified filler.

[0045] The weight ratio of nano-silver oxide to mica powder is 1:9.

[0046] Preparation method: Polylactic acid resin, polybutylene adipate / terephthalate, modified filler, and...

[0047] point

[0048] The powder is mixed evenly, and then extruded and granulated by a twin-screw extruder to obtain the biodegradable polylactic acid composite material with antibacterial properties.

[0049] Example 3: Preparation of a biodegradable polylactic acid composite material with antibacterial properties

[0050] Raw material composition by weight: 50 parts polylactic acid resin; 60 parts polybutylene adipate / terephthalate; 20 parts modified filler; 1 part magnesium stearate dispersant;

[0051] The modified filler was prepared by the following method:

[0052] (1) Take mica powder and add it to water and stir for 10 minutes to obtain dispersion A; wherein the weight ratio of mica powder to water is 1:10;

[0053] (2) Add cocamidopropylamine oxide to dispersion A, stir for 40 min, then add dodecyl dimethyl betaine, and continue stirring for 10 min to obtain dispersion B; wherein, the weight ratio of dispersion A to cocamidopropylamine oxide and dodecyl dimethyl betaine is 100:3:7.

[0054] (3) Add nano silver oxide to dispersion B, stir for 2 hours, separate the solid, and dry the solid to obtain the modified filler.

[0055] The weight ratio of nano-silver oxide to mica powder is 1:6.

[0056] Preparation method: Polylactic acid resin, polybutylene adipate / terephthalate, modified filler, and...

[0057] point

[0058] The powder is mixed evenly, and then extruded and granulated by a twin-screw extruder to obtain the biodegradable polylactic acid composite material with antibacterial properties.

[0059] Example 4: Preparation of a biodegradable polylactic acid composite material with antibacterial properties

[0060] Raw material composition by weight: 80 parts polylactic acid resin; 40 parts polybutylene adipate / terephthalate; 30 parts modified filler; 3 parts magnesium stearate dispersant;

[0061] The modified filler was prepared by the following method:

[0062] (1) Take mica powder and add it to water and stir for 20 minutes to obtain dispersion A; wherein the weight ratio of mica powder to water is 1:15;

[0063] (2) Add cocamidopropylamine oxide to dispersion A, stir for 20 min, then add dodecyl dimethyl betaine and continue stirring for 20 min to obtain dispersion B; wherein, the weight ratio of dispersion A to cocamidopropylamine oxide and dodecyl dimethyl betaine is 100:6:4.

[0064] (3) Add nano silver oxide to dispersion B, stir for 4 hours, separate the solid, and dry the solid to obtain the modified filler.

[0065] The weight ratio of nano-silver oxide to mica powder is 1:12.

[0066] Preparation method: Polylactic acid resin, polybutylene adipate / terephthalate, modified filler, and...

[0067] point

[0068] The powder is mixed evenly, and then extruded and granulated by a twin-screw extruder to obtain the biodegradable polylactic acid composite material with antibacterial properties.

[0069] Comparative Example 1: Preparation of a biodegradable polylactic acid composite material with antibacterial properties

[0070] Raw material composition by weight: 65 parts polylactic acid resin; 50 parts polybutylene adipate / terephthalate; 25 parts modified filler; 2 parts magnesium stearate dispersant;

[0071] The modified filler was prepared by the following method:

[0072] (1) Take mica powder and add it to water and stir for 15 minutes to obtain dispersion A; wherein the weight ratio of mica powder to water is 1:12;

[0073] (2) Add cocamidopropylamine oxide to dispersion A and stir for 45 min to obtain dispersion B; wherein the weight ratio of dispersion A to cocamidopropylamine oxide is 100:10.

[0074] (3) Add nano silver oxide to dispersion B, stir for 3 hours, separate the solid, and dry the solid to obtain the modified filler.

[0075] The weight ratio of nano-silver oxide to mica powder is 1:9.

[0076] Preparation method: Polylactic acid resin, polybutylene adipate / terephthalate, modified filler, and...

[0077] point

[0078] The powder is mixed evenly, and then extruded and granulated by a twin-screw extruder to obtain the biodegradable polylactic acid composite material with antibacterial properties.

[0079] Comparative Example 2: Preparation of a biodegradable polylactic acid composite material with antibacterial properties

[0080] Raw material composition by weight: 65 parts polylactic acid resin; 50 parts polybutylene adipate / terephthalate; 25 parts modified filler; 2 parts magnesium stearate dispersant;

[0081] The modified filler was prepared by the following method:

[0082] (1) Take mica powder and add it to water and stir for 15 minutes to obtain dispersion A; wherein the weight ratio of mica powder to water is 1:12;

[0083] (2) Add dodecyl dimethyl betaine to dispersion A and stir for 45 min to obtain dispersion B; wherein the weight ratio of dispersion A to dodecyl dimethyl betaine is 100:10.

[0084] (3) Add nano silver oxide to dispersion B, stir for 3 hours, separate the solid, and dry the solid to obtain the modified filler.

[0085] The weight ratio of nano-silver oxide to mica powder is 1:9.

[0086] Preparation method: Polylactic acid resin, polybutylene adipate / terephthalate, modified filler, and...

[0087] point

[0088] The powder is mixed evenly, and then extruded and granulated by a twin-screw extruder to obtain the biodegradable polylactic acid composite material with antibacterial properties.

[0089] The cantilever beam notched impact strength test results of the antibacterial biodegradable polylactic acid composite materials prepared according to claims 1 to 4 and comparative examples 1 and 2 are shown in Table 1.

[0090] Table 1. Impact strength test results of biodegradable polylactic acid composite materials with antibacterial properties

[0091] Notched impact strength Example 1: Biodegradable polylactic acid composite material with antibacterial properties <![CDATA[1.5KJ / m 2 ]]> Example 2: Biodegradable polylactic acid composite material with antibacterial properties <![CDATA[3.1KJ / m 2 ]]> Example 3: Biodegradable polylactic acid composite material with antibacterial properties <![CDATA[2.6KJ / m 2 ]]> Example 4: Degradable polylactic acid composite material with antibacterial properties <![CDATA[2.9KJ / m 2 ]]> Comparative Example 1: Biodegradable polylactic acid composite material with antibacterial properties <![CDATA[1.8KJ / m 2 ]]> Comparative Example 2: Biodegradable polylactic acid composite material with antibacterial properties <![CDATA[1.9KJ / m 2 ]]>

[0092] As can be seen from the experimental data in Table 1, the biodegradable polylactic acid composite material with antibacterial properties prepared in Example 1 has a cantilever beam notched impact strength of 1.5 KJ / m. 2 This indicates that adding fillers composed of nano-silver oxide and mica powder to biodegradable polylactic acid composites can give them better impact resistance.

[0093] As can be seen from the experimental data in Table 1, the cantilever beam notched impact strength of the biodegradable polylactic acid composite materials with antibacterial properties prepared in Examples 2-4 is significantly improved compared with that of the biodegradable polylactic acid composite material with antibacterial properties prepared in Example 1. This indicates that adding modified fillers obtained by modifying nano-silver oxide and mica powder using the method described in this invention to biodegradable polylactic acid composite materials can significantly improve the impact strength of biodegradable polylactic acid composite materials compared with adding unmodified fillers composed of nano-silver oxide and mica powder.

[0094] As can be seen from the experimental data in Table 1, the cantilever beam notched impact strength of the antibacterial biodegradable polylactic acid composite materials prepared in Comparative Examples 1 and 2 was not significantly improved compared with that of the antibacterial biodegradable polylactic acid composite material prepared in Example 1. The improvement was much smaller than that of the antibacterial biodegradable polylactic acid composite material prepared in Example 2. This indicates that step (2) is crucial in the modification method using nano-silver oxide and mica powder as fillers. Only by using cocamidopropylamine oxide and dodecyl dimethyl betaine to modify nano-silver oxide and mica powder can the impact strength of biodegradable polylactic acid composite materials be significantly improved. However, the modified fillers obtained by using only cocamidopropylamine oxide or only dodecyl dimethyl betaine to modify nano-silver oxide and mica powder cannot significantly improve the impact strength of biodegradable polylactic acid composite materials.

[0095] The antibacterial performance test results of the biodegradable polylactic acid composite materials with antibacterial activity prepared according to claims 1 to 4 are shown in Table 2.

[0096] Table 2. Impact strength test results of biodegradable polylactic acid composite materials with antibacterial properties

[0097]

[0098] As can be seen from the experimental data in Table 2, the biodegradable polylactic acid composite material of the present invention with antibacterial effect has an antibacterial rate of 99.9% against both Escherichia coli and Staphylococcus aureus. This indicates that by adding fillers composed of nano-silver oxide and mica powder to the biodegradable polylactic acid composite material, the present invention can enable the biodegradable polylactic acid composite material to have a good antibacterial effect.

Claims

1. A biodegradable polylactic acid composite material with antibacterial properties, characterized in that, The raw material components include the following by weight: 65 parts of polylactic acid resin; 50 parts of polybutylene adipate terephthalate; 25 parts of filler; and 2 parts of dispersant. The filler is a modified filler. The modified filler is prepared by the following method: (1) Mica powder is added to water and stirred for 10-20 min to obtain dispersion A; wherein the weight ratio of mica powder to water is 1:10-15; (2) Cocoamide propylamine oxide is added to dispersion A, stirred for 20-40 min, then dodecyl dimethyl betaine is added, and stirred for 10-20 min; to obtain dispersion B; wherein the weight ratio of dispersion A, cocoamide propylamine oxide and dodecyl dimethyl betaine is 100:3-6:4-8; (3) Nano silver oxide is added to dispersion B, stirred for 2-4 h, then the solid is separated, dried, and the modified filler is obtained; wherein the weight ratio of nano silver oxide to mica powder is 1:6-12.

2. The degradable polylactic acid composite material having an antibacterial effect according to claim 1, characterized by, The weight ratio of mica powder to water is 1:

12.

3. The degradable polylactic acid composite material having an antibacterial effect according to claim 1, characterized by, The weight ratio of dispersion A, cocoamide propylamine oxide and dodecyl dimethyl betaine is 100:4:

6.

4. The degradable polylactic acid composite material having an antibacterial effect according to claim 1, characterized by, The weight ratio of nano silver oxide to mica powder is 1:

9.

5. Use of the degradable polylactic acid composite material with antibacterial effect according to any one of claims 1-4 in the preparation of packaging materials.

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