Degradable bamboo fiber composite material master batch and preparation method thereof

Abstract

The invention relates to the technical field of degradable fibers, and discloses a degradable bamboo fiber composite material master batch and a preparation method thereof. The composite material is prepared from the following raw materials: modified bamboo fibers, modified polylactic acid, polyadipic acid / butylene terephthalate, a lubricant, an antioxidant and a plasticizer. The preparation method comprises the following steps: 1) performing alkali treatment and tannic acid-metal ion compound modification on the bamboo fibers to form a hydrophobic surface; 2) blending and modifying polylactic acid and bio-based elastomer polyhydroxybutyrate to construct a tough matrix; and 3) carrying out melt blending on the modified bamboo fiber, poly (adipic acid) / butylene terephthalate, the modified polylactic acid and an auxiliary agent, and then carrying out extrusion granulation. The degradable bamboo fiber composite material master batch prepared by the invention has good processability and mechanical properties, and can be widely applied to the fields of disposable tableware, packaging materials, agricultural plastic mulching films and the like.

Description

Technical Field

[0001] The invention relates to the technical field of degradable fibers, in particular to a degradable bamboo fiber composite material masterbatch and a preparation method thereof. Background Art

[0002] With the increasing global attention to the issue of "white pollution", the research and development of degradable materials has become an important direction for solving plastic pollution. As a natural renewable resource, bamboo fiber has the advantages of wide sources, biodegradability, and low cost, and is regarded as an ideal reinforcing material to replace petroleum-based plastics. However, existing bamboo fiber composites are difficult to balance in terms of interface compatibility, strength-toughness balance, full bio-based degradability, and processing economy, which limits their large-scale application in the fields of disposable packaging, agricultural mulch, etc. Therefore, it is urgent to develop a green and efficient bamboo fiber composite masterbatch with both high mechanical properties and rapid degradation characteristics and a preparation method thereof. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the deficiencies in the prior art, the present invention provides a degradable bamboo fiber composite material masterbatch and a preparation method thereof.

[0005] (II) Technical solution

[0006] To achieve the above object, the present invention provides the following technical solution: a degradable bamboo fiber composite material masterbatch, composed of the following raw materials in parts by weight:

[0007] 30-50 parts of modified bamboo fiber, 40-60 parts of modified polylactic acid, 10-20 parts of polybutylene adipate / terephthalate, 1-2 parts of lubricant, 0.5-1 part of antioxidant, and 0.5-1 part of plasticizer.

[0008] Preferably, the bamboo fiber has a length of 0.5 to 2 mm and a diameter of 10 to 20 μm.

[0009] Preferably, the lubricant is calcium stearate or polyethylene wax.

[0010] Preferably, the antioxidant is 1010 or 168.

[0011] Preferably, the plasticizer is citrate or polyethylene glycol.

[0012] Preferably, the method comprises the following steps:

[0013] S1. Soak the bamboo fiber in a 5% sodium hydroxide solution at 60-80°C for 1-2 hours, then wash with deionized water until neutral, and dry;

[0014] S2, soaking the treated bamboo fiber in a tannic acid solution with a mass fraction of 3-5%, treating it at 50-70°C for 1-2 hours, then washing it with deionized water, drying it, and then soaking the treated bamboo fiber in a metal salt solution with a mass fraction of 1-3%, treating it at 40-60°C for 0.5-1 hour, then washing it with deionized water, and drying it;

[0015] S3, soaking the bamboo fiber treated in step S2 in an ethanol solution of silane coupling agent KH550 with a mass fraction of 2-5%, treating at 60° C. for 1-2 hours, then washing with ethanol, and drying to obtain modified bamboo fiber;

[0016] S4, premixing polylactic acid, epoxy soybean oil, and dicumyl peroxide, adding bio-based elastomer polyhydroxybutyrate, and melt-blending in a twin-screw extruder at a temperature of 170-190° C. and a rotation speed of 200-300 rpm to obtain modified polylactic acid;

[0017] S5. The modified polylactic acid, polybutylene adipate / terephthalate, lubricant, antioxidant and plasticizer are mixed evenly in proportion, and then the modified bamboo fiber is added, and the mixing is continued evenly, and the mixture is added into a twin-screw extruder for melt blending, and extruded into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0018] Preferably, the metal salt in step S2 is aluminum sulfate, iron sulfate or zinc sulfate.

[0019] Preferably, in step S4, the mass ratio of polylactic acid, epoxy soybean oil, dicumyl peroxide, and bio-based elastomer polyhydroxybutyrate is 1: 0.1-0.3: 0.03-0.08: 0.1-0.4.

[0020] (III) Beneficial technical effects

[0021] The invention adopts polylactic acid and polyadipate / butylene terephthalate blended as the matrix material, which not only ensures the degradability of the composite material but also improves its processing performance and toughness.

[0022] The present invention removes part of the lignin and hemicellulose on the surface of the bamboo fiber by alkali treatment, exposing more hydroxyl groups; introduces phenolic hydroxyl groups on the surface of the bamboo fiber by tannic acid treatment to improve its reactivity; finally, forms a stable complex on the surface of the bamboo fiber by metal ion complexation, reduces the hydrophilicity of the bamboo fiber, improves the interface compatibility between the bamboo fiber and the non-polar polymer matrix, and improves the mechanical properties of the composite material. The bio-based elastomer polyhydroxybutyrate and polylactic acid in the modified polylactic acid form a cross-linked network, which effectively improves its mechanical properties.

[0023] The degradable bamboo fiber composite material masterbatch prepared by the invention has good processing performance and mechanical properties, and can be widely used in the fields of disposable tableware, packaging materials, agricultural mulch films, etc. DETAILED DESCRIPTION

[0024] Example 1

[0025] S1. Soak 50 parts by weight of bamboo fiber in a 5% by mass sodium hydroxide solution at 60° C. for 1 hour, then wash with deionized water until neutral, and dry.

[0026] S2. Soak the treated bamboo fiber in a 3% tannic acid solution at 50°C for 1 hour, then wash with deionized water and dry. Then soak the treated bamboo fiber in a 1% aluminum sulfate solution at 40°C for 0.5 hour, then wash with deionized water and dry.

[0027] S3, soaking the bamboo fiber treated in step S2 in a silane coupling agent KH550 ethanol solution with a mass fraction of 2%, treating at 60° C. for 1 hour, then washing with ethanol, and drying to obtain modified bamboo fiber.

[0028] S4. Premix 80 parts by weight of polylactic acid, 8 parts by weight of epoxidized soybean oil, and 2.4 parts by weight of dicumyl peroxide, add 8 parts by weight of bio-based elastomer polyhydroxybutyrate, melt-blend in a twin-screw extruder at a temperature of 170° C. and a rotation speed of 200 rpm to obtain modified polylactic acid.

[0029] S5. Evenly mix 40 parts by weight of modified polylactic acid, 10 parts by weight of polybutylene adipate / terephthalate, 1 part by weight of lubricant calcium stearate, 0.5 parts by weight of antioxidant 1010 and 0.5 parts by weight of plasticizer citrate, then add 30 parts by weight of modified bamboo fiber, continue to mix evenly, add into a twin-screw extruder for melt blending, and extrude into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0030] Example 2

[0031] S1. Soak 80 parts by weight of bamboo fibers in a 5% by mass sodium hydroxide solution at 80° C. for 2 hours, then wash with deionized water until neutral, and dry.

[0032] S2. Soak the treated bamboo fiber in a 5% by mass tannic acid solution, treat it at 70°C for 2 hours, then wash it with deionized water and dry it. Then soak the treated bamboo fiber in a 3% by mass iron sulfate metal salt solution, treat it at 60°C for 1 hour, then wash it with deionized water and dry it.

[0033] S3, soaking the bamboo fiber treated in step S2 in a 5% by mass silane coupling agent KH550 ethanol solution at 60° C. for 2 h, then washing with ethanol and drying to obtain modified bamboo fiber.

[0034] S4. Premix 80 parts by weight of polylactic acid, 24 parts by weight of epoxy soybean oil, and 6.4 parts by weight of dicumyl peroxide, add 32 parts by weight of bio-based elastomer polyhydroxybutyrate, melt-blend in a twin-screw extruder at a temperature of 190° C. and a rotation speed of 300 rpm to obtain modified polylactic acid.

[0035] S5. Mix 60 parts by weight of modified polylactic acid, 20 parts by weight of polybutylene adipate / terephthalate, 2 parts by weight of lubricant polyethylene wax, 1 part by weight of antioxidant 168 and 1 part by weight of plasticizer polyethylene glycol evenly, then add 50 parts by weight of modified bamboo fiber, continue to mix evenly, add to a twin-screw extruder for melt blending, and extrude and granulate to obtain a degradable bamboo fiber composite material masterbatch.

[0036] Example 3

[0037] S1. Soak 60 parts by weight of bamboo fibers in a 5% by mass sodium hydroxide solution at 70° C. for 1.5 hours, then wash with deionized water until neutral, and dry.

[0038] S2. Soak the treated bamboo fiber in a 4% tannic acid solution at 60°C for 1.5 hours, then wash with deionized water and dry. Then soak the treated bamboo fiber in a 2% zinc sulfate metal salt solution at 50°C for 1 hour, then wash with deionized water and dry.

[0039] S3, soaking the bamboo fiber treated in step S2 in a 3% by mass silane coupling agent KH550 ethanol solution at 60° C. for 1.2 h, then washing with ethanol and drying to obtain modified bamboo fiber.

[0040] S4. Premix 80 parts by weight of polylactic acid, 10 parts by weight of epoxidized soybean oil, and 3 parts by weight of dicumyl peroxide, add 15 parts by weight of bio-based elastomer polyhydroxybutyrate, melt-blend in a twin-screw extruder at a temperature of 180° C. and a rotation speed of 220 rpm to obtain modified polylactic acid.

[0041] S5. Evenly mix 50 parts by weight of modified polylactic acid, 15 parts by weight of polybutylene adipate / terephthalate, 1.2 parts by weight of lubricant calcium stearate, 0.7 parts by weight of antioxidant 1010 and 0.8 parts by weight of plasticizer citrate, then add 40 parts by weight of modified bamboo fiber, continue to mix evenly, add into a twin-screw extruder for melt blending, and extrude into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0042] Example 4

[0043] S1. Soak 70 parts by weight of bamboo fibers in a 5% by mass sodium hydroxide solution at 65° C. for 2 hours, then wash with deionized water until neutral, and dry.

[0044] S2. Soak the treated bamboo fiber in a 5% by mass tannic acid solution, treat it at 55°C for 1 hour, then wash it with deionized water and dry it. Then soak the treated bamboo fiber in a 3% by mass aluminum sulfate metal salt solution, treat it at 55°C for 0.8 hour, then wash it with deionized water and dry it.

[0045] S3, soaking the bamboo fiber treated in step S2 in a silane coupling agent KH550 ethanol solution with a mass fraction of 4%, treating at 60° C. for 2 hours, then washing with ethanol, and drying to obtain modified bamboo fiber.

[0046] S4. Premix 80 parts by weight of polylactic acid, 20 parts by weight of epoxidized soybean oil, and 4 parts by weight of dicumyl peroxide, add 20 parts by weight of bio-based elastomer polyhydroxybutyrate, melt-blend in a twin-screw extruder at a temperature of 170° C. and a rotation speed of 250 rpm to obtain modified polylactic acid.

[0047] S5. Evenly mix 45 parts by weight of modified polylactic acid, 18 parts by weight of polybutylene adipate / terephthalate, 1.5 parts by weight of lubricant calcium stearate, 0.8 parts by weight of antioxidant 1010 and 0.9 parts by weight of plasticizer citrate, then add 35 parts by weight of modified bamboo fiber, continue to mix evenly, add into a twin-screw extruder for melt blending, and extrude into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0048] Example 5

[0049] S1. Soak 80 parts by weight of bamboo fibers in a 5% by mass sodium hydroxide solution at 80° C. for 1 hour, then wash with deionized water until neutral, and dry.

[0050] S2. Soak the treated bamboo fiber in a 3.5% by mass tannic acid solution at 60°C for 1 hour, then wash with deionized water and dry. Then soak the treated bamboo fiber in a 2% by mass aluminum sulfate metal salt solution at 50°C for 1 hour, then wash with deionized water and dry.

[0051] S3, soaking the bamboo fiber treated in step S2 in a silane coupling agent KH550 ethanol solution with a mass fraction of 4%, treating at 60° C. for 2 hours, then washing with ethanol, and drying to obtain modified bamboo fiber.

[0052] S4. Premix 80 parts by weight of polylactic acid, 20 parts by weight of epoxy soybean oil, and 5 parts by weight of dicumyl peroxide, add 25 parts by weight of bio-based elastomer polyhydroxybutyrate, melt-blend in a twin-screw extruder at a temperature of 170° C. and a rotation speed of 280 rpm to obtain modified polylactic acid.

[0053] S5. Evenly mix 55 parts by weight of modified polylactic acid, 15 parts by weight of polybutylene adipate / terephthalate, 2 parts by weight of lubricant calcium stearate, 1 part by weight of antioxidant 1010 and 0.7 parts by weight of plasticizer citrate, then add 40 parts by weight of modified bamboo fiber, continue to mix evenly, add into a twin-screw extruder for melt blending, and extrude into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0054] Comparative Example 1

[0055] S1. Premix 80 parts by weight of polylactic acid, 8 parts by weight of epoxidized soybean oil, and 2.4 parts by weight of dicumyl peroxide, add 8 parts by weight of bio-based elastomer polyhydroxybutyrate, melt-blend in a twin-screw extruder at a temperature of 170° C. and a rotation speed of 200 rpm to obtain modified polylactic acid.

[0056] S2. Evenly mix 40 parts by weight of modified polylactic acid, 10 parts by weight of polybutylene adipate / terephthalate, 1 part by weight of lubricant calcium stearate, 0.5 parts by weight of antioxidant 1010 and 0.5 parts by weight of plasticizer citrate, then add 30 parts by weight of bamboo fiber, continue to mix evenly, add into a twin-screw extruder for melt blending, and extrude and granulate to obtain a degradable bamboo fiber composite material masterbatch.

[0057] Comparative Example 2

[0058] S1. Soak 50 parts by weight of bamboo fiber in a 5% by mass sodium hydroxide solution at 60° C. for 1 hour, then wash with deionized water until neutral, and dry.

[0059] S2. Soak the treated bamboo fiber in a 3% tannic acid solution at 50°C for 1 hour, then wash with deionized water and dry. Then soak the treated bamboo fiber in a 1% aluminum sulfate solution at 40°C for 0.5 hour, then wash with deionized water and dry.

[0060] S3, soaking the bamboo fiber treated in step S2 in a silane coupling agent KH550 ethanol solution with a mass fraction of 2%, treating at 60° C. for 1 hour, then washing with ethanol, and drying to obtain modified bamboo fiber.

[0061] S4, 40 parts by weight of polylactic acid, 10 parts by weight of polybutylene adipate / terephthalate, 1 part by weight of lubricant calcium stearate, 0.5 parts by weight of antioxidant 1010 and 0.5 parts by weight of plasticizer citrate are mixed evenly, and then 30 parts by weight of modified bamboo fiber are added, and the mixing is continued evenly, and the mixture is added into a twin-screw extruder for melt blending, and extruded into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0062] Example 1

[0063] 40 parts by weight of polylactic acid, 10 parts by weight of polybutylene adipate / terephthalate, 1 part by weight of lubricant calcium stearate, 0.5 parts by weight of antioxidant 1010 and 0.5 parts by weight of plasticizer citrate are mixed evenly, and then 30 parts by weight of bamboo fiber are added, and the mixing is continued evenly, and the mixture is added into a twin-screw extruder for melt blending, and extruded into granules to obtain a degradable bamboo fiber composite material masterbatch.

[0064] Performance Test:

[0065] The degradable bamboo fiber composite material masterbatches prepared in Examples 1 to 5 and Comparative Examples 1 to 3 were injection molded into standard specimens, and their mechanical properties were tested. The results are shown in Table 1.

[0066] Table 1

[0067]

[0068]

[0069] It can be seen from the table that the degradable bamboo fiber composite material masterbatch prepared in Examples 1 to 5 of the present invention has excellent mechanical properties, which are significantly better than those in Comparative Examples 1 to 3.

[0070] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A degradable bamboo fiber composite material masterbatch, characterized in that: It is composed of the following raw materials in parts by weight: 30-50 parts of modified bamboo fiber, 40-60 parts of modified polylactic acid, 10-20 parts of polybutylene adipate / terephthalate, 1-2 parts of lubricant, 0.5-1 part of antioxidant, and 0.5-1 part of plasticizer.

2. The degradable bamboo fiber composite material masterbatch according to claim 1, characterized in that: The bamboo fiber has a length of 0.5 to 2 mm and a diameter of 10 to 20 μm.

3. The degradable bamboo fiber composite material masterbatch according to claim 1, characterized in that: The lubricant is calcium stearate or polyethylene wax.

4. The degradable bamboo fiber composite material masterbatch according to claim 1, characterized in that: The antioxidant is 1010 or 168.

5. The degradable bamboo fiber composite material masterbatch according to claim 1, characterized in that: The plasticizer is citrate or polyethylene glycol.

6. A method for preparing a degradable bamboo fiber composite material masterbatch, characterized in that: The following steps are involved: S1. Soak the bamboo fiber in a 5% sodium hydroxide solution at 60-80°C for 1-2 hours, then wash with deionized water until neutral, and dry; S2, soaking the treated bamboo fiber in a tannic acid solution with a mass fraction of 3-5%, treating it at 50-70°C for 1-2 hours, then washing it with deionized water, drying it, and then soaking the treated bamboo fiber in a metal salt solution with a mass fraction of 1-3%, treating it at 40-60°C for 0.5-1 hour, then washing it with deionized water, and drying it; S3, soaking the bamboo fiber treated in step S2 in an ethanol solution of silane coupling agent KH550 with a mass fraction of 2-5%, treating at 60° C. for 1-2 hours, then washing with ethanol, and drying to obtain modified bamboo fiber; S4, premixing polylactic acid, epoxy soybean oil, and dicumyl peroxide, adding bio-based elastomer polyhydroxybutyrate, and melt-blending in a twin-screw extruder at a temperature of 170-190° C. and a rotation speed of 200-300 rpm to obtain modified polylactic acid; S5. The modified polylactic acid, polybutylene adipate / terephthalate, lubricant, antioxidant and plasticizer are mixed evenly in proportion, and then the modified bamboo fiber is added, and the mixing is continued evenly, and the mixture is added into a twin-screw extruder for melt blending, and extruded into granules to obtain a degradable bamboo fiber composite material masterbatch.

7. The method for preparing a degradable bamboo fiber composite material masterbatch according to claim 6, characterized in that: In step S2, the metal salt is aluminum sulfate, iron sulfate or zinc sulfate.

8. The method for preparing a degradable bamboo fiber composite material masterbatch according to claim 6, characterized in that: In the step S4, the mass ratio of polylactic acid, epoxy soybean oil, dicumyl peroxide, and bio-based elastomer polyhydroxybutyrate is 1: 0.1-0.3: 0.03-0.08: 0.1-0.4.

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