CN113292865A - Plant fiber-based composite material and preparation method and application thereof - Google Patents

Abstract

The invention discloses a plant fiber-based composite material and a preparation method and application thereof, wherein the composite material comprises the following components in parts by weight: 50-59 parts of plant fiber, 10-20 parts of plasticizer, 16-22 parts of adhesive, 1.8-3.5 parts of antioxidant, 1.2-1.7 parts of lubricant, 13-24 parts of polybasic acid curing agent and 26-40 parts of inorganic filler. The plant fiber-based composite material has good degradability, excellent mechanical property, high toughness and long service life, is not easy to brittle failure, is nontoxic and can be completely biodegraded, and can be widely applied to the fields of environment-friendly tableware, food, medical packaging and the like; meanwhile, the preparation method is easy to control, strong in operability and easy for industrial production.

Description

Plant fiber-based composite material and preparation method and application thereof

Technical Field

The invention relates to the field of biodegradable fiber materials, in particular to a plant fiber-based composite material and a preparation method and application thereof.

Background

The application of plastics in real life is ubiquitous at present, and the harm to the environment caused by the difficulty of degradation of the plastics is obvious. With the increasing public awareness of environmental protection, degradable plastics are beginning to be used to protect the human living environment. In the field of food packaging, most of the packaging materials for medical disposable instruments are common plastic films, and a large amount of fresh-keeping materials are required to be used after packaging, so that great material waste (a large amount of disposable packaging materials are used) and environmental pollution are caused.

Today, environment-friendly biodegradable polymer materials are undoubtedly favored by people as a subject of environmental and sustainable development, and become research hotspots in recent years, however, polylactic acid is considered to be one of the most promising traditional plastic substitutes. Polylactic acid (PLA) is biodegradable aliphatic polyester prepared by taking lactic acid formed by fermenting corn or potato starch as a raw material through chemical synthesis, has sufficient and renewable raw material sources, not only gets rid of the dependence on petroleum resources, but also has lower energy consumption in the production and manufacturing process than petroleum-based polymers such as PP and the like, and is a polymer material with low environmental load. However, the polylactic acid degradable plastic is not easily degraded in nature in the absence of corresponding microorganisms, and the polylactic acid material is brittle and easy to break in the using process and short in service life, so that the wide-range application of the polylactic acid degradable plastic is limited.

Plant fiber is another renewable biomass resource which widely exists in nature, has high length-diameter ratio and specific strength, and is a very important raw material for preparing the bio-based composite material. The plant fiber with higher length-diameter ratio and specific strength can construct a three-dimensional structure in the composite material to form a supporting framework, and the supporting framework is connected with the continuous phase matrix to form a structural reinforcing material.

Therefore, a plant fiber-based composite material with better comprehensive performance is urgently needed.

Disclosure of Invention

The invention aims to provide a plant fiber-based composite material, a preparation method and application thereof aiming at the defects in the prior art, wherein the plant fiber-based composite material has excellent degradation performance and mechanical property.

In order to achieve the purpose, the invention adopts the technical scheme that:

the invention provides a plant fiber-based composite material, which comprises the following components in parts by weight: 50-59 parts of plant fiber, 10-20 parts of plasticizer, 16-22 parts of adhesive, 1.8-3.5 parts of antioxidant, 1.2-1.7 parts of lubricant, 13-24 parts of polybasic acid curing agent and 26-40 parts of inorganic filler.

Preferably, the plant fiber is selected from one or more of straw stalk, wheat stalk, soybean stalk and corn stalk.

Preferably, the plasticizer is one or more selected from glycerol, stearic acid, epoxidized soybean oil, white oil, polyethylene glycol, citric acid, dimethyl phthalate and acetylated triethyl citrate.

Preferably, the adhesive is selected from one or more of polyvinyl alcohol, starch paste, cellulose, tannin, gum arabic, sodium alginate, bone glue, fish glue, shellac, white latex, silicate and calcium oxide.

Preferably, the antioxidant is selected from one or more of antioxidant DSTDP, antioxidant 168 and antioxidant 1010.

Preferably, the lubricant is selected from one or more of polyethylene wax, N-ethylene bis stearamide, glycerol tristearate and N-butyl stearate.

Preferably, the polybasic acid curing agent is selected from one or more of oxalic acid, citric acid, maleic acid, succinic acid and butane tetracarboxylic acid.

Preferably, the inorganic filler is selected from one or more of talcum powder, quartz powder and wollastonite powder.

The second aspect of the present invention provides a method for preparing the plant fiber-based composite material, comprising the following steps:

(1) uniformly mixing the plant fibers, the plasticizer, the adhesive, the antioxidant, the lubricant, the polybasic acid curing agent and the inorganic filler according to the proportion to obtain a mixed material;

(2) and (2) adding the mixed material prepared in the step (1) into a hopper of a double-screw extrusion granulator, and conveying the mixed material into the double-screw extrusion granulator by a screw for extrusion granulation, wherein the extrusion temperature is 210-240 ℃, and the screw rotation speed is 160-185r/min, so as to prepare the plant fiber-based composite material.

The third aspect of the invention provides the application of the plant fiber-based composite material prepared by the method in preparing plastic packaging materials.

By adopting the technical scheme, compared with the prior art, the invention has the following technical effects:

the plant fiber-based composite material has good degradability, excellent mechanical property, high toughness and long service life, is not easy to brittle failure, is nontoxic and can be completely biodegraded, and can be widely applied to the fields of environment-friendly tableware, food, medical packaging and the like; meanwhile, the preparation method is easy to control, strong in operability and easy for industrial production.

Detailed Description

The present invention is further illustrated by the following examples, which are not to be construed as limiting the invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

Example 1

A plant fiber-based composite material comprises the following components in parts by weight: 50 parts of straw stalk, 10 parts of stearic acid, 16 parts of starch paste, 1.8 parts of antioxidant DSTDP, 1.2 parts of polyethylene wax, 13 parts of oxalic acid and 26 parts of talcum powder.

The preparation method of the plant fiber-based composite material comprises the following steps:

(1) uniformly mixing the straw stalk, stearic acid, starch paste, antioxidant DSTDP, polyethylene wax, oxalic acid and talcum powder according to the proportion to obtain a mixed material;

(2) and (2) adding the mixed material prepared in the step (1) into a hopper of a double-screw extrusion granulator, and conveying the mixed material into the double-screw extrusion granulator by a screw to perform extrusion granulation, wherein the extrusion temperature is 210 ℃, and the screw rotation speed is 160r/min, so as to prepare the plant fiber-based composite material.

Example 2

A plant fiber-based composite material comprises the following components in parts by weight: 55 parts of wheat straw, 15 parts of epoxidized soybean oil, 19 parts of gum arabic, 1682.5 parts of antioxidant, 1.4 parts of N, N-ethylene bis-stearamide, 18 parts of maleic acid and 32 parts of quartz powder.

The preparation method of the plant fiber-based composite material comprises the following steps:

(1) uniformly mixing the wheat straws, the epoxidized soybean oil, the gum arabic, the antioxidant 168, the N, N-ethylene bis-stearamide, the maleic acid and the quartz powder according to the proportion to obtain a mixed material;

(2) and (2) adding the mixed material prepared in the step (1) into a hopper of a double-screw extrusion granulator, and conveying the mixed material into the double-screw extrusion granulator by a screw to perform extrusion granulation, wherein the extrusion temperature is 225 ℃, and the screw rotating speed is 172r/min, so as to prepare the plant fiber-based composite material.

Example 3

A plant fiber-based composite material comprises the following components in parts by weight: 59 parts of soybean straw, 20 parts of dimethyl phthalate, 22 parts of bone glue, 10103.5 parts of antioxidant, 1.7 parts of glycerol tristearate, 24 parts of butane tetracarboxylic acid and 40 parts of wollastonite powder.

The preparation method of the plant fiber-based composite material comprises the following steps:

(1) uniformly mixing the soybean straws, dimethyl phthalate, bone glue, an antioxidant 1010, glycerol tristearin, butane tetracarboxylic acid and wollastonite powder according to the proportion to obtain a mixed material;

(2) and (2) adding the mixed material prepared in the step (1) into a hopper of a double-screw extrusion granulator, and conveying the mixed material into the double-screw extrusion granulator by a screw to perform extrusion granulation, wherein the extrusion temperature is 240 ℃, and the screw rotation speed is 185r/min, so as to prepare the plant fiber-based composite material.

Application example

1. The plant fiber-based composite materials prepared in examples 1 to 3 and the commercially available biodegradable materials were blown and processed to prepare plastic bags, which were then tested for their degradability. The evaluation method comprises the following steps: a soil burying biodegradation experiment is adopted (the biodegradation experiment adopts a simpler outdoor soil burying method, the soil is common flower bed soil, the soil burying depth is 12cm, a certain amount of water is added every 10 days after the degradation experiment is started, the soil is kept moist, a sample is taken out after the first soil is buried for 30 days, the surface soil is washed away, the sample is placed in an oven at 55 ℃ for drying for 20 hours, and then the weight loss rate is calculated). The test results are shown in table 1:

TABLE 1

Serial number	Original weight (g)	Final weight (g)	Weight loss ratio (%)
				Example 1	23.12	11.55	50.02
Example 2	23.24	11.65	49.85
				Example 3	23.45	11.72	50.00
Commercially available product	23.22	19.47	16.15

As can be seen from the data in Table 1, in the soil burial degradation test in the natural environment, when the composite material is degraded for 30 days, compared with the commercially available biodegradable material, the degradation rate of the plant fiber-based composite material prepared in the embodiments 1 to 3 of the invention is obviously improved by about 33.70 to 33.87 times.

2. The plant fiber-based composite materials prepared in examples 1 to 3 and commercially available biodegradable materials were subjected to mechanical property tests. The test results are shown in table 2:

TABLE 2

As can be seen from the data in Table 2, the plant fiber-based composite material of the invention has good mechanical properties and toughness

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims (10)

1. The plant fiber-based composite material is characterized by comprising the following components in parts by weight: 50-59 parts of plant fiber, 10-20 parts of plasticizer, 16-22 parts of adhesive, 1.8-3.5 parts of antioxidant, 1.2-1.7 parts of lubricant, 13-24 parts of polybasic acid curing agent and 26-40 parts of inorganic filler.

2. The plant fiber-based composite material according to claim 1, wherein the plant fiber is selected from one or more of straw stalk, wheat stalk, soybean stalk and corn stalk.

3. The plant fiber-based composite material according to claim 1, wherein the plasticizer is one or more selected from the group consisting of glycerin, stearic acid, epoxidized soybean oil, white oil, polyethylene glycol, citric acid, dimethyl phthalate, and acetylated triethyl citrate.

4. The plant fiber-based composite material according to claim 1, wherein the adhesive is selected from one or more of polyvinyl alcohol, starch paste, cellulose, tannin, gum arabic, sodium alginate, bone glue, fish glue, shellac, white latex, silicate, and calcium oxide.

5. The plant fiber-based composite material according to claim 1, wherein the antioxidant is one or more selected from the group consisting of antioxidant DSTDP, antioxidant 168, and antioxidant 1010.

6. The plant fiber-based composite material according to claim 1, wherein the lubricant is one or more selected from polyethylene wax, N-ethylene bis stearamide, glycerol tristearate, and N-butyl stearate.

7. The plant fiber-based composite material according to claim 1, wherein the polybasic acid type curing agent is one or more selected from oxalic acid, citric acid, maleic acid, succinic acid and butane tetracarboxylic acid.

8. The plant fiber-based composite material according to claim 1, wherein the inorganic filler is one or more selected from talc powder, quartz powder and wollastonite powder.

9. Method for the preparation of a plant fiber based composite material according to any one of claims 1 to 8, characterized in that it comprises the following steps:

(1) uniformly mixing the plant fibers, the plasticizer, the adhesive, the antioxidant, the lubricant, the polybasic acid curing agent and the inorganic filler according to the proportion to obtain a mixed material;

(2) and (2) adding the mixed material prepared in the step (1) into a hopper of a double-screw extrusion granulator, and conveying the mixed material into the double-screw extrusion granulator by a screw for extrusion granulation, wherein the extrusion temperature is 210-240 ℃, and the screw rotation speed is 160-185r/min, so as to prepare the plant fiber-based composite material.

10. Use of the plant fiber-based composite material prepared according to the method of claim 9 for preparing a plastic packaging material.