阅读说明：本技术 一种植物塑料及其制备方法 (Plant plastic and preparation method thereof ) 是由 祝名伟 吴佳扬 黄大方 陈延峰 于 2019-11-06 设计创作，主要内容包括：本发明公开了一种植物塑料及其制备方法。该塑料仅由微米级的植物纤维构成,植物纤维弯曲变形并紧密缠绕,形成致密的微结构。植物塑料外观性质类似普通塑料,光学半透明,质地硬,强度高,密度(约1.2-1.6g/cm～3)接近纤维素的理论密度(约1.6g/cm～3)；其成分为天然纤维素,无热塑性,可完全生物降解。本发明的制备方法为：将植物纤维表面用化学溶液处理；然后用酸或水溶液处理；最后用水清洗去除样品中的化学残留物、干燥,获得植物塑料。本发明制备的植物塑料是一种全新的材料,其制备方法具有原料来源广泛,成本低、制备步骤简单等特点,具有广阔的应用范围。(The invention discloses a plant plastic and a preparation method thereof. The plastic is only composed of micron-sized plant fibers, and the plant fibers are bent, deformed and tightly wound to form a compact microstructure. The plant plastic has the appearance similar to common plastic, optical translucency, hard texture, high strength and density (about 1.2-1.6 g/cm) 3 ) Close to the theoretical density of cellulose (about 1.6 g/cm) 3 ) (ii) a The components are natural cellulose, have no thermoplasticity, and can be completely biodegraded. The preparation method comprises the following steps: treating the surface of the plant fiber with a chemical solution; then treating with acid or water solution; and finally, cleaning with water to remove chemical residues in the sample, and drying to obtain the plant plastic. The plant plastic prepared by the invention is a brand new material, and the preparation method has the characteristics of wide raw material source, low cost, simple preparation steps and the like, and has a wide application range.)

1. The plant plastic is characterized by only comprising micron-sized plant fibers, wherein the plant fibers are bent, deformed and tightly wound to form a compact microstructure; the vegetable plastic is non-thermoplastic and completely biodegradable.

2. The plant plastic as claimed in claim 1, wherein the density of the plant plastic is 1.2-1.6g/cm³Shore hardness of 60 to 80.

3. The plant plastic as claimed in claim 1 or 2, wherein the micron-sized plant fiber is a wall-broken or non-wall-broken plant cell.

4. A method of preparing a plant plastic according to claim 1, comprising the steps of:

(1) treating the dispersed plant fibers with the A treatment solution for a certain time to improve the surface activity of micron-sized plant fibers;

(2) treating the plant fiber with the treatment solution B for a certain time to harden the plant fiber into a block;

(3) and (3) cleaning the block obtained in the step (2) with water to remove chemical residues, and drying to obtain the plant plastic.

5. A method for preparing plant plastic according to claim 4, wherein in the step (1), the treatment solution A comprises a strong alkali solution, a mixed alkali/urea solution, a lithium chloride/dimethylacetamide solution, an ionic liquid, a cuprammonium solution or an N-methylmorpholine-N-oxide solution.

6. A method for preparing plant plastic according to claim 4, wherein in step (1), the treatment is carried out for a certain time, specifically 5 minutes to 72 hours.

7. The method for preparing plant plastic as claimed in claim 4, wherein in step (2), the treatment solution B is hydrochloric acid solution, acetic acid solution, sulfuric acid solution, sodium hydroxide solution or water, or any safe combination of the above solutions.

8. A method for preparing plant plastic according to claim 4, wherein in step (2), the treatment is carried out for a certain time, specifically 1 minute to 72 hours.

Technical Field

The invention relates to a new material of plant plastic and a preparation method thereof, belonging to artificial microstructure materials, ecological materials and preparation technologies thereof.

Background

Plastics are important products of petrochemical industry, and are one of the greatest inventions of human beings. However, due to the difficulty in degrading plastics, with the increasing amount of plastic waste, the so-called "plastic crisis" has been triggered in recent years. Plastic particles are found not only on land, but even in the deepest parts of the ocean. Plastics not only cause environmental pollution, but also enter human bodies in the form of water, aquatic animals and the like, and affect human health. Therefore, the search for a substitute of plastics and the development of a completely biodegradable and environment-friendly new material are important guarantees for the sustainable development of the environment. The natural cellulose is the most abundant natural polymer in the nature, and has the advantages of low cost, reproducibility, environmental friendliness, biodegradability and the like, so that the preparation of the novel material by using the cellulose has great scientific value and social significance.

Traditionally, plant fibers contained in natural plants are bonded by means of adhesive glue and the like to form blocks with certain strength, such as floors, decorative wood boards and the like. Because of adding substances such as glue and the like, the environmental friendliness of the product is greatly influenced. The block material formed by bonding the plant fiber by adopting environment-friendly glue such as starch and the like has high cost and is easy to mildew. In another mode, plant fibers are completely dissolved into nano cellulose fibers, and then the nano cellulose fibers are precipitated and solidified again in the solution to obtain regenerated cellulose, and cellulose filaments or cellulose blocks are obtained. However, the preparation time and cost for extracting the nanofibers from the plants to form the nanofibers are very high, and the preparation time and cost for preparing the bulk materials from the nanofibers are also very high, so that the obtained materials are difficult to have production and application values.

The micron fiber of the plant, namely the cell of the plant (such as paper making fiber) is used for constructing a new material with the functional performance of the plastic, so that the cost is greatly reduced, and the obtained plant plastic has the possibility of replacing the difficultly degraded plastic to realize large-scale application. However, since strong interaction between plant micro fibers is difficult to realize without the assistance of foreign substances such as adhesive glue, etc., no report is found at present that pure plant micro fibers form a plastic-like material.

Disclosure of Invention

The invention aims to prepare a novel plant plastic material which can be completely biodegraded and has excellent performance by utilizing micron-sized plant fibers so as to meet the environment-friendly application of partially replacing plastics. It is another object of the present invention to provide a process for preparing the novel material.

The technical scheme adopted by the invention is as follows:

a plant plastic is only composed of micron-sized plant fibers, and the plant fibers are bent, deformed and tightly wound to form a compact microstructure; the vegetable plastic is non-thermoplastic and completely biodegradable.

Further, the density of the plant plastic is 1.2-1.6g/cm³Shore hardness of 60 to 80.

Further, the micron-sized plant fiber is a wall-broken or non-wall-broken plant cell.

The invention relates to a preparation method of plant plastic, which comprises the following steps:

(1) treating the dispersed plant fibers with the A treatment solution for a certain time to improve the surface activity of micron-sized plant fibers;

(2) treating the plant fiber with the treatment solution B for a certain time to harden the plant fiber into a block;

(3) and (3) cleaning the block obtained in the step (2) with water to remove chemical residues, and drying to obtain the plant plastic.

Further, in the step (1), the treatment solution a includes a strong alkali solution, a mixed alkali/urea solution, a lithium chloride/dimethylacetamide solution, an ionic liquid, a cuprammonium solution, or an N-methylmorpholine-N-oxide solution.

Further, in the step (1), the treatment is carried out for a certain time, specifically, 5 minutes to 72 hours.

Further, in the step (2), the treatment solution B is hydrochloric acid solution, acetic acid solution, sulfuric acid solution, sodium hydroxide solution or water, or any safe combination of the above solutions.

Further, in the step (2), the treatment is carried out for a certain time, specifically, 1 minute to 72 hours.

The invention takes plant fiber as raw material (such as papermaking fiber but not limited to papermaking fiber), and regulates the microstructure of the material by regulating the form of the fiber, thereby forming a new material with new macroscopic properties. The invention has the advantages that:

(1) the obtained plant plastic is only composed of plant fibers, does not contain any foreign substances, and has the appearance and mechanical properties of common plastics.

(2) The cellulose fiber is not required to be dissolved into the nano fiber in the whole preparation process, and the structure of the original plant fiber is only regulated, so that the performance of the plant fiber is kept, the cost is greatly reduced, and the production rate is improved.

(3) The plant fiber is a green and environment-friendly material, and the raw materials of the plant fiber are rich in source, so that the preparation method disclosed by the invention is strong in operability.

(4) The preparation process has low cost, low energy consumption and time consumption, and does not need mechanical pressure assistance.

(5) The plant plastic prepared by the invention is used as a completely biodegradable ecological new material with excellent performance, and is expected to replace the application of a plurality of plastics, so that the plant plastic has wide application prospect in the aspects of daily necessities, mechanical parts, military supplies, electric insulation parts, medical and health supplies and the like.

Drawings

FIG. 1 is a scanning electron microscope image of the surface topography of the plant plastic prepared in example 1;

FIG. 2 is a photograph of a block of the plant plastic prepared in example 1;

FIG. 3 is a graph showing the tensile strength of the vegetable plastic prepared in example 1;

FIG. 4 is a comparison of the hardness of the vegetable plastic prepared in example 1 with that of a conventional plastic.

Detailed Description

Example 1:

mixing 10g of cellulose fiber derived from cotton with 7% NaOH and 12% urea aqueous solution, fully and uniformly stirring, wherein the volume of the required sodium hydroxide urea aqueous solution is 100ml, freezing at-18 ℃ for 1 hour, taking out, changing the fiber shape from straight to twisted, slightly dissolving the fiber surface, exposing the fresh surface, taking out, immersing in dilute hydrochloric acid for 10 hours, washing with deionized water for multiple times, drying the washed sample, actively shrinking the fiber in the dehydration process to form a compact structure, and finally obtaining a new plant plastic material. The scanning electron microscope image is shown in fig. 1, wherein the plant plastic is composed of micron-sized plant fibers, and the plant fibers are bent, deformed and tightly wound to form a very compact structure.

As can be seen from FIG. 2, the plant plastic (white block) of this example is similar to ordinary plastic in appearance, optically translucent, hard in texture, high in strength, and high in density (about 1.2-1.6 g/cm)³) Close to the theoretical density of cellulose (about 1.6 g/cm)³). The plant plastic contains natural cellulose, has no thermoplasticity, and can be completely biodegraded.

Example 2:

8g of cellulose fiber from wood is mixed with 7% of NaOH and 12% of urea aqueous solution, the mixture is fully and uniformly stirred, the volume of the required aqueous solution is 100ml, the obtained mixture system is frozen at the temperature of-13 ℃ for 3 hours, the fiber shape is changed from straight to twisted, the fiber surface is slightly dissolved, the fresh surface is exposed, the fiber is taken out and immersed in dilute sulfuric acid for 72 hours, then the deionized water is used for cleaning, the cleaned sample is dried, and in the dehydration process, the fiber actively shrinks to form a compact structure, and finally the plant plastic is obtained.

Example 3:

10g of cellulose fibres from straw were mixed with 8g of lithium chloride/DMAc: mixing 100ml of solution, reacting at 140 ℃ for 30min, standing the obtained mixed system for 10 hours, slightly dissolving the surface of cellulose to expose fresh surface, washing with deionized water for multiple times, and drying the washed sample to obtain the plant plastic.

Example 4:

cellulose fiber 20g derived from bamboo was mixed with ionic liquid 150g of 1-butyl-3-methylimidazole hydrochloride, and then the mixture was reacted and treated at 100 ℃ under a pressure of 1MPa for 1 hour, at which time the fiber was swollen and distorted and the fiber surface was slightly dissolved. Exposing a fresh surface, standing for 30 minutes, washing with deionized water for multiple times, drying the washed sample, actively shrinking the sample to form a compact structure, and finally obtaining the plant plastic.

Example 5:

mixing 20g of cellulose fiber derived from wheat straws with 7% of NaOH and 12% of urea aqueous solution, fully and uniformly stirring, wherein the volume of the required sodium hydroxide urea aqueous solution is 160ml, freezing the mixture at the temperature of 15 ℃ below zero for 2 hours, then taking out the mixture, swelling and spirally twisting the fiber in the process, slightly dissolving the surface of the fiber to expose a fresh surface, soaking the fiber in hydrochloric acid for 48 hours after taking out the fiber, then washing the fiber for multiple times by using deionized water, then drying the washed sample, actively shrinking the fiber in the drying process to form a compact structure, and finally obtaining the plant plastic.

Example 6:

mixing 10g of cellulose fiber derived from cotton with 7% NaOH and 12% urea aqueous solution, fully and uniformly stirring, wherein the volume of the required sodium hydroxide urea aqueous solution is 110ml, freezing at-18 ℃ for 10min, taking out, swelling and spirally twisting the fiber, slightly dissolving the surface of the fiber, exposing the fresh surface, taking out, immersing in dilute sulfuric acid for 2 min, washing with deionized water for multiple times, drying the washed sample, actively shrinking the sample to form a compact structure, and finally obtaining the plant plastic.

Example 7:

mixing 100g of cellulose fiber derived from lianas with 7% NaOH and 12% urea aqueous solution, fully and uniformly stirring, wherein the volume of the required aqueous solution is 1000ml, freezing at-13 ℃ for 24 hours, at which time the fiber swells and twists, slightly dissolving the surface of the fiber, exposing the fresh surface, taking out, immersing in acetic acid for 50 hours, washing with deionized water for multiple times, drying the washed sample, actively shrinking the sample to form a compact structure, and finally obtaining the plant plastic.

Example 8:

mixing 10g of cellulose fiber from cotton with copper ammonia solution, and stirring thoroughly to obtain Cu/NH in the solution₃The mol ratio is 0.046/0.36, 50ml of the required cuprammonium solution is adopted, the obtained mixed system is treated for 1 hour, taken out and immersed in 10 percent NaOH solution for 10 hours, the fiber is twisted and wound, the surface of the fiber is slightly dissolved, and then deionized water is used for deionized waterAnd (3) cleaning for multiple times, drying the cleaned sample, actively contracting the sample during drying to form a compact structure, and finally obtaining the plant plastic.

Example 9:

mixing 10g of cellulose fiber derived from cotton with 87 percent of 150ml of NMMO solution, fully and uniformly stirring, reacting for two hours at the temperature of 120 ℃, swelling the fiber, slightly dissolving the surface of the fiber to expose a fresh surface, taking out, immersing in deionized water for 70 hours, washing with the deionized water for multiple times, drying the washed sample, actively contracting the sample to form a compact structure, and finally obtaining the plant plastic.

Example 10:

mixing 10g of cellulose fiber from cotton with a strong base solution of 18% NaOH, fully and uniformly stirring, treating the obtained mixed system for 20 hours by using 30ml of the required strong base solution, swelling the fiber, spirally twisting the fiber, winding the fibers with each other, taking out, immersing the fibers in hydrochloric acid for 1 hour, washing the fibers for multiple times by using deionized water, drying the cleaned sample, actively shrinking the sample during drying to form a compact structure, and finally obtaining the plant plastic.