阅读说明：本技术 制备淀粉离聚物的方法以及其改性的全降解塑料 (Method for preparing starch ionomer and modified fully-degradable plastic thereof ) 是由 李波 梁胜轲 王武聪 金华 杜中杰 孙佩鑫 侯斌 于 2020-12-24 设计创作，主要内容包括：本发明提供一种制备淀粉离聚物的方法以及其改性的全降解塑料。属于高分子材料领域,该方法包括：将高直链淀粉和水混合,进行糊化处理,以便获得糊化产物；将所述糊化产物和有机酸式盐、二羟基羧酸进行反应,以便获得所述淀粉离聚物。该淀粉离聚物可以用于制备全降解塑料,所制备的全降解塑料在保证力学性能的同时,还可以有效降低全降解塑料的成本。(The invention provides a method for preparing starch ionomer and modified fully-degradable plastic thereof. Belongs to the field of high polymer materials, and the method comprises the following steps: mixing high amylose starch with water, and performing gelatinization treatment to obtain a gelatinized product; reacting the gelatinized product with an organic acid salt, a dihydroxy carboxylic acid, to obtain the starch ionomer. The starch ionomer can be used for preparing fully-degradable plastics, and the prepared fully-degradable plastics can effectively reduce the cost of the fully-degradable plastics while ensuring the mechanical property.)

1. A method of making a starch ionomer, comprising:

(1) mixing high amylose starch with water, and performing gelatinization treatment to obtain a gelatinized product;

(2) reacting the gelatinized product with an organic acid salt, a dihydroxy carboxylic acid, to obtain the starch ionomer.

2. The method according to claim 1, wherein the amylose content in the high amylose starch in step (1) is 40-95%;

optionally, the mass ratio of the high amylose starch to the water in step (1) is 1:0.1-1: 1.

3. the method according to claim 1, wherein the temperature of the gelatinization treatment in the step (1) is 80-110 ℃, and the time of the gelatinization treatment is 20-80 minutes;

optionally, the mass ratio of the gelatinized product to the organic acid salt in the step (2) is 1:0.3-1: 0.8;

optionally, the organic acid salt is selected from at least one of monosodium citrate, monosodium fumarate, monosodium malate, monosodium succinate.

4. The method of claim 1, wherein the mass ratio of the gelatinized product to the dihydroxy carboxylic acid in step (2) is 1:0.3-1: 0.8;

optionally, the dihydroxy carboxylic acid is selected from at least one of dimethylol propionic acid and dimethylol butyric acid.

5. The method of claim 1, wherein step (2) further comprises:

(2-1) reacting the gelatinized product with an organic acid salt and a dihydroxy carboxylic acid in a supercritical carbon dioxide fluid environment to obtain a reaction product;

(2-2) subjecting the reaction product to separation under reduced pressure to obtain the starch ionomer;

optionally, the reaction is carried out in a supercritical carbon dioxide reaction kettle;

optionally, the reaction temperature is 40-50 ℃ and the pressure is 8-12 MPa.

6. A starch ionomer prepared by the method of any one of claims 1 to 5.

7. A starch ionomer production device, comprising:

the gelatinizing unit is used for mixing the high amylose starch with water and carrying out gelatinizing treatment so as to obtain a gelatinized product;

a grafting unit connected with the pasting unit, wherein the grafting unit is used for reacting the pasting product with organic acid salt and dihydroxy carboxylic acid so as to obtain the starch ionomer;

optionally, the temperature of the gelatinization treatment is 80-110 ℃, and the time of the gelatinization treatment is 20-80 minutes;

optionally, the mass ratio of the gelatinized product to the organic acid salt is 1:0.3-1: 0.8;

optionally, the mass ratio of the gelatinization product to the dihydroxy carboxylic acid is 1:0.3-1: 0.8.

8. a fully degradable plastic comprising the starch ionomer of claim 6;

optionally, the content of the starch ionomer in the fully degradable plastic is 15-80%;

optionally, the plastic material is selected from at least one of PLA, PBAT, PBS, PBSA.

9. A method of making a fully degradable plastic comprising:

mixing the starch ionomer of claim 6 with a plastic material, melt extrusion granulation to obtain the fully degradable plastic;

optionally, the temperature of the melt extrusion is 110-180 ℃;

optionally, the mass ratio of the starch ionomer to the plastic material is 1: 0.25-1: 5.

10. a fully degradable plastic material production system, comprising:

a starch ionomer production device according to claim 7;

the melting device is connected with the starch ionomer generation device and is used for carrying out melt extrusion granulation on the mixed starch ionomer and plastic material so as to obtain fully-degradable plastic;

optionally, the temperature of the melt extrusion is 110-180 ℃;

optionally, the mass ratio of the starch ionomer to the plastic material is 1: 0.25-1: 5.

Technical Field

The invention relates to the technical field of high polymer materials, in particular to a method for preparing a starch ionomer and a modified fully-degradable plastic thereof.

Background

With the rapid increase in the number of non-degradable polymers in recent years, environmental problems have become more and more serious. Among them, the non-degradable polymer film is particularly heavy in pollution because it is difficult to recycle. Therefore, it is imperative to research degradable polymer film materials to replace non-degradable polymer films. Among the degradable polymers, starch, which is a natural polymer, is considered to be one of the most promising degradable polymer film materials due to its advantages of abundant sources, short regeneration period, low cost, good degradability, etc. However, intermolecular and intramolecular hydrogen bonding of starch macromolecules presents difficulties in starch processing. The usual solution is to add a plasticizer to the starch to improve its processability, thereby obtaining a thermoplastic starch that is easy to process. Among the conventional plasticizers, a commonly used plasticizer is a polyhydric alcohol such as glycerin, sorbitol, xylitol, ethylene glycol, or the like.

In recent years, several reports have shown the processability of thermoplastic starch blown films under tightly controlled process conditions. Wenyong Liu et al report that with proper plasticizer content, blowing of film can produce thermoplastic starch film with higher elongation at break, nano SiO₂The mechanical property of the material can be further improved. The thermoplastic starch film is prepared by the group by using an original starch film blowing process, and the comprehensive mechanical property of the thermoplastic starch film is improved by adding the nano SiO 2. The influence of glycerol as plasticizer and nanosilica as reinforcing agent on the mechanical, thermal and structural properties of thermoplastic starch films was investigated.

However, pure starch plastics still have a large difference in mechanical properties from synthetic polymer materials. The compounding of starch and synthetic fully-degradable high-molecular materials is the main research direction of thermoplastic starch at present, and the synthetic fully-degradable high-molecular materials for compounding comprise PLA, PBAT, PBS, PBSA and the like.

However, the mechanical properties of polyester blends are reduced due to the addition of the traditional thermoplastic starch, so that the addition amount of the traditional modified thermoplastic starch elastomer in the synthetic degradable high polymer material is difficult to exceed 50 wt%. In addition, the thermoplastic starch elastomer has the problems of narrow processing window, low processing viscosity, poor thermal stability and the like.

Disclosure of Invention

The present invention addresses, at least to some extent, the problems of the prior art. To this end, the present invention prepares a starch ionomer. The starch ionomer adopts a mode of hyperbranched grafting of organic acid salt and dihydroxy carboxylic acid on high amylose starch to convert partial hydroxyl on a starch chain into hyperbranched carboxylate, so that the strong hydrogen bond action formed by the hydroxyl and the hydroxyl is prevented, and the thermoplastic processability of the starch is ensured; meanwhile, the carboxylate and hydroxyl can form weak hydrogen bond action, so that the mechanical property of the material is improved; in addition, the presence of the carboxylate can effectively improve the processing viscosity of the starch and improve the processing performance. The method comprises the steps of gelatinizing high amylose starch by water, and carrying out hyperbranched reaction on the gelatinized high amylose starch, organic acid salt and dihydroxy acid in a supercritical carbon dioxide medium in a fluidized bed manner to generate the amylose with hyperbranched carboxylate, namely the starch ionomer.

Meanwhile, the invention also provides application of the starch ionomer in composite fully-degradable plastics. The starch ionomer is applied to preparing the fully degradable plastic, so that the mechanical property and the processability of the fully degradable plastic can be improved, the requirement on the mechanical property is met, and the cost of the composite material can be effectively reduced.

Specifically, the invention adopts the following technical scheme:

in a first aspect of the invention, the invention provides a method of making a starch ionomer comprising:

(1) mixing high amylose starch with water, and performing gelatinization treatment to obtain a gelatinized product; (2) reacting the gelatinized product with an organic acid salt, a dihydroxy carboxylic acid, to obtain the starch ionomer. After the high amylose starch is gelatinized by water, the high amylose starch is esterified and grafted by organic acid salt, so that partial hydroxyl on a starch chain can be converted into carboxylate, the formation of strong hydrogen bond action between the hydroxyl on the starch chain and the hydroxyl can be prevented, the thermoplastic processability of the starch is ensured, and meanwhile, the carboxylate and the hydroxyl can form weak hydrogen bond action, so that the mechanical property of the material can be improved; in addition, the presence of the carboxylate is also effective in increasing the processing viscosity of the starch, thereby improving processability.

Mixing a certain amount of high amylose starch with a certain amount of water, and gelatinizing at a certain temperature for a certain time. Adding a certain amount of gelatinized high amylose starch, organic acid salt and dihydroxy carboxylic acid into a supercritical carbon dioxide reaction kettle, reacting in a supercritical carbon dioxide fluid at a certain temperature and under a certain pressure in a fluidized bed mode, enabling a reaction product to leave the reaction kettle along with the carbon dioxide fluid, and performing reduced pressure separation to obtain the starch ionomer.

According to an embodiment of the present invention, the method for preparing starch ionomer as described above may further include the following technical features:

in some embodiments, the high amylose starch of step (1) has an amylose content of 40-95%. In the research, the lower content of amylose in the starch is found to have poor thermoplasticity and difficult processing, and can influence the performance of the finally obtained starch ionomer. High amylose with amylose content of 40-95% is more likely to generate thermoplasticity, and the obtained starch ionomer has more excellent mechanical property and higher stability.

The gelatinization process can be accelerated by water with proper content, when the water content is low, the starch cannot be fully gelatinized, when the water content is excessive, the starch is difficult to dry, and the preparation time of the starch copolymer is prolonged to a certain extent. In some embodiments, the mass ratio of the water to the high amylose starch in step (1) is 0.1: 1 or more (the water content may continue to increase over this ratio). In some preferred embodiments, the mass ratio of the high amylose starch to the water in step (1) is from 1:0.1 to 1: 1. Thus, the gelatinized product can be obtained efficiently and quickly.

In some embodiments, the temperature of the gelatinization treatment in the step (1) is 80-110 ℃, and the time of the gelatinization treatment is 20-80 min. The ungelatinized starch has strong thermosetting property due to the existence of intramolecular hydrogen bonds, and is difficult to modify; the starch is gelatinized at a proper temperature, hydrogen bonds in the starch molecule can be opened, the gelatinized starch has strong thermoplasticity and can be esterified and grafted with organic acid salt, the thermoplastic processability of the starch is ensured, and the prepared starch polymer has excellent mechanical properties and processability.

When the gelatinized product reacts with the organic acid salt, the content of the organic acid salt is too low, and the prepared starch ionomer is difficult to show the performance of the ionomer; when the content of the organic acid salt is too high, some organic acid salts can not be connected to the main chain of the starch and are in a free state, and the mechanical property of the starch ionomer can be influenced to a certain extent. In some embodiments, the mass ratio of the gelatinized product and the organic acid salt in step (2) is 1:0.3 to 1: 0.8. Thus, a starch ionomer excellent in mechanical properties and thermoplastic properties can be obtained.

In some embodiments, the organic acid salt includes, but is not limited to, monosodium citrate, monosodium fumarate, monosodium malate, monosodium succinate, and the like.

When the content of dihydroxy carboxylic acid is too low in the reaction of gelatinization products and organic acid salts and in the reaction of dihydroxy carboxylic acid, the prepared starch ionomer is difficult to show the performance of the ionomer; when the content of the dihydroxy carboxylic acid is too high, some dihydroxy carboxylic acids cannot be connected to the starch backbone and are in a free state, and the mechanical properties of the starch ionomer are also influenced to a certain extent. In some embodiments, the ratio of the gelatinization product to dihydroxy carboxylic acid is 1:0.3 to 1: 0.8.

In some embodiments, the dihydroxy carboxylic acid includes, but is not limited to, dimethylol propionic acid, dimethylol butyric acid, and the like.

In some embodiments, step (2) further comprises: (2-1) reacting the gelatinized product with an organic acid salt and a dihydroxy carboxylic acid in a supercritical carbon dioxide fluid environment to obtain a reaction product;

(2-2) subjecting the reaction product to separation under reduced pressure to obtain the starch ionomer;

in some embodiments, the reaction is performed in a supercritical carbon dioxide reaction vessel.

In some embodiments, the reaction temperature is 40-50 ℃ and the pressure is 8-12 MPa.

In a second aspect of the invention, there is provided a starch ionomer prepared by a process as described in any of the examples of the first aspect of the invention.

In a third aspect of the invention, the invention provides a starch ionomer production device comprising: the gelatinizing unit is used for mixing the high amylose starch with water and carrying out gelatinizing treatment so as to obtain a gelatinized product; and the grafting unit is connected with the gelatinizing unit and is used for reacting the gelatinized product with organic acid salt and dihydroxy carboxylic acid so as to obtain the starch ionomer. Thereby rapidly preparing starch ionomers excellent in properties.

According to the embodiment of the invention, the temperature of the pasting treatment is 80-110 ℃, and the time of the pasting treatment is 20-80 minutes.

According to an embodiment of the present invention, the mass ratio of the gelatinized product and the organic acid salt is 1:0.3-1: 0.8.

according to an embodiment of the invention, the mass ratio of the gelatinization product to the dihydroxy carboxylic acid is 1:0.3-1: 0.8.

in a fourth aspect of the invention, there is provided a fully degradable plastic comprising the starch ionomer of the second aspect of the invention.

According to an embodiment of the present invention, the content of the starch ionomer in the fully degradable plastic is 15% to 80%.

According to an embodiment of the invention, the plastic material comprises, but is not limited to, PLA, PBAT, PBS, PBSA.

In a fifth aspect of the invention, the invention provides a method of preparing a fully degradable plastic comprising: the starch ionomer of the second aspect of the present invention and a plastic material are mixed and subjected to melt extrusion granulation to obtain the fully degradable plastic. And mixing the starch ionomer and a plastic material according to a certain proportion, and performing double-screw melting extrusion granulation to obtain the fully degradable plastic.

In some embodiments of the present invention, the melt extrusion temperature is 110 to 180 ℃. In some embodiments of the invention, the mass ratio of the starch ionomer and the plastic material is 1: 0.25-1: 5.

in a sixth aspect of the present invention, the present invention provides a fully degradable plastic generating system comprising: a starch ionomer generating device according to the third aspect of the present invention;

and the melting device is connected with the starch ionomer generation device and is used for carrying out melt extrusion granulation on the mixed starch ionomer and plastic material so as to obtain the fully degradable plastic.

According to an embodiment of the invention, in the fully degradable plastic generation system, the melt extrusion temperature is 110-180 ℃.

According to an embodiment of the present invention, in the fully degradable plastic generation system, the mass ratio of the starch ionomer to the plastic material is 1: 0.25-1: 5.

the beneficial effects obtained by the invention are as follows:

1. the invention provides a starch ionomer, which adopts a mode of esterifying and grafting high amylose starch by organic acid salt to convert partial hydroxyl on a starch chain into carboxylate, thereby preventing the hydroxyl from forming strong hydrogen bond action with the hydroxyl and ensuring the thermoplastic processing performance of the starch; meanwhile, the carboxylate and hydroxyl can form weak hydrogen bond action, so that the mechanical property of the material is improved; in addition, the presence of the carboxylate can effectively improve the processing viscosity of the starch and improve the processing performance.

2. The invention provides a method for preparing starch ionomer, which is carried out in supercritical carbon dioxide fluid, does not need catalyst, does not generate three wastes, and is environment-friendly.

3. The invention relates to application of a starch ionomer in composite fully-degradable plastics. When the starch ionomer is used in combination with other synthetic fully-degradable high polymer materials, the addition amount can reach 80 wt%, and the cost of the composite material can be effectively reduced while the requirement on mechanical properties is met. Particularly, the ionomer has obvious toughening effect on PLA and can be blown into a film at a certain adding amount.

Drawings

FIG. 1 is a flow diagram of a method of making a starch ionomer of the present invention.

FIG. 2 is a schematic diagram of the structure of a starch ionomer production device of the present invention.

FIG. 3 is a schematic structural diagram of a fully degradable plastic production system of the present invention.

Detailed Description

The following detailed description of embodiments of the invention is intended to be illustrative, and is not to be construed as limiting the invention. The description and illustrations of certain terms herein are intended only to facilitate understanding by those skilled in the art and should not be construed as limiting the scope of the invention.

Ionomers are generally understood in the art to refer to materials that have non-bonded weak interactions between molecules that can occur or disappear under certain conditions. Accordingly, herein, "starch ionomer" refers to starch in which groups capable of generating non-bond weak fragrancing effects are introduced into the starch chain, thereby exhibiting ionomer characteristics.

As used herein, reference to high amylose starch means that the amylose content is higher than that of normal starch, typically above 40%. According to an embodiment of the invention, the amylose content of the high amylose starch is 40-95%. According to embodiments of the invention, the high amylose starch has an amylose content of 40-90%, 40-85%, 40-80%, 40-70%, 40-60%, 45-95%, 50-95%, 55-95%, 60-95%, 65-95%, 70-95%, 75-95%, or 80-95%.

The present invention provides a method of preparing a starch ionomer comprising:

1. mixing high amylose starch with water, and performing gelatinization treatment to obtain a gelatinized product;

2. reacting the gelatinized product with an organic acid salt, a dihydroxy carboxylic acid, to obtain the starch ionomer.

After the high amylose starch is gelatinized by water, the high amylose starch is esterified and grafted by organic acid salt, so that partial hydroxyl on a starch chain can be converted into carboxylate, the formation of strong hydrogen bond action between the hydroxyl on the starch chain and the hydroxyl can be prevented, the thermoplastic processability of the starch is ensured, and meanwhile, the carboxylate and the hydroxyl can form weak hydrogen bond action, so that the mechanical property of the material can be improved; in addition, the presence of the carboxylate is also effective in increasing the processing viscosity of the starch, thereby improving processability.

When the gelatinization treatment is carried out, a certain amount of high amylose starch and a certain amount of water are mixed and gelatinized for a certain time at a certain temperature. In some embodiments, the temperature of the gelatinization treatment in the step (1) is 80-110 ℃, and the time of the gelatinization treatment is 20-80 min. In some embodiments, the temperature of the gelatinization process is 80-100 degrees celsius. In some embodiments, the time of the gelatinization treatment is 30 to 50 minutes, for example 30 minutes, 40 minutes or 50 minutes. In some embodiments, the mass ratio of the high amylose starch to the water in step (1) is from 1:0.1 to 1: 1. The mass ratio of the high amylose starch to the water is 1:0.3,1: 0.4,1: 0.5,1: 0.6,1: 0.7,1: 0.8, or 1: 0.9.

adding a certain amount of gelatinized high amylose starch, organic acid salt and dihydroxy carboxylic acid into a supercritical carbon dioxide reaction kettle, reacting in a supercritical carbon dioxide fluid at a certain temperature and under a certain pressure in a fluidized bed mode, enabling a reaction product to leave the reaction kettle along with the carbon dioxide fluid, and performing reduced pressure separation to obtain the starch ionomer. In some embodiments, the mass ratio of the gelatinized product and the organic acid salt in step (2) is 1:0.3 to 1:0.8, for example the gelatinized product and the organic acid salt are in a mass ratio of 1: 0.4,1: 0.5,1: 0.6 or 1: 0.7,1: 0.8. the organic acid salts include, but are not limited to, monosodium citrate, monosodium fumarate, monosodium malate, monosodium succinate, and the like. In some embodiments, the ratio of the gelatinization product to dihydroxy carboxylic acid is 1:0.3 to 1: 0.8; the dihydroxy carboxylic acids include, but are not limited to, dimethylol propionic acid, dimethylol butyric acid, and the like.

In some embodiments, step (2) further comprises: (2-1) reacting the gelatinized product with an organic acid salt and a dihydroxy carboxylic acid in a supercritical carbon dioxide fluid environment to obtain a reaction product;

(2-2) subjecting the reaction product to separation under reduced pressure to obtain the starch ionomer;

in some embodiments, the reaction is performed in a supercritical carbon dioxide reaction vessel.

In some embodiments, the reaction temperature is 40-50 ℃ and the pressure is 8-12 MPa.

The present invention also provides a starch ionomer generating apparatus, as shown in fig. 2, comprising: the gelatinizing unit is used for mixing the high amylose starch with water and carrying out gelatinizing treatment so as to obtain a gelatinized product; and the grafting unit is connected with the gelatinizing unit and is used for reacting the gelatinized product with organic acid salt and dihydroxy carboxylic acid so as to obtain the starch ionomer. The device can be used for quickly preparing the starch ionomer with excellent performance.

The invention also provides a fully degradable plastic generating system, as shown in fig. 3, comprising: a starch ionomer generating apparatus, the above-mentioned apparatus;

and the melting device is connected with the starch ionomer generation device and is used for carrying out melt extrusion granulation on the mixed starch ionomer and plastic material so as to obtain the fully degradable plastic. The scheme of the invention will be explained with reference to the examples. It will be appreciated by those skilled in the art that the following examples are illustrative of the invention only and should not be taken as limiting the scope of the invention. The examples, where specific techniques or conditions are not indicated, are to be construed according to the techniques or conditions described in the literature in the art or according to the product specifications. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available. The mechanical properties of the prepared fully-degradable plastic are characterized by referring to a method given by national standards.

Example 1

1) Mixing high amylose starch with water at a ratio of 1:0.1, and gelatinizing at 80 deg.C for 80 min. Adding the gelatinized high amylose starch, monosodium citrate and dimethylolpropionic acid into a supercritical carbon dioxide reaction kettle according to the proportion of 1:0.3:0.8, reacting in a supercritical carbon dioxide fluid at 40 ℃ and 12MPa in a fluidized bed mode, enabling a reaction product to leave the reaction kettle along with the carbon dioxide fluid, and performing reduced pressure separation to obtain the starch ionomer.

2) And mixing the synthesized starch ionomer with PLA at a ratio of 1:0.25, and performing melt extrusion granulation by using a double screw at an extrusion temperature of 180 ℃ to obtain the fully degradable plastic.

Example 2

1) Mixing high amylose starch with water at a ratio of 1:0.2, and gelatinizing at 90 deg.C for 40 min. Adding gelatinized high amylose starch, monosodium fumarate and dimethylolpropionic acid into a supercritical carbon dioxide reaction kettle according to the proportion of 1:0.5:0.4, reacting in a supercritical carbon dioxide fluid at 40 ℃ and under 10MPa in a fluidized bed mode, enabling a reaction product to leave the reaction kettle along with the carbon dioxide fluid, and performing reduced pressure separation to obtain the starch ionomer.

2) And mixing the synthesized starch ionomer with PBAT at a ratio of 1:0.5, and performing double-screw melt extrusion granulation at an extrusion temperature of 110 ℃ to obtain the fully degradable plastic.

Example 3

1) Mixing high amylose starch with water at a ratio of 1:0.5, and gelatinizing at 100 deg.C for 30 min. Adding the gelatinized high amylose starch, monosodium malate and dimethylolbutyric acid into a supercritical carbon dioxide reaction kettle according to the proportion of 1:0.8:0.3, reacting in a supercritical carbon dioxide fluid at 40 ℃ and under 8MPa in a fluidized bed mode, enabling a reaction product to leave the reaction kettle along with the carbon dioxide fluid, and performing reduced pressure separation to obtain the starch ionomer.

2) And mixing the synthesized starch ionomer with PBS in a ratio of 1:3, and performing melt extrusion granulation by a double screw at an extrusion temperature of 150 ℃ to obtain the fully degradable plastic.

Example 4

1) Mixing high amylose starch with water at a ratio of 1:1, and gelatinizing at 110 deg.C for 20 min. Adding the gelatinized high amylose starch, monosodium succinate and dimethylolbutyric acid into a supercritical carbon dioxide reaction kettle according to the proportion of 1:0.6:0.4, reacting in a supercritical carbon dioxide fluid at 50 ℃ and 12MPa in a fluidized bed mode, enabling a reaction product to leave the reaction kettle along with the carbon dioxide fluid, and performing reduced pressure separation to obtain the starch ionomer.

2) And mixing the synthesized starch ionomer with PBSA in a ratio of 1:5, and performing double-screw melt extrusion granulation at an extrusion temperature of 160 ℃ to obtain the fully degradable plastic.

The mechanical property data of each example are shown in table 1 below:

TABLE 1 examination results of the examples

	Tensile Strength (MPa)	Elongation at Break (%)
			Example 1	35.2	84.2
Example 2	24.3	420
			Example 3	39.6	463
Example 4	32.2	395

Therefore, the prepared fully-degradable plastic has excellent mechanical properties.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.