阅读说明：本技术 聚乳酸材料生物降解性能调节剂及原料配方、制备方法 (Polylactic acid material biodegradation performance regulator, raw material formula and preparation method ) 是由 李勇锋 蒋旭玲 白成坡 唐普林 曲世朝 于 2020-12-31 设计创作，主要内容包括：本发明属于生物降解技术领域,具体涉及一种聚乳酸材料生物降解性能调节剂及原料配方、制备方法。本聚乳酸材料生物降解性能调节剂包括：爪型结构的聚酯多元醇或爪型结构的聚酯多元酸。有效解决了聚乳酸材料自然环境下解决速率慢的问题,少量添加调节剂就可以大幅改善聚乳酸材料的生物降解速率,而且保持了聚乳酸材料的刚性材料性能。(The invention belongs to the technical field of biodegradation, and particularly relates to a polylactic acid material biodegradation performance regulator, a raw material formula and a preparation method. The biodegradable performance regulator for polylactic acid material comprises: polyester polyol with a claw-shaped structure or polyester polybasic acid with a claw-shaped structure. The problem of slow solution rate of the polylactic acid material in a natural environment is effectively solved, the biodegradation rate of the polylactic acid material can be greatly improved by adding a small amount of regulator, and the rigid material performance of the polylactic acid material is kept.)

1. A modulator, comprising:

polyester polyol with a claw-shaped structure or polyester polybasic acid with a claw-shaped structure.

2. The regulator according to claim 1,

the polyester polyol is ternary or higher polyol with molecular formulaWherein

R1, R2, R3 and R4 … Rn are linear polyester chains;

the molecular weight of the branch chains of R1, R2, R3 and R4 … Rn is between 1000 and 50000;

the branched molecules of R1, R2, R3 and R4 … Rn contain lactic acid block structural units.

3. The regulator according to claim 1,

the polyester polybasic acid is ternary or higher polybasic acid with molecular formula

Wherein

R1, R2, R3 and R4 … Rn are linear polyester chains;

the molecular weight of the branch chains of R1, R2, R3 and R4 … Rn is between 1000 and 50000;

the branched molecules of R1, R2, R3 and R4 … Rn contain lactic acid block structural units.

4. The raw material formula of the regulator is characterized by comprising the following components:

low molecular weight polylactic acid;

low molecular weight poly (butylene succinate);

glycerol, a salt thereof and a solvent.

5. The stock formulation of claim 4,

the low molecular weight polylactic acid is suitable for being prepared by reacting lactic acid with a catalyst;

the low molecular weight polybutylene succinate is suitable for being prepared by reacting succinic acid with butanediol.

6. A method of preparing a modulator, comprising:

preparing low molecular weight polylactic acid;

preparing low molecular weight poly (butylene succinate);

mixing low-molecular-weight polylactic acid and low-molecular-weight polybutylene succinate for reaction; and

the reaction was continued after the addition of glycerol.

7. The raw material formula of the regulator is characterized by comprising the following components:

low molecular weight polylactic acid;

low molecular weight polysebacic acid butanediol ester;

pentaerythritol.

8. The stock formulation of claim 7,

the low molecular weight polylactic acid is suitable for being prepared by reacting lactic acid with a catalyst;

the low molecular weight poly (butylene sebacate) is suitable for being prepared by reacting sebacic acid with butanediol.

9. A method of preparing a modulator, comprising:

preparing low molecular weight polylactic acid;

preparing low molecular weight poly (butylene succinate);

mixing low molecular weight polylactic acid and low molecular weight polysebacic acid butanediol ester for reaction; and

the reaction was continued after the addition of pentaerythritol.

10. The raw material formula of the regulator is characterized by comprising the following components:

low molecular weight polylactic acid;

low molecular weight poly (hexanediol sebacate);

pentaerythritol.

11. The stock formulation of claim 10,

the low molecular weight polylactic acid is suitable for being prepared by reacting lactic acid with a catalyst;

the low molecular weight poly (butylene sebacate) is suitable for being prepared by reacting sebacic acid with hexanediol.

12. A method of preparing a modulator, comprising:

preparing low molecular weight polylactic acid;

preparing low molecular weight poly (hexanediol sebacate);

mixing low-molecular-weight polylactic acid and low-molecular-weight polysebacic acid hexanediol ester for reaction; and

the reaction was continued after the addition of pentaerythritol.

Technical Field

The invention belongs to the technical field of biodegradation, and particularly relates to a polylactic acid material biodegradation performance regulator, a raw material formula and a preparation method.

Background

The polylactic acid material is a biomass and biodegradable material, the raw material of the material is derived from plants, and the biodegradable performance can be met under the controlled composting condition, but the glass transition temperature of the polylactic acid material is about 60 ℃, the polylactic acid material is in a glass state at normal temperature, the molecular chain is highly frozen, and the moisture and microorganisms are difficult to corrode, so the natural biodegradation performance of the polylactic acid material is poor, even the polylactic acid material is not obviously degraded for 2 to 3 years, and the difficulty is brought to the wide application of the product.

There are many common adjustment methods currently used. For example, the blending modification of the flexible linear high molecular material is blended with flexible biodegradable materials such as PBAT or PBS and the like, so that the biodegradation performance of the flexible linear high molecular material is improved. The addition amount of the flexible linear polymer material is large, and the rigid material performance of the polylactic acid can not be maintained after modification. For another example, natural polymer materials, such as starch and cellulose, are added to the polylactic acid material, so as to improve the biodegradability thereof. After the natural high polymer material is added and blended in the scheme, the material performance is greatly reduced, and the practical application is difficult.

Disclosure of Invention

The invention provides a biodegradable performance regulator of a polylactic acid material, a raw material formula and a preparation method.

In order to solve the technical problems, the invention provides a biodegradable property regulator of polylactic acid material, which comprises: polyester polyol with a claw-shaped structure or polyester polybasic acid with a claw-shaped structure.

As a further improvement of the invention, the polyester polyol is a ternary or higher polyol with the molecular formula of

Wherein R1, R2, R3, R4 … Rn are linear polyester chains; the molecular weight of the branch chains of R1, R2, R3 and R4 … Rn is between 1000 and 50000; the branched molecules of R1, R2, R3 and R4 … Rn contain lactic acid block structural units.

As a further improvement of the invention, the polyester polybasic acid is a ternary or higher polybasic acid with a molecular formula of

Wherein R1, R2, R3, R4 … Rn are linear polyester chains; the molecular weight of the branch chains of R1, R2, R3 and R4 … Rn is between 1000 and 50000; the branched molecules of R1, R2, R3 and R4 … Rn contain lactic acid block structural units.

In a second aspect, the invention also provides a raw material formula of the regulator, which comprises: low molecular weight polylactic acid; low molecular weight poly (butylene succinate); glycerol, a salt thereof and a solvent.

As a further improvement of the present invention, the low molecular weight polylactic acid is suitable for being prepared by reacting lactic acid with a catalyst; the low molecular weight polybutylene succinate is suitable for being prepared by reacting succinic acid with butanediol.

In a third aspect, the present invention also provides a method for preparing a modulator, comprising: preparing low molecular weight polylactic acid; preparing low molecular weight poly (butylene succinate); mixing low-molecular-weight polylactic acid and low-molecular-weight polybutylene succinate for reaction; and the reaction was continued after the addition of glycerol.

In a fourth aspect, the present invention further provides a raw material formulation of a regulator, comprising: low molecular weight polylactic acid; low molecular weight polysebacic acid butanediol ester; pentaerythritol.

As a further improvement of the present invention, the low molecular weight polylactic acid is suitable for being prepared by reacting lactic acid with a catalyst; the low molecular weight poly (butylene sebacate) is suitable for being prepared by reacting sebacic acid with butanediol.

In a fifth aspect, the present invention also provides a method for preparing a modulator, comprising: preparing low molecular weight polylactic acid; preparing low molecular weight poly (butylene succinate); mixing low molecular weight polylactic acid and low molecular weight polysebacic acid butanediol ester for reaction; and continuing the reaction after adding pentaerythritol.

In a sixth aspect, the present invention further provides a raw material formulation of a regulator, comprising: low molecular weight polylactic acid; low molecular weight poly (hexanediol sebacate); pentaerythritol.

As a further improvement of the present invention, the low molecular weight polylactic acid is suitable for being prepared by reacting lactic acid with a catalyst; the low molecular weight poly (butylene sebacate) is suitable for being prepared by reacting sebacic acid with hexanediol.

In a seventh aspect, the present invention also provides a method for preparing a regulator, comprising: preparing low molecular weight polylactic acid; preparing low molecular weight poly (hexanediol sebacate); mixing low-molecular-weight polylactic acid and low-molecular-weight polysebacic acid hexanediol ester for reaction; and continuing the reaction after adding pentaerythritol.

The invention has the beneficial effects that the polylactic acid material biodegradation performance regulator, the raw material formula and the preparation method adopt the polyester polyol with the claw-shaped structure or the polyester polybasic acid with the claw-shaped structure as the regulator, effectively solve the problem of slow solution rate of the polylactic acid material in the natural environment, greatly improve the biodegradation rate of the polylactic acid material by adding a small amount of the regulator, and keep the rigid material performance of the polylactic acid material.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a flow chart of a process for preparing a first conditioning agent of the present invention;

FIG. 2 is a flow chart of a process for preparing a second modulator of the present invention;

FIG. 3 is a flow chart of a process for preparing a third modulator of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

A first part: elucidating the specific technical scheme

The invention provides a biodegradable performance regulator of polylactic acid material, comprising: polyester polyol with a claw-shaped structure or polyester polybasic acid with a claw-shaped structure.

Optionally, the polyester polyol is a ternary or higher-ternary polyol with a molecular formula of

Wherein R1, R2, R3, R4 … Rn are linear polyester chains; the molecular weight of the branch chains of R1, R2, R3 and R4 … Rn is between 1000 and 50000; the branched molecules of R1, R2, R3 and R4 … Rn contain lactic acid block structural units.

Optionally, the polyester polybasic acid is a ternary or higher polybasic acid with a molecular formula of

Wherein R1, R2, R3, R4 … Rn are linear polyester chains; the molecular weight of the branch chains of R1, R2, R3 and R4 … Rn is between 1000 and 50000; the branched molecules of R1, R2, R3 and R4 … Rn contain lactic acid block structural units.

In the scheme, the lactic acid material biodegradation performance regulator is claw-shaped polyester polyol or claw-shaped polyester polybasic acid. Can be prepared by various raw material formulas. The three raw material formulas and the corresponding preparation methods are described below.

The raw materials of the first regulator and the preparation method thereof are as follows:

the invention also provides a raw material formula of the first regulator, which comprises the following components: low molecular weight polylactic acid; low molecular weight poly (butylene succinate); glycerol, a salt thereof and a solvent.

Alternatively, the low molecular weight polylactic acid is suitable for preparation by reaction of lactic acid with a catalyst (e.g. copper sulfate); the low molecular weight polybutylene succinate is suitable for being prepared by reacting succinic acid with butanediol.

Referring to fig. 1, the present invention also provides a method for preparing a first modulator, comprising: preparing low molecular weight polylactic acid; preparing low molecular weight poly (butylene succinate); mixing low-molecular-weight polylactic acid and low-molecular-weight polybutylene succinate for reaction; and the reaction was continued after the addition of glycerol.

Specifically, a proper amount of lactic acid (water removal) is added into a reactor, 1.5 wt% of copper sulfate is added as a catalyst, and the reaction is carried out for 1 to 5 hours at the temperature of between 50 and 120 ℃ to prepare the low molecular weight polylactic acid. According to a molar ratio of 1: 1, putting succinic acid and butanediol into a reaction kettle, and stirring and reacting for 1-5h at the temperature of 80-150 ℃ to obtain the low molecular weight poly (butylene succinate). Mixing low molecular weight poly (butylene succinate) and low molecular weight polylactic acid according to the mass ratio of (1-5): 1, reacting at 90-160 ℃ for 1-5h, adding 2-8 wt% of glycerol, and continuing to react for 1-3h to obtain the polyester polyol or polyester polybasic acid with the three-branched-chain claw-shaped structure and different molecular weights, namely the first regulator.

The raw materials of the second regulator and the preparation method thereof are as follows:

the invention also provides a raw material formula of a second regulator, which comprises the following components: low molecular weight polylactic acid; low molecular weight polysebacic acid butanediol ester; pentaerythritol.

Alternatively, the low molecular weight polylactic acid is suitable for preparation by reaction of lactic acid with a catalyst (e.g. copper sulfate); the low molecular weight poly (butylene sebacate) is suitable for being prepared by reacting sebacic acid with butanediol.

Referring to fig. 2, the present invention also provides a method for preparing a second modulator, comprising: preparing low molecular weight polylactic acid; preparing low molecular weight poly (butylene succinate); mixing low molecular weight polylactic acid and low molecular weight polysebacic acid butanediol ester for reaction; and continuing the reaction after adding pentaerythritol.

Specifically, a proper amount of lactic acid (water removal) is added into a reactor, 1.5 wt% of copper sulfate is added as a catalyst, and the reaction is carried out for 1 to 5 hours at the temperature of between 50 and 120 ℃ to prepare the low molecular weight polylactic acid. According to a molar ratio of 1: 1, putting sebacic acid and butanediol into a reaction kettle, and stirring and reacting for 1-5h at the temperature of 80-150 ℃ to obtain low molecular weight poly-sebacic acid butanediol ester. Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of (1-5): 1, reacting at 90-160 ℃ for 1-5h, adding 2-8 wt% of pentaerythritol, and continuing to react for 1-3h to obtain the polyester polyol or polyester polybasic acid with the four-branched-chain claw-shaped structure, namely the second regulator, with different molecular weights.

The raw materials of the third regulator and the preparation method thereof are as follows:

the invention also provides a raw material formula of a third regulator, which comprises the following components: low molecular weight polylactic acid; low molecular weight poly (hexanediol sebacate); pentaerythritol.

Alternatively, the low molecular weight polylactic acid is suitable for preparation by reaction of lactic acid with a catalyst (e.g. copper sulfate); the low molecular weight poly (butylene sebacate) is suitable for being prepared by reacting sebacic acid with hexanediol.

Referring to fig. 3, the present invention also provides a method for preparing a third modulator, comprising: preparing low molecular weight polylactic acid; preparing low molecular weight poly (hexanediol sebacate); mixing low-molecular-weight polylactic acid and low-molecular-weight polysebacic acid hexanediol ester for reaction; and continuing the reaction after adding pentaerythritol.

Specifically, a proper amount of lactic acid (water removal) is added into a reactor, 1.5 wt% of copper sulfate is added as a catalyst, and the reaction is carried out for 1 to 5 hours at the temperature of between 50 and 120 ℃ to prepare the low molecular weight polylactic acid. According to a molar ratio of 1: 1, adding sebacic acid and hexanediol into a reaction kettle, and stirring and reacting for 1-5h at the temperature of 80-150 ℃ to obtain the low molecular weight poly-sebacic acid hexanediol ester. Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of (1-5): 1, reacting at 90-160 ℃ for 1-5h, adding 2-8 wt% of pentaerythritol, and continuing to react for 1-3h to obtain the polyester polyol or polyester polybasic acid with the four-branched-chain claw-shaped structure and different molecular weights, namely the third regulator.

A second part: some examples are given below

Example 1

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 50 ℃ for 5 hours to prepare the low molecular weight polylactic acid.

(2) According to a molar ratio of 1: 1, putting succinic acid and butanediol into a reaction kettle, and stirring and reacting for 5 hours at the temperature of 80 ℃ to obtain the low molecular weight poly (butylene succinate).

(3) Mixing low molecular weight poly (butylene succinate) and low molecular weight polylactic acid according to the mass ratio of 1: 1, reacting at 90 ℃ for 5 hours, adding 2 wt% of glycerol, and continuing to react for 1 hour to obtain polyester polyol or polyester polybasic acid with a three-branched chain claw-shaped structure, namely the first regulator.

Example 2

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 120 ℃ for 1h to prepare the low-molecular-weight polylactic acid.

(2) According to a molar ratio of 1: 1, putting succinic acid and butanediol into a reaction kettle, and stirring and reacting for 1h at 150 ℃ to obtain low molecular weight poly (butylene succinate).

(3) Mixing low molecular weight poly (butylene succinate) and low molecular weight polylactic acid according to the mass ratio of 5: 1, reacting at 160 ℃ for 1 hour, adding 8 wt% of glycerol, and continuing to react for 3 hours to obtain polyester polyol or polyester polybasic acid with a three-branched chain claw-shaped structure, namely the first regulator.

Example 3

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 100 ℃ for 2h to prepare the low-molecular-weight polylactic acid.

(2) According to a molar ratio of 1: 1, putting succinic acid and butanediol into a reaction kettle, and stirring and reacting for 3 hours at 120 ℃ to obtain low molecular weight poly (butylene succinate).

(3) Mixing low molecular weight poly (butylene succinate) and low molecular weight polylactic acid according to the mass ratio of 3: 1, reacting at 130 ℃ for 4 hours, adding 5 wt% of glycerol, and continuing to react for 1.5 hours to obtain polyester polyol or polyester polybasic acid with a three-branched chain claw-shaped structure and a claw-shaped structure, namely the first regulator.

Example 4

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 50-DEG C for 1h to prepare the low-molecular-weight polylactic acid.

(2) According to a molar ratio of 1: 1, putting sebacic acid and butanediol into a reaction kettle, and stirring and reacting for 1h at the temperature of 80 ℃ to obtain low molecular weight poly-sebacic acid butanediol ester.

(3) Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of 1: 1, reacting at 90 ℃ for 1 hour, adding 2 wt% of pentaerythritol, and continuing to react for 1 hour to obtain the polyester polyol or polyester polybasic acid with the four-branched-chain claw-shaped structure, namely the second regulator.

Example 5

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 120 ℃ for 5 hours to prepare the low molecular weight polylactic acid.

(2) According to a molar ratio of 1: 1, putting sebacic acid and butanediol into a reaction kettle, and stirring and reacting for 5 hours at 150 ℃ to obtain low molecular weight poly-sebacic acid butanediol ester.

(3) Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of 5: 1, reacting at 160 ℃ for 5 hours, adding 8 wt% of pentaerythritol, and continuing to react for 3 hours to obtain polyester polyol or polyester polybasic acid with a four-branched chain claw-shaped structure, namely the second regulator.

Example 6

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 80 ℃ for 3 hours to prepare the low molecular weight polylactic acid.

(2) According to a molar ratio of 1: 1, putting sebacic acid and butanediol into a reaction kettle, and stirring and reacting for 2 hours at the temperature of 100 ℃ to obtain low molecular weight poly-sebacic acid butanediol ester.

(3) Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of 2: 1, reacting at 140 ℃ for 1-5h, adding 6 wt% of pentaerythritol, and continuing to react for 2h to obtain the polyester polyol or polyester polybasic acid with the four-branched-chain claw-shaped structure, namely the second regulator.

Example 7

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 50 ℃ for 5 hours to prepare the low molecular weight polylactic acid.

(2) According to a molar ratio of 1: 1, adding sebacic acid and hexanediol into a reaction kettle, and stirring and reacting for 5 hours at 150 ℃ to obtain the low molecular weight poly-sebacic acid hexanediol ester.

(3) Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of 5: 1, reacting at 160 ℃ for 1 hour, adding 8 wt% of pentaerythritol, and continuing to react for 3 hours to obtain polyester polyol or polyester polybasic acid with a four-branched chain claw-shaped structure, namely the third regulator.

Example 8

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 120 ℃ for 1h to prepare the low-molecular-weight polylactic acid.

(2) According to a molar ratio of 1: 1, adding sebacic acid and hexanediol into a reaction kettle, and stirring and reacting for 1h at the temperature of 80 ℃ to obtain the low molecular weight poly-sebacic acid hexanediol ester.

(3) Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to the mass ratio of 1: 1, reacting at 90 ℃ for 5 hours, adding 2 wt% of pentaerythritol, and continuing to react for 1 hour to obtain polyester polyol or polyester polybasic acid with a four-branched chain claw-shaped structure, namely the third regulator.

Example 9

(1) Adding a proper amount of lactic acid (water removal) into a reactor, adding 1.5 wt% of copper sulfate as a catalyst, and reacting at 90 ℃ for 2 hours to prepare the low molecular weight polylactic acid.

(2) According to a molar ratio of 1: 1, adding sebacic acid and hexanediol into a reaction kettle, and stirring and reacting for 4 hours at the temperature of 110 ℃ to obtain the low molecular weight poly-sebacic acid hexanediol ester.

(3) Mixing low-molecular weight poly (butylene sebacate) and low-molecular weight poly (lactic acid) according to a mass ratio of 4: 1, reacting at 120 ℃ for 2 hours, adding 4 wt% of pentaerythritol, and continuing to react for 2.5 hours to obtain polyester polyol or polyester polybasic acid with a four-branched chain claw-shaped structure, namely the third regulator.

And a third part: comparative analysis of performance parameters

(1) The polyester polyol (first modifier) having a claw-type structure prepared in example 1 was added in a proportion of 0.5 to 15% by mass of the polylactic acid and tested, and the procedure and results were as follows:

vacuum drying the polylactic acid PLLA particles for 2-10h until the water content is lower than 0.2%, and adding the polyester polyol with the claw-shaped structure according to the proportion of 0.5-5% and 15-50% of the mass of the polylactic acid. And (3) extruding, blending and modifying by adopting a double screw. The polylactic acid particles are fed by a normal hopper, and the structural polyester polyol with the claw-shaped structure is fed in a lateral feeding mode. And extruding, granulating and drying the polylactic acid modified particles. 60g of the particles were pressed at 180 ℃ into 0.5mm sheets and tested for relevant properties. The control temperature of the extruder is shown in table 1, the performance of the first regulator is shown in table 2, and the proportion of the regulator 1 in the experiment number in table 2 is 0, namely, various regulators are not added, and the extruder can be used as a comparative example in the scheme.

TABLE 1 extruder control temperature of the first modifier

Region I

Region II

Zone III

Zone IV

V region

Zone VI

Region VII

Zone VIII

Zone IX

Die head

90℃

150℃

160℃

170℃

180℃

180℃

175℃

170℃

165℃

160℃

TABLE 2 Properties of the first modifier

Experimental number	Proportion of regulator (%)	Glass transition temperature (. degree. C.)	Tensile modulus (MPa)	90 days biodegradation Rate (%)
					1	0	65	4200	38
2	0.5	63	4100	42
					3	1.0	61	4000	55
4	2.0	60	4000	60
					5	5.0	58	3950	81
6	7.0	55	3500	82
					7	10.0	50	2100	83
8	15.0	46	1500	83

(2) The polyester polybasic acid (second regulator) with claw-shaped structure prepared in example 4 was selected, added and tested at a ratio of 0.5-15% by mass of polylactic acid, and the test procedures and results were as follows:

vacuum drying the polylactic acid PLLA particles for 2-10h, wherein the water content is lower than 0.2%, and adding the polyester polybasic acid with the claw-shaped structure according to the proportion of 0.5-15% of the mass of the polylactic acid. And (3) extruding, blending and modifying by adopting a double screw. The polylactic acid particles are fed by a normal hopper, and the second regulator is fed in a lateral feeding mode. The extruder control temperature is shown in Table 3, and the properties of the second modifier are shown in Table 4.

TABLE 3 extruder control temperature for the second modifier

Region I

Region II

Zone III

Zone IV

V region

Zone VI

Region VII

Zone VIII

Zone IX

Die head

90℃

150℃

160℃

170℃

180℃

180℃

175℃

170℃

165℃

160℃

TABLE 4 Properties of the second modifier

Experimental number	Proportion of regulator (%)	Glass transition temperature (. degree. C.)	Tensile modulus (MPa)	90 days biodegradation Rate (%)
					9	0.5	65	4150	40
10	1.0	63	4100	53
					11	2.0	61	4100	58
12	5.0	58	4000	78
					13	7.0	56	3600	79
14	10.0	53	2300	79
					15	15.0	50	1700	79

(3) The polyester polybasic acid (third regulator) with claw structure prepared in example 7 was selected, added at a ratio of 0.5-15% by mass of polylactic acid and tested, and the procedure and results were as follows:

vacuum drying the polylactic acid PLLA particles for 2-10h, wherein the water content is lower than 0.2%, and adding the polyester polyol with the claw-shaped structure according to the proportion of 0.5-15% of the mass of the polylactic acid. And (3) extruding, blending and modifying by adopting a double screw. The polylactic acid particles are fed by a normal hopper, and the third regulator is fed by a lateral feeding mode. And extruding, granulating and drying the polylactic acid modified particles. 60g of the particles were pressed at 180 ℃ into 0.5mm sheets and tested for relevant properties. The extruder control temperature is shown in Table 5, and the properties of the third modifier are shown in Table 6.

TABLE 5 extruder control temperature for the third modifier

Region I

Region II

Zone III

Zone IV

V region

Zone VI

Region VII

Zone VIII

Zone IX

Die head

90℃

150℃

160℃

170℃

180℃

180℃

175℃

170℃

165℃

160℃

TABLE 6 Properties of the third regulator

Experimental number	Proportion of regulator (%)	Glass transition temperature (. degree. C.)	Tensile modulus (MPa)	90 days biodegradation Rate (%)
					16	0.5	65	4200	41
17	1.0	63	4100	55
					18	2.0	61	4100	54
19	5.0	58	4000	75
					20	7.0	58	3800	78
21	10.0	53	2200	79
					22	15.0	48	1800	79

In conclusion, the biodegradable property regulator of the polylactic acid material, the raw material formula and the preparation method of the biodegradable property regulator of the polylactic acid material are characterized in that the polyester polyol with the claw-shaped structure or the polybasic acid with the claw-shaped structure is prepared by synthesis and used as the regulator, and the polylactic acid is blended, because the branched chain comprises the lactic acid unit structure, the branched chain of the regulator can effectively interpenetrate with the polylactic acid molecules, the compactness of the polylactic acid molecules is weakened, and the glass transition temperature of the polylactic acid material is reduced. The existence of a large amount of hydroxyl and carboxyl in the regulator improves the polarity of the polylactic acid material, is beneficial to the erosion of moisture and microorganisms to the blended material, and greatly improves the biodegradation performance of the material.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.