CN107189388B - Preparation method of environment-friendly polylactic acid film - Google Patents
Preparation method of environment-friendly polylactic acid film Download PDFInfo
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- CN107189388B CN107189388B CN201710558393.1A CN201710558393A CN107189388B CN 107189388 B CN107189388 B CN 107189388B CN 201710558393 A CN201710558393 A CN 201710558393A CN 107189388 B CN107189388 B CN 107189388B
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- polylactic acid
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/16—Nitrogen-containing compounds
- C08K5/20—Carboxylic acid amides
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
- C08J5/18—Manufacture of films or sheets
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/04—Oxygen-containing compounds
- C08K5/05—Alcohols; Metal alcoholates
- C08K5/053—Polyhydroxylic alcohols
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/04—Polyesters derived from hydroxy carboxylic acids, e.g. lactones
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/06—Biodegradable
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/10—Transparent films; Clear coatings; Transparent materials
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Biological Depolymerization Polymers (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
Abstract
The present invention belongs to the field of polyester organic polymer film making technology. The preparation method of the environment-friendly polylactic acid film is characterized by comprising the following steps: 1) respectively dissolving polylactic acid and a plasticizer by using a solvent, and mixing and stirring the solution uniformly after the polylactic acid and the plasticizer are fully dissolved to obtain a uniformly mixed solution; the solvent is a mixed solvent of acetone and 1-4 dioxane, and the mixed mass ratio of the acetone to the 1-4 dioxane is 3: 7; 2) putting the uniformly mixed solution into a thickening kettle, heating, and recovering part of the solvent through a steam recovery device; 3) extruding the solution thickened by the thickening kettle through a screw extruder, and collecting part of the solvent; 4) removing bubbles through extrusion of a secondary screw extruder, and 5) blowing a film by using a film blowing method after the extrusion of the secondary screw extruder; and obtaining the environment-friendly polylactic acid film after film blowing. The method has the advantages of simple process, less investment equipment, lower cost and good use effect.
Description
Technical Field
The invention belongs to the technical field of polyester organic polymer film preparation, and particularly relates to a preparation method of an environment-friendly polylactic acid film.
Background
Polylactic acid is a common organic high molecular polymer, has wide and sufficient raw material sources, can be regenerated, has no pollution in the production process, can be biodegraded, and is an ideal green high molecular material. There are currently three methods for the synthesis of polylactic acid. The first is a direct polycondensation method, in which lactic acid is directly condensed into an oligomer. Secondly, the lactic acid is made to generate cyclic dimer lactide, and then the cyclic dimer lactide is subjected to ring-opening polycondensation to form polylactic acid, so that the method is mature. Thirdly, preparing the high molecular polylactic acid by a reaction extrusion polycondensation method.
The second method is used in the present invention to prepare polylactic acid. After the polylactic acid film is heated and extruded by a two-stage screw machine in a grading way, the polylactic acid film is prepared by a film blowing method. The film is used as a disposable packaging film, and has good biodegradability, compatibility, luster and hand feeling. And polylactic acid is a renewable resource, and compared with petrochemical products such as traditional plastic films PVC and the like, the polylactic acid has wide and stable sources, and under the major trend of the current environmental protection theme, the development of an environment-friendly packaging film is very hot, and the degradable and energy-saving packaging film is actively researched and developed, so that the polylactic acid is a necessary way for the development of the packaging industry in future.
Disclosure of Invention
The invention aims to provide a preparation method of an environment-friendly polylactic acid film, which has the advantages of simple process, less investment equipment, lower cost and good use effect.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: the preparation method of the environment-friendly polylactic acid film is characterized by comprising the following steps:
1) respectively dissolving polylactic acid and a plasticizer by using a solvent, and mixing and stirring the solution uniformly after the polylactic acid and the plasticizer are fully dissolved to obtain a uniformly mixed solution;
wherein the mass ratio of the polylactic acid to the plasticizer is 1: 1; when dissolving polylactic acid, the mass ratio of polylactic acid to solvent is 1: 10, selecting a solvent; when the plasticizer is dissolved, the mass ratio of the plasticizer to the solvent is 1: 4, selecting a solvent;
the solvent is a mixed solvent (or called composite solvent) of acetone and 1-4 dioxane, and the mixing mass ratio of the acetone to the 1-4 dioxane is 3: 7;
2) putting the uniformly mixed solution into a thickening kettle, heating to volatilize a part of solvent, and recovering a part of solvent through a steam recovery device;
3) extruding the solution thickened by the thickening kettle through a screw extruder, arranging a steam recovery device in a grading heating area of the screw extruder, and recovering part of the solvent;
wherein the heating of the screw extruder is gradual change type graded heating, and a steam recovery device is arranged in a graded heating interval;
4) removing bubbles through a secondary screw extruder in an extruding way, setting graded heating as the same structure of the screw extruder shown in the step 3), and recovering partial solvent in a region;
5) blowing the film by using a film blowing method after the second-stage screw extruder extrudes; and obtaining the environment-friendly polylactic acid film after film blowing.
The polylactic acid is L-polylactic acid.
The plasticizer is a composite plasticizer of water, caprolactam and glycerol, and the mass ratio of the water to the caprolactam to the glycerol is 1:1: 1.
the heating temperature in the step 2) is 60 ℃, and the time is 5 minutes.
The grading heating zone in the step 3) has three gradients of 40 ℃, 50 ℃ and 60 ℃.
The model of the screw extruder in the step 3) is a co-rotating twin-screw extruder, SHJ-20B model.
The natural organic polymer polylactic acid film is suitable for disposable packaging.
The invention has the beneficial effects that: 1) the polylactic acid film-making biodegradation performance is good 2) a solvent recovery device is arranged in the whole process 3) two-stage screw extrusion is carried out, so that solutes are fully and uniformly mixed. The method has the advantages of simple process, less investment equipment and lower cost, and the finally prepared polylactic acid film has high biochemical quantity, is easy to biodegrade and cannot cause secondary pollution to the environment.
Detailed Description
The invention will now be further illustrated by reference to specific examples, which are intended to be illustrative only and not to limit the scope of the invention. Further, it should be understood that the skilled in the art can make changes or modifications to the present invention after reading the teaching of the present invention, and these equivalents also fall within the scope of the claims appended to the present application.
Example 1:
the preparation method of the environment-friendly polylactic acid film comprises the following steps:
1) dissolving 10g of plasticizer in 40g of solvent, dissolving 10g L-polylactic acid in 100g of solvent, fully stirring the solution when dissolving the plasticizer, and putting the solution on one side until the plasticizer is completely dissolved to obtain a plasticizer solution for later use. When dissolving polylactic acid, the mixture of the solvent and L-polylactic acid is placed in a water bath and heated, and the temperature is set to be 50 ℃. After the materials are fully dissolved, standing for 5 minutes, mixing with the plasticizer solution, stirring for ten minutes, and putting into a thickening kettle after uniform mixing.
The solvent is a mixed solvent (or called composite solvent) of acetone and 1-4 dioxane, and the mixing mass ratio of the acetone to the 1-4 dioxane is 3: 7;
the plasticizer is a composite plasticizer of water, caprolactam and glycerol, and the mass ratio of the water to the caprolactam to the glycerol is 1:1: 1.
2) Thickening in the thickening kettle, and setting the heating temperature to 60 ℃. After thickening for 5 minutes, a thickened kettle solution was obtained (the mixture was extruded through a screw extruder).
3) The solution thickened by the thickening kettle is extruded by a screw extruder, the temperature gradient of the screw extruder is three gradients of 40 ℃, 50 ℃ and 60 ℃, and the solution is extruded again by a secondary screw extruder.
4) Removing bubbles by extruding through a secondary screw extruder, and performing graded heating (40 ℃, 50 ℃ and 60 ℃) with the same structure of the screw extruder shown in the step 3), and recovering partial solvent in intervals;
5) blowing the film by using a film blowing method after the second-stage screw extruder extrudes; and obtaining the environment-friendly polylactic acid film after film blowing.
The obtained environment-friendly polylactic acid film has better strength, elongation and light transmission. The tensile test was carried out to obtain a tensile strength at break of 10.532MPa, an elongation of 63.4% and a light transmittance of 62.3%. Description of the drawings: the environment-friendly polylactic acid film has good use effect.
Claims (1)
1. The preparation method of the environment-friendly polylactic acid film is characterized by comprising the following steps:
1) respectively dissolving polylactic acid and a plasticizer by using a solvent, and mixing and stirring the solution uniformly after the polylactic acid and the plasticizer are fully dissolved to obtain a uniformly mixed solution;
wherein the mass ratio of the polylactic acid to the plasticizer is 1: 1; when dissolving polylactic acid, the mass ratio of polylactic acid to solvent is 1: 10, selecting a solvent; when the plasticizer is dissolved, the mass ratio of the plasticizer to the solvent is 1: 4, selecting a solvent;
the solvent is a mixed solvent of acetone and 1-4 dioxane, and the mixed mass ratio of the acetone to the 1-4 dioxane is 3: 7;
the polylactic acid is L-polylactic acid; the plasticizer is a composite plasticizer of water, caprolactam and glycerol, and the mass ratio of the water to the caprolactam to the glycerol is 1:1: 1;
2) putting the uniformly mixed solution into a thickening kettle, heating to volatilize a part of solvent, and recovering a part of solvent through a steam recovery device;
the heating temperature is 60 ℃, and the time is 5 minutes;
3) extruding the solution thickened by the thickening kettle through a screw extruder, arranging a steam recovery device in a grading heating area of the screw extruder, and recovering part of the solvent;
wherein the heating of the screw extruder is gradual change type graded heating, and a steam recovery device is arranged in a graded heating interval;
the grading heating zone has three gradients of 40 ℃, 50 ℃ and 60 ℃;
4) removing bubbles through a secondary screw extruder in an extruding way, setting graded heating as the same structure of the screw extruder shown in the step 3), and recovering partial solvent in a region;
5) blowing the film by using a film blowing method after the second-stage screw extruder extrudes; and obtaining the environment-friendly polylactic acid film after film blowing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710558393.1A CN107189388B (en) | 2017-07-11 | 2017-07-11 | Preparation method of environment-friendly polylactic acid film |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710558393.1A CN107189388B (en) | 2017-07-11 | 2017-07-11 | Preparation method of environment-friendly polylactic acid film |
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| Publication Number | Publication Date |
|---|---|
| CN107189388A CN107189388A (en) | 2017-09-22 |
| CN107189388B true CN107189388B (en) | 2020-01-14 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201710558393.1A Active CN107189388B (en) | 2017-07-11 | 2017-07-11 | Preparation method of environment-friendly polylactic acid film |
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Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1908041A (en) * | 2006-08-10 | 2007-02-07 | 李广洲 | Production method of recovering and regenerating high purity ABS from waste and old ABS plastic |
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2017
- 2017-07-11 CN CN201710558393.1A patent/CN107189388B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1908041A (en) * | 2006-08-10 | 2007-02-07 | 李广洲 | Production method of recovering and regenerating high purity ABS from waste and old ABS plastic |
Non-Patent Citations (1)
| Title |
|---|
| 聚乳酸的增塑改性;金水清;《化工新型材料》;20070130;第35卷(第1期);61-63 * |
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| CN107189388A (en) | 2017-09-22 |
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Effective date of registration: 20200824 Address after: 277412 east side of South Head Central Road, malantun Ligou Village (Xuzhuang natural village), Taierzhuang District, Zaozhuang City, Shandong Province Patentee after: Zaozhuang TIANYAO starch Technology Co.,Ltd. Address before: 430200 No. 1 Sunshine Road, Jiangxia District, Hubei, Wuhan, Wuhan Textile University sunshine campus, Wuhan Textile University Textile Institute Patentee before: Wuhan Textile University |