CN111410822B

CN111410822B - PBAT/PLA starch-based completely biodegradable material and preparation method thereof

Info

Publication number: CN111410822B
Application number: CN202010229433.XA
Authority: CN
Inventors: 何莉; 何炬帅
Original assignee: Sichuan Kaiyuan Chuangyi Biotechnology Co ltd
Current assignee: Sichuan Kaiyuan Chuangyi Biotechnology Co ltd
Priority date: 2020-03-27
Filing date: 2020-03-27
Publication date: 2022-09-16
Anticipated expiration: 2040-03-27
Also published as: CN111410822A

Abstract

The invention belongs to the technical field of high polymer materials, and provides a PBAT/PLA starch-based completely biodegradable material and a preparation method thereof. The biodegradable material comprises the following raw materials: PBAT, PLA, modified starch, monodisperse mesoporous molecular sieve, biomass activated carbon, bonding auxiliary agent, defoaming agent and release agent. The preparation method of the biodegradable material comprises the following steps: (1) preparing the citrus peel residue active carbon; (2) ultrasonically mixing the citrus peel residue activated carbon and the nano silicon dioxide to obtain a mixture; (3) adding PBAT, PLA, modified starch, the mixture, an adhesive auxiliary agent, a defoaming agent and a release agent into high-speed shearing equipment, mixing and dispersing, and granulating by using a double-screw machine to prepare a degradable master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material. Compared with the traditional degradable material, the biodegradable material has greatly improved mechanical property, can achieve the effect of complete biodegradation, and has controllable degradation time. The preparation method is simple and easy to operate.

Description

PBAT/PLA starch-based complete biodegradable material and preparation method thereof

Technical Field

The invention belongs to the technical field of high polymer materials, and particularly relates to a PBAT/PLA starch-based completely biodegradable material and a preparation method thereof.

Background

PBAT belongs to thermoplastic biodegradable plastic, is a copolymer of butanediol adipate and butanediol terephthalate, and has good ductility and elongation at break as well as good heat resistance and impact resistance; in addition, the biodegradable plastic has excellent biodegradability, and is one of the best degradable materials for active research and market application of biodegradable plastics. However, they are expensive and have drawbacks in terms of mechanical properties and thermal stability.

Polylactic acid (PLA) is a novel bio-based and renewable biodegradable material, has good biodegradability, can be completely degraded by microorganisms in the nature under specific conditions after being used, finally generates carbon dioxide and water, and does not pollute the environment. However, it has low elongation at break, high brittleness and poor mechanical properties.

In the prior art, the comprehensive performance of the two materials is improved by blending the two materials, but the defects of poor toughness, incomplete degradation, environmental pollution, uncontrollable degradation time and the like still exist.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a PBAT/PLA starch-based complete biodegradable material; compared with the traditional degradable material, the biodegradable material has greatly improved mechanical property, can achieve the effect of complete biodegradation, and has controllable degradation time.

Aiming at the defects in the prior art, the second purpose of the invention is to provide a preparation method of PBAT/PLA starch-based complete biodegradable material; the preparation method is simple and easy to operate, and the biodegradable material which can be completely degraded and has excellent mechanical properties can be prepared.

In order to achieve the above purpose, the solution adopted by the invention is as follows:

a PBAT/PLA starch-based complete biodegradable material comprises the following raw materials in parts by weight: PBAT35-55 parts, PLA25-35 parts, modified starch 25-35 parts, monodisperse mesoporous molecular sieve 0.8-2.5 parts, biomass activated carbon 3-6 parts, adhesion promoter 0.05-0.15 part, defoaming agent 0.05-0.15 part and release agent 0.05-0.15 part.

A preparation method of the PBAT/PLA starch-based complete biodegradable material comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) ultrasonically mixing the citrus peel residue activated carbon and the nano silicon dioxide according to the parts by weight, and filtering and drying to obtain a mixture; (3) adding PBAT, PLA, modified starch, a mixture, an adhesive aid, a defoaming agent and a release agent into high-speed shearing equipment according to parts by weight, mixing and dispersing, and granulating by using a double-screw machine to prepare a degradation master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

The PBAT/PLA starch-based complete biodegradable material and the preparation method thereof provided by the invention have the beneficial effects that:

(1) the PBAT/PLA starch-based complete biodegradable material provided by the invention is prepared by adding the monodisperse mesoporous molecular sieve and the biomass active carbon into a mixture of PBAT and PLA, and compounding the mixture with other auxiliary materials within the range of the mixture ratio required by the application, so that the tensile strength and the fracture growth rate of the biodegradable material can be greatly improved, and the completely degradable material can be completely degraded. The biomass activated carbon has the advantages of large yield, easy obtainment, capability of changing waste into valuable, cost saving, environmental protection, complete degradation, very large specific surface area and excellent dispersion effect, and can disperse the monodisperse mesoporous molecular sieve more uniformly into gaps of PLA and PBAT blending raw materials on one hand and simultaneously generate coupling with the PLA and the PBAT on the other hand. In the process of extruding and blowing the film, the monodisperse mesoporous molecular sieve can be stretched and crystallized, interface stripping occurs between the polymer and molecular sieve particles during stretching, and mutually communicated interface channels are formed around the molecular sieve, so that the film is endowed with stronger stretching performance and a smoother interface.

(2) The preparation method of the PBAT/PLA starch-based completely biodegradable material provided by the invention can be used for preparing the citrus peel residue activated carbon with high specific surface area and preparing the completely degradable and mechanically excellent biodegradable material. The preparation method is simple and easy to operate.

Drawings

FIG. 1 is a film obtained in example 3 provided in Experimental example 2 of the present invention;

FIG. 2 is a drawing showing a film prepared in example 3 according to Experimental example 2 of the present invention mixed with general compost soil;

FIG. 3 is a view showing that the film obtained in example 3 according to the present invention in Experimental example 2 was mixed with general compost soil, sealed and put into the general compost soil;

FIG. 4 is a graph of the film provided in inventive Experimental example 2 after disintegration in compost for one month;

FIG. 5 is a graph of the film provided in inventive Experimental example 2 after two months of disintegration in compost soil;

FIG. 6 is a graph of the film provided in inventive Experimental example 2 after three months of disintegration in compost soil.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The following is a detailed description of the PBAT/PLA starch-based completely biodegradable material provided by the embodiment of the invention.

A PBAT/PLA starch-based complete biodegradable material comprises the following raw materials in parts by weight: PBAT35-55 parts, PLA25-35 parts, modified starch 25-35 parts, monodisperse mesoporous molecular sieve 0.8-2.5 parts, biomass activated carbon 3-6 parts, adhesion promoter 0.05-0.15 part, defoaming agent 0.05-0.15 part and release agent 0.05-0.15 part. The biodegradable material prepared by adopting the raw materials in the proportioning range has excellent mechanical property and thermal stability.

Further, the biodegradable material prepared in the range has the advantages of 40 parts of PBAT, 30 parts of PLA, 30 parts of modified starch, 2 parts of monodisperse mesoporous molecular sieve, 5 parts of biomass activated carbon, 0.1 part of bonding auxiliary agent, 0.1 part of defoaming agent and 0.1 part of release agent by weight, and can obtain the best mechanical property and thermal stability.

In this example, the monodisperse mesoporous molecular sieve was nano silica in the form of monodisperse microspheres. The monodisperse microspheres herein have the same composition and shape, and the particle size tends to be uniform. The monodisperse microspherical nano silicon dioxide is a non-toxic, tasteless and pollution-free non-metallic material, is dispersed in a mixture of PBAT and PLA, and can greatly improve the strength of a polymer.

In this embodiment, the biomass activated carbon is citrus peel residue activated carbon. Mandarin orange is produced in Sichuan area, and the orange peel of the Mandarin orange is usually thrown away as waste. The citrus peel contains carbonaceous materials such as cellulose and hemicellulose as main components. In this example, the inventors have creatively found that the biodegradable material prepared by adding the citrus peel residue activated carbon prepared by the preparation method of this example and the monodisperse mesoporous molecular sieve described above into a mixture of PBAT and PLA has excellent tensile strength and elongation at break, and is completely decomposed.

In this example, modified acetylated starch was used as the modified starch. The defoaming agent is at least one of zinc stearate, polyoxyethylene polyoxypropylene pentaerythritol ether and polyether ether ketone emulsion. The release agent adopts at least one of ethylene bis stearamide, ethylene bis stearamide and stearic acid amide.

In this example, the adhesion promoter was a mixed liquid prepared from a polymerized fat and oil, a mineral white oil, and glycerin. Wherein the volume ratio of the polymerized grease to the mineral white oil to the glycerol is 0.8-1.2: 0.8-1.2: 1.8-2.2, and the prepared bonding auxiliary agent can further enhance the mechanical property of the biodegradable material.

The embodiment also provides a preparation method of the PBAT/PLA starch-based complete biodegradable material, which comprises the following steps: the method comprises the following steps:

(1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; the citrus peel activated carbon obtained in the method has excellent specific surface area; (2) ultrasonically mixing the citrus peel residue activated carbon and the nano silicon dioxide according to the weight parts, and filtering and drying to obtain a mixture; the nano carbon dioxide can be uniformly mixed with the citrus peel active carbon by adopting mixed ultrasound; (3) adding PBAT, PLA, modified starch, the mixture, the bonding auxiliary agent, the defoaming agent and the release agent into high-speed shearing equipment according to the parts by weight, mixing and dispersing, and granulating by using a double-screw machine to prepare a degradable master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material. In the application, the citrus peel residue activated carbon can more uniformly disperse the monodisperse mesoporous molecular sieve into gaps of the PLA and PBAT blending raw materials on one hand, and can also be coupled with the PLA and the PBAT simultaneously on the other hand. In the process of extruding and blowing the film, the monodisperse mesoporous molecular sieve can be stretched and crystallized, interface stripping occurs between the polymer and molecular sieve particles during stretching, and mutually communicated interface channels are formed around the molecular sieve, so that the film is endowed with stronger stretching performance and a smoother interface. Thereby improving the mechanical property of the biodegradable material.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The embodiment provides a preparation method of a PBAT/PLA starch-based complete biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) carrying out ultrasonic mixing on 3 parts of citrus peel residue activated carbon and 0.8 part of nano silicon dioxide, and then filtering and drying to obtain a mixture; (3) putting 35 parts of PBAT and 25 parts of PLA into a high-speed mixer, setting the temperature to be 120 ℃, stirring for 2min, then adding 0.05 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 0.8: 0.8: 1.8), stirring for 5min, adding 25 parts of modified starch, continuing stirring for 10min, then adding the mixture obtained in the step (3), adding 0.05 part of defoaming agent and 0.05 part of release agent, continuing stirring for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare the degradable master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

Example 2

The embodiment provides a preparation method of a PBAT/PLA starch-based complete biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) carrying out ultrasonic mixing on 6 parts of citrus peel residue activated carbon and 2.5 parts of nano silicon dioxide, and then filtering and drying to obtain a mixture; (3) putting 55 parts of PBAT and 35 parts of PLA into a high-speed mixer, setting the temperature to be 120 ℃, stirring for 2min, then adding 0.15 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 1.2: 1.2: 2.2), stirring for 5min, adding 35 parts of modified starch, continuing stirring for 10min, then adding the mixture obtained in the step (3), adding 0.15 part of defoaming agent and 0.15 part of release agent, continuing stirring for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare the degradable master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

Example 3

The embodiment provides a preparation method of a PBAT/PLA starch-based complete biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) ultrasonically mixing 5 parts of citrus peel residue activated carbon and 2 parts of nano silicon dioxide, and filtering and drying to obtain a mixture; (3) putting 40 parts of PBAT and 30 parts of PLA into a high-speed mixer, setting the temperature at 120 ℃, stirring for 2min, then adding 0.1 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 1: 1: 2), stirring for 5min, adding 30 parts of modified starch, continuing to stir for 10min, then adding the mixture obtained in the step (3), adding 0.1 part of defoaming agent and 0.1 part of release agent, continuing to stir for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare the degradation master batch; (4) blowing the degradable master batch by film blowing equipment to obtain the biodegradable material.

Example 4

The embodiment provides a preparation method of a PBAT/PLA starch-based complete biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) carrying out ultrasonic mixing on 4 parts of citrus peel residue activated carbon and 1.5 parts of nano silicon dioxide, and then filtering and drying to obtain a mixture; (3) putting 50 parts of PBAT and 28 parts of PLA into a high-speed mixer, setting the temperature to be 120 ℃, stirring for 2min, then adding 0.09 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 1: 1: 2), stirring for 5min, adding 28 parts of modified starch, continuing stirring for 10min, then adding the mixture obtained in the step (3), adding 0.12 part of de-foaming agent, continuing stirring for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare the degradation master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

Example 5

The embodiment provides a preparation method of a PBAT/PLA starch-based complete biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) 3.5 parts of citrus peel residue activated carbon and 2.2 parts of nano silicon dioxide are subjected to ultrasonic mixing, and then are filtered and dried to obtain a mixture; (3) putting 52 parts of PBAT and 32 parts of PLA into a high-speed mixer, setting the temperature to be 120 ℃, stirring for 2min, then adding 0.12 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 1: 1: 2), stirring for 5min, adding 32 parts of modified starch, continuing stirring for 10min, then adding the mixture obtained in the step (3), adding 0.08 part of defoaming agent and 0.12 part of release agent, continuing stirring for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare degradation master batches; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

Comparative example 1

The comparative example provides a preparation method of a PBAT/PLA starch-based completely biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) 2.5 parts of citrus peel residue activated carbon and 3 parts of nano silicon dioxide are subjected to ultrasonic mixing, and then are filtered and dried to obtain a mixture; (3) putting 30 parts of PBAT and 40 parts of PLA into a high-speed mixer, setting the temperature to be 120 ℃, stirring for 2min, then adding 0.2 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 1: 1: 2), stirring for 5min, adding 20 parts of modified starch, continuing stirring for 10min, then adding the mixture obtained in the step (3), adding 0.04 part of defoaming agent and 0.18 part of release agent, continuing stirring for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare degradation master batches; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

Comparative example 2

The comparative example provides a preparation method of a PBAT/PLA starch-based completely biodegradable material, which comprises the following steps: the method comprises the following steps: (1) cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon; (2) ultrasonically mixing 5 parts of citrus peel residue activated carbon and 2 parts of nano silicon dioxide, and filtering and drying to obtain a mixture; (3) putting 40 parts of PBAT and 30 parts of PLA into a high-speed mixer, setting the temperature to be 120 ℃, stirring for 2min, then adding 0.1 part of bonding auxiliary agent (the volume ratio of polymerized grease, mineral white oil and glycerol is 0.5: 1.5: 1.5), stirring for 5min, adding 30 parts of modified starch, continuing stirring for 10min, then adding the mixture obtained in the step (3), adding 0.1 part of defoaming agent and 0.1 part of release agent, continuing stirring for 5min, and then putting the mixture into a storage tank of a double-screw extruder to prepare the degradable master batch; (4) and blowing the degradable master batches by using film blowing equipment to obtain the biodegradable material.

Experimental example 1

The experimental method comprises the following steps: the modified master batches obtained in examples 1 to 5 and comparative examples 1 to 2 were injection molded into corresponding tensile bars according to ISO 527/1-1993 and tested for mechanical properties, the results of which are shown in Table 1.

TABLE 1 mechanical Properties of modified degradation Master batch

Comparison of mechanical Properties	Tensile Strength (MPa)	Elongation at Break (%)
			Example 1	15.5	410
Example 2	15.3	408
			Example 3	16.0	425
Example 4	15.8	418
			Example 5	15.6	420
Comparative example 1	13.7	380
			Comparative example 2	14.5	405
Common polyethylene	14.2	400

As can be seen from the data in Table 1, the mechanical properties of the degradation masterbatch provided in examples 1 to 5 are significantly improved, and the tensile strength and elongation at break are significantly improved, as compared to the conventional polyethylene. The mechanical property of the degradation master batch provided by the comparative example 1 is obviously poorer than that of common polyethylene, and the proportion range of the raw materials provided by the comparative example 1 is out of the range provided by the invention. The mechanical properties of the masterbatch provided in comparative example 2 are poorer than those of examples 1 to 5, and the mixing ratio range of the components of the bonding auxiliary agent provided in comparative example 2 is out of the range provided by the present invention. The results show that the degradable master batch prepared from the raw materials and the mixture ratio of the raw materials provided by the embodiment of the invention has excellent mechanical properties.

Experimental example 2

The modified degradation master batch prepared in example 3 is blown into a film to prepare a film, and then a burying degradation experiment is performed in a natural environment, as shown in fig. 1 to 6. According to the observation of burying experiments, the film is decomposed and reduced in a natural environment for more than 2 months, and can be naturally degraded into fragments in a natural environment for more than 3 months, so that the effect of complete biodegradation is achieved.

In conclusion, the PBAT/PLA starch-based complete biodegradable material and the preparation method thereof provided by the invention are adopted; compared with the traditional degradable material, the biodegradable material has greatly improved mechanical property, can achieve the effect of complete biodegradation, and has controllable degradation time. The preparation method is simple and easy to operate, and the biodegradable material which can be completely degraded and has excellent mechanical properties can be prepared.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A PBAT/PLA starch-based complete biodegradable material is characterized in that: the raw materials comprise the following components in parts by weight: PBAT35-55 parts, PLA25-35 parts, modified starch 25-35 parts, monodisperse mesoporous molecular sieve 0.8-2.5 parts, biomass activated carbon 3-6 parts, adhesion promoter 0.05-0.15 part, defoaming agent 0.05-0.15 part and release agent 0.05-0.15 part;

the monodisperse mesoporous molecular sieve adopts nano silicon dioxide of monodisperse microspheres;

the biomass activated carbon is citrus peel residue activated carbon; cleaning citrus peel, drying and crushing to obtain pretreated citrus peel, and mixing the pretreated citrus peel with a zinc chloride solution according to the ratio of 1: 3, activating, and carbonizing at 600 ℃ for 1.5h to obtain the citrus peel residue activated carbon;

the modified starch is modified acetylated starch;

the bonding auxiliary agent is a mixed liquid prepared from polymerized grease, mineral white oil and glycerol; the volume ratio of the polymerized grease to the mineral white oil to the glycerol is 0.8-1.2: 0.8-1.2: 1.8-2.2.

2. The PBAT/PLA starch-based fully biodegradable material of claim 1, characterized in that: comprises the following components in parts by weight: the composite material comprises PBAT40 parts, PLA30 parts, modified starch 30 parts, monodisperse mesoporous molecular sieve 2 parts, biomass activated carbon 5 parts, bonding auxiliary agent 0.1 part, defoaming agent 0.1 part and release agent 0.1 part.

3. The PBAT/PLA starch-based fully biodegradable material of claim 1, characterized in that: the defoaming agent comprises at least one of zinc stearate, polyoxyethylene polyoxypropylene pentaerythritol ether and polyether ether ketone emulsion.

4. The PBAT/PLA starch-based fully biodegradable material of claim 1, characterized in that: the release agent comprises at least one of ethylene bis stearamide, ethylene bis stearamide and stearic acid amide.

5. A method for preparing PBAT/PLA starch-based completely biodegradable material according to claim 1, characterized in that: the method comprises the following steps:

(1) ultrasonically mixing the citrus peel residue activated carbon and the nano silicon dioxide according to the weight part, and filtering and drying to obtain a mixture;

(2) adding the PBAT, the PLA, the modified starch, the mixture, the bonding auxiliary agent, the defoaming agent and the release agent into high-speed shearing equipment according to the parts by weight, mixing and dispersing, and granulating by using a double-screw machine to prepare a degradation master batch;

(3) and blowing the degradable master batch by using film blowing equipment to obtain the biodegradable material.