CN114085509A - Universal masterbatch for anaerobic digestion degradation and preparation method thereof - Google Patents

Abstract

The master batch consists of 20-40 parts by weight of PLA base material, 10-15 parts by weight of anaerobic degradation auxiliary agent and 45-70 parts by weight of external components, wherein the anaerobic degradation auxiliary agent comprises nano cellulose, aliphatic-aromatic copolyester, mannose, fructose, polylactide, graphene oxide and starch. The invention is made by injecting anaerobic degradation auxiliary agent into traditional plastic, the master batch leads the plastic into biodegradation stage through chemical activity caused by bacteria, and finally natural gas and biological energy are left. After the master batch is added, the plastic can be degraded in landfill of garbage landfill sites through anaerobic digestion, and also can be degraded in seawater and wastewater, and the plastic meets the standards of China, Europe and North America.

Description

Universal masterbatch for anaerobic digestion degradation and preparation method thereof

Technical Field

The invention relates to the technical field of plastics, in particular to a universal master batch for anaerobic digestion degradation and a preparation method thereof.

Background

The plastic is a synthetic high molecular chemical product, and most of the plastic is prepared by polycondensation of polyhydric alcohol and polybasic acid, wherein the non-renewable petroleum is used as a raw material. In addition to establishing environmental awareness and reducing the use of disposable plastic products, another important method for dealing with white pollution is to replace common plastic with degradable plastic.

Under the push of the 'plastic limit order', degradable plastics are still rapidly developed in China. The method has the advantages of being recyclable, easy to recover and degradable, developing and popularizing a plastic product and a substitute product with standard performance, environmental protection, economy and applicability,

in 1 month 2020, the "opinion on further enhancement of plastics pollution control" issued by the national institute of improvement and improvement. Clear comments: by the end of 2020, places such as shopping malls, supermarkets, drug stores, bookstores and the like in built-up areas of direct prefecture cities, provincial cities and planning single-row city cities, catering packaging and takeout services and various exhibition activities, non-degradable plastic bags are forbidden to be used, and trade market specifications and limited use of the non-degradable plastic bags are restricted; by the end of 2022, the implementation range is expanded to the built-up areas of cities above all the grade and the built-up areas of counties and cities along the coast. By the end of 2025, the trade markets in the above mentioned areas banned the use of non-degradable plastic bags. Places with the encouragement of the conditions stop using the non-degradable plastic bags in urban and rural junctures, villages and towns, rural areas and other places. The method creates a new mode of new state which is beneficial to standardizing recovery and recycling and reducing plastic pollution, is a basic principle for further strengthening plastic pollution treatment in China, and is a direction for developing biodegradable plastics.

Disclosure of Invention

The master batch can be biodegraded in a garbage landfill area through anaerobic digestion after being added into plastic, supports marine degradation, and meets the standards of China, Europe and North America.

The technical scheme adopted by the invention for realizing the purpose is as follows: the master batch for anaerobic digestion and degradation comprises 20-40 parts by weight of PLA base material, 10-15 parts by weight of anaerobic degradation auxiliary agent and 45-70 parts by weight of external components, wherein the anaerobic degradation auxiliary agent comprises nano cellulose, aliphatic-aromatic copolyester, mannose, fructose, polylactide, graphene oxide and starch.

In the invention, the additional components comprise polybutylene terephthalate, succinate, polycaprolactone, polyhydroxyalkanoate, a polyester stabilizer and a lubricant.

The anaerobic degradation auxiliary agent comprises 5-8 parts of nano cellulose, 15-20 parts of aliphatic-aromatic copolyester, 1-5 parts of mannose, 1-5 parts of fructose, 5-10 parts of polylactide, 3-4 parts of graphene oxide and 3-5 parts of starch.

The weight portions of polybutylene terephthalate, succinate, polycaprolactone, polyhydroxyalkanoate, polyester stabilizer and lubricant contained in the additional components are 10-15 portions, 0.5-1 portion and 0.5-3 portions in sequence.

In a preferred embodiment of the present invention, the lubricant is one or more of PE wax, calcium stearate, and iron dimethyldithiocarbamate.

A preparation method of anaerobic digestion degradation universal master batch comprises the following steps:

step one, mixing raw materials of anaerobic digestion degradation universal master batches in a high-speed mixer and conveying the mixed raw materials to an extruder;

step two, setting the extrusion flow rate of the extruder to be 300kg/h, the screw rotation speed to be 300-;

and step three, bracing the extruded material, cooling at room temperature, air-drying, granulating, vibrating and screening, drying, homogenizing and packaging to obtain the anaerobic digestion degradation universal master batch.

The present invention adds nanocellulose, graphene oxide, aldohexose, ketose, and starch, and as the nanocellulose and graphene oxide are distributed in the polymer matrix, making the structure heterogeneous, the microorganism can more easily contact the biodegradable component, and at the same time, aldohexose and ketose can attract the bacterial microorganism, which results in an increase of the available surface of the bacteria and an acceleration of the degradation process.

The components of the assistant can enlarge the molecular structure of the matrix, make more space for microorganisms and send chemical signals for attracting other microorganisms on a polymer chain to feed plastics, thereby improving the biodegradation rate.

The present invention relates to an organic additive, which is made up by injecting anaerobic organic adjuvant into traditional plastics, and said mother granules can utilize chemical action induced by bacteria to introduce the plastics into biodegradation stage, and finally retain natural gas and biological energy. After the master batch is added, the plastic can be degraded in landfill of garbage landfill sites through anaerobic digestion, also can be degraded in seawater and wastewater, and meets the standards of China, Europe, North America and the like.

The present invention introduces plastics into the anaerobic environment of microbial degradation through a series of chemical and biological processes (a process known as bioassimilation). Allowing the microorganisms to make a biofilm structure to permeate the plastic. The biofilm is formed under the condition of no oxygen/anaerobism, namely in a refuse landfill and a deep sea environment; meanwhile, the molecular structure is expanded, a larger space is created for the microorganisms, chemical signals for attracting other microorganisms are sent out on the polymer chain to feed plastics, and the degradation rate of the microorganisms is improved. The present invention promotes plastic degradation in two forms:

(1) as an attractant for microbial growth on and within plastics; (2) further weakness is exhibited by weakening or by weakness in the PP chain or in the form of additives. When the master batch is added into the plastic mixture, the plastic mixture is interfered, enzymes in a refuse landfill or seawater search weak points in matrix chains, and the master batch can reduce the bonding strength of the matrix chains and interfere carbon-carbon bonds of the matrix, so that the plastic can be easily used as a food source of the enzymes.

The degradation of anaerobic microorganisms in nature occurs at a moment, and the process is relatively slow and is not easy to be perceived, but the solid organic plastic added with the master batch can greatly accelerate the process, so that the plastic can complete the biodegradation process at a higher speed. Allowing the plastic product to produce carbon dioxide, biogas (methane) and humus (organic matter), which is the same biological process and residue as organic matter.

The degradation realization process comprises the following steps:

(1) an aerobic stage: at this stage, the enzymes and breakdown chemicals act as catalysts for the plastic-covered biofilm. During this time, aerobic microorganisms are gradually formed and moisture in the waste is continuously accumulated. Standard P plastics have a relatively small moisture absorption capacity, but the masterbatch can cause further swelling, weakening the polymer bonds. This creates a molecular space for microbial growth, which begins an aerobic degradation process in which oxygen is converted to carbon dioxide.

(2) Anaerobic, non-methanation stage: after the oxygen concentration is sufficiently reduced, an anaerobic process is started. In the initial stage (hydrolysis), the microbial colony phagocytoses the particle and enzymatically reduces the macromolecular polymer to a simpler monomer. The organic masterbatch causes additional swelling and splaying of the polymer chains and increases quorum sensing. This further motivates the microorganisms to increase their colonization and consumption of polymer chains. Over time, acid generation occurs, wherein simple monomers are converted to fatty acids. At this stage, the production of carbon dioxide occurs rapidly.

(3) Anaerobic, unsteady state of methanogenesis: microbial colonies continue to grow, engulf polymer chains and create an increasingly larger molecular space. At this stage, acetogenesis occurs, converting fatty acids into acetic acid, carbon dioxide and hydrogen. As this process continues, CO₂The rate drops and hydrogen production eventually stops.

(4) Anaerobic, steady state phase of methanogenesis: the final stage of decomposition involves methane production. As the microbial colony continues to phagocytose the remaining surface of the polymer, the acetate is converted to methane and carbon dioxide, and hydrogen is consumed. This process continues until the remaining element is humus. This highly nutritious soil creates and improves the environment for the microorganisms and enhances the final stages of decomposition.

When in application, the master batch is added into a plastic base material by 1 percent by weight, the plastic base material can be PP, PE, EVA, PLA and the like, and the complete degradation is realized within 3 to 5 years; the degradation product added with the master batch disclosed by the invention supports European and American standards, supports landfill degradation and marine degradation of refuse landfills, conforms to ISO15985, ENISO15985, ASTM D5511 and GB/T33797-2017, and is a degradation material which can be used abroad for export.

Drawings

FIG. 1 shows the results of the degradation experiment of the PP film of example 1;

FIG. 2 is the experimental system information of example 2;

FIG. 3 is a graph of the mean percent biodegradation versus time for the reference material of example 2 versus a sample set (H210304-0026);

FIG. 4 is a photograph of a sample mixed with compost at day 0 of the experiment of example 2;

FIG. 5 is a photograph of the sample mixed with compost at day 45 of the end of the experiment in example 2;

FIG. 6 shows the results of the test of example 4EPE plastic ASTM D5511-11.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Example 1

The master batch for anaerobic digestion degradation comprises 40 parts by weight of PLA base material, 15 parts by weight of anaerobic degradation auxiliary agent and 45 parts by weight of additional components, wherein the anaerobic degradation auxiliary agent comprises the following components: 5.5 parts of nano-cellulose, 15 parts of aliphatic-aromatic copolyester, 1 part of mannose, 2 parts of fructose, 5 parts of polylactide, 3 parts of graphene oxide and 5 parts of starch, wherein the components of the added components are as follows: 10 parts of polybutylene terephthalate, 10 parts of succinate, 10 parts of polycaprolactone, 10 parts of polyhydroxyalkanoate, 0.5 part of polyester stabilizer and 0.5 part of iron dimethyldithiocarbamate. The preparation method comprises the following steps:

step one, mixing raw materials of the anaerobic biodegradable universal master batch in a high-speed mixer and conveying the mixture to an extruder;

step two, setting the extrusion flow of the extruder as 100kg/h, the rotating speed of a screw rod as 300rpm, the processing temperature as 240 ℃, and performing melt extrusion on the materials by adopting a 350-mesh filter screen;

and step three, bracing the extruded material, cooling at room temperature, air-drying, granulating, vibrating and screening, drying, homogenizing and packaging to obtain the anaerobic digestion degradation universal master batch.

The master batch of the embodiment is added into PP plastic according to the weight ratio of 1.0wt%, the plastic can be biodegraded in a landfill (refuse landfill and deep sea) filled with active anaerobic organisms, and the master batch is mixed with the existing plastic material for use, and the mixture is directly blended and then enters a blow molding process through a hopper to prepare the PP film.

The PP film of example 1 was incubated in the dark or under diffuse light at 52 ℃ (± 2 ℃) for 15 days, and the inoculum: anaerobic digesters of wastewater treatment facilities and methane inocula (sludge from organic composting plants incubated at 53 ℃, solids content 47.5%, pH7.7-8.2, volatile fatty acids 0.7g/kg, ammonium nitrogen 1.4mg/kg) produced by the cultivation of post-consumer pre-treated household waste; reference standard: ASTM D5511; wherein, ASTM D5511 high solid anaerobic digestion conditions under the determination of plastic material anaerobic biodegradation standard test method, test method: the test method comprises selecting and analyzing test material, obtaining concentrated anaerobic inoculum from anaerobic laboratory scale digester, exposing material to more than 20% solids of anaerobic static batch fermentation, and measuring total Carbon (CO) in gas₂And CH₄) As a function of time evolution and to assess the degree of biodegradability. By measuring gas (CO)₂And CH₄) The percent biodegradability can be obtained from the conversion of the test material to carbon. The percentage of biodegradability does not include the amount of carbon in the test substance that is converted to cellular biomass, nor does it include the amount of carbon that is metabolized to carbon dioxide and methane.

The test method is equivalent to GB/T33797 (method for determining final anaerobic biological decomposition capability of national standard plastics of the people's republic of China under the condition of high-solid compost by analyzing and determining released biogas).

In FIG. 1, a is a PP film of example 1, b is a commercially available biodegradable plastic film, and c is a conventional PP film of a comparative example. The biodegradation rate of the PP film of example 1 is more than 70% after about 17 days, and the biodegradation levels of b and c are about 52.9% and 1.0%.

The composition of the present invention is capable of inducing the attachment of microorganisms to the surface of plastics and the formation of biofilms, for example. The addition of a component that is a high nitrogen content material induces the nitrogen atoms bonded to the carbonyl side of the substrate to form amide groups, thereby attracting microorganisms.

Example 2

The master batch for anaerobic digestion degradation comprises 20 parts by weight of PLA base material, 10 parts by weight of anaerobic degradation auxiliary agent and 70 parts by weight of external components, wherein the anaerobic degradation auxiliary agent comprises the following components: 5 parts of nano-cellulose, 20 parts of aliphatic-aromatic copolyester, 2 parts of mannose, 1 part of fructose, 10 parts of polylactide, 4 parts of graphene oxide and 3 parts of starch. The components of the additional components are as follows: 10 parts of polybutylene terephthalate, 10 parts of succinate, 15 parts of polycaprolactone, 10 parts of polyhydroxyalkanoate, 1 part of polyester stabilizer and 1 part of PE wax. The preparation method comprises the following steps:

step one, mixing raw materials of the anaerobic biodegradable universal master batch in a high-speed mixer and conveying the mixture to an extruder;

step two, setting the extrusion flow of the extruder to be 250kg/h, the rotating speed of a screw to be 600rpm, the processing temperature to be 210 ℃, and performing melt extrusion on the materials by adopting a 500-mesh filter screen;

and step three, bracing the extruded material, cooling at room temperature, air-drying, granulating, vibrating and screening, drying, homogenizing and packaging to obtain the anaerobic digestion degradation universal master batch.

The master batch is added into the common disposable PP tableware by the weight ratio of 1.0wt% to prepare the disposable tableware.

The tableware is subjected to a biological decomposition experiment, and the detection standard is as follows: the GB/T33797-2017/ISO 15985:2014 plastic is used for measuring the final anaerobic biological decomposition capacity under the condition of high solid content compost, and the information of an experimental system is as follows: the experiment was carried out in a 2L experimental system at a constant temperature of 52 ± 2 ℃ under low light, inoculum source: self-made anaerobic digestion compost, the manure age is four months, and the compost is pre-cultured for 7 days at 52 ℃ before use; the microcrystalline cellulose as the positive reference substance is (C)₆H₁₀O₅) n; the ratio of the actual biogas release from the test material to the total organic carbon content of the material as measured is the percentage of biodegradation, excluding the amount of carbon that has been converted to new cellular biomass. The experimental system information is shown in figure 2. Example 2 mean percent biodegradation-time curves for the reference material and the sample set (H210304-0026) are shown in fig. 3, where the reference material showed a biodegradation rate of 71.5% or more after 15 days of the experiment. Wherein, figure 4 is the picture of mixing the sample and the compost at the 0 th day of the experiment, and figure 5 is the picture of mixing the sample and the compost at the 45 th day after the experiment is finished.

Example 3

The master batch for anaerobic digestion degradation comprises 20 parts by weight of PLA base material, 15 parts by weight of anaerobic degradation auxiliary agent and 65 parts by weight of additional components, wherein the anaerobic degradation auxiliary agent comprises the following components: 8 parts of nano-cellulose, 18 parts of aliphatic-aromatic copolyester, 5 parts of mannose, 3 parts of fructose, 7 parts of polylactide, 3.5 parts of graphene oxide and 4 parts of starch. The components of the additional components are as follows: 12 parts of polybutylene terephthalate, 13 parts of succinate, 10 parts of polycaprolactone, 10 parts of polyhydroxyalkanoate, 0.5 part of polyester stabilizer and 1 part of calcium stearate.

The preparation method comprises the following steps:

step one, mixing raw materials of the anaerobic biodegradable universal master batch in a high-speed mixer and conveying the mixture to an extruder;

step two, setting the extrusion flow of the extruder to be 300kg/h, the rotating speed of a screw to be 500rpm, the processing temperature to be 230 ℃, and performing melt extrusion on the materials by adopting a 400-mesh filter screen;

and step three, bracing the extruded material, cooling at room temperature, air-drying, granulating, vibrating and screening, drying, homogenizing and packaging to obtain the anaerobic digestion degradation universal master batch.

The master batch is added into a common EVA foam surface by the weight ratio of 1.0wt%, and the test result of ASTM D5511-12 of EVA foam shows that the decomposition rate reaches 86%.

Example 4

The master batch for anaerobic digestion degradation comprises 40 parts by weight of PLA base material, 10 parts by weight of anaerobic degradation auxiliary agent and 50 parts by weight of external components, wherein the anaerobic degradation auxiliary agent comprises the following components: 7 parts of nano-cellulose, 20 parts of aliphatic-aromatic copolyester, 4 parts of mannose, 4 parts of fructose, 10 parts of polylactide, 4 parts of graphene oxide and 4 parts of starch. The components of the additional components are as follows: 15 parts of polybutylene terephthalate, 15 parts of succinate, 15 parts of polycaprolactone, 15 parts of polyhydroxyalkanoate, 0.5 part of polyester stabilizer and 3 parts of iron dimethyldithiocarbamate. The master batch is added into the process of common PE plastic according to the weight ratio of 1. wt%. The ASTM D5511-11 test for PE plastic is shown in FIG. 6, updated-856 days.

The master batch of the invention is added into the production process of plastic products by the weight ratio of 1.wt%, and after blending, the plastic products become degradable plastics in anaerobic organism and microorganism environments. In a refuse landfill, the traditional plastics can be completely and naturally biodegraded within 1 to 5 years by attracting specific microorganisms to phagocytize the plastics, and the products are decomposed substances, carbon dioxide and methane. It is suitable for various resin types, such as rubber, PET, PS, PE, PP, etc., and does not affect the integrity, shelf life and strength of the used plastic.

The performance characteristics are as follows: 1. being able to biodegrade in landfill: the plastic added with the master batch can be biologically degraded in a garbage landfill area through anaerobic digestion and can be naturally decomposed in household compost. Tested according to astm d 5511. 2. Clean renewable energy sources: carbon dioxide, biogas and biomass (humus) are produced during the decomposition process, and the biogas is collected as clean energy. 3. Cleaning and safety: after the biodegradation process is completed, the microorganisms will continue to consume the plastic treated with the anaerobic plastic degradant. Testing and passing astm e 1963 simply enhances the natural process by allowing microbes to enter the polymer chain. 4. The physical properties of the plastic were not changed. 5. Need not to change production facility: after the anaerobic plastic degradation agent is added in the production process, equipment is not required to be added, and only a traditional mixer is used. 6. The application range is as follows: the anaerobic plastic degradation agent is suitable for any polymer type such as PVC, PET, PP, PO, PE, PC, PS and the like. 7. And (3) recovery: the anaerobic plastic degradation agent does not influence the recovery of the plastic, and the plastic added with the anaerobic plastic degradation agent not only has anaerobic degradation characteristic, but also can be recovered for multiple times without influencing the prior recovery system. According to international detection standard ISO-15985 (standard of world standardization organization), EN-15985 (European standard), ASTM-D5511 (American standard), GB-33797 (Chinese national standard), ASTM-D6691 (ocean degradation standard), 20197-.

The above description is only a preferred embodiment of the present application, and not intended to limit the present application, the scope of the present application is defined by the appended claims, and all changes in equivalent structure made by using the contents of the specification and the drawings of the present application should be considered as being included in the scope of the present application.

Claims (6)

1. A universal master batch for anaerobic digestion degradation is characterized in that: the master batch consists of 20-40 parts by weight of PLA base material, 10-15 parts by weight of anaerobic degradation auxiliary agent and 45-70 parts by weight of external component, wherein the anaerobic degradation auxiliary agent comprises nano cellulose, aliphatic-aromatic copolyester, mannose, fructose, polylactide, graphene oxide and starch.

2. The universal masterbatch for anaerobic digestion degradation according to claim 1, wherein: the additional components comprise polybutylene terephthalate, succinate, polycaprolactone, polyhydroxyalkanoate, a polyester stabilizer and a lubricant.

3. The universal masterbatch for anaerobic digestion degradation according to claim 1, wherein: the anaerobic degradation auxiliary agent contains 5-8 parts of nano cellulose, 15-20 parts of aliphatic-aromatic copolyester, 1-5 parts of mannose, 1-5 parts of fructose, 5-10 parts of polylactide, 3-4 parts of graphene oxide and 3-5 parts of starch.

4. The universal masterbatch for anaerobic digestion degradation according to claim 2, wherein: the weight portions of polybutylene terephthalate, succinate, polycaprolactone, polyhydroxyalkanoate, polyester stabilizer and lubricant contained in the additional components are 10-15 portions, 0.5-1 portion and 0.5-3 portions in sequence.

5. The universal masterbatch for anaerobic digestion degradation according to claim 4, wherein: the lubricant is one or more of PE wax, calcium stearate and iron dimethyldithiocarbamate.

6. Preparing the universal masterbatch for anaerobic digestion degradation according to claim 1, comprising the steps of:

step one, mixing raw materials of anaerobic digestion degradation universal master batches in a high-speed mixer and conveying the mixed raw materials to an extruder;

step two, setting the extrusion flow rate of the extruder to be 300kg/h, the screw rotation speed to be 300-;

and step three, bracing the extruded material, cooling at room temperature, air-drying, granulating, vibrating and screening, drying, homogenizing and packaging to obtain the anaerobic digestion degradation universal master batch.

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