KR102407611B1 - A process for preparation of biodegradable biocompostable biodigestible peplene polymer - Google Patents

Abstract

The present invention relates to a process for preparing a biodegradable, biocompostable, biodigestible PEPlene polymer comprising the steps of:
- mixing one or more peptides with one or more proteins and enzymes;
- adding composting material;
- blending with at least one polymer in the presence of additives to obtain said PEPlene polymer material.

Description

A PROCESS FOR PREPARATION OF BIODEGRADABLE BIOCOMPOSTABLE BIODIGESTIBLE PEPLENE POLYMER

The present invention relates to a biodegradable, biocompostable, biodigestible plastic and a method for manufacturing the same.

Plastics, such as polyethylene and polypropylene, are made from petroleum and take years to degrade in the environment, polluting water, soil and air.

Synthetic polymers vary in speed and degree of decomposition in the environment depending on the characteristics of the polymer and the environment. Decomposition is catalyzed by light, heat, air, water, microorganisms, and physical forces such as wind, rain, vehicle traffic, and the like. Stability and/or degradability enhancement of the polymer is generally achieved by additives, modification of the polymer backbone, introduction of functional groups or blending of suitable fillers to make the polymer/plastic material from hydrophobic to hydrophilic. However, many of these degradation techniques produce unfavorable properties in the polymer product.

In order to solve these problems and overcome the limitations of natural resources due to excellent physical properties, light weight, cost-effectiveness, and plasticity, petroleum-based synthetic polymers/plastics are the characteristics of modern science established by developing various hydrophilic polymers, especially hydrophilic plastics. one of them However, in each country of the world, the pollution problem caused by numerous plastic products is becoming serious worldwide, and it is difficult to solve the pollution problem caused by plastic waste, and various national measures are being prepared.

In order to solve this environmental pollution problem caused by various solid wastes such as plastics, recycling, incineration and landfill have been mainly used. However, disposal and recycling of waste through landfill cannot completely solve the environmental pollution problem due to its inherent problems.

Accordingly, there has been a significant increase in interest and research in recent years to develop biodegradable and/or biocompostable plastics that can decompose itself in the life cycle. Technologies for degradable plastics are divided into photodegradation, oxo-degradation, oxo-biodegradation, biodegradation, bio-photolysis and plastics manufacturing technology with a combination of photo- and/or oxo and/or biodegradability, which have recently been produced on an industrial scale. is increasing

There are numerous types of biodegradable plastics, for example, microbially produced polymers such as PHB (poly-β-hydroxybutyrate), microbially produced polymers from biochemicals, or polymers containing natural polymers such as chitin or starch. . Problems addressed in the present technology for polymers containing various additives such as starch are mentioned, and improvements are described in the literature.

U.S. Pat. No. 4,021,388 to G. J. L. Griffin relates to an improved process for preparing biodegradable films by treating the surface of the starch with a silane coupling agent to make it hydrophobic, which only increases the strength of the physical interaction between the matrix resin and the starch. However, it is difficult to solve the problem of decomposition among the physical properties of the film by incorporation of starch.

U.S. Pat. Nos. 4,133,784 and 4,337,181 to F. H. Otey et al. disclose a method for preparing biodegradable films by adding α-starch to an ethylene-acrylic copolymer. Due to the high price of the ethylene-acrylic copolymer and the deterioration of the physical properties of the produced film, it is difficult to generalize.

Korean Patent Publication Nos. 90-6336 and 91-8553 of Seonil Glucose Co., Korea, by increasing the hydrophobic property of starch or the hydrophilic property of the matrix resin in order to increase the miscibility of the matrix resin and starch, the matrix resin and It relates to a method of enhancing the strength of the physical interaction between starches.

U.S. Patent 5281681A co-processes ethylene and 2-methylene-1,3-dioxepane (MDOP), whereby additional carbonyl groups in the polymer are cleaved when light such as sunlight or UV light is absorbed, resulting in superior photodegradability than the copolymer Disclosed is a photodegradable and biodegradable polyethylene formulation to prepare a terpolymer showing This terpolymer can be photodegradable and biodegradable, as both the ester and the carbonyl are functionalized.

U.S. Patent 5461094A discloses a biodegradable polyethylene composition to which starch is chemically bound and a method for preparing the same.

Therefore, there is a need to provide a high yield of peptide-polyethylene referred to herein as PEPlene having excellent biodegradability/biocompostability/biodigestibility in the environment.

An object of the present invention is to provide a biodegradable, biocompostable, biodigestible plastic and a method for manufacturing the same, which solves the problems in the prior art.

Another object of the present invention is to improve the biodegradability/biocompostability/biodigestibility of polymers without compromising physical strength, structural characteristics, and recycling opportunities to the main recycling stream can be given without affecting the stream. , to present a biodegradable, biocompostable, biodigestible plastic and a manufacturing method thereof.

Another object of the present invention is to provide a cost-effective biodegradable/biocompostable/biodigestible plastic and a method for manufacturing the same.

Another object of the present invention is to provide an environmentally friendly biodegradable/biocompostable/biodigestible plastic and a manufacturing method thereof.

The present invention, for example, by adding biodegradable / biocompostable / biodigestible additives during processing of the polymer to give biodegradability / biocompostability / biodigestibility to the polymer, to replace general petroleum-based plastics, shopping cart We propose biodegradable/biocompostable/biodigestible plastic or polymer products such as market carry bags, mulch film for agricultural use, packaging film, etc. That is, the plastic formulation is intended for use in the preparation of non-biodegradable petroleum-based polymers, i.e. polyolefins such as polyethylene, polypropylene and their various grades, into biodegradable/biocompostable/biodigestible polyolefin polymers, edible It has been developed by adding natural peptides/enzymes/proteins derived from raw materials.

Accordingly, the present invention relates to a biodegradable/biocompostable/biological, polyolefin, prepared by chemically bonding peptides/enzymes/proteins and other additives with, for example, polyethylene chains, and having very wide universal applicability. An extinguishing film and a method for making the same are described. This may be a processing technique that also applies to other polyolefins such as polypropylene.

Other objects and advantages of the present invention will become more apparent from the following detailed description when understood with reference to the accompanying drawings of exemplary embodiments of the present invention.

1 : Depicts the biodegradability of PEPlene films in the environment.
Figure 2: Biodegradability of the PEPlene film after 150 days in a soil environment.
Figure 3: FTIR of the PEPlene master batch loaded with peptide/enzyme/protein.
Figure 4: FTIR of the PEPlene film to which the peptide/enzyme/protein is added.
Figure 5: Percent biodegradation of PEPene.

The present invention describes biodegradable, biocompostable, biodigestible plastics and methods of making them.

That is, the present invention provides a method for preparing a composition for accelerating the biodegradability/biocompostability/biodigestibility of a PEPlene material and the composition thereof.

The method comprises preparing a composition by combining one or more peptides with one or more proteins and enzymes, and a composting agent. This is followed by a step of blending one or more polymers in the presence of additives, preferably at a temperature of 45-300° C. in order to retain the basic catalytic properties and properties of the peptide/enzyme/protein.

The composition thus obtained can be used directly or encapsulated in a polymer and used as a coated composition or in liquid form. Various examples of the above ingredients can be listed below:

Peptides - cellulase, papain. However, it is not limited to the examples herein.

Protein/Enzyme - Vegetable (soybean, lady finger), milk (vegetable). However, it is not limited to the examples herein.

Compostable material - carboxymethyl cellulose, hydrolyzed mutton tallow. However, it is not limited to the examples herein.

Polymer - which may be one of linear low density polyethylene (LLDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene, ethylene vinyl acetate (EVA) and ethylene butyl acrylate (EBA) and any combinations thereof , polyethylene.

Additives - citric acid, lactic acid bacillus, hydrolyzed mutton tallow, yeast and any combination thereof for improving the biodegradation/biocomposting/biodigestive properties of the polymeric material.

The natural ingredients of the composition of the present invention are food grade materials. It may also contain other carbohydrates such as lactose, starch, and the like.

In the present invention, the production cost becomes low due to the simplification of the method for preparing the composition. This prevents the problem of deterioration of the physical properties of the film by strengthening only the strength of the physical interaction between the matrix resin and the peptide/enzyme/protein and the above-described additive to be added.

In another embodiment, the biodegradable/biocompostable/biodigestible polyethylene composition may be chemically bound to the starch.

The PEPlene composition has a molecular weight of at least about 7000 and has good biodegradability/biocompostability/biodigestibility characteristics. See FIG. 1 .

In plastic polymers, x, y and z in the space integer of peptide/enzyme/protein groups such as carboxyl are randomly or uniformly distributed within the polymer throughout the backbone of the polyethylene polymer, depending on the varying concentration of functional groups. do. See Figures 3 and 4.

The blend of plastic composition is extruded at a temperature of about 100-350°C. So, during extrusion, the composition is injected or permeated into the cells or molecular structure of the polymer, where the polymer is in a pre-molten state. The plastic products obtained according to the method of the present invention are secondary packaging/plastic films, vest bags, bin liners, rubbish bags, agricultural mulch films and Many other types of films are included. The composition blends of the present invention can also be applied to polymers, for example 3D printing materials, fiber spun materials, and non-woven spinning using, for example, injection molding and melt spinning processes. Suitable for materials (nonwoven spun).

A biodegradation mechanism may include the following steps:

Action : Peptide/Enzyme/Protein helps to introduce hydrophilicity into the polymer chain. The polymer is in a pre-melted state during the extrusion process in which peptides/enzymes/proteins are infiltrated into the polymer to render the polymer formulation hydrophilic.

Thermal Decomposition : Hydrophilic natural polymers are further processed into polymer films, which under experimental conditions undergo thermal decomposition or destruction into smaller fragments, which occur due to temperature conditions and moisture in the environment, as well as light and oxygen do.

Action of Soil : After thermal decomposition (under experimental conditions or natural environment), the peptides/enzymes/proteins present in the composition of the present invention attract soil microorganisms to attack the polymer due to their hydrophilic properties. The intrinsic moisture of the polymer formulation and/or moisture in the soil (eg, 58% moisture) due to the hydrophilicity of the composition may cause the chain linkages of the polymer, which are already separated or weakened molecular state, to undergo a natural composting process, where The depolymerization product becomes a nutrient source for soil microorganisms, and the other products become biomass.

Degradation : The biodegradable end products are carbon dioxide and water due to microbial metabolism of the polymer.

In one embodiment, the enzyme composition of the present invention is blended with a pulverized copolymer, ie, LLDPE. Polyethylene used to make secondary packaging films, such as best bags, bins, garbage bags, and agricultural mulching films, requires copolymer LLDPE for the elasticity and scalability of the film. Peptides/enzymes/proteins and other additives present in the polyethylene attract soil microbes, thereby triggering material composting. Residues are biomass, water and carbon dioxide. However, in the PEPlene polymer of the present invention, the biodegradation residues are carbon dioxide and water.

Other products produced through biodegradation or bio-refining include gases (eg methane), ketones (eg acetone) and alcohols (eg methanol, ethanol, propanol and butanol). Products such as methane and ethanol are known energy sources and it is believed that these or other products produced can be obtained for future use to serve as energy sources.

One advantage of the present invention is that the polymer product obtained by the present invention retains the recyclability of the polymer in addition to the same desirable mechanical properties and shelf life as non-biodegradable polymers - eg polyethylene. Unlike photo-oxidative or oxo-degradable materials, which spontaneously initiate the degradation of polymers and their by-products shorten the shelf life of polymer products, enzymatically initiated biodegradation/biocomposting/biodigestion processes end their life cycle. (life cycle end) initiated only upon exposure to microorganisms in the environment.

The PEPlene film produced using the peptide / enzyme / protein composition by directly dispersing or encapsulating in the present invention is biodegradable and ecotoxic, and ASTM D 5988, ISO 14855, Tested successfully according to ISO 17556 and EN 13432/ASTM D6400 (and other domestic similar methods). For example, the EN protocol for cellulosic products requires at least 90% degradation within 180 days. The product according to the present invention begins to decompose from day 90 under the decomposition conditions of FIGS. 1 and 2 . The rate of degradation is generally affected by environmental microbial conditions, the amount of peptide/enzyme/protein composition and the thickness of the product. For example, degradation of products prepared according to the present invention is achieved with extruded films 5-50 microns thick.

Accordingly, another advantage of the present invention is that the composition comprises natural and food grade materials, does not leave toxic residues after biodegradation and/or is within the heavy metal limits specified in various countries for plastic materials/products. .

In addition, the product of the present invention is recyclable according to the ASTM D 7209 protocol and EN 15347. Furthermore, the product of the invention is compostable according to standard EN 13432; It is biodegradable according to ASTM D 5988, ISO 14855, ISO 17556 and EN 13432/ASTM D6400 (and other domestic similar methods) test protocols for biodegradability in FIG. 5 .

In addition, the present invention was evaluated according to US FDA 177.1520 for food contact safety compliance.

A further advantage of the present invention is that the material produced according to the present invention biodegrades when subjected to suitable environmental conditions. In addition, the PEPlene film, a product of the present invention, is stable until discarded, such as in soil, compost, landfill, bio-digestible, etc. and anaerobic conditions. This material can be metabolized into biomass by the colony-forming bacteria group present in the composition of the present invention and the microorganisms available in the soil.

It has been shown that compositions of the present invention with polyolefins such as polyethylene can fully biodegrade and biocompost poly films by oxidative microbial attack under anaerobic conditions.

It should be noted that the present invention can be readily modified, adapted, and modified by those skilled in the art. Alternative implementations to which these inventive concepts and features are applied are intended to be within the scope of the invention as further set forth in the claims below.

Claims (9)

A method for producing a biodegradable/biocompostable/biodigestible plastic, comprising the steps of:
- mixing milk protein or vegetable protein with papain or cellulase;
- adding a composting agent;
- blending with a polyolefin polymer in the presence of an additive selected from citric acid, lactic acid bacillus, hydrolyzed mutton tallow, yeast and any combination thereof to obtain said plastic. The process according to claim 1 , wherein the blending is carried out at a temperature of 45-300° C. in order to maintain in solid or liquid form the basic catalytic properties and properties of milk protein or vegetable protein with papain or cellulase. The method according to claim 1, wherein the vegetable protein is selected from soya bean and ladyfinger. The method of claim 1 , wherein the compostable material is carboxymethyl cellulose. The method of claim 1 , wherein the polymer comprises polyethylene selected from linear low density polyethylene (LLDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), MDPE, EVA, EBA, and combinations thereof. According to claim 1, wherein the plastic mix (mix) is extruded at a temperature of 350 °C or lower, blow / injection molding (blown / injection molding) products, melt spinning (melt spinning) products and 3D printing products, and others A process for making a plurality of products. The plastic product according to claim 1, wherein the plastic product obtained by the method is a secondary packaging/plastic film, a best bag, a bin liner, a rubbish bag, an agricultural mulch film), a polymer fiber, or a nonwoven spun material. A biodegradable/biocompostable/biodigestible plastic obtainable by the method of any one of claims 1 to 6. delete

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