Process for preparation of biodegradable biocompostable biodigestible polyolefins

Abstract

This invention relates to a process for preparation of biodegradable biocompostable biodigestible PEPlene polymer (polyolefins) comprising steps of: Mixing at least one peptide with at least one protein and enzyme, Adding a composting agent, Blending with at least one polymer in presence of additive to obtain said PEPlene polymer (polyolefins) material.

Claims

1. A process for preparation of a biodegradable, biocompostable, and biodigestible plastic, comprising the steps of: mixing papain with at least one milk protein, adding a composting agent containing cellulose or modified cellulose, and blending with at least one polyolefin in the presence of an additive selected from citric acid, lactic acid bacillus, hydrolyzed mutton tallow, yeast, and combinations thereof to obtain said plastic.

2. The process for preparation of a biodegradable, biocompostable, and biodigestible plastic as claimed in claim 1, wherein said blending is carried out at a temperature of 45-300 C. to retain the essential catalytic properties and nature of the mixture of papain and milk protein in the solid or liquid form.

3. The process for preparation of a biodegradable, biocompostable, and biodigestible plastic as claimed in claim 1, wherein the composting agent is carboxymethyl cellulose.

4. The process for preparation of a biodegradable, biocompostable, and biodigestible plastic as claimed in claim 1, wherein the polyolefin comprises polyethylene.

5. The process for preparation of a biodegradable, biocompostable, and biodigestible plastic as claimed in claim 1, further comprising the step of: subjecting said plastic to extrusion at a temperature of up to 350 C.

6. The process for preparation of a biodegradable, biocompostable, and biodigestible plastic as claimed in claim 1, further comprising the steps of: fabricating said plastic into plastic products including at least one of secondary packaging/plastic films, vest bags, bin liners, rubbish bags, agricultural mulch films, polymer fibers, and nonwoven spun materials.

7. The process for the preparation of a biodegradable, biocompostable, and biodigestible plastic as claimed in claim 4, wherein the polyethylene is selected from a group including: low density polyethylene (LLDPE), high density polyethylene (HDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), ethylene vinyl acetate (EVA), ethylene butyl acrylate (EBA), and combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be apparent to those skilled in the art by reading the following description of preferred embodiments thereof, with reference to the attached drawings, wherein:

(2) FIG. 1 is an environmental biodegradation of the PEPlene film;

(3) FIG. 2 is a 150 days environmental soil biodegradation of the PEPlene film;

(4) FIG. 3 is a FTIR indicating the peptides/enzyme/protein incorporation in the PEPlene master batch;

(5) FIG. 4 is a FTIR indicating the peptides/enzyme/protein incorporation in the PEPlene film;

(6) FIG. 5 is a PEPlene percentage degree of biodegradation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) The instant invention makes a disclosure in respect of biodegradable biocompostable biodigestible plastic and a process for preparation thereof.

(8) Accordingly, the Present invention provides a process for composition and composition thereof for accelerating the biodegradation/biocompostability/biodigestion of PEPlene materials.

(9) The process comprises preparing a composition by combing at least one peptide with at least one protein and enzyme, and a composting agent. This is followed by blending with at least one polymer in the presence of additive preferably at a temperature of 45-300 C. so as to retain the essential catalytic properties and nature of the peptides/enzyme/protein.

(10) The composition thus obtained can be directly used or encapsulated in a polymer constituting a coated composition or in liquid form. Various examples of above ingredients can be listed herein below:

(11) Peptidecellulase, papain, but not restricted to the examples herein.

(12) Protein/enzymemilk, vegetable. (Soya bean, lady finger). But not restricted to the examples herein.

(13) Composting Agentcarboxy methyl cellulose, hydrolyzed mutton tallow. But not restricted to the examples herein.

(14) Polymerpolyethylene, which can be at least 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 combination thereof.

(15) Additivecitric acid, lactic acid bacillus, hydrolyzed mutton tallow, yeast and any combination thereof to improve biodegradation/biocompostability/biodigestion properties of polymeric material.

(16) The natural components of the composition of the present invention are food grade materials. This can also include other carbohydrates such as lactose, starch etc.

(17) The present invention leads to reduction in production cost owing to simplification in the process for preparation of the composition. It avoids the problem of degradation in the physical properties of film by enhancing solely physical interacting strength between matrix resin and peptides/enzyme/protein and added additives referred above.

(18) Further according to another embodiment, a biodegradable/biocompostable/biodigestible polyethylene composition can be chemically bonded with starch.

(19) The composition of PEPlene has molecular weight of at least about 7000 with good biodegradable/biocompostable/biodigestible characteristics FIG. 1.

(20) In plastic polymer, x, y and z in space integers of the peptide/enzyme/protein groups such as carboxyl are randomly or uniformly distributed in the polymer along the backbone of the polyethylene polymer, according to the varying concentrations of the functional groups FIGS. 3 and 4.

(21) The blend of plastic composition is subjected to extrusion at a temperature of about 100-350 C. So that during the extrusion process, the composition infuses or penetrates into the cells or molecular structure of the polymer while the polymer is in a pre-molten state. The plastic products obtained from the present process include secondary packaging/plastic films, vest bags, bin liners, rubbish bags, agricultural mulch, and many other types of films. The present blend of composition is also suitable for the polymers e.g. 3D printing, fiber spun, and nonwoven material using injection molding and melted spun process technologies to name a few.

(22) The mechanisms of biodegradation may include the following stages:

(23) Action: Peptide/enzyme/protein help to introduce the hydrophilicity in the chains of the polymer. While the polymer is in the pre-molten state during the process of extrusion the Peptide/enzyme/protein penetrates into the polymer so as to enable the hydrophilicity in the polymer formulation.

(24) Thermal degradation: The hydrophilic nature polymer is processed further into a polymer film which undergoes a thermal degradation or breakdown into smaller fragments, under laboratory conditions this takes place due to temperature conditions and the moisture in the environment and also due to light and oxygen.

(25) Soil action: After thermal degradation (either in laboratory conditions or in the natural environment) the presence of peptide/enzyme/protein in the composition of the present invention due to hydrophilic nature attracts soil microorganisms which attack the polymer. Inherent moisture in the polymer formulation due to hydrophilicity of the composition and/or moisture in the soil (for example 58% moisture) enables the chain links of the polymer, already in a separated or weakened molecular state, to undergo a natural composting process wherein the products of depolymerisation provide nutrients for the soil microorganisms and the remaining products to become biomass.

(26) Degradation: The ultimate products of biodegradation include carbon dioxide and water due to the microbial metabolism of the polymer.

(27) In one example, the enzyme compositions of the present invention are blended with a pulverized co-polymer i.e. LLDPE. Polyethylene used for the manufacturing of films for secondary packaging like vest bags, bin liners, rubbish bags, agricultural mulch films need the co polymer LLDPE both for elasticity and scalability of the film. The presence of peptide/enzyme/proteins and other additives in the polyethylene attracts the soil microorganisms to act on the composted material. The residue is biomass, water and carbon dioxide. However, in the present PEPlene polymer the biodegradation residues are carbon dioxide and water.

(28) Other products resulting from biodegradation or bio-refining include gases (e.g. Methane), Ketones (e.g. Acetone) and alcohols (e.g. Methanol, Ethanol, Propanol, and Butanol). Products such as Methane and Ethanol are known sources of energy and it is envisaged that these, or other resulting products, may be captured for further use, such as to act as energy sources.

(29) One advantage of the present invention is that the polymer products obtained by the present invention retain the desired mechanical properties and shelf life plus recycling of polymers equal to the non-biodegradable polymerexample polyethylene. Unlike the photo-oxidative or oxodegradable agents which initiate the degradation of the Polymer spontaneously and their-by reduce the shelf life of the polymer products, enzymatically initiated biodegradation/biocompostability/biodigestion process begins only upon exposure to microbes in the environment as life cycle end.

(30) The PEPlene films prepared using the peptide/enzyme/protein composition either by directly dispersed or encapsulated in the present invention have been successfully tested as per ASTM D 5988, ISO 14855, ISO 17556 and EN 13432/ASTM D6400 (and other national equivalents) test protocols for bio degradability and Eco toxicity and plant germination capability of the soil in which these films biodegrade. For example, EN protocols for cellulose based products require greater than 90% degradation within 180 days. Products according to the present invention start to degrade from 90 days under composting conditions FIGS. 1 and 2. Speed of degradation is generally affected by environmental microbial conditions, the amount of peptide/enzyme/protein composition and the thickness of the product. By way of example, degradation of products prepared according to the present invention has been achieved with extruded film of 5-50 microns thickness.

(31) Accordingly, a further advantage of the present invention is that the compositions comprise natural and food grade materials and leave no toxic residues after biodegradation and/or are within the heavy metal limits as prescribed by various countries for the plastic material/products.

(32) The present invention product is also recyclable in accordance with ASTM D 7209 protocol and EN 15347; The present invention product is also compostable according to standard EN 13432; and biodegradable according to standards ASTM D 5988, ISO 14855, ISO 17556 and EN 13432! ASTM D6400 (and other national equivalents) test protocols for biodegradability FIG. 5.

(33) Also, the present invention evaluated under US FDA 177.1520 for food contact safety compliance.

(34) A further advantage of the present invention is that the materials prepared according to the invention biodegrade when subjected to suitably environmental conditions. The product PEPlene films of the present innovation are also stable until disposal, such as into soil, compost, landfill, bio-digester or the like and under anaerobic conditions. The materials are able to be metabolized into biomass by the colony forming bacterial groups present in the compositions of the present invention and the microorganisms available in the soil.

(35) The compositions of the present invention with polyolefin such as polyethylene under aerobic conditions have shown that it is possible to subject poly films to complete biodegradation and bio-compostable by oxidative microbial attack.

(36) It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims.