Transcript Document
MANUFACTURING OF BIODEGRADABLE POLYETHYLENE
PRESENTED BY: HASAN IJTABA KHAN MAFTUN FAISAL NADEEM KHAWAJA OWAIS KAMAL SYED HASSAN SAEED AHMED IMRAN QUREISHI 09-PE-12 09-PE-07 09-PE-14 09-PE-34 09-PE-03
BIODEGRADATION
Process by which organic substances are environmental effects and by the living organisms.
broken down by the Organic material can be degraded aerobically or anaerobically .
Biodegradable matter is generally organic material such as plant and animal matter and other substances originating from living organisms, or artificial materials that are similar enough to plant and animal matter to be put to use by microorganisms.
Biodegradable polymers are a kind of materials which degrades biologically.
The biodegradability of plastics is dependent on the chemical structure of the material and on the constituent of the final product, not just on the basic materials used in the production.
THE RANGE OF BIODEGRADABLE PLASTIC
Starch based products including thermoplastic starch, starch and synthetic aliphatic polyester blend, and starch and PVOH (polyvinyl alcohol) blends.
Naturally produced polyester including PVB (polyvinyl butadiene).
Renewable resource polyesters such as PLA (poly lactic acid).
Synthetic aliphatic polyesters including PCL (poly caprolactone).
Aliphatic-aromatic (AAC) co polyester.
Hydro-biodegradable polyester such as modified PET.
Water-soluble polymers such as polyvinyl alcohol and ethylene vinyl alcohol.
Photo-biodegradable plastics.
Controlled degradation additive master batches.
CLASSES OF BIODEGRADABLE PLASTICS
Compostable Hydro-biodegradable Photo-biodegradable Bioerodable Biodegradable
BACKGROUND OF STARCH-BASED POLYMERS
Our work relates to a biodegradable film prepared by chemical bonding of starch and polyethylene.
Polyethylene is polyolefin having the most widest general application, coupling agent such as maleic anhydride, methacrylic anhydride or maleimide which bonds with starch and polyethylene, and Lewis acid catalyst and to a process for preparing thereof.
BACKGROUND OF STARCH-BASED POLYMERS
Starch
Chemical formula of starch
(
C 6 H 10 O 5
)
n Starch is a linear polymer (polysaccaride) made up of repeating glucose groups linked by glucosidic linkage in the 1-4 carbon position.
The length of the starch chain will vary with plant sources but in general the average length is between 500-20,000 glucose units.
There are actually two types of starch molecules: – Amylose – Amylopectin.
The only difference between the two is the arrangement of the molecules.
Amylose is essentially linear while amylopectin has many branches like a tree.
CHEMISTRY OF STARCH
–
Amylose
Amylose molecules consist of single mostly-unbranched chains with 500-20,000 α-(14)-D-glucose units dependent on source.
– Hydrogen bonding between aligned chains causes retro gradation and releases some of the bound water.
CHEMISTRY OF STARCH
–
Amylopectin
Amylopectin is formed by non-random amylose-type α-(14)-D-glucose structure.
α-16 branching of the – – Each amylopectin molecule contains a million or so residues.
Each amylopectin molecule contains up to two million glucose residues in a compact structure with hydrodynamic radius 21-75 nm.
VARIETIES OF STARCH
Corn Starch
VARIETIES OF STARCH
– Common cornstarch has 25% amylose. The two remaining cornstarches are high-amylose cornstarches; one has 50% to 55% amylose, while the second has 70% to 75%. Their size ranges between 5 microns and 20 microns
Maize Starch
– Maize starch has irregularly shaped granules.
High-amylose starches also have an irregular shape, but tend to be smooth. Some of these are even rod-shaped. High-amylose starches have a narrower size range: 5 to 15 microns, or even 10 to 15 microns, depending on the variety.
VARIETIES OF STARCH
Potato Starch
– Potato starch has about 20% amylose. Potato starch granules are large with a smooth round oval shape. Of the starches commonly used for food, potato starch is the largest; its granules range in size from 15 to 75 microns.
Rice Starch
– Common rice starch has an amylose: amylopectin ratio of about 20:80, while waxy rice starch has only about 2% amylose. Both varieties have small granule sizes ranging from 3 to 8 microns.
VARIETIES OF STARCH
Tapioca Starch
– Tapioca starch has 15% to 18% amylose. Tapioca granules are smooth, irregular spheres with sizes ranging from 5 to 25 microns.
Wheat Starch
– Wheat starch has an amylose content of around 25%. Its granules are relatively thick at 5 to 15 microns with a smooth, round shape ranging from 22 to 36 microns in diameter.
Soya bean Starch
– Soya bean starch has irregular shaped granules. Common Soya bean starch has 7% amylose. Its granules range in size from 10 to 90 microns.
VARIETIES OF STARCH
CATEGORIES OF STARCH BASED POLYMERS
Thermoplastic starch products.
Starch synthetic aliphatic polyester blend Starch PBS/PBSA polyester blends Starch PVOH blends
.
CATEGORIES OF STARCH BASED POLYMERS
Thermoplastic Starch Products
– Thermoplastic starch biodegradable plastics (TPS) have a starch (amylose) content greater than 70%.
– It is based on vegetable starch, and with the use of specific plasticizing solvents, can produce thermoplastic materials with good performance properties and inherent biodegradability.
– This can be overcome through blending, as the starch has free hydroxyl groups, which readily undergo a number of reactions such as acetylation, esterification and etherification.
CATEGORIES OF STARCH BASED POLYMERS
Starch Synthetic Aliphatic Polyester Blends
– Blends of biodegradable synthetic aliphatic polyesters and starch are often used to produce high quality sheets and films for packaging by flat-film extrusion using chill-roll casting or by blown film methods – Approximately 50% of the synthetic polyester (at approximately $4.00/kg) can be replaced with natural polymers such as starch (at approximately $1.50/kg), leading to a significant reduction in cost.
– Furthermore, the polyesters can be modified by incorporating a functional group capable of reacting with natural starch polymers.
CATEGORIES OF STARCH BASED POLYMERS
Starch and PBS/PBSA Polyester Blends
– Polyesters that are blended with starch to improve material mechanical properties are Polybutylene succinate (PBS) or polybutylene succinate adipate (PBSA).
– At higher starch content (>60%), such sheets can become brittle.
– Plasticizers are often added to reduce the brittleness and improve flexibility.
– Starch and PBS or PBSA blends are used to produce biodegradable plastic sheet, which can be thermoformed into products such as biscuit trays or film products.
CATEGORIES OF STARCH BASED POLYMERS
Starch-PVOH Blends
– Polyvinyl alcohol (PVOH) is blended with starch to produce readily biodegradable plastics.
MARKET SURVEY REPORT
MARKET ANALYSIS OF BIODEGRADABLE MATERIAL
– The technology surrounding biopolymers been in the and biodegradable packaging has development stage for the last 15-20 years.
– In the last five years have markets developed and much commercial growth been seen.
– Only few scale to successful.
companies be are currently biodegradable producing packaging materials on a large enough commercially
NUMBER OF COMPANIES WITH BIODEGRADABLE PLASTICS
Figure illustrates the trend, showing that the number of companies applying for patents increased through the 1990s and appears to have peaked in 2005.
BIODEGRADABLE MATERIAL’S MARKET OVERVIEW
Figure Identifying the top 30 companies listed as first assignee indicates which companies are most active in patenting new technologies and processes.
According to the Rapra report, 30 suppliers are currently active in the global biopolymer market, with BASF, DuPont and Mitsubishi Gas Chemicals dominating.
Novamont and Mitsubishi are also found among the patent leaders, suggesting that competition could heat up over the next few years.
GEOGRAPHICAL DISTRIBUTION OF PATENT ACTIVITY FOR USE OF BIODEGRADABLE MATERIALS
Following figure shows that nearly half of the filings examined were published in the United States (USPTO).
The other half is divided among World patents (WIPO), European patents, Japanese and British patents.
ACTIVE SUPPLIERS OF BIODEGRADABLE MATERIAL
Proctor and Gamble Limited.
BASF Germany.
DuPont.
Mitsubishi Gas Chemicals.
Nova Mont.
Nature Works.
Rodenburg Biopolymers.
Biotech.
Mitsubishi.
Merck Chemicals.
LOCAL MARKET SURVEY
We have conducted local market survey and have reached to the conclusion that the biodegradable material is not available in the market.
We also have contacted the following companies and the results are the same as mentioned above.
– – – – – Bin Rasheed Umair Petrochemicals MERCK Chemicals P & G Pakistan BASF Pak Ltd.
LOCAL MARKET SURVEY
a.DENSO HALL SADDAR KARACHI b) LIAQUATABAD KARACHI NAME BISMILLAH PLASTICS
Deals in all kinds of plastic raw materials and waste.
PERSON CONTACTED
Mr. M Asif Abdul Sattar
SATTAR PLASTICS
Purchasers and sellers of all kinds of plastic waste and powder.
Mr. Mohammad Siddique Mr. Umair Siddique Mr. Abdul Rehman
ADDRESS
Shop No 1-2-B, Noori center, 1/98, Khachi Gali No-2, Marriott Road Tel:- 0092-21 7085200 Cell:- 0092-322 2872835 Shop No-1 Moonpur Wala Center Kutchi Gali No-2 Marriott Road Tel:-0092-21 2435892 0092-21 2434071 Cell:-0092-300 2104966 0092-321 8297514 E-mail: umairshiwani@ho tmail.com
NAME AYUB PLASTICS
Deals in all kinds of powder and scrap, sale and purchasing.
PLASTIC MARKAZ
Deals in all kinds of plastic sale and purchase.
MAHBOOB PLASTICS
Specialist in all kinds of plastic material sales and purchase
INTERNATIONAL PLASTIC POINT
Deals in all kinds of plastic materials.
PERSON CONTACTED
Mr. M Ayub Raza Mr. M Alam Mr. Mateen Khan Mr. Shafiq Ahmed
ADDRESS
Shop No 14, B-Road near Police Station Liaquatabad Tel:- 0092-21 4914687 0092-21-4854754 Cell:-0092-333 2192847 Shop No-32 Commercial Area B Road Dakkhana Karachi Tel:- 0092-21 4917872 Cell:-0092-300 2197630 Shop No-29 “B”-Road Liaquatabad Karachi Tel:- 0092-21 4920314 Cell:-0092-333 2307411 233-B, Road Liaquatabad Karachi Tel:-0092-21-4120798 Cell:-0092-346 2716744
DISPOSAL ENVIRONMENTS
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
Composting facilities or soil burial Anaerobic digestion Wastewater treatment facilities Plastics reprocessing facilities Landfill Marine and freshwater environments General open environment as litter.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
COMPOSTING FACILITIES AND SOIL BURIAL
– Composting and soil burial is the preferred disposal environment for most biodegradable plastics.
– The degradation mechanism of biodegradable plastics in a composting environment is primarily hydrolysis combined with aerobic and anaerobic microbial activity.
– Typically for full degradation, composting occurs over a 10 to 12 week period.
– The degradation products of aerobic composting are compost and CO2.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
ANAEROBIC DIGESTION
– Anaerobic digestion is also gaining support as an alternative to landfills.
– Methane production may be faster, more efficient and more predictable in this system and a useful end-product, compost, is also produced.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
WASTE WATER TREATMENT PLANTS
– Activated sewage sludge will convert approximately 60% of a biodegradable polymer to carbon dioxide.
– The remaining 40% will enter the sludge stream where, under anaerobic digestion, it will be converted to methane.
– Any biodegradable polymer that meets the compostability criteria will degrade even faster in a sewage environment.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
REPROCESSING FACILITIES
It is to be expected that if biodegradable plastics began to occupy a significant market share of the plastics market in the world that some material would end up in plastics reprocessing facilities. This could have significant effects on the sorting procedures required and the quality of recycled end products.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
LANDFILLS
– When conventional low density polyethylene film was under bioactive soil for almost 40 years, the surface of the film shows signs of biodegradation with the molecular weight dropping by half the original.
– The inner part of the sample was almost unchanged with the molecular weight being retained.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
LANDFILLS
– Environmentally degradable polymers could increase the capacity of landfill sites by breaking down in a relatively short time and freeing other materials for degradation, such as food scraps in plastic bags.
– Typical landfill gas contains 50% methane and 45% CO2, with the balance composed of water and trace compounds.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
MARINE AND FRESHWATER ENVIRONMENTS
The rate of biodegradation in marine environments is affected by the water temperature.
– In cold waters, the plastic material may still be in a form that could endanger marine life for an extended period of time. It is found that plastic is fully degraded in 20-30 days in a compost environment .
– Thus seasonal and climatic effects on biodegradation rates need to be considered in relevant applications.
MAJOR DISPOSAL ENVIRONMENTS FOR BIODEGRADABLE PLASTICS
LITTER
Plastic litter causes aesthetic problems as well as danger to wildlife resulting from entanglement and ingestion of plastic packaging materials and lightweight bags. Wildlife losses are an issue for the conservation of biodiversity, and losses due to litter have caused public concern.
PROCEDURE OF MANUFACTURING STARCH BASED POLYETHYLENE
BIODEGRADABLE POLYETHYLENE COMPOSITION CHEMICALLY BONDED WITH STARCH
Contents Polyethylene
Biodegradable incorporating material
{Selected from the group consisting of corn starch, acid treated starch, esterifies starch, etherified starch, cationic starch and mixtures} Coupling agent maleimide}
{Selected from the group consisting of maleic anhydride, methacrylic anhydride and Lewis acid catalyst
Radical initiator
Autoxidizing agent
Plasticizer
Amount 100 parts by weight 5 - 400 parts by weight 0.01 - 10 parts by weight 0.01 - 6 parts by weight 0.01 - 1.0 parts by weight 0.01 - 10 parts by weight 0.01 - 10 parts by weight
BIODEGRADABLE POLYETHYLENE COMPOSITION CHEMICALLY BONDED WITH STARCH
In this composition the polyethylene is selected from the group consisting of low density polyethylene LDPE. The LDPE which we have selected for our biodegradable starch based film is PETLIN-MALAYSIA of extrusion grade.
The radical initiator may be di-cumyl peroxide.
The Autoxidizing agent is one or more selected from the group consisting of manganese oleate, manganese stearate, ferrous oleate (II). Since we were unable to find autoxidizing agent due to its unavailability in the market, so as per our advisor recommendation we have not used autoxidizing agent in our formulation.
The Lewis acid catalyst is one from the group consisting of stearic acid and acetic acid . We have used stearic acid as a catalyst in our formulation.
The plasticizer is one selected from group consisting of oleamide, Viton poly (hexaflouropropylene)-copoly (vinylidene fluoride) or Erucamide Cis-13-1 docosenoamide. In our formulation we have not used plasticizer due to its unavailability in the local market.
PROPOSED RATIO OF POLYETHYLENE AND STARCH
POLYETHYLENE PERCENTAGE
80 60
RAFHAN MAIZE STARCH PERCENTAGE
20 40
Starch
COMPATIBILTY OF LDPE WITH DIFFERENT TYPES OF STARCHES
Temperature o C Pressure Psi Time Minutes Compatibility Melting Point o C Microscopic View Maize Starch 230 110 20 Yes 265 Wheat Starch 230 Corn Starch 230 110 20 110 20 No 285 No 280
PROJECT DESCRIPTION
Initially we have been suggested to make a starch based biodegradable polyethylene blown film through single screw extruder.
Afterwards the management of PLASTICS TECHNOLOGY CENTRE proposed us to manufacture a strip of starch based biodegradable polyethylene by using a profile die on BRABENDER PLASTICORDER.
FORMULATION FOR BRABENDER
CONTENTS STANDARDS PHR 250gms FORMULATION 80/20 Ratio 250gms FORMULATION 60/40 Ratio
LDPE Maize Starch Maleic Anhydride Stearic Acid Di-Cumyl Per Oxide Manganese Stearate Viton 100 5-400 0.01-10 0.01-06 0.01-1.0
0.01-10 0.01-10 199 gms 50 gms 0.25 gms 0.25 gms 0.25 gms N/A N/A 149 gms 100 gms 0.25 gms 0.25 gms 0.25 gms N/A N/A
MIXING
Mixing of the above two proposed formulation is carried out in a HANSCHEL MIXER for about 15 minutes. Before putting the material in the mixer for mixing, the mixer should completely and thoroughly be cleaned with a clean cloth so as to avoid contamination of the two proposed batches.
PROCESSING AT BRABENDER
After mixing, the compound has been taken to the BRABENDER PLASTICORDER.
Profile die is used and the extrudate is manually cut with the help of a cutter to have it in a shape of a strip.
Initially the BRABENDER is operated to remove the last traces of the material left in the barrel in the last processing operation.
Once all the old material’s been removed, virgin LDPE has been added through the hopper to achieve the required temperature.
Since we were processing starch with LDPE for the first time in our carrier, we were stock feeding the machine so that the material should not block the nozzle of the machine.
Fans in the processing hall were kept closed to achieve the desired temperatures on the machine.
PROCESSING AT BRABENDER
Firstly we processed 80/20 ratio formulation so as to check the behavior of the machine with the starch incorporated batch.
After the production of 80/20 ratio batch, we processed pure LDPE so as to clean the barrel of the extruder for next formulation.
For 60/40 ratio formulation, the temperatures at the machine are slightly increased as the content of starch is greater as compared with the previous composition. Once the desired temperature range has been achieved, the strips of the proposed formulation have been produced.
Water bath has been used immediately after the die so as to cool the formed product.
PROCESSING PARAMETERS AT BRABENDER
PARAMETERS 80/20 RATIO 60/40 RATIO
Size of the Batch Temperature at Feeding Section Temperature at Compression Section Temperature at Metering Section Die Temperature Screw Speed Die Shape Time Consumed 249.75 grams 210 o C 215 o C 190 o C 190 o C 35 RPM Profile Die 4 Hours 249.75 grams 230 o C 230 o C 215 o C 210 o C 35 RPM Profile Die 4 Hours
TESTING
INTERNATIONAL ORGANISATIONS FOR STANDARDS AND TEST METHODS
American Society For Testing And Materials (ASTM) European Standardization Committee (CEN) International Standards Organisation (ISO) Institute for Standards Research (ISR) German Institute for Standardization (DIN) Organic Reclamation and Composting Association (ORCA) (Belgium)
DIFFERENCE BETWEEN STANDARDS FOR BIODEGRADATION
STANDARD
DIN ASTM CEN ORCA
BIODEGRADATION REQUIREMENTS
60 % 6 Months 60 % 6 Months 90 % 60 % (for chemicals) NIL 28 Days
TENSILE STRENGTH
Machine Load = Instron-4302 Universal Testing Machine UTM = 01 KN Sample Clamping Testing Length (GL) = 25 mm Speed = Pneumatic = 50 mm / min
80/20 FORMULATION
01 02 03 04 05 06 07 08
SAMPLE AREA W X T
4.05x1.8=7.29mm
4.10x1.95=7.99mm
4.10x2.0 =8.2mm
4.05x2.0=8.1mm
4.05x1.95=7.89mm
4.05x2.0=8.1mm
4.2x201=8.8mm
4.05x2.0=8.1mm
FORCE AT PEAK LOAD
2.046 Kgf 1.895 Kgf 2.132 Kgf 2.070 Kgf 2.244 Kgf 0.5396 Kgf 2.040 Kgf 1.981 Kgf
ELONGATION AT PEAK EXTENSION
2.62 x 4 =10.48 % 2.54 x 4 = 10.16 % 4.68 x 4 = 18.72 % 2.94 x 4 = 11.76 % 4.11 x 4 = 16.44 % 1.97 x 4 = 7.88 % 3.69 x 4 = 14.76 % 4.72 x 4 = 18.88 %
60/40 FORMULATION
SAMPLE
01 02 03 04
AREA W X T
4.15x1.05=4.357mm
4.15x0.95=3.94mm
4.15x0.9=3.73mm
4.2x0.7=2.94mm
05 06 07 08 4.2x0.9=3.78mm
4.2x0.75=3.15mm
4.15x1.0=4.15mm
4.2x0.9=3.78mm
FORCE AT PEAK LOAD
1.407 Kgf 0.7007 Kgf 0.8859 Kgf 0.6497 Kgf 1.219 Kgf 0.8349 Kgf 1.323 Kgf 1.216 Kgf
ELONGATION AT PEAK EXTENSION
5.30 x 4 = 21.2% 3.90 x 4 = 15.6% 4.12 x 4 = 16.48 % 2.93 x 4 = 11.72 % 4.14 x 4 = 16.56 % 3.69 x 4 = 14.76 % 4.75 x 4 = 19 % 4.37 x 4 = 17.48 %
DENSITY TEST
Machine Units
MATERIAL
= Electronic Densimeter SD-120L = grams / cubic centimeter Pure LDPE 80/20 Ratio 60/40 Ratio
DENSITY Grams/cubic centimeter
0.915
N/A 0.929
The density of 80 / 20 ratio cannot be found as the material was unable to flow through the die of melt flow index (MFI).
Machine Load Cut of Time Units Feed in Factor
MELT FLOW INDEX
= Melt Flow Index (MFI) Davenport = 2.16 Kg = 3 minutes = grams / 10 minutes = 3 – 5 grams = 3.33
PURE LDPE MFI
SAMPLE
01 02 03 04 05 Mean Value MFI = Mean Value x Factor MFI = 0.8544 x 3.33
MFI = 2.5623 grams / 10 minutes
WEIGHT Grams / 10 minutes
0.891
0.833
0.827
0.867
0.854
0.8544
80 / 20 RATIO MFI
The MFI of 80 / 20 ratio batch cannot be done as the material was not flowing through the die of MFI.
Flakes of 80 / 20 ratio for MFI Extrudate of 80 / 20 formulation
60 / 40 RATIO MFI
SAMPLE WEIGHT Grams / 10 Minutes
01 02 03 04 05 Mean Value MFI = Mean Value x Factor MFI = 0.485 x 3.33
MFI = 1.61505 grams / 10 minutes 0.48
0.462
0.498
0.49
0.495
0.485
BURY TEST
The strips of both the batches of starch based biodegradable polyethylene are buried in soil with the cow dung. The ratio of the soil and the cow dung is 50: 50. Cow dung is used to make the production of the microorganisms faster. It will fasten the biodegradation process. 15 cm sample of both the formulation are buried in the mixture of soil and the cow dung. The mixture is placed in the open sun for next three months.
The strip of biodegradable composition will be obtained after three months and will be taken into observation for the mechanical tests.
MELTING POINT
Machine = Hot Stage Microscope
FORMULATION PE / Starch MELTING TEMPERATURE o C
80 / 20 60 / 40 220 255
PROS AND CONS OF STARCH BASED BIODEGRADABLE POLYETHYLENE
PROS
Biodegradable means that, under certain conditions, the material will be degraded into small pieces that can be absorbed by microorganisms and transformed into CO2, H2O, energy and neutral residue.
Reduced fossil fuel content (depending on loading of filler) Faster degradation of litter No net increase of carbon dioxide in global ecosystem.
CONS
PROS AND CONS OF STARCH BASED BIODEGRADABLE POLYETHYLENE
Degradation in a sealed landfill takes at least 6 months.
Limited Shelf life.
Poorer mechanical strength than additive based example – filling a starch bag with wet leaves and placing it curbside can result in the bottom falling out when a hauler picks it up. However, some biodegradable and compostable films are now very close to polyethylene or polypropylene, depending on the starch used.
Some need to be composted in industrial facilities because the temperature of the compost needs to be at 58 °C. Others ( OK-compost) are home composting (temperature 20 °C).
EMERGING APPLICATION AREAS
Adapted from Watson 1992
EMERGING APPLICATION AREAS
COATED PAPER AGRICULTURE MULCH FILM SHOPPING BAGS FOOD WASTE FILMS AND BAGS CONSUMER PACKAGING MATERIALS LANDFILL COVER FILMS OTHER APPLICATIONS
FUTURE OUTLOOK FOR BIODEGRADABLE PLASTICS
It is estimated that plastic waste generation will grow by 15% per year for the next decade.
There is room for growth and expansion in many areas of the biodegradable plastic industry.
Researchers development.
worldwide are interested in the area of biopolymer Organic recovery (composting spent materials) is the most commonly applied waste reduction method.
FUTURE OUTLOOK FOR BIODEGRADABLE PLASTICS
The nature of natural materials requires different considerations than those for synthetic materials.
The biopolymer industry has a positive future, driven mainly by the environmental benefits of using renewable resource feedstock sources.
The ultimate goal for those working in development is to find a material with optimum technical performance, and full biodegradability.