The Promise of BioPlasticsvegetables.wsu.edu/SCRI/ASHS-Narayan-Plenary.pdfNarayan • Plastic are...
Transcript of The Promise of BioPlasticsvegetables.wsu.edu/SCRI/ASHS-Narayan-Plenary.pdfNarayan • Plastic are...
Narayan
Ramani NarayanUniversity Distinguished [email protected]
The Promise of BioPlasticsUnderstanding Value Proposition of Biobased and Biodegradable
Plastics for Reducing Carbon Footprint and Improving Environmental Performance
If you use any of the slides/materials, please reference authorship and affiliation (Ramani Narayan, Michigan State University) – thank you
Copyright Ramani Narayan
• Ramani Narayan, Biobased & Biodegradable Polymer Materials: Rationale, Drivers, and Technology Exemplars; ACS (an American Chemical Society publication) Symposium Ser. 939, Chapter 18, pg 282, 2006;
• Ramani Narayan, Carbon footprint of bioplastics using biocarbon content analysis and life cycle assessment, MRS (Materials Research Society) Bulletin, Vol 36 Issue 09, pg. 716 – 721, 2011
ASHS Plenary lectureJuly 31, 2012 Miami FL
Narayan
• Plastic are pervasive, universally used, and find applications in all parts of our lives
• from agriculture to electronics to construction materials, to transportation, to sports & leisure to medical devices to packaging.
• Packaging prevents spoilage, keep products safe, lightweight (saves energy); hygienic, health care
• From 1.7 million tons in 1950 to 265 million tons in 2010 worldwide expected to grow at a steady pace of 3–4% per year.
• rapid industrialization in populous countries such as India and China has resulted in an accelerated pace of plastic materials growth.
• Plastics offer “value” in every aspect of our life making it safe, functional, energy efficient, improved efficiencies and more –
PLASTICS
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• Horticulture (Plasticulture) -- mulch film, greenhouses, small tunnels, fruit and vegetable coverings, and other uses
• increased yields, earlier harvests, less reliance on herbicides and pesticides, better protection of food products and more efficient water conservation
• improve product quality and yield by mitigating extreme weather changes, optimizing growth conditions, extending the growing season and reducing plant diseases
• About 5 million tons used world-wide and growing
PLASTICS
Biodegradable Mulches for Specialty Crops Produced Under Protective Covers
Debra Inglis and Carol Miles (Project Directors)1;Andrew Corbin, Jessica Goldberger, Karen Leonas, Tom Marsh and Tom Walters1;
Doug Hayes, Jaehoon Lee, Larry Wadsworth and Annette Wszelaki2;
Jennifer Moore‐Kucera3; Russ Wallace4; Marion Brodhagen5 ; and Eric Belasco6
1 25
SCRI Grant Award
No. 2009-51181-05897
43 6
ASHS Colloquium Miami, Florida
Tuesday July 31, 20122:00- 6:00 pm
Biodegradable Plastic Mulches for Specialty Crop Production:
Current Status and Future Directions
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• Carbon footprint – material carbon footprint • origin of the carbon in the product • Biological carbon feedstock vs petro/fossil carbon feedstock
• Carbon footprint – process carbon footprint • arising from the conversion of feedstock to product – process
• Life Cycle Assessment (LCA) methodology
• End of life—what happens to the product after use when it enters the waste stream
• Recycling
• Biodegradability – composting & anaerobic digestion
• Soil – agriculture/horticulture films
• Misleading and Deceptive biodegradability/compostabilityclaims – BEWARE !
MAJOR ISSUES FOR CARBON BASED PLASTICS USE
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Switching from the “petro/fossil” carbon in plastics to “biobased” carbon reduces the material carbon footprint
• Reducing heat trapping CO2 emissions -- Minimizing global warming/climate change problems
• Using (renewable) biomass feedstock as opposed to petro/fossil feedstock – energy/environmental security
• Economic development – empowering rural farm, forestry and allied manufacturing industry
Carbon footprint reduction strategy using bio contentWhat Value Proposition does Biobased Plastics offer?
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Material Selection for “beginning of life”
bio vs petro/fossil feedstock
BIOBASED PLASTICS
Biobased plastics are not necessarily biodegradable(end-of-life) and biodegradable plastics are not necessarily biobased (beginning of life, origins of the carbon)
BioPlastics encompasses both biobased and biodegradable –compostable plastics
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VALUE PROPOSITION BASICS –MATERIAL CARBON FOOTPRINT – Origins of the carbon
CHCH3
CO
O
PLAn
Bio/renewable feedstock
Crops & residues (e.g. Corn, soybean sugarcane)
Tree plantations Lignocellulosics
Algal biomass
Oil, Coal, Natural gas
MATERIAL CARBON FOOTPRINTPROCESS CARBON FOOTPRINT
PLA, PHA’s
Naptha ethylene/propylene Polyethylene (PE) polypropylene (PP)
BIO monomers
sugars, Oils
EtOH H2C CH2nPE
H2C CH
CH3 nPP
C
O
O CH2 CH2 OC
O nBIOPET
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Carbon footprint reduction strategy using bio contentUnderstanding the Value Proposition based on the origins of the carbon in the product -- bio carbon vs petro/fossil carbon
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CO2 + H2O (CH2O)X + O2photosynthesis
sunlight energy
Biomass, Ag & Forestry crops & residues
NEW CARBON
Fossil Resources (Oil, Coal, Natural gas) -- OLD CARBON
> 106 YEARSUSE – for materials, chemicals and fuels
Rate and time scales of CO2 utilization is in balance using bio/renewable feedstocks (1-10 years) as opposed to using fossil feedstocks
1-10 years
1-10 years
MATERIAL CARBON FOOTPRINT
Short (in balance) sustainable carbon cycle using bio renewable carbon feedstock
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Carbon emissions – the problem
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Global warming –climate change
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Planet temperatures Mercury is the planet closest to the Sun, so one would assume that it is a burning
furnace. While the temperature on Mercury can reach 465°C, it can also drop to frigid temperatures of -184°C. There is such a big variation in Mercury’s temperature because the planet has no atmosphere, and it spends relatively slowly compared to some of the other planets.
Venus, the second closest planet to the Sun, has the highest average temperatures of any planet in our Solar System, regularly reaching temperatures over 460°C. Venus is so hot because of its proximity to the Sun and its thick atmosphere. Venus’ atmosphere is composed of thick clouds containing carbon dioxide and sulfur dioxide. This creates a strong greenhouse effect, trapping the Sun’s heat in the atmosphere and turning the planet into a furnace.
Earth is the third planet from the Sun, and so far the only planet known capable of supporting life. The average temperature on Earth is 7.2°C, but it varies much more than that at its extremes. The hottest temperature ever recorded on Earth was 70.7°C in Iran. The lowest temperature was -89.2°C in Antarctica.
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Carbon emissions – the problem
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What is the impact of the products material carbon footprint on the environment ?
Impact of the carbon’s origins in the product?
Impact of manufacturing 100 Kg of PE and bio-PE or bio-PLA in terms of Kg of CO2 released from the origins of the carbon
Carbon footprint reduction strategy using bio contentMaterial Carbon Footprint
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C
O
O CH2 CH2 OC
O nPET
H2C CH2nPE
CHCH3
CO
O
PLAn
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314 kg of CO2 emissions reduction for every 100 kg of PE resin in which the petro carbon is replaced with bio carbon
Material Carbon Footprint
0
50
100
150
200
250
300
350
PE/PP PET Bio-PE/PET/PLA
Kg of CO2 per 100 Kg resin
ZERO CARBON FOOTPRINT
314 kg of CO2 emissions reduction for every 100 kg of PE resin in which the petro carbon is replaced with bio carbon
Experimentally determine using ASTM D6866 based on the principle of C-14 analysis
Ramani Narayan, Michigan State University
Cradle to factory gate LCA scenario
Material Carbon FootprintKg of CO2 per 100 kg of resin
-320
-270
-220
-170
-120
-70
-20
30
80
1 2
Zero footprint -- product recycled, no release of gas to the environment
PE/PP BIO-PE
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Ramani Narayan, Michigan State University
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BIO-PET – Value Proposition
Oil, Coal, Natural gas
Naptha Ethylene Ethylene oxide Ethylene Glycol
MATERIAL CARBON FOOTPRINT PROCESS CARBON FOOTPRINT
C
O
O CH2 CH2 OC
O nBIOPET
Bio/renewable feedstock
Crops & residues (e.g. Corn, soybean sugarcane)
Tree plantations Lignocellulosics
Algal biomass
BIO monomers
Sugars, Oils
EtOH
OH CH2 CH2 OH
COOHHOOC
For bottles:37.5 MM tons PET used17.2 MM tons CO2 savings40 million barrels of oil/yr savings
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2009
Introduced innovative PlantBottle® package
2010
Over 2.5 Billion bottles10 Countries
2011
Over 7 Billion bottles20 Countries
2020
All bottles made with PlantBottle® plastic
Scaling across the world
Biobased & compostable PLA products
Courtesy Ford Motor Company
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Carbon footprint reduction strategy using bio contentMeasurement of bio (carbon) content – an important and critical Standard for the bio industry
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C-14 signature forms the basis of Standard test method to quantify biobased content (ASTM D6866)
12CO2
Biomass
Fossil Resources(petroleum, natural gas, coal)
> 106 years
14CO2 – Solar radiation
(12CH2O)x (14CH2O)x
(12CH2)n (12CHO)x
NEW CARBON
OLD CARBON
Narayan, ACS (an American Chemical Society publication) Symposium Ser.939, Chapter 18, pg 282, 2006; Narayan, MRS (Materials Research Society) Bulletin, Vol 36 Issue 09, pg. 716 – 721, 2011
14N 14C 14CO2
Cosmicradiation
12CO2
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Carbon footprint reduction strategy using bio contentMeasurement of biobased (carbon) content – ASTM D6866
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C-product combusted to CO2
14C/12C ratio is compared directly with a oxalic acid radiocarbon standard reference material (SRM 4990c) that is 100% new (bio) carbon.
• 13.56 dpm/g is the absolute value of the primary oxalic acid standard (SRM 4990b) and corresponds to 100% biobased (carbon) content
• 14.27 dpm/g is the value to use to correct for the post 1950 14C injection into the atmosphere.
• pMC values (after correction for isotopic fractionation) must be multiplied by 0.95 (as of 2010) to better reflect the true biobased content of the sample
• Contains concentration of 1.2 x 10-12 % of C-14 isotope equivalent to 100% bio carbon content
IMPORTANT NOTE:To calculate percent bio carbon present in product
multiply the experimental biobased content (from ASTM D6866) with the percent total organic carbon (TOC) (as determined by standard elemental analysis)
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Carbon footprint reduction strategy using bio contentTerminology
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BIOBASED PLASTICS/POLYMERS
Polymers containing in whole or part biogenic carbon (carbon from biological sources)
Biobased (carbon) Content -- The bio content is based on the amount of biogenic carbon present, and defined as the amount of bio carbon in the plastic as fraction weight (mass) or percent weight (mass) of the total organic carbon in the plastic. (ASTM D6866)
% bio or biobased content = Bio (organic) carbon/total (organic carbon) * 100
ASTM D6866 – Standard Test Methods for Determining the BiobasedContent of Solid, Liquid, and Gaseous Samples Using Radiocarbon Analysis
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1. Product ‘O’ is a fiber reinforced composite with the composition 30% biofiber (cellulose fiber) + 70% PLA (biobased material)
2. Product ‘P’ is a fiber reinforced composite with the composition 30% glass fiber + 70% PLA (biobased material
3. Product ‘N’ is a fiber reinforced composite with the composition 30% PLA + 70% polypropylene (petroleum based organic)
PROBLEM SOLVING EXERCISE
Calculate the biobased carbon content:
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Carbon footprint reduction strategy using bio contentProcess Carbon Footprint -- LCA
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Carbon footprint from the conversion of feedstock to product –cradle to factory gate scenario and total environmental footprint to be calculated using LCA methodology ASTM D7075 or ISO 1440
End of life scenarios – disposal system can give skewed/misused LCA’s
Transport (of product from factory/production point to customer) and disposal can have major impact on carbon footprint
B2B value chain analysis OR carbon to factory gate analysis
• Practitioners and users of LCA need to be careful in comparative analysis of products because of the data used, the boundary conditions
Ramani Narayan, Michigan State University 30
Naturalresources Emiss.
ProductPost-consumerwaste
Land Emiss.
Emiss.
Cradle-to-Factory Gate
Cradle-to-Grave
Processing
Process waste
Mining/ Extraction
Agriculture,Forestry
Use WasteM'mt
Landfill
Sewage Treatment
Emiss.
System boundaries
THE PROCESS -- LCA
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What is Life Cycle Assessment?
Assessment of Environmental impacts of Products/Processes or Services throughout the Life Cycle: resource extraction,
manufacturing, product use, waste management
It is “assessment” not “analysis”
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Kg of CO2 released per 100 kg resin
Process carbon footprint Material carbon footprint
zero
Process Carbon Footprint – the LCA trap
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Includes:• Definition, content verification, ASTM D6866• Biodegradability using ASTM D6400 and D6868 (paper coatings) D7021 (marine)• performance requirements; and• assurance that products are available
U.S. Farm Security and Rural Investment Act of 2002 (P. L. 107-171), Title IX Energy, Section 9002
FARM BILL
Federal Procurement of Biobased Products – the “biopreferred program” (www.biopreferred.gov)• develop guidelines for designating biobased products for federal
procurement• “USDA Certified Biobased Product” labeling program
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What happens to product after use when it enters the waste stream Design for recovery by recycling Mechanical – same product (example bottle to bottle) or another long life
product (example PET bottle to carpets)
Chemical – back to monomer
Design for biodegradability (in what disposal environment and time to complete biodegradation)
Composting -- COMPOSTABLE PLASTICS!
anaerobic digestion
Landfill gas (CO2 + CH4) for energy but digestate residue needs to treated by composting
Marine
Soil – agriculture/horticulture Misleading and Deceptive biodegradability/compostability claims –
BEWARE !
Carbon footprint reduction strategy using bio contentEND OF PRODUCT LIFERECYCLING & BIODEGRADABILITY-COMPOSTABILITY
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Carbon footprint reduction strategy using bio contentBiodegradability – A misused and abused term
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• Can microorganisms present in the disposal environment (soil, composting) utilize/assimilate the plastic carbon substrate – the biotic process
• What extent and in what time frame?
• Need complete microbial assimilation and removal from the environmental compartment in a short time period otherwise may have environmental and health consequences
• Degradable, partial biodegradable not acceptable – serious health and environmental consequences
• Phil. Trans. Royal. Soc. (Biology) July 27, 2009; 364
QUESTION
Misleading and Deceptive biodegradability/compostabilityclaims – BEWARE !
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What does Biodegradable Mean?Can the microorganisms in the target disposal system (composting, soil, anaerobic digestor) assimilate/utilize the carbon substrate as food source completely and in a short defined time period?
Biodegradation(Step 2): Only if all fragmented residues consumed by microorganisms as a food & energy source as measured by evolved CO2 in defined time and disposal environment
Hydrolytic
Polymer chains with susceptible linkages
EnzymaticOxidative
Oligomers & polymer fragments
Environment – soil, compost, waste water plant, marine
STEP 1
CO2 + H2O + Cell biomass
Completemicrobial assimilation
defined time frame, no residuesSTEP 2
Ramani Narayan, Michigan State University
Carbon footprint reduction strategy using bio contentBiodegradability/microbial utilization fundamentals
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Microorganisms extract chemical energy for use in their life processes by the aerobic oxidation of glucose and other utilizable substrates – BIODEGRADBLE PLASTICS, food waste, paper, forest residues biological matter
Glucose/C-bioplastic + 6 O2 6 CO2 + 6 H2O; G0’ = -686 kcal/molAEROBIC (composting environment)
ANAEROBIC
Glucose/C-bioplastic 2 lactate; G0’ = -47 kcal/mol
CO2 + CH4
CO2 is the quantitative measure of the ability of the microrganisms present in
the disposal environment to utilize/assimilate the test C-bioplastic, which is
the sole C-source available for the microorganisms – biodegradation or
bioassimilation
Ramani Narayan, Michigan State University
More Biodegradation/Bioassimilation Facts The aerobic oxidation process (a highly specialized cellular phenomenon) requires the participation of three metabolically interrelated processes:
1. Tricarboxylic acid cycle (TCA cycle)2. Electron transport3. Oxidative phosphorylation
All of the processes take place inside the cell
For these processes to occur:The substrates needs to be transported inside the cell
Thus, molecular weight, hydrophobic/hydrophilic balance, other molecular and structural features govern transport across cell membrane into the cell for utilization of the C-substrate.
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Carbon footprint reduction strategy using bio contentMeasuring biodegradability
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0
10
20
30
40
50
60
70
80
90
100
0 20 40 60 80 100 120 140 160 180 200
Time (days)
% C
con
vers
ion
to C
O2
(% b
iode
grad
atio
n)
lagphase
biodegradation phase
plateau phase
biodegradation degree
O2
Compost & Test
Materials
CO2
ASTM D5338; ISO 14855; EN 13432
level of biodegradation needed to claim safe and efficacious removal of the plastic carbon from the environmental compartment
Visual – COMPOSTING BIO films
Ramani Narayan, Michigan State University
DAY 0 DAY 5 DAY 10 DAY 18
DAY 26 DAY 45 DAY 60
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Carbon footprint reduction strategy using bio content
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Biodegradability Test MethodsASTM • Soil D5988; • Anaerobic digestors D 5511, ISO 15985• Biogas energy plant• Accelerated landfill D 5526• Guide to testing plastics ASTM D 6954
Must provide results from the test methods – could be zero or 50 or 100 percent ---generally not provided but claim of complete biodegradability made
ISOISO 14852, Determination of the ultimate aerobic biodegradability of plastic materials in an aqueous medium – Method by analysis of evolved carbon dioxideISO 14853, Determination of the ultimate anaerobic biodegradability in an aqueous system – Method by measurement of biogas productionISO 14855; Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions – Part 1: Method by analysis of evolved carbon dioxide and Part 2: Gravimetric measurement of carbon dioxide evolved in a laboratory-scale test
Ramani Narayan, Michigan State University
Carbon footprint reduction strategy using bio content
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Biodegradability under composting conditions
• Specification Standards ASTM D6400, D6868 (coatings)• Specification Standards EN 13432 (European Norm)• Specification Standards ISO 17088 (International Standard)
Biodegradability under marine conditions• Specification Standard D 7021
ISO DIS 18606 “Packaging & the environment – Organic Recycling”
Standard Specification for Aerobically Biodegradable Plastics in Soil Environment ASTM work item 29802
ISO 17556 Plastics -- Determination of the ultimate aerobic biodegradability in soil by measuring the oxygen demand in a respirometeror the amount of carbon dioxide evolved
ASTM D 5988 Standard Test Method for Determining Aerobic Biodegradation in Soil
Ramani Narayan, Michigan State University
Carbon footprint reduction strategy using bio contentProblems with incomplete and partial biodegradation
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plastic pieces can attract and hold hydrophobic elements like PCB and DDT up to one million times background levels. As a result, floating plastic is like a poison pill
• From Algalita Marine Research Foundation –www.algalita.org/pelagic_plastic.html
PCBs, DDE, and nonylphenols (NP) were detected in high concentrations in degraded polypropylene (PP) resin pellets collected from four Japanese coasts.
Plastic residues function as a transport medium for toxic chemicals in the marine environment.
• Takada et al Environ. Sci. Technol. 2001, 35, 318-324
• Blight, L.K. & A.E. Burger. 1997. Occurrence of plastic particles in seabirds from the Eastern North Pacific. Mar. Poll. Bull. 34:323-325
• Phil. Trans. Royal. Soc. (Biology) July 27, 2009; 364
Thompson, R.C. et al. 2004. Lost at sea: Where is all the plastic? Science 304, 838, 2004
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Sorting through facts, hypes, and misleading claims
GREEN WASHING
Additives (oxo or organic) added to polyethylene (PE) or polypropylene (PP) or polyethylene terephthalate (PET) or any polyolefin polymer will “degrade” the polymer to small fragments which will eventually biodegrade or biodegrade in 9 months to 5 years in soil, landfill
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Green Washing Claims -- Additive Technology
“Plastic products with our additives at 1% levels will fully biodegrade in 9 months to 5 years wherever they are disposed like composting, or landfills under both aerobic and anaerobic conditions”
The 50% Bio-Batch film did not degrade as completely or as quickly as the cellulose. At the end of the test, 19% of the film had degraded.The results of the aerobic degradation tests indicate that, in time, plastics produced using Bio-Batch pellets will biodegrade in aerobic conditions.DATA DOES NOT SUPPORT THE CONCLUSIONS!
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MISLEADING BIODEGRADABILITY CLAIMS
Ramani Narayan, Michigan State University
MISLEADING CLAIMS – UNSUPPORTED BY DATA
Oxo-biodegradable polyethylene (PE) film claims –“Combined with an oxo-biodegradable proprietary application method to produce films for bags. This product, when discarded in soil in the presence of microorganisms, moisture, and oxygen, biodegrades, decomposing into simple materials found in nature. Completely breakdown in a landfill environment in 12-24 months leaving no residue or harmful toxins and have a shelf life of 2 years”No scientific substantiation showing complete microbial utilization using established standard test methods
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BIODEGRADABILITY CLAIMS Chem. Commun., 2002, (23), 2884 - 2885
– A hypothesis was developed, and successfully tested, to greatly increase the rates of biodegradation of polyolefins, by anchoring minute quantities of glucose, sucrose or lactose, onto functionalized polystyrene (polystyrene-co-maleic anhydride copolymer) and measuring their rates of biodegradation, which were found to be significantly improved
PRESS Sugar turns plastics biodegradable. Bacteria make a meal of sweetened polythene
and polystyrene.
weight loss of only 2-12%,
Only sugar is being assimilated, PE chain intact – Is this a genuine example of biodegradable plastic?