<ul><li>Beijing, China 2009 </li></ul>Landfill Biodegradability of Plastics
Goal - To develop additive systems that will permit common, cost effective, inherently non-biodegradable plastics to biodegrade in a landfill to useful products without loss of resistance to heat or weather in ordinary service. To biodegrade only in a landfill.
Landfill Environment Dark, 30-40ºC, limited oxygen, bad conditions for usual degradation paths. Variable moisture content. At 35-45% moisture, many plastics can be induced to biodegrade. At very low levels (15-20%) found in poorly managed landfills, not even food waste will biodegrade.
Oxidative Degradation (not in a landfill) In damp loose soil inherently biodegradable plastics such as PLA, polyvinyl alcohol or polyacrylic acid, or Polyolefin/starch compositions or modified with Ferric or Manganese stearate will degrade. Outdoor service life and water resistance are extremely limited
ASTM D 5526 Landfill 90% Processed sterile sewage waste of 35-65% water content 10% actively fermenting compost This method simulates landfills in which the gas generated is recovered. In well managed landfills, there is periodic addition of water and sewage waste.
What’s suitable food? Water is vital Sources of carbon and nitrogen Necessary trace elements Absence of active biocides – Zinc, cadmium and mercury and lead compounds
<ul><li>Control degradation so that the polymer molecules break into pieces during aging instead of resinifying to higher MW </li></ul><ul><li>PVC can do both but in the natural course of events tends to resinify rather than break apart </li></ul>How do we get low MW?
Biodegradable Plastisol with BIOchem ® Additives
What is readily consumed in the landfill? (at least, under some conditions) Process oil, low wax, plasticizers from natural products (Not phthalates), stearic acid, cellulose, if the moisture content is high. (If not, paper may persist indefinitely.)
Decomposition of Cellulose Requires High Moisture
Landfill Degradation Develops Useful Fuel in Biogas
Is PVC immortal in the landfill? 2003 report that after 32 years in a landfill, plasticized PVC sheet showed only minor holes where fungi had consumed plasticizer or other additives. 1994 report that addition of 8% starch resulted in microbes eating only the starch
Landfill Decomposition of Vinyl Plastics Additives leading to landfill biodegradation of PVC and related materials under anaerobic conditions are described in US Patent 7,390,841, now also WO 2008/140552. Organotitanates and zirconates of certain specific structure enable microbes to attack weak points in the large molecules of the plastic.
Typical results, ASTM D 5526 (IF moisture level is optimum) Filter paper – gone in 60 days at high H2O PLA, Starch - 30 days at high moisture 2 mil PVC film – no change 180 days With 2% additive – consumed in 60 days 5 mil film “ “ - 90-120 days, brittle in 60 days
Landfill Decomposition with Additive (BIOflex) Optimum landfill moisture is 35-45%, very slow at 60% and almost zero at 97%, as in sewage treatment facilities. In ordinary service, heat resistance and outdoor weatherability equals that of the highest quality PVC compositions.
Current Commercial Application <ul><li>Vinyl backings for billboards, displays, banners Bioflex® landfillable composition </li></ul><ul><li>Plastisol coated on scrim reinforcement up to 5 meters wide – Ultraflex Systems, Inc. </li></ul><ul><li>Compost using landfill contains ~400 ppm soluble chloride – when used in soil, adds to fertilizer value by increasing rate of nitrogen uptake </li></ul>
BIOflex ® <ul><li>Left Photo : BIOflex®, Day # 1 </li></ul><ul><li>Right Photo : BIOflex® after 6 months-only polyester remains </li></ul>
BIOflex® 100 mil sample after 6 months – Microbes eating PVC BIOflex®
<ul><li>Solvay Type 910 PVDC. ( Polyvinylidene chloride ) </li></ul><ul><li>Only Microscopic fragments are left after 30 days. </li></ul>
<ul><li>This sample is Solvay PVDC which contains zinc, cadmium and mercury. These heavy metals discourage microbes. Solvay Type A050 after 30 days with zero effect. </li></ul>
<ul><li>What was a 1” x 0.5” in sample of 5 mil thick BIOflex ® plastisol after 30 days, showing massive microbial attack. </li></ul>
<ul><li>Heavy gauge BIOflex® and wood fiber composite after 6 months. </li></ul>
Dr. Richard Grossman receives the Pinnacle Award from PDMA
Is PVC immortal? <ul><li>Reports indicate that PVC persists indefinitely in landfills </li></ul><ul><li>Why is this? Contrary to popular belief, many microbes eat chlorinated compounds, in fact have been used to remediate sites contaminated with PCBs </li></ul><ul><li>But these are low molecular weight </li></ul>
Below is a piece of Bioflex® plastisol, 100 mils thick, that had been cast on release paper and oven fused. After 3 months in the landfill it shows considerable microbial attack. It may take a year or more to vanish.
<ul><li>Here is the end result, after BIOflex® has vanished, only filler particles are left, plus unhappy microbial colonies that have run out of food. </li></ul>
<ul><li>This year’s school-lunch set has yet another green option: reusable, biodegradable lunch bags. </li></ul>
<ul><li>Vinyl is final, or at least we always used to think so. But advertising and marketing company Adrac, which is trying to get into the Guinness Book of World Records for placing the world's longest billboard in the city of Dubai next spring, promises that its 1.5 kilometer long billboard will be environmentally friendly and made from biodegradable PVC plastic. </li></ul>World’s Largest Billboard Will Be ‘BIOflex® Biodegradable’ PVC
<ul><li>Doug Kanter for The New York Times </li></ul>Since Mr. Tian migrated from Sichuan province, the multibillion-dollar recycling industry has gone into a nosedive because of the global economic crisis and a concomitant fall in commodity prices. Bottles now sell for half of what they did in the summer. “ Even trash has become worthless,” Mr. Tian said recently as he made his way to a collection center, his sacks nearly bursting. The collapse of the recycling business has affected people like Mr. Tian, the middlemen who buy the waste products and the factories that refashion the recyclable waste into products bound for stores and construction sites around the world. American and European waste dealers who sell to China are finding that their shipments are being refused by clients when they arrive in Asia. The ultimate victim may be the environment, already overrun with enough trash in places to threaten people’s health, now further burdened with refuse that until recently would have been recycled. The effect is being felt acutely in China, the world’s largest garbage importer. The United States, for example, exported 11.6 million tons of recovered paper and cardboard last year to China, up from 2.1 million tons in 2000, according to the American Forest and Paper Association. China’s Big Recycling Market Is Sagging
<ul><li>Data and information provided by: </li></ul><ul><li>John Schleicher, Jr. </li></ul><ul><li>John Sulano </li></ul><ul><li>BIOtech Products </li></ul><ul><li>1578 Sussex Turnpike, Building #4 </li></ul><ul><li>Randolph, NJ USA 07869 </li></ul><ul><li>www.biotech-products.net </li></ul><ul><li>Copyright: March, 2009 </li></ul>