Q & A – About the Science:The most frequently asked question: "If ordinary plastics are synthetic materials made from petroleum, can they really be made to biodegrade"?What are the origins & characteristics of ordinary plastics?So why don’t ordinary plastics disintegrate and biodegrade?What are the consequences of “bioinert” plastics and what can be done?What additives are used in "Eco" products and how do they work?So this science stuff is all well and good but what happens to the plastic?Can you describe the oxo-biodegradation process more scientifically?[Top]Answers about the Science:The most frequently asked question: “If ordinary plastics are synthetic materials made from petroleum, can they really be made to biodegrade"?• The response is a definitive “YES”. This is an answer that many people find quite surprising but the fact is, the origins of plastic are “organic” and as such, it is not surprising that Nature can also safely return it to the natural bio-cycle.[Top] What are the origins & characteristics of ordinary plastics?• Petroleum was created hundreds of millions of years ago when organic matter such as plankton was compressed and trapped in huge carbon reservoirs as petroleum. • Petroleum iis a naturally occurring mixture compsed primarily of hydrocarbons in a gaseous, liquid or solid state. • “Organic” carbon is different than carbon metal in that its origins are primarily organic plant tissue and like any organic material in our environment, it is the primary food source for the tens of thousands of different microorganisms (bacteria and fungi) that survive and thrive in our air, soil and water. • Like paper that is made from another organic material – cellulose, plastic is made from the hydrogen and the “organic” carbon in petroleum, and like paper, plastics can also be made biodegrade. • Every combination of elements has a gram molecular weight (GMw). A water molecule (h2O has a GMw of 18. C2O has a GMw of 44. Ethene (CH2) with a GMw of 14, is higly polymerized. A plastic molecule with a GMw of 100,000 to 1,000,000 or more is formed through a process of combining smaller molecules to form larger molecules that contain repeating structural units of the original molecule. The polymerization of Ethene creates a relatively large plastic molecule that is far too big to be attacked by the colonies of tiny microbes which exist everywhere. • While there is some contention as to how small a molecule must be before it can be ingested, mineralized and biodegraded by the microbes – the lower end of the range of 5,000 to 40,000 Mw is widely accepted in the science world.[Top] So why don’t ordinary plastics disintegrate and biodegrade?• The answer is quite simple. In the production of polyolefin plastics (plastics that float – polyethylene, polypropylene and polystyrene), resins are polymerized and then highly stabilized into very large and “bioinert” carbon chains. While over a long period of time they will naturally oxidize and degrade, the timeframe is simply not convenient for our societal needs. • In the development and production of light weight, versatile and tough plastic materials made for millions of different uses, industry has very successfully achieved higher performance at lighter and lighter weights (less virgin resources, less energy, less cost) without compromising any of the good characteristics of the plastic materials. • The light weight, ubiquity, low cost, stability and lack of toxicity makes plastic a very energy efficient and effective packaging material – all qualities that continue to drive the displacement of many other packaging alternatives. • It is the size and stability of the plastic molecule that cause it to be “bioinert”, a good characteristic during use but a property that works against it after disposal.[Top] What are the consequences of “bioinert” plastics and what can be done?• Under current practices, the accumulating effect of plastic litter in our watersheds and oceans has given rise to serious concern for the sustainability of our ecosystem, particularly accumulations in our watersheds and oceans. • It has become so serious that many countries, states, provinces and even local governments are driving a worldwide backlash against single use disposable plastic products. • Unfortunately, punitive taxation and even total bans on single use plastics deal only with the symptoms of the problem. The real issue is “ordinary plastics are bioinert” and will persist as landfill or litter for a very long time. • The only real solution is to control the lifecycle of polyolefin products after disposal with the introduction of additive technologies that accelerate degradation and biodegradation in “controlled life-cycle materials”. • EcoBio® Oxo-Biodegradable and EcoDegradable® degradable products safely and economically achieve this objective by quickly (weeks and months versus years) and safely returning polyolefins to the natural bio-cycle after they are used and discarded.[Top] What are the proprietary additives and how do they work?• A strategic partner of EcoBio® has developed a family of proprietary additives. • The proprietary additives are included in the plastic at the time of production that enable manufacturers of our products to customize EcoBio® Oxo-biodegradable and EcoDegradable® products to perform as ordinary plastic products during use but, once discarded, accelerate natural oxidative degradation characteristics of polyolefins by 100 to a 1000 or more, enabling the organic carbon in the plastic to be safely returned to the natural bio-cycle as a natural food source for microbes. • This two step process of oxidation and degradation/biodegradation enables used and discarded EcoBio® and EcoDegradable® products to totally degrade, disintegrate, mineralize and biodegrade. • The prodegradant additives control these processes in a highly predictable and controllable manner in all conditions in the environment in which you find a source of oxygen and naturally occurring microorganisms (air, soil, landfill, compost, litter). • This two-step process is now commonly referred to as “oxo-biodegradation”.[Top] So this science stuff is all well and good but what happens to the plastic?• The simple answer is, depending on where it is disposed of (or if it is simply left in your cupboard or closet for too long) it will discolor, become brittle and totally disintegrate and ultimately, it will be used as a food source by the tens of thousands of different microbes that survive and thrive in our air, soil and water. • Just like humans eat and digest organics to survive, once the accelerated oxidative process has broken the hydrocarbon molecules that was once plastic into bite sized pieces of organic carbon, the microbes will ingest, mineralize and biodegrade it. Through this process they consume the “carbon” to create CO2 and the “hydrogen” to create H2O and again just like us, they grow and propagate to create more cells and biomass. • The best news is – it is all totally natural and safe, and because we know all the elements in the plastic and the processes they under go – there are no harmful residues that could accumulate in our soil. As a matter of fact, in compost it contributes to the fertility of the compost for soil application.[Top] Can you describe the oxo-biodegradation process more scientifically?• First, ordinary plastics because of their molecular make-up are not inherently biodegradable even though their molecular structure is simply organic carbon and hydrogen. Because polyolefin plastics are relatively large molecules, they are too large to be ingested by microbes. • With the use of prodegradant additives, products' life-cycle can be controlled by accelerating the natural oxidative process to fracture these large carbon chains into small ingestible fragments of organic carbon. • Additives such as those used in EcoBio® and EcoDegradable® products, lie dormant in the plastic until exposed to sufficient UV light, heat or mechanical stress, any one or combination of which will trigger the process. • Once triggered it cannot be stopped; and depending on the available oxygen and microbial activity, the process will continue in air or soil. • The only by-products from the process are CO2, H2O and biomass – there are no harmful residues. • These processes are controlled and measured under various standards and regulations including but not limited to the American Society of Testing and Materials (ASTM) terminology and compliance to various testing methods:• D3826 - Degradation End Point in Degradable PE and PP Films • D5208 - Photodegradable Plastic Exposed to UV Light • D5272 - Outdoor Exposure Testing of Photodegradable Plastics • D5510 - Heat Aging of Oxidatively Degradable Plastics • D1238 - Test Method for Flow Rates of Thermoplastics • D882 - Tensile Properties• D883 - Definitions of Technical Terms[Top]
