Why do we need to replace plastic bags? Simple. They take hundreds of years to biodegrade.
What is the solution? One is OXO.
Oxo Biodegradable (OXO) plastic is polyolefin plastic to which has been added amounts of metal salts. These catalyze the natural degradation process to speed it up so that the OXO plastic will degrade resulting in microfragments of plastic and metals which will remain in the environment but will not be seen as a visual contaminant.
The degradation process is shortened from hundreds of years to years and/or months for degradation and thereafter biodegradation depends on the micro-organisms in the environment.
Degradation is a process that takes place in some materials. The speed depends on the environment. Conventional polyethylene and polypropylene plastics will typically take hundreds of years to degrade. But oxo-degradable products utilize a prodegradant to speed up the molecular breakdown of the polyolefins and incorporate oxygen atoms into the resulting low molecular mass. This chemical change enables the micro breakdown of the plastics.
A two-step process whereby the conventional polyolefin plastic is first oxo-degraded to short-chain oxygenated molecules (typically 2–4 months exposed) .The process of degradation in OXO treated plastic is an oxidative chain scission that is catalyzed by metal salts leading to oxygenated (hydroxylated and carboxylated) shorter chain molecules .
OXO plastic if discarded in the environment, will fragment and degrade to oxygenated low molecular weight (typically MW 5-10.000 amu) within 2–18 months depending on the material (resin, thickness, anti-oxidants, etc.) and the temperature and other factors in the environment.
OXO plastics will not degrade in a landfill environment due to insufficient oxygen present below a depth of approximately 15 cm. A PE plastic bag for example 30 µm thick with 2% prodegradant additive degrades within 3 months if left exposed in an open air environment in Thailand and a 150 µm thick PP container or sheet will degrade within 3–6 months.
Oxo treated products do not degrade rapidly because they are stabilized to control the service-life of the product. They will nevertheless degrade more quickly than nature’s wastes such as twigs and straw (10 years) and much more quickly than ordinary plastic (many decades).
Send your comments to sharad@go-green.ae