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Plastic degradation in marine bacteria describes when certain pelagic bacteria break down polymers and use them as a primary source of carbon for energy. Polymers such as polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET) are incredibly useful for their durability and relatively low cost of production, however it is their persistence and difficulty to be properly ...
All biodegradable polymers should be stable and durable enough for use in their particular application, but upon disposal they should easily break down. [citation needed] Polymers, specifically biodegradable polymers, have extremely strong carbon backbones that are difficult to break, such that degradation often starts from the end-groups.
The largest ocean-based source of plastic pollution is discarded fishing gear (including traps and nets), estimated to be up to 90% of plastic debris in some areas. [56] [57] Continental plastic litter enters the ocean largely through storm-water runoff, flowing into watercourses or directly discharged into coastal waters. [58]
Biodegradable plastics that have not fully degraded are disposed of in the oceans by waste management facilities with the assumption that the plastics will eventually break down in a short amount of time. However, the ocean is not optimal for biodegradation, as the process favors warm environments with an abundance of microorganisms and oxygen.
Biodegradable additives can convert the plastic degradation process to one of biodegradation. Instead of being degraded simply by environmental factors, such as sunlight (photo-oxidation) or heat (thermal degradation), biodegradable additives allow polymers to be degraded by microorganisms and bacteria through direct or indirect attack.
Biodegradable polymers are classified into three groups: medical, ecological, and dual application, while in terms of origin they are divided into two groups: natural and synthetic. [18] The Clean Technology Group is exploiting the use of supercritical carbon dioxide , which under high pressure at room temperature is a solvent that can use ...
[143] yet, biodegradation-promoting additives for polymers have been shown not to significantly increase biodegradation. [144] Although biodegradable and degradable plastics have helped reduce plastic pollution, there are some drawbacks. One issue concerning both types of plastics is that they do not break down very efficiently in natural ...
An example of a compostable polymer is PLA film under 20μm thick: films which are thicker than that do not qualify as compostable, even though they are "biodegradable". [14] In Europe there is a home composting standard and associated logo that enables consumers to identify and dispose of packaging in their compost heap.