Biodegradable Polymer
Distinguishing between the different character of the biodegradable charge plate is important, as their monetary value s and uses are very different. Oxo-biodegradable and hydro-biodegradable are the two principal cases. In both slip degradation starts with summons of a chemical product (respectively oxidation and hydrolysis), followed by a biological cycle. Both types emit CO2 while degrading but but hydro-biodegradable can also emit methane.
Both types are compostable, but only oxo-biodegradable can
be economically recycled. Hydro-biodegradable is much more expensive than
oxo-biodegradable.
OXO-BIODEGRADABLE PLASTICS
OXO-BIODEGRADABLE PLASTICS
- This new technology produces credit card which degrades by a process of
OXO-degradation.
The technology is
based on a very small amount of pro-degradant additive being introduced into
the manufacturing process, thereby changing the behaviour of the charge card .
Abasement begins when the programmed service life is over (as controlled by the
additive formulation) and the product is no longer required.
There is little or no additional cost involved in products
made with this technology, which can be made with the same machinery and
workforce as conventional plastic products. The plastic does not just fragment,
but will be consumed by bacteria and fungi after the additive has reduced the molecular
structure to a level which permits living micro-organisms approach to the
carbon and hydrogen.
It is therefore
“biodegradable.” This process continues until the stuff has biodegraded to
nothing more than CO2, water, and hoummos , and it does not leave fragments of
petro-polymers in the soil. Oxo-biodegradable plastic passes all the usual
ecotoxicity tests, including semen germination, plant growing and organism
survival of the fittest (daphnia , earthworms) tests carried out in accordance
with ON S 2200 and ON S 2300 national criterion .
They are protected from degradation by special antioxidant
until ready for use, and storage-life will be extended if the ware are kept in
cool, dark experimental condition . Unlike PVC, the polymers from which oxo-biodegradable
plastic are made do not contain organo-chlorine. Nor do oxo-biodegradable
polymers contain PCBs, nor do they emit methane or nitrous oxide even under
anaerobic conditions .
HYDRO-BIODEGRADABLE PLASTICS
HYDRO-BIODEGRADABLE
PLASTICS - Hydro-biodegradation is initiated by hydrolysis. Some plastics
in this category have a senior high starch content edness and it is sometimes
said that this justifies the claim that they are made from renewable resources.
However, many of them contain up to fifty % of synthetic
substance plastic derived from fossil oil color , and others (e.g. some
aliphatic polyesters) are entirely based on oil-derived intermediates.
Genetically-modified caltogether may also have been used in the manufacture of
hydro-biodegradable plastics.
Hydro-biodegradable plastics are not genuinely “renewable”
because the appendage of making them from crops is itself a significant user of
dodo -fuel push and a producer therefore of glasshouse gases. Fossil fuels are
burned in the autoclaves used to ferment and polymerise material synthesised
from biochemically produced intermediates (e.g. polylactic pane from
carbohydrate etc); and by the agricultural machinery and road fomite employed;
also by the manufacture and transport of fertilisers and pesticides.
They are sometimes described as made from “non-food” crops,
but are in fact usually made from food crops. A disproportionate amount of land
would be required to produce sufficient raw material to replace conventional
plastic products, and a huge amount of water, which is in such short provision
in so many parts of the world.
Residues from some aboriginal starches can be seriously
toxic; bitter cassava for example (tapioca ) has a high level of hydro-cyanic
glucoside present, which has to be removed by careful washing. During
development the plant life life is toxic to wildlife.
0 Comments