Polymer problems
What makes synthetic polymers so useful?
Synthetic polymers are so useful.
Synthetic polymers are plastics. They
are useful, because they can be
recycled, they are cheap, they are light
and strong. Plastics' versatility allow it
to be used in everything; car parts, doll
parts, soft drink bottles, refrigerators .
Plastics help make your life easier and
better.
Many synthetic polymers are not biodegradable.
What does this mean?
Biodegradable means- (of a substance or object) capable
of being decomposed by bacteria or other living
organisms.
One advantage of polymers is that they are unreactive, so they are suitable for storing
food safely. Unfortunately, this property makes it difficult to dispose of polymers. They are
normally buried in landfill sites or incinerated.
Most polymers, including poly(ethene) and
poly(propene), are not biodegradable. This means
microorganisms cannot break them down, so they may
last for many years in rubbish dumps.
However, it is possible to include chemicals that cause
the polymer to break down more quickly. Carrier bags
and refuse bags made from degradable polymers are
already available.
Describe the problems caused by the
disposal by incineration and in landfill sites…
Landfill
Waste polymers are disposed of in landfill sites. This uses up valuable land, and suitable
sites often fill up quickly.
Incineration
Polymers release a lot of heat energy when they burn. This energy can be used to heat
homes or generate electricity. But there are problems with incineration. Carbon dioxide is
produced, which adds to global warming. Toxic gases are also produced, unless the
polymers are incinerated at high temperatures.
Many polymers can be recycled, explain the
challenges of recycling polymers…
Many polymers can be recycled. This reduces
disposal problems and the amount of crude oil used.
But first the different polymers must be separated
from each other. This
expensive.
can be difficult and
Explain why scientists are developing ways of
making some polymers biodegradable…
Scientists are developing ways of making
polymers biodegradable, due to the
amount of room they take up at landfill
sites. Landfill sites are already filling up at
a very fast rate and with items that don’t
biodegrade, it’s filling up even faster. If
they do make some polymers
biodegradable that will be mean the
majority of them will either be recycled or
they will biodegrade.
New types of polymers
Chemists are developing new types of polymers. Most polymers, including polyethene and polypropene, are not
biodegradable. This means microorganisms cannot break them down, so they may last for many years in rubbish
dumps. However, it is possible to include chemicals that cause the polymer to break down more quickly. Carrier
bags and refuse bags made from degradable polymers are already available.
Some polymers are water-soluble, which means they dissolve in water. These polymers are often used to wrap
products such as dishwasher tablets and pouches containing detergent for washing machines.
Describe the benefits and drawbacks of making
disposable bags from corn-starch…
Advantages
1.Comes from corn, which is a renewable resource
2.Does not contain toxins
3.Producing this kind of plastic creates much less greenhouse gas emissions than conventional plastic
production (a reduction of 68 percent)
4.Corn starch plastic can be composted in facilities for industrial composting
5.65 percent less energy is needed to produce corn-based plastic than to produce conventional plastic
6.PLA plastic is competitive with conventional plastic in terms of cost, since petroleum prices are only going
up
7.PLA is more safe, since there is no danger of explosions in its production (as is the case with using
petroleum)
http://www.bionomicfuel.com/corn-starchplastic-the-advantages-and-disadvantages/
Disadvantages
1.Although PLA is compostable, there are very few facilities where this can actually be done (in the USA only about 113 sites for this exist)
2.Most likely consumers will not compost corn starch plastics properly, and just put them in regular recycling. This could contaminate the
recycling stream
3.Composting PLA in large quantities could undermine conventional composting, since the polymer contained in corn-based plastic makes
regular compost more acidic.
4.Since there is a lack of adequate infrastructure to compost PLA, most of it will probably still go into landfills.
5.MRFs – Material Recovery Facilities – are responsible for paying for sorting and disposing of PLA
6.Because PLA is derived from corn, there are moral issues with it being used for packaging, since there are people in the world dying of
hunger
7.PLA is mostly produced from genetically modified corn