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STATE THAT PLASTICS ARE MADE FROM POLYMERS
Plastics are synthetically produced compounds, made from polymers. Polymers are large
molecules made from linking many small molecules called monomers. Each repeat unit is
connected by covalent bonds
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Describe the environmental challenges caused by plastics limited to:
Disposal in landfill sites
In landfills, waste polymers take up valuable space since they are not biodegradable. This
means that microorganisms cannot break them down. If land spaces keep getting filled up,
then natural habitats would have to be destroyed to from mor eland fills. This displaces
many organisms are also reduces biodiversity. When they break down, it contaminates
water bodies, soil etc.
Accumulation in oceans
Most plastics are not biodegradable, so they find their way into oceans and water bodies,
that causes visual pollution. This also affects marine organisms since they can digest or get
entangled in plastic.
Formation of toxic gases from burning
Polymers Realses lots of heat, when they are incinerated and produce Carbon dioxide which
is a greenhouse gas which contributes to climate change. If they combust and there is a lack
of O2 (incomplete combustion), then they produce CO which is toxic since it reduces the
capacity if the blood to carry oxygen.
State that PET can be converted back into monomers and re-polymerized
PET (polyethylene terephthalate) is a common polymer used to make things like plastic
bottles.
PET is a polyester made from dicarboxylic acid monomers (-cooh at either end) and diols (oh group at either end)
It is made by condensation polymerization.
PET can be depolymerized using enzymes or chemical methods.
Enzymes present in microbes breakdown PET into the original monomers
The same result can be achieved by using solvents as a catalyst and mild heating.
The monomers are recovered and can be polymerized into new PET.
This saves resources and reduces carbon footprint, which reduces climatic changes.
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