Addition polymers such as poly(ethene), poly(propene) and PVC are cheap, strong, light and long-lasting, so huge amounts are made. The same properties cause a waste problem.Why they persist: an addition polymer chain is saturated and held together by strong, non-polar C-C and C-H bonds. There are no polar bonds for water or enzymes to attack, so most addition polymers are non-biodegradable: microorganisms cannot break them down. A plastic bag may last for hundreds of years.Consequences:
• waste plastics fill landfill sites, which uses up land and wastes a useful material
• litter harms wildlife, for example animals trapped in or swallowing plastic
• plastics break into tiny fragments called microplastics, which spread through oceans and food chains
• most polymers are made from crude oil, a finite resource, so discarding them wastes itWays of dealing with waste polymers (each in its own lesson):
• recycling: reusing the polymer, or cracking it to make feedstock for new plastics and chemicals
• incineration: burning waste to release energy for electricity, with the toxic gases removed
• biodegradable polymers: replacing some plastics with materials microorganisms can break downChemists work to make processing polymers more sustainable: saving energy and raw materials, reducing emissions of harmful gases, and removing toxic waste products.
• waste plastics fill landfill sites, which uses up land and wastes a useful material
• litter harms wildlife, for example animals trapped in or swallowing plastic
• plastics break into tiny fragments called microplastics, which spread through oceans and food chains
• most polymers are made from crude oil, a finite resource, so discarding them wastes itWays of dealing with waste polymers (each in its own lesson):
• recycling: reusing the polymer, or cracking it to make feedstock for new plastics and chemicals
• incineration: burning waste to release energy for electricity, with the toxic gases removed
• biodegradable polymers: replacing some plastics with materials microorganisms can break downChemists work to make processing polymers more sustainable: saving energy and raw materials, reducing emissions of harmful gases, and removing toxic waste products.