Degradable polymers
Degradable polymers
- Some polymers break down in the environment; others barely do.
- It depends on the bonds in the chain.
- This matters for waste and pollution.
What degrades, and what doesn't
- poly(alkene)s are chemically inert — only strong, non-polar C–C and C–H bonds — so they are hard to biodegrade and last a long time.
- some polymers are made photodegradable (light breaks them down).
- polyesters and polyamides are biodegradable — their ester and amide links can be broken by acidic or alkaline hydrolysis.
Practice
Poly(alkene)s are hard to biodegrade because they have:
With no polar links to attack, microbes cannot easily break poly(alkene)s down.
Practice
Polyesters and polyamides are biodegradable because:
Acidic or alkaline hydrolysis breaks the ester/amide links, so these polymers degrade.
Practice
Some polymers are made photodegradable so that light can break them down.
Photodegradable polymers are designed to be broken down by light.
You've got it
Key idea
- poly(alkene)s = inert (strong non-polar bonds) → hard to biodegrade
- some polymers are photodegradable (broken by light)
- polyesters/polyamides are biodegradable — their links can be hydrolysed