Biodegradability
Biodegradable polymers
- Both polyesters and polyamides can be broken down using hydrolysis reactions
- This is a major advantage over the polymers produced using alkene monomers (polyalkenes)
- When polyesters and polyamides are taken to landfill sites, they can be broken down easily and their products used for other applications
Hydrolysis of polyesters and polyamides
- Simple esters and amides can be hydrolysed by reaction with either aqueous acids or bases into carboxylic acids and alcohols (in the case of esters) or amines (in the case of amides)
- Condensation polymers are linked by ester or amide linkages and so can undergo hydrolysis
- Under the action of acid catalysts or biological enzymes the amide and ester links in polyamides and polyesters can be hydrolysed into smaller fragments
- Polyalkenes are inert and non biodegradable as a result of the C-C bonds between the monomers in addition polymers
Examiner Tip
The conditions present in different environments can influence the rate of hydrolysis and therefore the rate of biodegradation. Be mindful that some environments may have a different moisture content, oxygen levels, bacterial content and access to UV light. All of which can influence the rate of hydrolysis of biodegradable polymers.
