Uses of PolymersOxford AQA IGCSE Chemistry: Revision notes
Section 1
What are polymers used for?
Polymers have a huge range of useful applications because their properties can be tailored to specific jobs. Uses include:
- Packaging materials - lightweight, durable containers and films
- Waterproof coatings for fabrics - keeping clothing and outdoor gear dry
- Dental polymers - used in fillings and other dental applications
- Wound dressings - flexible, protective coverings for injuries
- Hydrogels - polymers that can absorb and retain large amounts of water
- Smart materials, including shape memory polymers, which can return to a pre-set shape after being deformed
Key termshydrogelshape memory polymer
Section 2
Why do different polymers have different properties?
The properties of a polymer depend on:
- What it is made from - the identity of the monomer(s) used
- The conditions under which it is made - such as the temperature, pressure and catalyst used during polymerisation
This means that even polymers made from the same monomer can have different properties depending on how they were produced.
Example
Low-density poly(ethene) (LDPE) and high-density poly(ethene) (HDPE) are both made from ethene, but they are manufactured using different catalysts and conditions, giving LDPE a flexible, stretchy structure suited to bags and films, and HDPE a more rigid structure suited to bottles and pipes.
Must Know
- Polymers are used in packaging, waterproof fabric coatings, dental materials, wound dressings, hydrogels and smart materials such as shape memory polymers
- A shape memory polymer can return to a pre-set shape after being deformed
- A polymer's properties depend on what it is made from (the monomer) and the conditions used to make it
- Low-density and high-density poly(ethene) are both made from ethene but are produced using different catalysts and conditions, giving them different properties
That's the notes covered.
Carry on to the next subtopic.