This question is about polymers.
Polyesters are condensation polymers. When the monomers react together, a small molecule is lost.
Name a small molecule that can be lost during the formation of a polyester.
Poly(phenylethene) is an addition polymer produced from phenylethene.
Complete the structure of poly(phenylethene) in the polymerisation equation below:
Outdoor activewear jackets can be made from:
- newly synthesised poly(ester)
- organic wool
- a blend of recycled poly(ester) and organic wool
Recycled poly(ester) is more durable and water-resistant than organic wool.
A jacket made from a blend of recycled poly(ester) and organic wool is more sustainable than using 100% newly synthesised poly(ester) or 100% organic wool.
Suggest why.
Polymer nets are used in commercial marine aquaculture (fish farming cages submerged in the sea).
The table below shows some properties of two polymer fibres.
| Property | Polyester (PET) | Polyurethane (PU) |
|---|---|---|
| Density in g/cm3\text{g/cm}^3g/cm3 (density of seawater ≈1.03 g/cm3\approx 1.03\text{ g/cm}^3≈1.03 g/cm3) | 1.381.381.38 | 1.201.201.20 |
| Tensile strength in MPa\text{MPa}MPa | 120120120 | 454545 |
| Resistance to marine biofouling (growth of algae/barnacles) | Good | Poor |
| Elasticity / flexibility | Low | High |
Evaluate the suitability of polyester (PET) and polyurethane (PU) for aquaculture nets.