This question is about polymers - AQA - GCSE Chemistry - Question 6 - 2018 - Paper 2

The structure of poly(propene) is represented as follows:

    CH₃         
     |         
   n  C = C   
     |         
    C – C     
     |         
     H         

This structure shows the continuation of carbon chains, with the repeating unit being CH₃-CH-.

A mixture of poly(propene) and wool is more sustainable because:

1. Resource Source: Poly(propene) comes from non-renewable sources, while wool is a renewable resource, which can be regrown every year.
2. Decomposition: Wool is biodegradable, meaning it can decompose and return nutrients to the soil, whereas poly(propene) contributes to plastic waste and takes hundreds of years to break down.

Both poly(propene) and polyester have distinct properties that affect their suitability for firefighter uniforms:

Advantages of Polyester:

• Flame Resistance: Polyester has better flame resistance, which is essential for protecting firefighters from burns.
• Higher Melting Point: It melts at a higher temperature compared to poly(propene), reducing the risk of it melting onto the skin.
• Water Absorption: Polyester absorbs less water, which keeps the uniform lighter.

Disadvantages of Polyester:

• Weight: Polyester can be heavier, making it less comfortable for longer wear.
• Cost: Generally more expensive than poly(propene), which could be a consideration for budget constraints.

Overall, while both materials have pros and cons, polyester's better flame resistance makes it the more suitable choice for firefighter uniforms.