Question 1: Describe the key differences between thermoplastics and thermosetting plastics in terms of their structure and how they respond to heat.

Answer: Thermoplastics have a linear or branched structure allowing them to melt and reshape when heated, making them recyclable. Thermosetting plastics have a cross-linked structure that does not melt upon heating; instead, they decompose or burn, and cannot be reshaped once set.

Question 2: List three common uses of polypropylene and explain why this polymer is suitable for each application.

Answer: 1. Food containers: lightweight, chemical resistant, and durable. 2. Car bumpers: tough, impact-resistant, and lightweight. 3. Medical devices: sterilizable, chemically resistant, and inexpensive.

Question 3: Identify two environmental concerns associated with the disposal of polymers and suggest a way to reduce their impact.

Answer: Concerns include non-biodegradability leading to pollution, and microplastic formation harming wildlife. Reducing impact can involve increased recycling and developing biodegradable polymers.

Question 4: Design Brief: You need to create a lightweight, impact-resistant helmet for cycling. Which type of polymer would you choose and why?

Answer: A suitable choice would be a thermoplastic such as polycarbonate because it is lightweight, impact-resistant, and can be moulded into complex shapes. It also offers good strength-to-weight ratio and can be recycled.

Question 5: Sketch a simple design for a container that uses a polymer with good chemical resistance and transparency. Label the key features of your design.

Answer: A clear, rectangular storage container with a snap-on lid, made from a transparent polymer such as polycarbonate or acrylic. Labels should highlight transparency, impact resistance, and ease of cleaning.

Question 6: Explain why polymers are often used in the manufacture of consumer goods such as toys and packaging.

Answer: Polymers are versatile, lightweight, durable, and inexpensive. They can be easily moulded into various shapes, are resistant to moisture, and can be produced in large quantities.

Question 7: Compare the properties of nylon and polyethylene, giving an example of a product made from each polymer.

Answer: Nylon is strong, wear-resistant, and has good elasticity, used in products like fishing lines. Polyethylene is lightweight, chemically resistant, and flexible, used in plastic bags and bottles.

Question 8: Create a plan for recycling a polymer-based product, including steps from collection to reprocessing.

Answer: Step 1: Collect used polymer products. Step 2: Sort by polymer type. Step 3: Clean to remove contaminants. Step 4: Shred into small pieces. Step 5: Melt and extrude into pellets. Step 6: Use pellets to manufacture new products.

Question 9: Identify a polymer that can be used in electrical insulation and justify your choice based on its properties.

Answer: Polyvinyl chloride (PVC) is suitable because it has good electrical insulating properties, is durable, and resistant to fire and chemicals.

Question 10: Draw a cross-section of a plastic bottle made from a polymer suitable for packaging liquids. Label the main features such as the body, neck, and cap area.

Answer: A correct sketch would depict a cylindrical shape with a narrower neck at the top, a threaded area for the lid, and a thicker wall to withstand pressure. Labels should indicate 'body', 'neck', and 'cap area'.