Topic 10 (Using recourses) Flashcards
What are ceramics?
Ceramics are non-metal solids with high melting points that are not made from carbon-based compounds.
What is the matrix or binder in a composite?
The material that surrounds and binds together the reinforcement material.
Give examples of composite materials.
Fibreglass (glass + polymer), carbon fibre (carbon + polymer), concrete (sand + gravel + cement), and wood (natural composite of cellulose fibres + lignin).
Why are composites useful?
They are strong, lightweight, and resistant to corrosion and wear.
What are polymers?
Long chains of repeating monomer units made by polymerisation, usually from alkenes.
What do the conditions of a Polymer rely on
Depends both on the monomers and conditions used to make polymer
How do we change property of a polymer using conditions
- Change temperature in reaction
- Change the pressure in reaction
- Different Catalyst
What happens when thermosoftening polymers are heated and cooled?
-Thermosoftening polymers melt when we heat them
- We can reshape them while they are soft
- They then go back to a solid when we cool them down
What happens to the intermolecular forces (IMFs) in thermosoftening polymers when they are heated and cooled?
: When heated, the intermolecular forces break, causing the polymer strands to separate and melt. Upon cooling, the intermolecular forces reform, and the polymer solidifies, allowing it to be reshaped.
What are the key differences between thermosetting and thermosoftening polymers?
Thermosoftening polymers melt when heated and can be reshaped; they solidify again when cooled.
Thermosetting polymers do not melt upon heating; they remain rigid due to strong cross-links between polymer chains.
Why do thermosetting polymers not melt when heated?
The strong cross-links between the polymer chains are not broken by heat, which is why thermosetting polymers do not melt.
What is meant by the word corrosion
Corrosion is the destruction of materials by chemical reactions with substances in the environment
Conditions required for rusting
Rusting occurs when iron (or steel) is exposed to both oxygen and water (moisture).
Name methods to prevent corrosion
Barrier methods (e.g. paint, oil, grease)
Galvanizing
Sacrificial protection
Coating with plastic
Electroplating
Cathodic protection
How can you carry out an experiment to investigate the conditions required for rusting?
Materials: Iron nails, test tubes, water, oil, and a drying agent (e.g., anhydrous calcium chloride).
Set-up:
Test tube 1: Place an iron nail and add water (with oxygen in the air). Leave it open to air.
Test tube 2: Place an iron nail, add water, but seal the tube to prevent oxygen from entering.
Test tube 3: Place an iron nail, and add oil to prevent moisture (water) from contacting the nail.
Test tube 4: Place an iron nail in dry conditions with a drying agent (to remove moisture) and no water.
Observation: After a few days, check the nails for signs of rusting (red-brown color). Rusting should only occur in the test tube with both water and oxygen.
What is the barrier method
The barrier method involves coating a metal with a protective layer to prevent contact with oxygen and moisture, which causes rusting.
e.g grease, paint, electropainting
What is electro painting and how does it work?
Electro painting is a process where electrically charged paint particles are applied to a metal surface. The metal is made positively charged, while the paint particles are negatively charged. The metal attracts the paint, which is deposited evenly, creating a smooth and durable coating.
What is galvanising and how does it stop corrosion?
Galvanising is the process of coating iron or steel with a layer of zinc. The zinc acts as a barrier to protect the metal from moisture and oxygen, preventing corrosion. Additionally, if the zinc layer is scratched, it still offers protection by acting as a sacrificial anode, corroding before the iron or steel.
What is sacrificial protection?
Sacrificial protection involves attaching a more reactive metal (like zinc or magnesium) to a less reactive metal (like iron or steel). The reactive metal corrodes first, protecting the less reactive metal from corrosion.
What is the difference between reusing and recycling materials?
Reusing involves using an item again for the same or similar purpose, while recycling involves processing materials to create new products.
Why is recycling important for sustainable development?
Recycling helps reduce the need for raw materials, conserves energy, reduces landfill waste, and lowers environmental pollution.
What are some environmental benefits of recycling?
Recycling reduces energy consumption, raw material extraction, and pollution while conserving natural resources and reducing landfill waste.
How does recycling reduce the impact on the environment?
Recycling reduces the need for new raw materials, cuts down on energy use, and minimizes pollution from mining and processing materials.
What is the role of the recycling symbol on materials?
The recycling symbol indicates that a material is recyclable and can be processed to create new products, promoting the recycling of waste.
What are the main challenges of recycling?
Some challenges include contamination of recyclable materials, high costs of collection and sorting, and limited recycling facilities for certain materials.
How can recycling help in reducing greenhouse gas emissions?
Recycling reduces the energy needed to extract and process raw materials, which in turn helps reduce greenhouse gas emissions associated with production.
What materials can typically be recycled?
Common recyclable materials include paper, glass, metal, and certain plastics
What are the environmental impacts of not recycling?
Not recycling leads to increased landfill waste, greater energy consumption, and more pollution, as raw materials must be extracted and processed.
What are the social benefits of recycling?
Recycling creates job opportunities, raises environmental awareness, and fosters a more sustainable economy by encouraging the use of renewable resources.
How does the recycling of metals help conserve natural resources?
Recycling metals reduces the need to mine for new ores, conserving valuable natural resources and reducing the environmental damage caused by mining.
What are the benefits of reusing items instead of recycling them?
Reusing items requires less energy and resources compared to recycling, and it extends the lifetime of products, which helps reduce overall waste.
What is closed-loop recycling?
Closed-loop recycling is when materials are recycled into identical products (e.g., plastic bottles being recycled into new plastic bottles), creating a circular economy.
What is a LCA (life cycle assessment)
A life-style assessment tries to put a number on the environmental impact of a product
4 main stages of a life cycle assessment
1-Extracting and Processing raw materals
2- Manufacturing and packaging product.
3- using product
4- disposing of it
Explain how we assess the impact of extracting and processing raw materials in a Life Cycle Assessment (LCA). :)
-Extracting raw materials can have significant effects on the local environment, such as deforestation (cutting down forests) or mining, which may lead to habitat destruction, loss of biodiversity, and soil erosion.
- Processing the raw materials can cause indirect environmental damage, including pollution, energy consumption, and the release of greenhouse gases.
How do we assess the environmental impact of manufacturing and packaging in a Life Cycle Assessment (LCA)?
Manufacturing: We assess energy use, pollution, waste production, and resource depletion during production.
Packaging: We evaluate the materials used (e.g., plastic, paper), the energy required for production, and the waste created.
How do we assess the environmental impact of using a product in a Life Cycle Assessment (LCA)?
Energy consumption during use, such as electricity or fuel usage.
Emissions produced, like carbon dioxide (CO₂) or other greenhouse gases.
Wear and tear, which may lead to waste or the need for repairs.
How do we assess the environmental impact of disposal in a Life Cycle Assessment (LCA)?
We consider the method of disposal (e.g., landfill, incineration, recycling).
Landfill: Impact on land, pollution, and greenhouse gas emissions.
Incineration: Air pollution and energy consumption.
Recycling: Reduced waste and energy use, but requires resources and energy for processing.
What are the environmental impacts of plastic versus paper?
Plastic:
Produced from Crude oil
Non-renewable
Extracting crude oil can be harmful to enviroment
e.g oil leak
Plastic shopping bags strong and often reused
Plastic is not bio-degradable
Remains in environment for long time so in litter/landfills
Paper:
Produced from trees
Renewable
Deforistation is extremely harmful to habitats like forest
Reqires large amounts of water
paper shopping bags are not as strong so not reused
Paper bags heavier than plastic bags
Paper breaks down quickly
Both
Both need to be chemically procced realising lots of waste products
Issues of lifestyle assessments
We can measure values like use of water and energy. Also production of waste products
We cannot always be certain of the damage these cause on the environment
This means we have to estimate or value judgements which may not always be accure
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