CH 11: The Development of Plastics for the Future Flashcards
What is the main non-renewable material used in the production of plastic?
Crude oil
What are the uses of plastics?
- Food and drink packaging.
- Mobile phones, tablets and other electronic devices.
- Clothes.
- Window frames.
- Electrical cables.
- Toys.
What is the main use of plastics?
Packaging
What is the trend in the global production of plastic each year?
Continues to increase
What are the 2 main uses of crude oil?
Transportation - fuels such as diesel and petrol.
Energy sectors - fossil fuel power plants to produce electricity.
What is the name of the process required to convert crude oil into the feedstocks required for plastic manufacture?
Fractional distillation
What is the name of the molecules in crude oil?
Hydrocarbons
How is feedstock is obtained from crude oil?
Crude oil undergoes fractional distillation to separate it into different substances including gases that can be used to make plastics.
How is the feedstock prepared for storage before use?
The gases obtained by fractional distillation are cooled and liquefied because liquids are much easier than gases to store, transport and use.
What fraction of crude oil is used for the production of plastics?
Naphtha
What are two pollution problems associated with the use of plastics derived from fossil fuels?
- Cannot be broken down by microorganisms.
- Incineration produces toxic materials.
What are the toxic gases that may be released during the incineration of plastics?
- Carbon monoxide
- Hydrogen cyanide
- Hydrochloric acid
Why do plastics cause pollution problems in the oceans?
Plastics cannot be broken down by micro-organisms or easily recycled so they build up in the environment creating pollution issues such as the great Pacific garbage patch.
What are the advantages associated with plastics derived from naphtha?
- Plastics are readily available in a range of colours and different mechanical properties.
- They are currently very cheap. This has the unfortunate outcome of promoting buying a new item rather than the consumer choosing to get an item fixed or refurbished.
- Can be formed and shaped into many various design forms from mobile phones, televisions to keys for your car.
- Plastics are durable, which means they last a long time. A laptop made from plastic, while it may slow down over the years, will look and behave mechanically the same for decades.
How can we overcome plastics taking hundreds or thousands of years to break down?
- Increase the quantity of plastic recycled. This reduces the amount of crude oil required and so releases less greenhouse gases into the atmosphere. This also has the added advantage of sending less plastic to landfill.
- Make plastic degrade quicker. It will be made apparent later in this chapter, that the manufacturing process can be altered to enable plastics to decompose much more rapidly in the environment.
What is meant by the term ‘biodegradable plastic’?
Plastics that can be broken down by micro-organisms, bacteria or other biological means.
What are the applications of biodegradable plastics?
- Biodegradable plastics can be used as packaging for single use items such as carrier bags, food packaging and drink and food cartons for the takeaway food industry.
- Films. Biodegradable plastic agricultural films as mulch can be used to supress weeds, increase soil temperature, prevent loss of water and minerals from the soil. It can be ploughed into the soil after use.
What are the applications for photodegradable plastic and what are the impacts on crops or the environment?
- Plastic Mulch
Used as a growth promoter for saplings. In forestry or poor land. Allows soil to be stabilised whilst sapling takes root in otherwise unstable soil. - Coatings for slow release fertiliser / pesticide pellets
Controlled release of active agent. Particularly where risk of leaching. Or where risk of run off is high.
What are the drawbacks of applying fertiliser?
- Low absorption of nutrients from the fertiliser into the soil, which causes economic losses in terms of a reduced yield.
- The fertiliser pellet can be dissolved into liquid form and it then leaches into the soil. However, this leachate could be washed away by heavy rain into water courses, such as streams and rivers having a devastating impact on eco systems.
3.The fertiliser on the soil surface can be transported away before it infiltrates the soil structure. This can happen in a flash flood that takes place shortly after spreading the fertiliser. This fertiliser can be transported to local water courses, such as streams and rivers having a devastating impact on eco systems.
What is the process of the slow release fertiliser?
- A fertiliser pellet is coated in a plastic which can be photodegradable.
2.This fertiliser is applied to a field. Fields that are susceptible to leaching and or a high probability of surface run off, are particularly suitable. - Over a period of time, which can be determined and controlled by the plastic coating thickness, the fertiliser will diffuse through the plastic coating into the ground. The time periods can be as large as six to nine months, ensuring a more uniform distribution of nutrients to the crops as they grow. This considerably reduces the issues associated with leaching and surface water run off associated with traditional fertilisers, as the larger mass pellets are more difficult to displace in heavy rain.
What is a piece of laboratory apparatus that could be used to measure the tensile strength of photodegradable plastics.
The Newton meter
