1.11 The Development of plastics for the future Flashcards
State the main non-renewable material used in the production of plastic
Crude oil
State the trend in the global production of plastic each year
Continues to increase
State the name of the process required to convert crude oil into the feedstock required for plastics manufacture
Fraction distillation
Explain how the 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.
Explain how and why the feedstock is 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.
Identify two pollution problems associated with the use of plastics derived from fossil fuels.
Cannot be broken down by microorganisms.
Incineration produces toxic materials.
Name two toxic gases that may be released during
the incineration of plastics
Carbon monoxide / hydrogen cyanide/ hydrochloric acid.
List two toxic gases that may be released during the incineration of plastics.
Carbon monoxide
hydrogen cyanide
hydrogen chloride
Explain why 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.
If BPE is not recycled, it may be disposed of by incineration. Name two toxic gases that may be released during the incineration of plastics such as BPE.
Hydrogen cyanide
Hydrogen chloride/Hydrochloric acid
Carbon monoxide
Explain what is meant by the term ‘biodegradable plastic’.
Can be broken down by micro-organisms, bacteria or other biological means.
Describe two 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.
• Improvement of soil structure when the decomposed plastic can make the soil more fertile and improve plant growth.
Identify a piece of laboratory apparatus that could be used to measure the tensile strength of photodegradable plastics.
A Newton meter.
Explain how the additive in the key above can cause a plastic bag to be broken down at the end of its useful life.
Stage 1 – Additive is included in the basic polymer resin during the manufacturing process.
Stage 2 – Breaks the molecular chains so that at the end of its predetermined service life the plastic starts degrading in the presence of oxygen by a process of oxidation, which is accelerated by light, heat and stress
Stage 3 – Bio-degradation is completed by microorganisms
Explain one other option, apart from the use of an additive, that can be used in modern plastic manufacturing processes to improve biodegradability.
Option 1;
Modification of the process to enhance thermal and photodegradation Addition of different chemical links into long chain molecules of plastic which breaks up when hit by UV light
Option 3;
Production of compostable plastics Made from e.g. corn starch fully biodegradable and compostabl
Many plastics are photodegradable. Describe how a plastic can be modified during the manufacturing process to make it photodegradable.
It is manufactured to contain a chemical additive which absorbs light, attacks the polymer and breaks it down.
Describe one agricultural use of compostable plastics.
Compostable plastics can be used to improve soil composition They break down in the environment to provide useful soil nutrients
- They can be used as weed suppressant as they can cover ground around plants preventing weed growth
Describe a modern manufacturing process used to address the polluting effect of plastics.
Plastics can be manufactured to include a bond in the structure that breaks down when heated or when it absorbs uv light.This increases their thermal or photodegradability.
Describe how bioderived polyethylene produced
Ethylene is then polymerised by addition polymerisation
The production of bioderived polyethylene (BPE), is often described as not being ‘a sustainable manufacturing process’.
Why is this so?
It is energy intensive process.
And energy used in its production will almost certainly come from a non- renewable source.
BPE is an example of a recyclable plastic. What does it stand for
Bioderived polyethylene.
Describe fully how BPE is manufactured,
plant such as corn/sugar cane undergoes fermentation to produce ethanol.
• Ethanol is converted to ethylene (dehydration).
• Ethylene then undergoes (addition) polymerisation to form BPE.
Explain the term ‘sustainable manufacture of plastics.
Sustainable manufacture of plastics refers to design and development that incorporates replenishable raw materials. Together with efficient manufacturing and production techniques.
