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 feedstocks required for plastic manufacture
Fractional distillation
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
State 1 application for photodegradable plastics and describe its impact on crops or the environment
Option 1 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
Option 2 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
Option 3 Germination enhancing in maize Where the soil temperature is raised Above the ambient seasonal temperatures Thereby speeding up the germination rate
Option 4 Solarisation Where plastic over film Builds up heat To temperatures harmful to soil pathogens
Modern plastic production processes are moving towards the production of biodegradable plastics
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 simple 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 suppress weeds, increase soil temperature, prevent loss of water and minerals from the soil. It can be ploughed into the soil after use.
- Improvements 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
Incorporating an additive into a polymer during the manufacturing process can enhance the biodegradability of the plastics.
Complete the figure below by identifying the additive which can cause a plastic bag to be broken down at the end of its useful life
Oxygen
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 2
Production of bio plastics
Addition of starch which is digested by microorganisms- break up plastics into smaller pieces
Option 3
Production of compostable plastics
Made from e.g. corn starch fully biodegradable and compostable
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 how bioderived polyethylene (BPE) is produced
Ethanol from fermentation of crop biomass converted to ethylene
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 an energy intensive process
And energy used in its production will almost certainly come from a non-renewable source