9. Development Of Plastics For The Future Flashcards
State the trend in the global production of plastic each year. {1}
Continues to increase. {1}
State the name of the process required to convert crude oil into the feedstocks required for plastic manufacture. {2}
Distillation. {1} Fractional distillation. {2}
Identify two pollution problems associated with the use of plastics derived from fossil fuels.
Cannot be broken down by microorganisms. {1} Incineration produces toxic materials. {1}
Name two toxic gases that may be released during the incineration of plastics {2}
Any two from;
Carbon monoxide / hydrogen cyanide/ hydrochloric acid.
State 1 application for photodegradable plastic and describe its impact on crops or the environment. {2}
Plastic Mulch {1} Used as a growth promoter for saplings {1} In forestry or poor land {1} 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 {1} Particularly where risk of leaching {1} Or where risk of run off is high {1}
Option 3;
Germination enhancing in maize {1} Where the soil temperature is raised {1} Above the ambient seasonal temperatures {1} Thereby speeding up the germination rate
Option 4;
Solarisation {1} Where plastic over film {1} Builds up heat {1} To temperatures harmful to soil pathogens {1}
Modern plastic production processes are moving towards the production of biodegradable plastics.
Explain what is meant by the term ‘biodegradable plastic’. {1}
Can be broken down by micro-organisms, bacteria or other biological means.
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. {3}
Stage 1 – Additive is included in the basic polymer resin during the manufacturing process. {1}
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 {1}
Stage 3 – Bio-degradation is completed by microorganisms. {1}
Explain one other option, apart from the use of an additive, that can be used in modern plastic manufacturing processes to improve biodegradability. {2}
Option 1;
Modification of the process to enhance thermal and photodegradation {1}
Addition of different chemical links into long chain molecules of plastic which breaks up when hit by UV light
Option 2;
Production of bioplastics {1}
Addition of starch which is digested by microorganisms – breaks up plastics into smaller pieces {1}
Option 3;
Production of compostable plastics {1}
Made from e.g. corn starch fully biodegradable and compostable {1}
Many plastics are photodegradable. Describe how a plastic can be modified during the manufacturing process to make it photodegradable. {2}
It is manufactured to contain a chemical additive {1} which absorbs light, attacks the polymer and breaks it down. {1}.
Describe how bioderived polyethylene (BPE) is produced. {2}
Ethanol from fermentation of crop biomass converted to ethylene {1} Ethylene is then polymerised by addition polymerisation {1}
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. {1}
And energy used in its production will almost certainly come from a non- renewable source. {1}
The figure below details annual world plastic production. Comment on the trend shown and explain why there is a need for a global move towards more sustainable manufacture and use of plastics. {2}
Graph demonstrates the increased global production of plastics. {1}
This results in an increased demand for and use of finite natural resources such as oil needed for plastic production. {1}
Explain the term ‘sustainable manufacture of plastics’.
Sustainable manufacture of plastics refers to design and development that incorporates replenishable raw materials. {1}
Together with efficient manufacturing and production techniques. {1}
Two advantages of moving towards the manufacture of biodegradable plastics are;
• They can be manufactured using renewable materials.
• They reduce environmental pollution.
Describe how each of the points above can be considered as an advantage. {4}
Discussion should focus on the following;
Manufacture using renewable raw materials;
• Renewable raw materials are readily replaced unlike fossil fuels {1} that are used during current production, so the process is more sustainable {1}.
• There is greater security of supply of feedstocks {1} as there is less reliance on crude oil which can come from politically unstable regions {1}.
• Finite crude oil supplies are conserved for future generations energy needs {1} and for other uses such as transport {1}.
Environmental pollution;
Biodegradable plastics break down {1} so there is less of a build-up of plastics in the environment. This benefits wildlife and reduced the impact on ecosystems {1}.
• The manufacture and disposal of biodegradable plastics produces fewer harmful gases and emissions {1} so there is a lower impact on global warming {1}.
• Less plastic in the environment reduced littering {1} and therefore reduces the clean-up costs associated with this {1}.
