F7 Flashcards
Polymeric materials, raw materials
Today’s polymeric materials are made 95% from fossil raw materials (oil and
natural gas)
Renewable raw materials are mainly used for natural rubber, mainly sap from
rubber trees and for bioplastics, for example from cellulose and starch
Name of the most popular polymers
➢ Polyethylene (PE),
➢ Polyethylene terephthalate (PET),
➢ Polypropylene (PP),
➢ Polystyrene (PS),
➢ Polyvinyl chloride (PVC),
Why are polymeric materials used?
- Low density, lightweight, and good mechanical properties
- Relatively free design
- Rational and energy-efficient production possibility
- Adaptable to different applications
- Durability
The application of polymeric materials
➢ Packaging, 40%
➢ Building products, 20%
➢ Electrical applications, 8%
➢ Vehicles, 7%
➢ Agriculture, 3%
Additives (not only one but many in one plastic)
➢ Plasticizers (to make parts more flexible) (e.g., Phthalates),
➢ Flame retardants,
➢ Stabilizers (e.g., antioxidants and antimicrobial agents),
➢ Colorants,
➢ Lubricants.
➢ Fillers
➢ Reinforcing agents
2 different plastics
Thermoplastic: a material that can be deformed when subjected to thermal effects, indicating that these
polymeric materials can be softened at high temperature, followed by reforming into new shapes or structures.
➢ Thermoset plastic: a kind of polymer that is fixed or crosslinked after the first thermal processing.
What to do with plastic wastes
prevent, reduce, reuse, refill, mechanical recyling, chemical recyling, landfill, incinerate
Limitations of Mechanical recycling (downcycling)
- Plastic from different batches have
different grades in molecular weight and
additives - The resulting recycled plastic exhibit a
larger distribution in molecular weight - Contamination in the recycled plastic from
the additives in different plastics - Molecular structure of polymer changes
thorough shortened polymer chains,
oxidation, or react with contaminations or
additives. - limited number of recycling cycles due to
degrading during recycling
Benefit and Limitations of chemical recycling
Chemical recycling offers new, alternative options that can
actively reduce waste, promote sustainability and eliminate our
reliance on fossil fuels to produce plastics.
➢ Reducing plastic pollution
➢ Lowering emissions
➢ Economic opportunities
o Release toxic substances - including benzene and lead.
o Result in a larger carbon footprint than traditional recycling
methods.
o Need Money and investment
o Energy consumption for the chemical recycling (heat)
o Use of the other chemicals for example organic solvent
problems recycling plastic
Specific challenges
➢ Price
➢ Features, in particular the remaining
technical lifetime; appearance and odor
➢ Processability
➢ Prohibition of contact with food
Pollution is divided into three major environmental
categories:
➢ Terrestrial (soil),
➢ Aquatic (water)
➢ Atmospheric (air).
Why is so little bioplastic used?
5 main challenges
- Economics Most bioplastics are currently more expensive to produce than fossil-based plastics,
mostly owing to economies of scale and the price competitiveness of crude oil. - Efficiency Bioplastic manufacturing processes can be less energy efficient than fossil-based plastic
processes and come with other environmental burdens associated with agricultural farming. - End of life For most bioplastics, recycling streams have yet to be established to make them truly
‘circular’. Consumers remain uncertain of how to deal with bioplastics after use. Compostable
bioplastics are often rejected by composters. - Ethics Using first-generation biomass, which is often edible, remains controversial owing to potential
competition with food production. Processes to efficiently use second-generation biowastes need to be
established. - Education Consumers and plastic converters are confused about the usefulness of bioplastics, owing
to inconsistent labelling, contradicting life cycle assessments and ‘greenwashing’. Improved
information distribution and consistent global standards need to be established.
Bioplastic
The monomer were derived from renewable
resources (biomass) and then polymerized.
➢ The polymer was extracted from biomass
➢ The polymer or plastic is biodegradable
➢ The materials is produced through biological
processes
➢ A bioplastic is to some extent bio-based,
biodegradable or both.
➢ It can also mean that the plastic is
biocompatible as a medical implant
Resorbable cruciate
ligament (Artimplant)
In the future how to achieve circular economies
of plastics
➢Drastic reduction in plastic consumption
➢Design of products that can be reused and recycled in their markets
➢Improved process energy efficiency in plastic and bioplastic manufacturing
➢Use of renewable power
➢Increased collection rates
➢Market penetration of robust and circular recycling and ‘upcycling’ methods
