Bio-plastics
Contents |
[edit] Introduction
Bio-plastics can made as thermoplastics or thermosets, but as a relatively new field general understanding of their potential is often limited. Bio-plastics are non-recyclable in the sense of the standard processes of recycling plastics, they are however bio-degradable over time might be considered a form of recycling in that they return to their natural state.
[edit] Biobased biodegradable materials
The 2022 paper by Jan-Georg Rosenboom, Robert Langer & Giovanni Traverso 'Bio-plastics for a circular economy" publish in Nature, describes ‘bioplastic’ as a term used increasingly but often misunderstood. 'Bio-plastics are plastics that are either made from renewable resources (‘bio-based’), are biodegradable, are made through biological processes or a combination of these. Some biodegradable but fossil-based plastics are also referred to as bio-plastics, however, the use of this terminology is advised against, as it is misleading' the paper discusses.
'Although most commercial plastics are made from fossil resources, these materials can also be made from renewableresources and are commonly referred to as bio-plastics. In this case, the monomers are extracted or synthesised from biomass compounds (such as sugars in plants) and then polymerised to either make a direct replacement for an existing plastic, such as polyethylene (PE), or novel polymers, such as polyhydroxyalkanoates (PHAs). Biomass extraction can also yield non-synthetic natural polymers, such as starch, natural rubber and proteins.'
[edit] Compostable vs biodegradable
Whilst fossil fuel based plastics are degradable over time through sunlight and weathering, they never fully return to a natural organic state, and thus remain a source of pollution, allowing the leaching of chemicals and micro fragments into the environment. Bio-plastics bio-degrade over time, at varied but faster rates than fossil fuel based plastics leaving behind no toxins or residue. The time that it takes for the plastics to biodegrade relates to them either being defined as compostable ( degrading over a matter of months) or biodegradable (somewhat longer - and by different processes).
Some bio-plastics are compostable in a similar way to organic matter and can be broken down by microorganisms, and will decompose into nutrient-rich biomass in less than 6 months leaving behind no toxins or residue. However most bio-plastics are biodegradable, meaning they can be broken down by microorganisms such as bacteria, fungi and algae into water, carbon dioxide, methane, biomass and inorganic compounds. In many cases bio-plastics that are biodegradable need to be treated in industrial composting plants or treatment centres, however the end result decomposes in the same way as compostable material.
[edit] Bioplastic base materials
There are a great number of bio-based and bioplastic innovations being developed. Below are five examples of common types of base material that are being used to create bio-plastics:
[edit] Starch-based bioplastic
Starch-based bioplastic (often corn starch). Often mixed with biodegradable polyesters to create small hard cases and food packaging.
[edit] Cellulose-based bioplastic
Cellulose-based bioplastic (cellulose esters and cellulose derivatives) can be used for films, moulded frames, and electronic devices
[edit] Protein-based bioplastic
Protein-based bioplastic (wheat gluten, casein and milk) for food packaging and some development of films and coatings.
[edit] Bio-derived polyethylene
Bio-derived polyethylene (fermented raw agricultural materials such as sugarcane and corn) has been used to produce high density polyethylene for crates, trays, bottles and caps, as well industrial containers.
[edit] Aliphatic polyesters
Aliphatic polyesters, are mainly in development phase, sensitive to water, and can be mixed with other compounds. Bio-based polyesters such as polylactic acid (PLA), polyglycolic acid (PGA), poly-ε-caprolactone (PCL), polyhydroxybutyrate (PHB), and poly(3-hydroxy valerate).
[edit] Conclusions
Bioplastics and bio-based polymer materials are still a relatively new field with many innovations developing, some examples are bioplastics created from avacado, banana peel, waste frying oil, rice as well as sugar and CO2. In terms of construction industry the growth of bio-based materials as well as developments in bioplastics are key areas to watch.
[edit] Related articles on Designing Buildings
- Biogenic.
- Biobased materials.
- Glass reinforced plastic GRP.
- Glass fibre reinforced plastic.
- Polycarbonate plastic.
- Plastic cladding.
- Plastic coating market.
- Plastic in construction.
- Plastic in concrete.
- Recycled plastic bridges.
- Types of biobased materials.
- Wood plastic composites market for construction.
Featured articles and news
Classroom electrician courses a 'waste of money'
Say experts from the Electrical Contractors’ Association.
Wellbeing in Buildings TG 10/2025
BSRIA topic guide updates.
With brief background and WELL v2™.
From studies, to books to a new project, with founder Emma Walshaw.
Types of drawings for building design
Still one of the most popular articles the A-Z of drawings.
Who, or What Does the Building Safety Act Apply To?
From compliance to competence in brief.
The remarkable story of a Highland architect.
Commissioning Responsibilities Framework BG 88/2025
BSRIA guidance on establishing clear roles and responsibilities for commissioning tasks.
An architectural movement to love or hate.
Don’t take British stone for granted
It won’t survive on supplying the heritage sector alone.
The Constructing Excellence Value Toolkit
Driving value-based decision making in construction.
Meet CIOB event in Northern Ireland
Inspiring the next generation of construction talent.
Reasons for using MVHR systems
6 reasons for a whole-house approach to ventilation.
Supplementary Planning Documents, a reminder
As used by the City of London to introduce a Retrofit first policy.
The what, how, why and when of deposit return schemes
Circular economy steps for plastic bottles and cans in England and Northern Ireland draws.
Reporting on Payment Practices and Performance Regs
Approved amendment coming into effect 1 March 2025.
Comments
[edit] To make a comment about this article, or to suggest changes, click 'Add a comment' above. Separate your comments from any existing comments by inserting a horizontal line.