Sustainability is preserving the environment today for the generations of tomorrow to be able to live in it safely. However, sustainability goes deeper than that to incorporate three main dynamics, called the three E’s of sustainability; those are environment, equity, and economics.

Evidently, the environment is what we are making every effort to protect and maintain.

When it comes to making environmental decisions, equity is what ensures fairness is at the forefront of our considerations.

Whereas economics mainly considers the fact that in our endeavours to preserve the environment, subsistence and livelihoods are also well safeguarded.

In our modern-day world, it is quite challenging and almost unavoidable not to impact our planet’s environment in one way or another.

However, studying, understanding, and applying sustainability measures can help minimise our impact as individuals, organisations, and societies.

Furthermore, a pan-effective event as in the coronavirus pandemic putting the world through a lengthy downtime has been a wake-up call to many governments, organisations, and individuals across the world that arguably the most effective way to survive economic damages is through sustainability.

As mentioned in Global Recycling’s editorial in its second issue, the World Bank Group has stated that supporting a country’s development through sustainability-based approaches in the recovery phase from the pandemic can help build the country’s resilience and prosperity.

When it comes to materials selection, sustainability has become an increasingly critical factor to consider.

In addition to a material’s properties, ease of manufacturing, cost, and other attributes relevant to its application areas, its impact on the environment has become an indispensable consideration.

Every material and end product hold an environmental footprint, characterised by their fabrication, processing, design, durability, and reusability.

In 2017 alone, the global use of material resources hit the 90 billion metric tons mark. This is expected to increase at least twofold by the year 2050.

With a shift in the extraction of materials from the conventional Asian, European, and North American regions to more local sites throughout the developing world – Africa, in particular – the living standards there are definitely on the rise.

However, all this has raised red flags from an environmental standpoint, whether it is the impacts on the climate, the land, the biodiversity of species, or the biogeochemical cycles.

As we embark on a future that could bring unprecedented dangers, it is imperative that we all contribute to mitigating our impact on the environment, especially that of materials use.

Not only is it urgent to proactively evaluate our impact, but it is also vital that we devise new interdisciplinary approaches and apply solutions that would slow down the rate at which the world is impinging on the environment.

In the following sections, we will explore the many aspects of sustainability that materials suppliers and users have been undertaking as part of their collective mission towards a more sustainable future.

As material resources are becoming less and less abundant, waste piling up with limited disposal spaces, and CO₂ emissions triggering dangerous changes in our climate, there is an exigency that we begin transitioning from the tradition linear economy scheme to a reasonably circular economy.

The difference between both economic structures lies in the waste output of industrial or commercial processes, in which a linear economy follows the progression from the input level, where raw materials are mined, to processing and product usage, followed by waste disposal in landfills at the output level.

In other words, it follows the old-fashioned sequence of “take – make – use – dispose”.

On the other hand, a circular economy is designed particularly with minimising waste in mind.

That is through reducing, reusing, recycling, and remanufacturing products and materials for further use instead of discarding them after their first use.

Such an economic scheme highlights the importance and potential of sustainability-based thinking, especially in how it helps reduce:

our dependency on diminishing resources through reusing certain materials,

our global carbon footprint by circumventing many production processes, and;

our waste that is winding up in the oceans.

This helps reduce the input and output of materials and keep them, as much as possible, within that loop of “make – use – recycle”.

Materials that can help bring a circular economy into existence are those that can be reused without or with as little as possible additional processing.

That means reusability takes precedence over recyclability and remanufacturability, making sure that materials are reused sufficiently and effectively enough before reaching the point of recycling or remanufacturing.

As Michael F. Ashby puts it in his book Materials and Sustainable Development, “Materials in a circular economy are seen, not as a disposable commodity, but as a valued asset to be tracked and conserved for reuse.”

Such materials range from transition metals (e.g. titanium, gold, and steel) to post-transition metals (e.g. aluminium), alkali metals (e.g. lithium), and plastics (e.g. PET, PLA).

Recyclable materials are materials that can be made into new products to be reused with little to no waste. Recycling is a valuable consideration that fits well in the scheme of a circular economy, as it is intended towards minimising the input and output of a material’s life cycle.

An advantage that recycling has over reuse lies in the fact that whereas reused products are used merely within the limits of their initial system, recycled products can re-join the primary production cycle to be utilised in more ways. However, this comes at the expense of a greater loss in value.

The ability of a material to be recycled has been an increasingly important factor in material selection, especially in application areas where waste disposal has resulted in a dangerous impact on the environment.

For instance, plastics, glass, metal, paper, textiles, and organics – known as the six main categories of household waste – are all recyclable materials that, instead of getting discarded, can be remade into new products to be reused.

Moreover, the global metal recycling market is forecast to grow at a rate of 7% over the next 7 years, mainly owing to industrialisation, urbanisation, and the increased commodity consumption coupled with alarmingly depleting natural resources3.

Nowadays, the 5 most common recyclable engineering materials include:

Biodegradability represents a material’s ability to decompose upon its interactions with biological elements.

It may disintegrate completely or partially, depending on its level of biodegradability, the microorganisms contacting it, and its environmental conditions.

A biodegradable polymer material, for instance, that comes from renewable resources is generally classified as a green polymer, as it is characterised as an alternative to materials derived from petrochemical resources.

Since biodegradable polymers can naturally be composted with microorganisms and enrich soils, they hold a significant advantage in degradation over other polymers.

This helps stabilise the environment, extend the lifespan of landfills, and consequently, reduce the labour cost of removing nonbiodegradable traditional plastics from polluted areas.

Furthermore, biodegradable polymers can be reprocessed by certain treatments that involve microbes, enzymes, or hydrolysis, to make oligomers that are useful for different applications.

Biodegradability of materials is determined by biodegradability tests, which measure the complex biochemical processes taking place when microorganisms consume the given material. The ability of a product to degrade relies mainly on how much carbon is present for microbes to consume it.

Claims of biodegradability are required by regulations today to be based on aerobic biodegradation. This refers to the disintegration of the organic material in the presence of oxygen, and it measures the consumption of oxygen, the production of carbon dioxide, and the state of inorganic carbon intermediates.

Two main biodegradable polymers that have started gaining commercial traction are PLA (polylactide) and PHA (polyhydroxybutyrate). They are cost-competitive materials and have begun replacing a few of their nonbiodegradable counterparts, especially PLA in food packaging applications.

However, there is still a lot of research required to develop blends of biodegradable polymers that can have adequate properties and usability to replace the majority of current nonbiodegradable polymers. Basically, such materials play a significant role in areas where there is no infrastructure for recycling or recyclable materials are not much of an option, but they are not considered a circular solution.

The table below shows a variety of biopolymers and biodegradable polyester materials that are provided by Matmatch suppliers, which are used, for the most part, in packaging or 3D printing applications.

It is commonly known that one of the most significant sources of greenhouse gas emissions today is materials production.

Between 1995 and 2015, a 120% increase in CO₂ emissions from material production has been observed to account for 23% of global emissions, two fifth of which are used in manufacturing machinery, vehicles, and other products. Correspondingly, policies and processes today are aimed at augmenting the efficiency of materials and transitioning to a circular economy.

One of the most acknowledged and commonly used techniques to evaluate a material’s environmental impact is the Life Cycle Assessment (LCA). It is a cradle-to-grave analysis method that determines the environmental burdens relative to every stage of a product’s life cycle, from the extraction of raw materials through processing and manufacture all the way to its distribution, use, and disposal.

Throughout this life cycle, it is critical that the carbon emissions at every stage are monitored, assessed, and minimised to the lowest levels possible. However, LCA being a scrupulous quantitative assessment requires a lot of time and skill to be well implemented.

With that in mind, scientists and engineers look at simpler and faster approaches to evaluate a material’s impact on the environment. They strongly recommend the selection of materials with lower environmental burdens in the initial stages of a product’s development. And in order to understand and evaluate those burdens, they utilise two main indicators in their materials selection: embodied energy and carbon footprint.

Embodied energy is the total amount of energy associated with the extraction, processing, production, and delivery of a material or product. It does not cover the operation and disposal of the material but rather the ‘upstream’ sections of an LCA. This concept helps simplify the evaluation of a product’s environmental impact.

The figure below shows the different energy values typically required to produce different engineering materials..

Minimising the embodied energy of a product is crucial in reducing its environmental impact.

For example, in an LCA mentioned in the book “Use of Recycled Plastics in Eco-efficient Concrete”, it was shown that producing polypropylene (PP) with a 70% recycle fraction can reduce the embodied energy by two thirds from that of virgin PP, to about 25 MJ/kg.

Similarly, producing aluminium that is only 30% recycled can results by a reduction of at least 50 MJ/kg from the embodied energy of primary aluminium (~ 215 MJ/kg).

On the other hand, a material’s carbon footprint is the total amount of greenhouse gas emissions generated through the material’s lifecycle.

It can also be defined as the amount of biocapacity demand to close off the CO₂ emissions from the combustion of fossil fuels taking place due to the production of the material or product.

As described in BIR’s 2019 Annual Report, for example, recycling has helped save a significant amount of CO₂ emissions for many recyclable materials, as shown in the table below.

Here at Matmatch, we believe it is essential that a materials selection platform incorporates the aspect of environmental impact in the strategies of material selection and decision making for engineers.

That is why we have incorporated this sustainability section.

We want to help engineers and product developers make more informed decisions about preserving the environment while conducting their projects.

If you need help finding sustainable materials or have any feedback, get in touch with us below.

If you are a materials supplier that wants to promote your sustainable material solutions, we’d be happy to show you how we can help.