Polymers

Polymers: Bio-based – Biodegradable – Recyclable – same fight?

Plastics are materials that are widely used in our daily lives.

At the molecular level, they resemble strings of pearls with complex and varied entanglements, each of these beads being called monomers.

These polymers can be natural, such as rubber and cellulose, or synthetic, such as nylon or polyethylene. They are appreciated for their unique features, such as their flexibility, lightness and strength. However, a common misunderstanding is the confusion between terms that refer to distinct but often related concepts: recyclable, recycled, bio-based and biodegradable. 

Here we come back to these concrete differences, clarifying what these terms really mean and highlighting the issues related to the use of bio-based, recyclable or biodegradable plastics in the current context of environmental sustainability.

Polymers

Polymers are sequences of monomers mixed with additives, dyes and mineral fillers to form a so-called “plastic” material.

Polymers can be natural, such as cellulose and rubber, or synthetic, such as nylon or polyethylene. They are widely used in various fields, ranging from the textile industry to packaging, to medicine.

There are two main families of polymers: thermosets and thermoplastics

Thermoplastics have the ability to be structurally modified through a successive temperature change in a reversible manner. **This will allow them to be molded and reshaped several times without altering their chemical structure. Thermoplastics can be recycled and reused. **

This family is appreciated by manufacturers thanks to its possibility of being part of the plastic waste recycling cycle. Common examples of thermoplastic polymers include polyethylene, polypropylene, and polystyrene.

Thermosets form a resin that will turn into a finished and insoluble object. Once cured by a heating process or by the addition of a curing agent, they can no longer be reshaped or melted. This property gives them excellent resistance to heat, chemicals and wear, making them ideal for applications in fields such as aerospace, automotive and electronics. However, these materials are difficult to recycle, if at all. Common examples include epoxy resins and phenolic resins. 

Bio-based polymers

The term “bio-based” refers to materials, products or resources that are derived from renewable biomass, i.e. organic matter from plants, animals or biological waste. Unlike fossil resources, such as oil or coal, which are not renewed on a human scale, bio-based materials come from natural sources that can be regenerated, such as wood, agricultural crops or algae.

 

 

 

 

Bio-based products can include bioplastics, composites, textiles, and fuels. The use of these materials aims to reduce the environmental impact by decreasing greenhouse gas emissions, promoting the circular economy and supporting sustainable agricultural practices.

However, it is important to consider production methods and impacts on ecosystems when assessing their sustainability.

 

 

 

Biodegradable polymers

The term “biodegradable” refers to the ability of a material or product to break down naturally through the action of microorganisms, such as bacteria and fungi, into non-toxic substances under normal environmental conditions.

Biodegradable materials can be naturally derived, such as paper, wood, some plant-based or synthetic plastics, which are designed to break down more easily than traditional plastics.

Biodegradability is an important criterion for assessing the environmental impact of a product, as it helps to reduce the accumulation of waste in landfills and oceans. 

However, the speed and efficiency of decomposition depend on several factors, including the composition of the material, temperature, humidity, and oxygen conditions. It is also essential to distinguish between biodegradability and compostability, the latter requiring specific conditions for optimal decomposition.

Bio-based does not mean systematically biodegradable!

Indeed, a material can be bio-based without being biodegradable. For example, some bio-based plastics do not break down easily in nature.

In summary, “bio-based” refers to the renewable origin of materials, while “biodegradable” focuses on their ability to break down and reduce environmental waste.

Recyclable polymers

The term “recyclable” refers to the ability of a material or product to be collected, processed and reused to make new products, rather than being disposed of as waste. Recyclable materials can include metals, plastics, paper, cardboard, and glass.

Recycling typically involves several steps, including collecting used materials, sorting them, cleaning them, and turning them into secondary raw materials. 

One of the main benefits of recycling is that it reduces the consumption of virgin resources, reduces waste sent to landfill, and limits the environmental impact associated with the production of new materials. However, the recyclability of a product depends on its composition, the recycling infrastructure available and public awareness of the importance of recycling.

 

 

 

In conclusion, plastics and other polymer-derived materials, whether bio-based, recyclable or biodegradable, have a strong potential to support the environmental transition.

Their use can promote practices such as the circular economy and decarbonisation, reducing dependence on fossil resources and limiting waste generation. In addition, their lightness and specific properties make plastics essential allies in reducing CO2 emissions, particularly in the transport and industrial sectors.

However, for these materials to truly fulfil their role in a more sustainable future, it is crucial to carry out a detailed analysis of their environmental impacts.

It is not enough to rely on labels or ecological claims, often used for marketing purposes, without taking into account the real conditions of production, recycling or biodegradation.

By avoiding greenwashing, we can ensure that these materials actually contribute to the reduction of our ecological footprint, while supporting more environmentally friendly industrial practices. It is also essential to prioritise the use of plastics in applications where their environmental benefits, such as lightness and durability, are truly optimised.