Bio-based Polyurethanes and How They Contribute to Sustainability

What’s on the label, it would seem, does matter after all.

• By Fraser Rankin
• May 26, 2021

Bio-based Polyurethanes are one of today’s most versatile materials, which can play a unique role in nurturing sustainability goals. By helping natural resources and materials last longer, polyurethanes can encourage sustainability and waste reduction simultaneously, whilst fostering a healthier use of natural resources. The stride in new material technology, including polyurethanes with a larger biomass content, is the early foundation of a ‘Circular Economy’.

In particular, end-of-life materials are often wasteful. Rather, thermoplastic polyurethanes (otherwise known as TPUs) that are used in the design of products can help minimize wastage, by promoting recyclable designs. Simply, these are reclaimable materials that, when one product expires, can be recycled into new applications.

This kind of innovation in material science and product design has opened opportunities for rethinking how sustainability can be achieved and supported. But just how far does this go?

What are Sustainable Polyurethanes?

In the materials industry (and wider afield), the subject of sustainability has led to an appetite for innovation with polyurethanes as one such focus. By nature, thermoplastics can be melted and reused between product lifecycles, meaning that products designed with TPUs can be truly recycled.

TPUs are so popular because they’re lightweight and versatile, especially in product design. Yet, the sustainability unlocked by TPUs is, ultimately, desirable. Thermoplastic polyurethanes lead to all types of reductions – the amount of material required per product, the amount of waste generated in the production cycle, and the amount of energy required to produce and transport materials. This equates to fewer natural resources being exhausted in production.

For example, Adidas trainers caught attention when the brand transitioned part of its production into a circular economy. This means that materials are reimagined at the end of their lifecycle, such as a pair of trainers being recycled from one wearer to a new pair by another. Interestingly, this example demonstrates the hidden value of materials at the end-of-life, rather than sending expired goods to a landfill.

Adidas’ innovation through footwear and TPUs is more than a feat of the imagination. Here is a positive example of how material scientists and industrialists can creatively collaborate to promote a new story for waste. In this take, trainers are produced identically to previous production runs, but the recyclability of materials means goals of sustainability can seemingly be accomplished.

Thermoplastic Polyurethane Films & Renewable Content

From material properties such as toughness and elasticity, TPU films are a key ingredient in product design for sophisticated markets and industries, such as motorsport or military. Tailored to demanding environments, TPU films - albeit recyclable - support product design and are performance materials. So, as a substitute to conventional materials, TPUs can offer recyclability without risking quality. Applications range from textiles, to hospital equipment, and military aircraft furnishings.

TPUs have a global reputation as a workhorse material. Yet, the recent drive for innovation has been somewhat spurred by this new appetite for sustainability in product design. Medical applications, like hospital tents, is another example of sustainable use. Here, materials can be reused into other forms, often through a process of compression moulding. In addition, new TPU technology is progressing quickly with +30 percent renewable content.

Biodegradability and The Future

Even though the immediate focus is on driving recyclability and rediscovering value at the end-of-life for products, early rumors place biodegradability as a potential area for growth in the coming years. Unlike materials such as PVC, a biodegradable TPU might further enhance environmental goals, especially when reducing the carbon footprint and wastage.

Traditional waste management, as per the conventional infrastructure, means that plastics are either recycled (where it’s suitable), incinerated, or placed in a landfill. None of these options have advanced sustainability like the changes promised by new material technology. Degradable or not, TPUs are an inspiring case study for rethinking sustainability goals by taking a closer look at product design. What’s on the label, it would seem, does matter after all.