How can a product be both durable and biodegradable?

Hint: consider your cotton t-shirt

Cotton is a fully biodegradable material, and yet you can wear your favorite old cotton t-shirt around for years, put it through a weekly wash, expose it to sun and rain and sweat, and it will remain ‘gently loved’ but intact. 

Just as biodegradable cotton doesn’t break down into compost through normal daily usage, a fully biodegradable material like Soleic won’t either. Instead, it needs a very specific context in order to biodegrade (more on that below!). 

From a materials science perspective, this seeming paradox is clarified by the fact that durability and biodegradability are two separate properties. At Soleic we rigorously design and test our materials to meet or exceed the performance metrics of petroleum counterparts, on properties such as abrasion loss, tensile strength, and compression.

What factors are needed for biodegradation?

To biodegrade, our materials must be constantly exposed to a microorganism-rich environment containing water. So the factors include time, the nature of the environment, and characteristics of the polymer itself.

At the end of their product lifetime, Soleic materials buried in soil or compost will biodegrade. Third-party testing using ASTM D5338 standards showed our Soleic Foam material degrading 100% compared to cellulose after 220 days in compost. And if Soleic materials end up in the ocean, they will also break down over time, as shown in a study we published in 2022. 

We also tested our BLUEVIEW shoes, made with Soleic Foams and all-natural hemp and eucalyptus knit uppers, in home composting conditions, and they looked substantially biodegraded after 6 months. 

At the same time, a member of our team decided they would wear their pair of BLUEVIEW shoes every day for six months. The results: like any other pair of sturdy shoes, they stood up to daily use with no issues.

The most important thing to remember is that biodegradability is dependent on very specific composting conditions – so you can take products made with Soleic materials into any normal day to day context and they’ll hold up wonderfully!

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