I’m basically thrilled about these rain coats from TERRA; fashion and function?! Prove it. TERRA’s outerwear is designed for urbanites and bikers to go about their business not looking like drowned rats, a significant feat to be sure. The designs are total win, so on to the science.

The most consistent points of failure in water proof outerwear are the seams, while a fabric could be completely impervious, every stitch is a punctured hole and a breach in the system. TERRA wisely solves this issue with thermal bonding, utilizing the melting and reforming properties of thermoplastic Polyurethane.

Thermoplastic polymers are the ones that melt, unlike thermoset polymers, which just burn. (We can have a longer discussion about thermoplasticity in the future, promise)

Polyurethane is a incredibly versatile polymer: adhesives, paint, elastomers, and more. what!? true.  Defined by the presence of urethane linkage, polyurethanes can be variant in their composition, and higly complex. In my opinion the finest example of this is the usage in block co-polymers, combining the highly crystalline sections with softer rubbery sections. 

In some publications (but not on their website) there is claim of biodegradability, I was completely befuddled by this, so I called up the fine folks at TERRA. Speaking with them I learned that the supplier they purchase the Polyurethane from claims that the polyurethane textile is biodegradable.  TERRA is planning to have independent ecological testing of the product undertaken in the near future, and only then advertise the confirmed results. 

In other Polyurethane news, there are two interesting developments. 1) bio-absorable for implantation and cell growth scaffolding.  2) Natural, made from plant oil based glycerol. (I vote this for the next TERRA line. Fancy!)

Now you know what to buy yourself after you return all those gifts. TERRA.