Have you heard the term goggle rot? It’s when the elasticity is sucked from your goggle straps and gaskets, and you’re left with crumbly, brittle, easy-to-snap goggles (scientifically speaking). Let’s take a closer look at goggle rot, its cousin polymer degradation, and how to avoid inviting these unwanted visitors to the goggle party.
Goggle rot was easy to find on this 9-year-old pair of Speedo Sprint goggles I found in an old swim bag. Look for goggle rot on the rubbery straps, it will appear as tiny imperfections or notches along the edge of the rubber. Goggle rot becomes even more apparent when you pull on the strap. Stretch it out, and you’ll notice the little tooth marks in the rubber get deeper. Also, look for brittle, stiff rubber that holds its shape – give this section a pull and it should snap cleanly in two.
Goggle rot is a form of polymer degradation, which is a change in the properties (tensile strength, colour, shape) of a polymer of polymer-based product (Wiki). It is caused by a variety of environmental factors such as heat (or rapid changes in heat), light (specifically exposure to ultraviolet light), or chemicals (acids, bases, salts, and gases).
Without knowing the specific composition of goggle straps, it is difficult to tell which factor of polymer degradation is to blame – ozonolysis, however, is a likely candidate. We can assume that goggle straps fall within the polymer classification of elastomers because they have viscoelasticity properties, and elastomers are particularly vulnerable to degradation by ozone naturally present in small amounts in the air.
Compare this image of natural rubber that has undergone ozonolysis to the photos I took of goggle rot:
According to Wikipedia, cracks in the rubber caused by ozonolysis always oriented at right angles to the strain axis. Notice how the “teeth mark” tears in the goggle strap always cut into the rubber perpendicular to the direction of the stretch.
Based on what I have gleaned from Wikipedia while writing this article, I would advise keeping goggles away from prolonged exposure to chlorine (however contradictory that is for swimmers), and keeping them out of cars that heat up during the summer (avoid extreme changes in temperature). But unless you plan to keep your goggles in an air-tight box, it’s impossible to avoid all types of polymer degradation occurring in goggle straps. Silicone is more resistant to Ozone and UV light, which is probably why manufacturers have switched to these materials for newer goggles like Speedo Vanquishers and TYR Tracer goggles.