I don’t know what these are made of, but rarely using them might make this more likely. A lot of PU will degrade like this if it just sits around but will last a long time if used regularly.
If you’ve ever had a pair of shoes with a PU sole that sat in the closet for a year or two and when you went to get them the sole was all gummy and/or crumbly, but you had a pair from the same company that you wore regularly that lasted years, you’ve experienced this.
Hydrolysis. Allegedly using shoes with PU soles often squeezes moisture out of them, preserving life, but idk if that’s actually true. I can definitely say heat combined with humidity will definitely degrade it pretty quick. Density of the PU really matters, though, cause some PU soles that are relatively rigid (like regular Chaco sandals) are basically bulletproof, while the more cushiony forms with air injected (like the Chaco “cloud” sandals i mistakenly bought, or blundstones) will break apart.
I don’t know what these are made of, but rarely using them might make this more likely. A lot of PU will degrade like this if it just sits around but will last a long time if used regularly.
If you’ve ever had a pair of shoes with a PU sole that sat in the closet for a year or two and when you went to get them the sole was all gummy and/or crumbly, but you had a pair from the same company that you wore regularly that lasted years, you’ve experienced this.
Hydrolysis. Allegedly using shoes with PU soles often squeezes moisture out of them, preserving life, but idk if that’s actually true. I can definitely say heat combined with humidity will definitely degrade it pretty quick. Density of the PU really matters, though, cause some PU soles that are relatively rigid (like regular Chaco sandals) are basically bulletproof, while the more cushiony forms with air injected (like the Chaco “cloud” sandals i mistakenly bought, or blundstones) will break apart.