Crumbling golf shoes and other disintegrating plastics: mystery solved!

The are several topics on the forum about "crumbling golf shoes", "Thailand destroyed my shoes", etc.

I was pretty sure I replied yesterday to one of these topics from 2017, but my post is nowhere to be found.

I had top quality sandals (Mephisto) and other items that were totally destroyed by just sitting in a plastic bag in a casket in Thailand and I never understood why. At the time searching the internet about "disintegrating rubber" or "crumbling plastics" didn't yield satifactory explanations other than "explanations" by tinfoil-hat wearers about bad magnetism, ionized air, ghosts, plastic-eating bacteria, fungus, etc.

a couple of days ago, the sole of my pair of Foot Joy golf shoes crumbled after I had them stored at home without playing for about a year. Then I also found an older underwater bag for cameras that also quietly disintegrated in the plastic bag where it was stored.

Since the shoes weren't exactly cheap, I dug more about possible explanations and finally found the reason: polyurethane hydrolysis.

hydrolysis occurs when water molecules stay in contact with urethanes or polyurethanes for a long time such as weeks, months, years. the water can be in liquid form, but also as vapor or gas form, such as in air with high humidity. a reaction then takes place, which lets water break down the polyurethane's structural stability with the result of making it crumble.

reading through some of the articles that turned up in google, this problem must be HUGE. but at the same time, it's not even mentioned in wikipedia, and there are less than a dozen webpages published about this issue.

Most hits are scientific papers dealing with polymer stability, and one of the newer ones from 2013 is "proposing a model" to understand polyurethane hydrolysis. In other articles it becomes clear that hydrlytic stability is an important criterion for polymer quality.

this leads to the conclusion that most sport equipment companies sell products that will be destroyed by a year of storage in normal cabinet in Thailand. BEWARE !

but apparently, there is a way to prevent hydrolysis.

I read, hydrolysis is aided by:

- high humidity

- temperature

- lack of ventilation

- obscurity

Next time I go away for some time, I will store my golf shoes in the fridge, with a bunch of dessicant bags.

What's unbelievable is that the industry does nothing to warn us against hydrolysis and doesn't say how to prevent it.