Just brainstorming here: anything temperature-based? Starts degrading above 10C for example. In your fridge it's no problem, chuck it out of the window like a savage and it will eventually degrade, unless you live on the poles.
Sounds like a good avenue for (organic) material science research.
Does something like that exist? Can something like that exist? don't forget it needs to be food safe - including whatever it breaks down to, and whatever bacteria might grow on it - so long as the food itself is safe to eat.
Materials science has come a long way, but some problems still are not solved and it isn't always clear if the problem can be solved.
I have found old buried plastic bags, from supermarkets - I remember the bag style from just a few years ago. The bags had severely degraded. When I tried to pick one up, it fell apart into small pieces, what integrity it had was gone. I've had the same experience with bags left in lofts - they degrade.
From my personal experience, I therefore assume that plastics already disintegrate after about 10 years, not 100 or 500 years, as you state.
You're just talking about a bag degrading into smaller and smaller plastic particles (microplastics) while the people above are talking about biodegrading into natural elements.
No, you're just confusing macroscopic level of degradation (the whole structure degrades) and microscopic degradation (molecules are being degraded).
The problem with plastic is that while the macroscopic structure can be altered in just a few years (depending on the conditions), the resulting parts aren't being metabolized away by micro-organisms and they remain as small plastic chunks, and then micro-plastic, then nano plastic, until they eventually break down entirely after decades, which is very unlike what happens with what we call biodegradable materials.
So, in your view, although the bag I see is breaking up into small brittle pieces, there are even smaller pieces that are not been degraded? Is that a theory to you, or do you have first hand knowledge?
If I have understood your position correctly, this is certainly counterintuitive... because if there is not much plastic bag left, you'd think that whatever broke down the bag, would also be able to break down these smaller bits (microplastics). But you are saying that small bits of the bag remain for decades, even though I can't see them.. I just don't see why small bits of plastic bag would remain, when it is evident that something in the ground already degraded the plastic bag as a whole.
Sounds like a good avenue for (organic) material science research.