I want to stress this is not temperature directly; these objects are reused from a glass point verification test, #PHA holds its shape to much higher temperatures than #PLA.
oh dang look - #PHA is showing some self-composting breakdown as it dries!
this is more along the lines of my expectations; #PLA and PHA do both biodegrade but PHA is (reportedly) better at it. I think we’re seeing that here, particularly since it’s mostly in the buried portion!
It’s interesting that the #PHA shows very little bleaching in the sun exposed portion but much more so from underground, the opposite of the #PLA, despite the layer compression. Neat!
The wood control really shows very little decomposition so do not mistake this for a composting experiment, it’s more of an outdoor durability experiment.