Ordinary plastic like PVC would not have the necessary strength to resist either an inflation or an orbit maneuver for scales of that size.

This means that if you pulled one part (or even several) of the plastic piece it would not move the entire piece. It would just rip apart.

Assuming that this plastic piece was already somehow in place notice that 1 Bar is almost the pressure we have, on Earth, at sea level. This is quite a bit. For your structure to support itself without collapsing (it would be in free fall after all) it would need to orbit the moon at speeds far from lunarsynchronous (can I use this expression?!) orbit requirement (I doubt 8000 meters is enough). In any case this isolation "plastic" would rip apart with the forces produced by the speed difference between plastic surface and moon surface.

I do not think you can get away with using such a conventional material, or such a simplistic (one piece?) structure, for such an unconventional use. Neither the implementation or maintenance would work. Off the top of my head I would say the deterioration would be immediate.

I think pursuing this idea in similar molds to the ones you have stated would require other type of structure (or composition of structures).

Ordinary plastic like PVC would not have the necessary strength to resist either an inflation or an orbit maneuver for scales of that size.

This means that if you pulled one part (or even several) of the plastic piece it would not move the entire piece. It would just rip apart.

Assuming that this plastic piece was already somehow in place notice that 1 Bar is almost the pressure we have, on Earth, at sea level. This is quite a bit. For your structure to support itself without collapsing (it would be in free fall after all) it would need to orbit the moon at speeds far from Selenosynchronous orbit requirement (I doubt 8000 meters is enough). In any case this isolation "plastic" would rip apart with the forces produced by the speed difference between plastic surface and moon surface.

I do not think you can get away with using such a conventional material, or such a simplistic (one piece?) structure, for such an unconventional use. Neither the implementation or maintenance would work. Off the top of my head I would say the deterioration would be immediate.

I think pursuing this idea in similar molds to the ones you have stated would require other type of structure (or composition of structures).