Here is some information on plastics used for bottles. Of particular interest is the permeability values.

HDPE Semi-rigid, translucent, very tough, very good chemical resistant
to dilute acids, dilute alkalis and alcohols, moderate resistance to
oils and greases, low water absorption, easily processed by most methods,
low cost.
LDPE Flexible, translucent/waxy, weatherproof, good low temperature
toughness (to -60? C), easy to process by most methods, low cost, very
good chemical resistance to dilute acids, dilute alkalis and alcohols,
moderate resistance to oils and greases.
PC Rigid, transparent, outstanding impact resistance (to -150? C) good
weather resistance, dimensional stability, resistant to flame, good
resistance to dilute acids and alcohols, very good resistance to oils
and greases
PC Rigid, transparent, outstanding impact resistance (to -150? C) good
weather resistance, dimensional stability, resistant to flame, good
resistance to dilute acids and alcohols, very good resistance to oils
and greases
PET Rigid, clear, extremely tough, good creep and fatigue resistance,
wide range temperature resistance (-40 to 200? C), does not flow on
heating, very good resistance to dilute acids, dilute alkalis, alcohols,
oils and greases
PVC Rigid or flexible, clear, durable, weatherproof, flame resistant,
good impact strength, good electrical insulation properties, limited
low temperature performance, very good resistance to dilute acids,
dilute alkalis, good resistance to alcohols, oils and greases


.................................................. .......O2 CO2
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|EVOH |Ethylene vinyl alcohol copolymer | 2 | - |
|HDPE |High density polyethylene | 2900 | 9100 |
|LDPE |Low density polyethylene | 7900 | 42500 |
|PC |Polycarbonate | 4700 | 17000 |
|PET |Polyethylene terphthalate | 95 | 240 |
|PVC |Polyvinyl chloride | 120 | 500 |
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values are for 1 mil thickness, units cm3/m2.24h.atm