PE	Polyethylene
V	Unwrapped
B	Biological activity
W/S	Physicochemical factors of water and sun
WA	Physicochemical factors of water and air
S/A	Physicochemical factors of sun and air
DTs	Degradation temperatures
DT1	First change in mass by water loss
DT2	Second change in mass by water loss
DT3	Third change by total mass loss
GTT	Glass transition temperature
CT	Crystallization temperature
MT	Melting temperature
Wi	Initial weight
Wf	Final weight