The molecular structure of HDPE is a linear backbone of the repeating unit (
–
CH
2
–
CH
2
–
)
n
with a
slight degree of branching
. Resin proper
ties are determined by the type and percentage of
comonomer within the polymer chain and overall molecular weight. Resins are classified by melt
index (MI), a function of molecular weight and branching. Compared to low density polyethylene
(LDPE) and linea
r low density polyethylene (LLDPE), HDPE resins have superior mechanical
properties, and higher service temperatures (110
–
130
°
C). HDPE can be blended with LDPE or
other polyolefin resins to tailor the
physical characteristics for specific