Molecular Structure of PE
PE is generally classified by the density and molecular structure such as branching.
High density PE (HDPE)
Polymer chain is linear and no or less short branches, so polymer chains pack closely together. Therefore it has higher density.
Linear low density PE (LLDPE)
LLDPE is produced by copolymerization ethylene with α-olefin such as butane-1, hexane-1.
It is linear polymer with a number of short branches, therefore polymer chains do not easily pack together. As a result it shows lower density.
Low density PE (LDPE)
It has a high degree of short- and long-chain branching, so the polymer chains do not pack well. Therefore it has lower density.
