Technology for branched polyethylene by metallocene catalysts was one of the most important advancements in polyolefin industry. Metallocene LLDPE was widely used in film and heavy duty packaging due to its high performance of anti-pierce and anti-impact. The property of m-LLDPE was highly related to the type

concentration and the distribution of comonomer incorporated. This review introduced the originality of the molecular heterogeneity in m-LLDPE from the point view of catalytic active center and the effect of the fluctuation in polymerization conditions. Method for molecular heterogeniety characterization in branched polyethylene by 13C NMR

TREF and DSC-SSA were discussed in detail to show the difference of the comonomer sequence composition

distribution and crystallization properties of the copolymers.