Ultra Low-Density Polyethylene ULDPE Resins

Some of the characteristics of the different PF types discussed previously are presented in Table 2.1. The type of chains and the degree of branching determine the ultimate properties of a polymer. The properties can be tailored by adjusting the polymerisation method or the reaction conditions to favour differing degrees and forms of branching along the backbone. 

PE Density (g/cm ) Number of branches (per 1000 carbon atoms) Degree of crystallinity (%) Comments 

LDPE 0.910-0.925 20-30 (methyl) 3-5 (w-butyl) 40-50 M-Butyl branches arise from backbiting 

HDPE 0.942-0.965 4 (Phillips) 5-7 (Ziefder) 60-80 No ethyl or butyl (Phillips) ethyl branches (Ziegler) 

MDPE 0.926-0.940 4-6 — Formed from blending LDPE/ HDPE or LLDPE copolymer 

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