High Melt Strength Polyolefin Elastomers (HMS POEs) and Olefin Block Copolymers (OBCs) Michio ONO* and Takahiko OHMURA(Dow Chemical Japan Ltd, Dow Japan Development Center, 8-1, Ukishimacho, Kawasaki-ku, Kawasaki-shi, Kanagawa-ken, 210-0862, Japan) *MOno@dow.com Novel polyolefin elastomers, HMS POE and OBC were introduced. HMS POE is a high melt strength ethylene- olefin random copolymer with certain level of long chain branches and high molecular weight which have provided unique rheological properties such as higher melt strength, higher melt elasticity, shear shining property under a given shear and strain hardening. These rheological attributes have enabled higher through-put for extrusion profile, thermoforming sheet without any tear and webbing and stable parison retention for blow molding. Moreover, OBC is a multi-block copolymer consisting of hard- and soft-blocks covalently bonded together. Due to the presence of crystalline hard blocks, it provides heat resistant elastomer, faster crystallization rate leading to cycle time reduction and comparable compression set property to that of cross-linked TPV products. Key Words Polyolefin Elastomer, Melt Strength, Elongational Viscosity, Melt Elasticity, Impact Modifier, Block Copolymer, Compression Set, Abrasion
Science Polymer Macromolecules Kagaku-to-Kogyo