Developmental Infuse thermoplastic olefin block copolymers (OBCs) from Dow Chemical, Midland, Mich., appear promising for a wide range of automotive applications as both neat resins and as impact modifiers.

Developmental Infuse thermoplastic olefin block copolymers (OBCs) from Dow Chemical, Midland, Mich., appear promising for a wide range of automotive applications as both neat resins and as impact modifiers. Initial work is focused on using OBCs as neat resins in two-shot molding of soft-touch interior components such as knobs, inlays, and trays of center consoles. Traditional metallocene elastomers, such as Dow's Engage, are random copolymers of ethylene and an alpha olefin. New Infuse elastomers consist of linear MDPE hard blocks and Engage-type ethylene-octene soft segments. OBCs have higher melting points (around 120 C vs. 60 to 90 C for Engage), and higher crystallization temperatures (about 100 C vs. 45 to 75 C). Faster set-up in molding and extrusion is said to result. However, the glass-transition temperature (Tg) of OBCs is similar to random ethylene copolymers, which translates into similar low-temperature ductility. OBCs also boast lower compression set and better abrasion resistance. They are expected to process much like random copolymers due to comparable shear rheology and melt strength. Tel: (800) 441-4369 . www.dow.com/infuse

Dow Chemical Company
200 Larkin Center Midland, MI 48674
Phone (517) 636-0782 Fax (517) 638-9925