Silicone hybrid TPE finds commercial use.

So-called hybrid TPEs of silicone elastomer joined to an organic polymer have entered commercial use, according to developer Wacker Chemie AG of Germany (parent of Wacker Silicones, Adrian, Mich.). The industry's first silicone-based TPE, called Geniomer, is being used as a heat-sink material in electronics applications and as a damping material in distance sensors for automotive applications, says Wacker. The material, composed of silicone/urea copolymer with a silicone soft segment and organic hard segment, was first introduced at the K 2004 show in Dusseldorf. Geniomer has also been approved for a coextruded polyolefin release film, according to Dr. Richard Weidner, director of innovation management at Wacker Silicones.

Wacker also introduced three grades of Genioperl, a core-shell-like impact modifier. These consist of a low-modulus, crosslinked silicone rubber core and an acrylic (PMMA) shell. Available in powder and masterbatches, Genioperl is said to improve the toughness of thermoplastics and thermoset polymers, especially at low temperatures. Wacker is also working with a major polycarbonate producer on a PC/silicone hybrid that would provide low-temperature flexibility down to -40 C. Tel: [phone] * www.wacker.com

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