Silicone elastomers take the heat

Multibase, a Dow Corning company, recently announced a new line of thermoplastic elastomers called TPSiV (pronounced tip-siv, short for thermoplastic silicone vulcanizates). These high-temperature, high-performance alloys combine a continuous matrix of engineering thermoplastics with fully cured silicone rubber particles.
?TPSiV materials combine the melt-processibility of thermoplastics with the high- and low-temperature resistance of silicone rubber,? says Fernando Cuccioli, global project leader for Multibase. ?Unlike other TPEs, these elastomers are free of plasticizer. Because the continuous phase is not silicone, they are also paintable, which gives them an advantage over silicone rubber.?

Four grades of TPSiV are now available. A polyamide-based version, 1180, brings flexibility and chemical resistance at a continuous-use temperature of 284F. Three other grades, based on a proprietary engineering thermoplastic, are known as the 3000 Series. They offer a softer (50 to 60 Shore A) choice for overmolding and bond readily to PC, ABS, PU, PVC, and PA without the use of adhesives.

Cuccioli believes it is the combination of properties that will make TPSiVs a replacement for high-performance thermoset rubber and ?organic? TPEs such as SEBS, PP-EPDM alloys, and TPUs. ?TPSiVs have a unique, silky feel combined with good tensile property retention at continuous use temperatures of 300F and higher. They are also hydrolytically stable with low tensile and compression set, and they remain soft at low temperatures. This combination will work well for automotive, agriculture, industrial, and marine applications.? The new elastomers are colorable at the press or via compounding, and pricing is set at $4.50 to $5.90/lb.?Michelle Maniscalco

Multibase, a Dow Corning Co., Freeland, MI
(989) 695-4407
www.dowcorning.com/plastics