QUESTRA crystalline polymer: a new material option for electrical insulation systems

Abstract

A new category of semi-crystalline engineering thermoplastics has been developed for electrical insulation systems. QUESTRA, crystalline polymers, are syndiotactic polystyrene (SPS) produced using metallocene catalyst technology. In addition to good heat and chemical resistance characteristic of semi-crystalline thermo-plastics, they also exhibit good electrical properties, dimensional stability and insensitivity to moisture. Injection molding processing is made easier with the low melt viscosity of SPS, which typically needs no pre-drying. Thin wall parts can be filled with modest injection pressure and runner diameters can be reduced. Electrical insulation systems testing according to IEEE 117 and IEC 61857 has been completed and this new thermoplastic is now recognized under UL 1446. This set of properties makes glass-reinforced SPS resin well suited for coil, transformer and motor applications.