GE Plastics’ (Pittsfield, Mass.) Extem polyimide resins, a new family of amorphous thermoplastic polymers, are said to eliminate the drawbacks of semicrystalline materials, imidized thermosets and competitive amorphous thermoplastics. Inherently flame-retardant (they contain no halogenated additives), the resins reportedly withstand high temperatures and harsh chemical environments while remaining stiff and dimensionally stable. Properties reportedly include continuous-use temperatures to 230°C/446°F; glass transition temperatures as high as 310°C/590°F; high stiffness/creep resistance under load; resistance to chlorinated solvents; and melt processability using conventional extrusion and molding equipment.