TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Material: The solvent is toluene or tetrahydrofuran.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The polymeric binder comprises a thermoplastic block copolymer, a first thermoplastic polymer, a second thermoplastic polymer different from the first thermoplastic polymer, and a plasticizer. The thermoplastic block copolymer comprises a copolymer of styrene and butadiene. The first thermoplastic polymer comprises polystyrene. The second thermoplastic polymer comprises polyindene. The polymeric binder further includes an antioxidant. The plasticizer comprises at least one oil and at least one wax. EXAMPLE - The preparation of the polymer binder system was initiated by the addition of Calprene (RTM: styrene-butadiene block copolymer) (4.8 g) to toluene heated at 50degreesC with stirring to provide shear. The antioxidant AgeRite (RTM: resin D powder) was then added. The two thermoplastic polymers (polystyrene and polyindene) (0.7 g and 0.7 g) were then added and completely dissolved in the toluene solution with continued stirring at 50degreesC. To the resulting homogeneous solution were added the two paraffinic waxes (each in 1 g)), and the two oils (1 g and 1.7 g). Into this homogeneous yellow binder solution the ceramic powder material was added and then mixed to form a slurry. The resulting opaque slurry was allowed to sit for hours with slight heating at 50degreesC with stirring to evaporate the toluene solvent. To perform the extrusion, the dried slurry was cut into pieces and put into an extruder. The extruder was preheated for 15-30 minutes at 80degreesC and then for an additional 5-10 minutes with heating up to 110 to 120degreesC to reach the softening point of the slurry. At extrusion temperature, a pressure of 13.8-20.6 MPa was used to obtain green ceramic tubes at an extrusion rate of 600 mm/minutes. After sintering, dense tubes having a diameter of 2.8 mm and wall thickness of 0.2 mm were obtained. The tubes maintained their as-extruded shape and exhibited a fine grain microstructure with only a small number of isolated pores.