Flexible biregional carbonaceous fiber, articles made from biregional carbonaceous fibers, and method of manufacture

Abstract

A novel flexible biregional carbonaceous fiber is disclosed comprising an inner core region of a thermoplastic polymeric material and an outer region of a carbonaceous sheath. The flexible biregional carbonaceous fibers are particularly characterized by having a ratio of the radius of the core region with respect to the total radius of the fiber (r:R) of from about 1:4 to about 1:1.05, a density of from about 1.45 to about 1.87 g/cm.sup.3, and a bending strain value of from greater than 0.01 to less than 50%. In a further embodiment of the invention, a biregional precursor fiber is disclosed having an inner core region of a thermoplastic polymeric material and an outer sheath region of a oxidation stabilized, thermoset polymeric material. The oxidation stabilized precursor fiber is characterized by having a density of from about 1.20 to about 1.32 g/cm.sup.3 The invention further resides in methods of making the biregional fibers. Preferred end uses for the biregional fibers are disclosed including thermal insulation; flame resistant and fire blocking insulation; blends of the biregional carbonaceous fibers with other natural or polymeric fibers; coated fibers, composites composed of a polymeric matrix reinforced with the biregional carbonaceous fibers of the invention, electron conductive fibers for battery electrodes, and the like.

Dependencies are inferred from the claim text.