The relaxation of liquid-crystalline polymer (LCP) fibers in the polycarbonate (PC)/LCP blend was examined under various conditions on a hot-stage microscope. LC5000 is a thermotropic LCP consisting of 80/20 hydroxybenzoic acid and poly(terephthalate). The geometry of the fibers is not an important factor in the relaxation process. Fibers of different aspect ratios and lengths relaxed at the same rate and exhibited identical onset times. Increasing the temperature caused the fibers to relax faster, especially near the nematic-transition temperature. The fibers relaxed almost immediately when subjected to a temperature of 285degreesC. At 280degreesC the fibers were stable for 43 min, whereas at 270degreesC no noticeable relaxation was evident. Addition of compatibilizer stabilized the fibers by enhancing the interfacial adhesion between the fibers and the PC matrix. Consequently, LCP fibers in the compatibilized. system relaxed at a much higher temperature (294degreesC) as compared with the uncompatibilized system (275-280degreesC). (C) 2003 Wiley Periodicals, Inc.