The effects of reclamation on a thermotropic liquid crystalline polymer

In previous work, a process was developed to reclaim a thermotropic liquid crystalline polymer (DuPont HX8000) from composites comprised of polypropyl ene (PP) reinforced with HX8000. The reclamation was accomplished by chemic ally degrading the PP and then dissolving the PP away in heated mineral oil . From this work, it was found that there were significant drops in dynamic and steady shear viscosity for the reclaimed HX8000, but that there were n o losses in mechanical properties when the recovered HX8000 was used to gen erate PP-HX8000 injection-molded composites. In the present work, the recla imed HX8000 was analyzed to understand the contradiction between rheologica l and mechanical properties. The effects of the reclamation process on the recovered HX8000 were investigated by using pycnometry (density), thermogra vimetric analysis (TGA), parallel plate rheometry, mechanical testing, scan ning electron microscopy (SEM), and differential scanning calorimetry (DSC) . (C) 1999 John Wiley & Sons, Inc.