Separation of a thermotropic liquid crystalline polymer from polypropylenecomposites

This work is concerned with determining how to effectively recycle wholly t hermoplastic composites comprised of a polypropylene (PP) matrix reinforced with a thermotropic liquid crystalline polymer (TLCP). A novel reclamation process was developed in which the TLCP could be recovered from the PP mat rix. Reactive extrusion was used to reduce the molecular weight of the PP ( Montell 6523) and to facilitate phase separation. The melt was then extrude d into a heated mineral oil bath, which separated the TLCP (DuPont HX8000) from the matrix by dissolving the PP. It was found that greater than 70 wt% of the TLCP could be reclaimed from the PP matrix at a purity of greater t han 96 wt%. In order to determine the ability to reuse the reclaimed HX8000 , injection molded in situ composites were generated and their mechanical p roperties were determined. When the neat HX8000 component was partially rep laced with reclaimed HX8000, the injection molded TLCP/PP composites showed no discernible difference in mechanical properties.