**4. Conclusions**

It has been found that the combination of TLCP fibrils and glass fiber can result in a high-performance and recyclable hybrid composite. The processing temperature of the injection-molding process was determined by rheological analyses and DSC. To provide a low viscosity blend to ensure that all the TLCP crystals were melted and to reduce excessive thermal degradation of polypropylene, the composites were processed at 305 ◦C. In situ hybrid composites were successfully generated at the optimized processing temperature. Due to the hybrid nature of the glass fiber and TLCP, the in situ hybrid composite exhibited balanced performance with respect to processability, mechanical properties, and recyclability. The 10 wt % glass fiber and 20 wt % TLCP hybrid composite material was the best formulation of the hybrid composite because it lowered the melt viscosity, thereby increasing its processability while maintaining high tensile properties, lowered mechanical anisotropy, and increased recyclability of the TLCP/GF hybrid composite.

**Author Contributions:** Conceptualization, T.C.; Methodology, T.C.; Validation, T.C.; Formal analysis T.C.; Investigation T.C., D.K. and L.J.; Writing—original draft preparation, T.C.; Writing—review and editing, D.K., L.J., D.A.O. and D.G.B.; Supervision, D.A.O. and D.G.B.; Funding acquisition, D.A.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** The funding is from General Motor with Project Number GAC3053.

**Acknowledgments:** Support from General Motor (GM) is gratefully acknowledged. The authors would like to thank Celanese and SABIC for providing materials.

**Conflicts of Interest:** The authors declare no conflict of interest.
