Self-Generation of a Nanofibrous Structure Enables Facile Preparation and Processing of a Liquid Crystalline Polymeric Composite with Intrinsic Flame Retardancy

Thermotropic liquid crystalline polymers (TLCPs) usually act as reinforcement to prepare composites; however, poor interfacial adhesion between two materials leads to restricted enhancement in performance. Although adding a flame retardant is an effective method to extend the application fields of composites, it results in serious phase separation. To address the above challenges, a new strategy to design high-performance in-situ-reinforced composites with intrinsic flame retardancy is presented in this work. A naphthalene monomer with a kinked structure reduces the regularity of molecular chains, which improves the processability and forms a relatively flexible polymer bulk. The rest of the domains are more rigid and peculiarly form nanofiber reinforcement. The resultant composites possess high glass transition temperature (Tg > 200 °C), excellent processability (minimum complex melt viscosity ∼6.4 × 103 Pa·s), and great intrinsic flame retardancy. This would be an effective solution to reconcile the contradictory processability, phase separation, and flame retardancy of composites.