Core-Shell Structured Polyamide 66 Nanofibers with Enhanced Flame Retardancy

We report the preparation of polymer nanofibers with enhanced flame retardancy by coaxial electrospinning polyamide 66 (PA 66) and nanoscale graphene hybridized with red phosphorus (NGRP). [GRAPHIC] Transmission electron microscopy and energy-dispersive X-ray spectroscopy revealed that the nanofibers contained a NGRP-based core surrounded by a PA 66 shell. The flame-retardant characteristics of the nanofibers were investigated by thermal gravimetric analysis, micro combustion calorimetry, and a series of vertical flame tests. The encapsulation of the NGRP not only enhanced the flame-retardant characteristics of the nanofibers, but also improved their mechanical properties while maintaining the color and luster of the polymer, making the resultant nanofibers appropriate for use in a wide range of applications.