Flame Retarding Nanoarchitectured Fibers – ArchiFlame

The development of polymer nanocomposites is very significant because of the strong improvement of the final properties and in particular, the reaction to fire of the materials.
The objective of ARCHIFLAME project is to develop textile structures composed of polyamide 6 (PA6) nanocomposite fibers with enhanced flame retardant properties. Attention will be focused on the fibers nanoarchitecture control during the extrusion process. In fact, to ensure the nanoparticles (NP) dispersion, one must act at the NP/polymer interface during the elaboration of nanocomposites materials. Among the different methods that can be considered, the one retained in this project is the grafting of components at the NP surface.
After a first step of selection of the coupling agents (CA) that can ensure a good compatibilization between the NP and the polymer matrix, the functionalization of NP will be achieved. Moreover if the presence of the unique NP is not sufficient to bring acceptable flame retardant (FR) properties, FR agents will be added in the systems. The influence of the type of NP, specially the aspect ratio, as well as the nature and quantity of CA and FR compounds on the nanoarchitecture (fillers dispersion and orientation) will be studied. The control of this nanoarchitecture depends not only on the above mentioned parameters linked to the chemistry of the system but also on the parameters related to the extrusion/melt spinning process. Thus, experimental conditions such as temperature, speed of the screw, draw ratio of the fibers… have to be taken into account because they affect the morphology of the end material.
Various PA6 nanocomposite fibers will be realized varying the “chemistry/process” parameters and the mechanical and flame retardant properties of the samples obtained in this way will be evaluated. The use of several characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), nuclear magnetic resonance (NMR)… will allow the observation and the quantification of the dispersion quality while studying the nanoparticules orientation inside the fibers. All the information derived from the different analyses will be joint and relations between morphology and flame retardant properties will be established. Then, the selected optimal experimental conditions will be applied to obtain high-performance material. The approach followed all along the project will be validated on the lab scale with the production of fibers but also knitted structures that will be submitted to mechanical and fire tests. A more fundamental study will complete the project to understand the physical and chemical mechanisms involved in the improved flame retardant properties.
In the frame of this project, a new collaboration between the laboratory “Materials Science and Engineering” of the University of Beijing and the laboratory “Unité Matériaux et Transformations” (UMET UMR/CNRS 8207) of the University of Lille will be established. The expertise of the two groups, chemical engineering on one hand and materials functionalization to achieve enhanced properties on the other hand will be combined to conduct the project. The dissemination of the results will be done through publications and communications but industrial applications can also be considered.