Flame retardancy of polyamide 6 nanocomposites: Synergistic effect between multiwall carbon nanotube, nanoclay, and flame retardants
X. L. Yin1, H. Wu1, M. Krifa1, M. Londa2, J. H. Koo2,3
1. School of Human Ecology – Textiles and Apparel, The University of Texas at Austin, Austin, TX 78712, USA
2. Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
3 KAI, LLC, Austin, TX 78739, USA
Abstract
The objective of this study is to process and characterize a polyamide 6 (PA6) nanocomposite with enhanced flame retardant, thermal, and mechanical properties for fire resistant fabrics. In this study, a small amount of Baytubes® multiwall carbon nanotube (MWNT) and Cloisite® 30B nanoclay will be introduced into Aegis H8202NLB polyamide 6 (PA6) using twin screw extrusion. To enhance the thermal and flammability properties, an intumescent flame retardant (FR) ®Exolit OP 1312 additive is added to this formulation. In order to improve the flexibility of PA6 nanocomposite, a thermoplastic elastomer Kraton® FG1901 G will also be incorporated into this multi-component polymer system.
Injection molded specimens will be prepared for thermal, flammability, and mechanical properties characterization. Flammability properties will be obtained by using UL 94 test and microscale combustion calorimetry (MCC). Scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDX) will be used to study the char residue of flame retardant PA6 nanocomposite after burning. Thermogravimetric analysis (TGA) will be performed to evaluate the thermal stability of the PA6 nanocomposite. Mechanical properties will also be measured using an automated tensile testing system. The optimized formulation of PA6 nanocomposite in terms of synergy between multiwall carbon nanotube, nanoclay, and flame retardants will be further explored and processed by using micro twin screw extrusion.
Flame retardant PA6 nanofibers with the optimized formulation will be fabricated by electrospinning. The morphology of PA6 nanofibers and the uniformity of MWNT dispersion in PA nanofibers will be determined by SEM. The basic mechanical properties will be characterized for PA6 nanofibers as well.