Development of flame retardant and antibacterial nanoparticle doped polypropylene fibers

The present study aimed to produce flame retardant (FR) and antibacterial nanoparticle doped polypropylene (PP) fibers containing phosphorus-based flame retardants (PBFRs). The synergistic effect of inorganic FR additives (Aluminum trihydroxide (ATH), zinc borate (ZnB), nano-silica (nano-SiO2), and carbon nanotube (CNT)) on the flammability of PBFR/PP systems were investigated to reduce the total amount of FRs which is essential for fiber spinning. Two different PBFRs, ammonium polyphosphate-based (APP) and cyclic phosphonate-based (CPP), were studied. In addition to the antibacterial additives (nano-cupric oxide (nano-CuO) and zinc oxide (ZnO)), a coupling agent (MPA) and a hindered amine light stabilizer (HAS) were also used in the FR formulations. Thermal properties and flammability of the prepared composites were determined by limiting oxygen index (LOI), thermogravimetric analysis (TG-DTG), cone calorimeter test and micro combustion calorimetry (MCC). All combinations of HAS and CPP showed a synergetic effect by acting with a gas phase mechanism. Only synergistic effect on PP/CPP/HAS system was found with nano-CuO resulting in an increase in LOI. Antibacterial analysis showed that only nano-CuO containing fibers had antibacterial activity. Flame retardant and antibacterial nanoparticle doped PP fibers were produced successfully by melt spinning at the loading of additives up to 5.5 wt%. Keywords: Technical textile, Flame retardant, Halogen-free, Polypropylene, Fiber