Super-Low-Addition Biobased Flame Retardant Dedicated to Polylactic Acid through Ionic Reaction between Phytic Acid and Taurine

The fully biobased flame retardant, which is based on the green and convenient ionic reaction of phytic acid (PA) and taurine (TA) in water, brings flame retardancy to polylactic acid (PLA) efficiently. PLA composite passes UL-94 V-0 rating in vertical combustion successively with only 0.5 wt % reactant of PA and TA (PA-TA). Moreover, the peak heat release rate (PHRR) and the total heat release rate (THR) of PLA composite are reduced by 13.1 and 10.0% with 5.0 wt % PA-TA. Moreover, the elongation at break of PLA with 5.0 wt % PA-TA is 92.7% higher than that of pure PLA due to the ultralow addition and the interaction of hydrogen bonds between the flame retardant and the matrix material. The resultant fully biodegradable flame-retardant PLA composites reported here could be widely applied in electronic appliances, automobiles, and other fields.