Grafting cellulose nanocrystals with phosphazene-containing compound for simultaneously enhancing the flame retardancy and mechanical properties of polylactic acid

Cellulose nanocrystals (CNCs) can be used as a bio-based carbon source in an intumescent system. However, CNCs have low onset decomposition temperature and decompose carbonize that may adverse impact on performance. We, herein, demonstrated the design of phosphazene-containing (P/N-CNCs) with great thermal stability outstanding charring ability. The TGA results showed initial P/N-CNCs increased from 202.4 to 272.2 °C, residual char at 700 °C 24.9 55.8 wt% comparing CNCs. Then, flame retardant PLA composites were prepared by blending PLA, ammonium polyphosphate (APP), melamine (MPP), aluminum hypophosphite (AHP) piperazine pyrophosphate (PPAP), respectively. stability, properties mechanical investigated. system constructed 7 APP 3 had best effect PLA. PLA/7APP/3P/N-CNCs highest limiting oxygen index value (28.1%), lowest peak heat release rate (266 kW/m2), reached UL 94 V-0 rating. Moreover, tensile strength, strength elongation break improved 7.3%, 18.6%, 29.4%, respectively, these PLA/7APP/3CNCs. This modified provides good It also offers new method for preparation high-performance flame-retardant composites.