Microfluidic‐assisted rapid synthesis of high‐molecular‐weight aramid libraries at minutes timescale

Rapid synthesis of high‐molecular‐weight (HMW) aramid remains a huge challenge, because of low iteration optimization of reaction conditions caused by uncontrollable step‐growth polymerization. Herein, for the first time, we develop microfluidic‐assisted strategy to rapidly synthesize HMW aramid libraries at minutes timescale, such as poly (paraphenylene terephthalamide) (M‐PPTA), poly (m‐phenylene isophthalamide) (M‐PMIA) and poly(p‐phenylene‐benzimidazole‐terephthalamide) (M‐PBIA). Due to rapid mass/heat transfer and good fluidic manipulation, the microfluidic‐assisted strategy can realize high iteration optimization of reaction conditions (e.g., residence time, volume flow and reaction temperature) by precisely manipulating step‐growth polymerization to firstly form low‐molecular‐weight (LMW) prepolymers and subsequently synthesize HMW aramid. Benefiting from high iteration optimization of reaction conditions, the aramid libraries prepared by microfluidic‐assisted strategy exhibit higher molecular weight (Mw) and less reaction times than that of traditional strategy (about several hours), which delivers potential in special protection field.