Ultra‐High‐Molecular‐Weight Polymers Produced by the Immortal Phosphine‐Based Catalyst System

A strong organophosphorus superbase, N‐(diphenylphosphanyl)‐1,3‐diisopropyl‐4,5‐dimethyl‐1,3‐dihydro‐2H‐imidazol‐2‐imine (IAP3) was combined with a sterically encumbered but modestly acidic Lewis acid (LA), (4‐Me‐2,6‐tBu2‐C6H2O)AliBu2 ((BHT)AliBu2), to synergistically promote the frustrated Lewis pair (FLP)‐catalyzed living polymerization of methyl methacrylate (MMA), achieving ultrahigh molecular weight (UHMW) poly(methyl methacrylate) (PMMA) with Mn up to 1927 kg mol−1 and narrow molecular weight distribution (MWD) at room temperature (RT). This FLP catalyst system exhibits exceptionally long lifetime polymerization performance even in the absence of free MMA, which could reinitiate the desired living polymerization after the resulting system was held at RT for 24 h. An immortal FLP system composed of organophosporus superbase and organoaluminum promoted the living polymerization of methyl methacrylate, achieving polymers with medium to ultrahigh molecular weight (Mn up to 1927 kg mol−1) and narrow molecular weight distribution.