Water-Involved Carbon-Nitrogen Triple-Bond Monomer Based Polymerization toward Processable Functional Polyamides under Ambient Conditions.

Abstract

Polyamide plays a pivotal role in engineering thermoplastics. Constrained by the harsh conditions and arduous procedures for its industrial synthesis, developing facile synthesis of polyamides is still challengeable and holds profound significance. Herein, we successfully utilized water as one of the monomers to synthesize functional polyamides under ambient conditions. A powerful multicomponent polymerization of water, isocyanides, and chlorooximes was established in phosphate-buffered saline. Soluble and thermally stable polyamides with high weight-average molecular weights (up to 53 900) were obtained in excellent yields (up to 95 %). The polymerization exhibits unique polymerization-induced emission characteristics, successfully converting non-emissive monomers into unconventional emissive polymers. Notably, the resultant polyamides could undergo effective post-modification via the hydroxyl-yne click reaction. By incorporating various functional groups into the polyamide, its emission color could be fine-tuned from blue to green and to red. Remarkably, the refractive index (n) of the polyamide at 589 nm could be increased from 1.6173 to 1.7227 and the Δn could be unprecedentedly as high as 0.1054 for non-heavy atom-containing polymers after post-modification, and its micron-thick films exhibited excellent transparency in the visible region. Thus, this work not only establishes a powerful polymerization toward novel polyamides but also opens up an avenue for their versatile functionalization.