Nanoporous well-defined reversible addition-fragmentation chain transfer polymer of N-acrylamido-l-tryptophan: synthesis and characterization

A nanoporous polymer with a chiral pendant chain of N-acrylamido-l-tryptophan was synthesized through a reversible addition-fragmentation chain transfer polymerization process using a dithiobenzoate derivative as chain transfer agent. The polymerization exhibited the usual characteristics of living processes, though slow polymerization rate and low percentage conversion for a chain extension experiment were observed. Depending on the monomer/chain transfer agent ratio, poly(N-acrylamido-l-tryptophan) with number-average molecular weights between 640 and 4340 g mol(-1) and molar mass dispersities between 1.10 and 1.24 was obtained, as evidenced from gel permeation chromatography. Scanning electron microscopy images indicated that the polymer was porous. Nitrogen adsorption analysis of the polymer evidenced the presence of mesopores (2-19 nm) associated with micropores (0.45-2 nm) according to the Barrett-Joyner-Halenda method with a specific Brunauer-Emmett-Teller surface area of 22.98 m(2) g(-1). (c) 2013 Society of Chemical Industry