@article{VacogneSchlaad2017, author = {Vacogne, Charlotte D. and Schlaad, Helmut}, title = {Controlled ring-opening polymerization of alpha-amino acid N-carboxyanhydrides in the presence of tertiary amines}, series = {Polymer : the international journal for the science and technology of polymers}, volume = {124}, journal = {Polymer : the international journal for the science and technology of polymers}, publisher = {Elsevier}, address = {Oxford}, issn = {0032-3861}, doi = {10.1016/j.polymer.2017.07.062}, pages = {203 -- 209}, year = {2017}, abstract = {The mechanism of the primary ammonium/tertiary amine-mediated ring-opening polymerization of gamma-benzyl-L-glutamate N-carboxyanhydride (BLG-NCA) was investigated. Kinetic analyses revealed that the normal amine mechanism (NAM) together with a dormant-active chain end equilibrium were responsible for the controlled nature of this polymerization pathway, but that the polymerization also proceeded via the activated monomer mechanism (AMM). Mixtures of primary amines (1 equiv) and tertiary amines (0-1.5 equiv) were therefore tested to confirm the co-existence of the NAM and AMM and determine the limits for a controlled polymerization. For tertiary amine molar fractions smaller than 0.8 equiv, the reaction times were greatly reduced (compared to primary amine-initiated polymerization) without compromising the control of the reaction. Hence, the polymerization of NCA can proceed in a controlled manner even when the AMM contributes to the overall chain growth mechanism. (C) 2017 Elsevier Ltd. All rights reserved.}, language = {en} } @article{SeckerRobinsonSchlaad2015, author = {Secker, Christian and Robinson, Joshua W. and Schlaad, Helmut}, title = {Alkyne-X modification of polypeptoids}, series = {European polymer journal}, volume = {62}, journal = {European polymer journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2014.08.028}, pages = {394 -- 399}, year = {2015}, abstract = {Poly(N-propargyl glycine) (PNPG) can be readily prepared by ring-opening polymerization of N-propargyl glycine N-carboxyanhydride (NCA) and modified using various addition reactions such as copper catalyzed [3+2] cycloaddition of azide, radical (photo-)addition of thiol, nucleophilic addition of ethylene oxide, and thermal induced cross-linking. It is demonstrated that PNPG can serve as a modular platform to produce a bibliography of novel functional polypeptoid or pseudopeptide materials, including polypeptoid ionic liquids and graft copolymers.}, language = {en} }