Azide/alkyne‐“click”‐reactions on amino resin materials: An LC‐ESI‐TOF analysis

Abstract

This article describes the reaction of amino resins with functional molecules using the azide/alkyne-''click''-reaction, opening a simple chemical modification of amino resins under aqueous conditions. Alkyne-modified melamine-formaldehyde resins are prepared via a direct cocondensation approach using propargylic alcohol (21.6-86.3 mmol) as additive. Subsequently, alkyne-modified mono-, bi-, and trinuclear melamine-species are identified via LC-ESI-TOF methods proving the covalent incorporation of alkyne-moieties in amounts of up to 3.9 mol %. Subsequent modification of the alkynemodified resins was accomplished by reaction of functional azides (octyl azide (1), (azidomethyl)benzene (2), 1-(6-azidohexyl) thymine (3), and 4-azido-N-(2,2,6,6-tetramethylpiperidin-4-yl)benzamide (4)) with Cu(I)Br and DIPEA as a base. The formation of triazolyl-modified MF-resins was proven by LC-ESI-TOF methods, indicating the successful covalent modification of the amino resin with the azides 1-4. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: [4855][4856][4857][4858][4859][4860][4861][4862][4863][4864][4865][4866] 2010

2D-LC/SEC-(MALDI-TOF)-MS Characterization of Symmetric and Nonsymmetric Biocompatible PEOm–PIB–PEOn Block Copolymers

“…Starting from the well-known LCCC conditions of PEO- and PMMA-based polymers, a large variety of different A n B m block copolymers (e.g., poly(ethylene oxide)- b -poly(propylene oxide), polystyrene- b -poly(ethylene oxide), and polystyrene- b -poly(methyl methacrylate)) have been analyzed using either one- or two-dimensional chromatography, ,,− where the block composition varies strongly in their polarities . Especially, the direct coupling of one- and two-dimensional chromatographic methods to mass spectrometry (MALDI and ESI) − has enabled to effectively combine the separation of BCPs based on functionality and hydrodynamic volume (SEC) into an online two-dimensional system, where an orthogonality criterion is fulfilled via distinctive separation mechanisms . Thus, fractions collected and separated in the second dimension (SEC) can be directly split into a MALDI-TOF MS via a sample transfer module or into a ESI-TOF MS by direct online coupling, where the mass spectra are recorded and correlated with the two-dimensional fractions …”

Synthesis and characterization of new photoswitchable azobenzene-containing poly(ε-caprolactones)

“…Subsequently, the polymers were attached to azido functionalized azobenzene dyes via the azide/ alkyne "click" reaction. 50,51 The developed synthetic route is presented in Scheme 1. The rst step for the synthesis of the photoswitchable polymeric compounds was an amidation reaction between a commercially available azobenzene dye (1) and 4-azidobenzoylchloride in the presence of a base (DIPEA) to yield a mono-substituted 4-(azidobenzamido)-4 0 -(amino) azobenzene (2) and a di-substitued 4,4 0 -bis(benzamido) azobenzene (3).…”

Azide/Alkyne‐“Click”‐Reactions of Encapsulated Reagents: Toward Self‐Healing Materials

“…The copper(I)-catalyzed azide/ alkyne-''click''-reaction therefore is often used in polymer science to effect chain-linkage in polymers [32][33][34][35][36][37] as well as crosslinking reactions. [38][39][40] A star-shaped poly(isobutylene) (3) acts as the liquid polymeric component at room temperature due to its low T g (% À80 8C), therefore leading to a high diffusion of the polymer through space. Based thereon, fast reaction kinetics between the low molecular weight alkynes 1 and 2 and the azide-modified poly-(isobutylene) component 3 can be expected.…”