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Polypeptoids, consisting of nitrogen-substituted analogues of polypeptides, have become a real asset in modern sciences especially in the biomedical field. To address the increasing demand for polypeptoid structures with specific properties, this work explores the combinatorial character of the Ugi-four component polymerization of amino acid derivatives such as dipeptides and aminobutyric acid compounds with different aldehydes and isocyanides. A library of structurally diverse polypeptoids is prepared accordingly. Thermal and solution properties of the latter are characterized and discussed in a structure–property relationship approach highlighting the impact of both the backbone and side chains. Some materials demonstrate pH-responsiveness, thermo-responsiveness with tunable transition temperatures and biocompatibility. Given the great variety of possible substrates and the promising properties of the obtained polypeptoids, this straightforward and combinatorial strategy is attractive for the future development of polypeptoids and resulting applications.

Recent advances in organometallic-mediated radical polymerization led to unique α,ω-difunctional poly(vinyl acetate) (PVAc) and ethylene/vinyl acetate copolymers (EVA). A copper-catalyzed Huisgen dipolar cycloaddition ring-closure reaction was applied to these difunctional precursors paving the way to unprecedented PVAc and/or EVA macrocycles, and to their PVOH- and EVOH-counterparts after hydrolysis.

In this study, poly((S)-3-(3′,7′-dimethyloctyl)thiophene) is synthesized via KCTCP, using a catechol-based external Ni-initiator. After characterization, the polymer's catechol functionality is deprotected and coupled with magnetite nanoparticles and the supramolecular organization is studied using UV/Vis, CD, AFM and Faraday measurements. We conclude that no long range supramolecular ordering is present in the hybrid material and that only interchain interactions between polymer chains attached on different nanoparticles are present. Also the effect of the new initiator and the branched monomer side chain on the controlled character of the KCTCP is investigated. It is found that a methyl group on the 3-position of the monomer sidechain already affects the controlled character of the polymerization. Also, a mechanism for the observed effects of the branched monomer and the new catechol-based initiator on the controlled character of the polymerization is proposed.

Linear polystyrenes carrying a mid-chain triazole, esters as well as terminal secondary bromines functionalities were synthesized via activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) using a bifunctional triazole containing initiator (3.8 kDa ≤ Mn,SEC ≤ 125 kDa, 1.08 ≤ ≤ 1.19) with the aim of understanding their behavior under thermal and thermomechanical stress. As reference materials-isolating the influence of individual functional groups-three polystyrene homopolymers carrying an ω-bromine chain-end functionality, α,ω-ester-bromine functionalities as well as α,ω-dibromine/mid-chain ester functionalities (2 kDa ≤ Mn,SEC ≤ 39 kDa, 1.06 ≤ ≤ 1.08) were prepared via ARGET ATRP. Furthermore, a well-defined triazole mid-chain functionalized block homopolymer, i.e. polystyrene-b-polystyrene (PS-b-PS, Mn,SEC = 4.4 kDa,= 1.08), was synthesized via a combination of ARGET ATRP and copper(i)-catalyzed azide-alkyne cycloaddition (CuAAC) as a reference material. Reference polymers without bromine and with ester/triazole functionalities were additionally investigated. Thermomechanical stress was applied to the polymers via small scale extrusion as well as a rheological assessment (G′(t), G′′(t)) under processing conditions. The thermally challenged polymers were analyzed by size-exclusion chromatography (SEC), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS), proton nuclear magnetic resonance (1H NMR) and X-ray photoelectron spectroscopy (XPS) to arrive at a detailed image of the degradation susceptibility of individual functional groups, especially esters, bromines and triazole functions. The findings indicate an enhanced degradation of ATRP polymers via an accelerated ester cleavage due to HBr release at high temperatures accompanied by a concomitant molecular weight increase due to the formation of triazolium salts via the reaction of triazole units with bromine terminal chain ends. This journal is © The Royal Society of Chemistry 2015.

International audience; A tandem mass spectrometry-based method is developed to determine the degree of purity achieved in the cyclization of a linear poly(L-lactide) prepared by copper-catalyzed alkyne-azide cycloaddition. When proton nuclear magnetic resonance, size-exclusion chromatography, and single-stage mass spectrometry are unable to demonstrate the presence of a residual linear polymer, the proposed ESI-tandem mass spectrometry methodology allows detection of starting material traces (

We describe a simple and facile method for quantitatively converting bromine end-groups of well-defined polystyrene (PS, Mn,SEC = 4000 Da, Đ = 1.08) prepared by activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) into terminal alkenes by heating at 100 °C in dimethylformamide (DMF) without additional reagents. Subsequently, a facile quantitative post-functionalization of the terminal double bonds to various end functional polymers was performed via light-induced thiol–ene reactions. The quantitative end-group modifications as well as their thermal stability were assessed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS), nuclear magnetic resonance (1H NMR) spectroscopy and size-exclusion chromatography (SEC), evidencing the generated functional polystyrenes to be highly stable up to 200 °C for extended periods of time (24 h).

The ring-opening polymerization (ROP) of L-lactide in dichloromethane with (+)-sparteine is described. Under aprotic conditions, (+)-sparteine leads to controlled cyclic polyesters mainly obtained by a backbiting process from the in situ generated tertiary amine-containing symmetrical binary zwitterion.

The synthesis of poly[(4,4′-(dihexyl)dithieno(3,2-b;2′,3′-d)silole)] has been carried out through Kumada catalyst transfer polycondensation and its copolymerization with 3-hexylthiophene (3HT) leads to well-defined diblock copolymers in terms of molecular characteristics. These copolymers show a wider absorption window than P3HT, which is of potential interest for photovoltaic applications.