Self-assembled conjugated polyelectrolyte-surfactant complexes as efficient cathode interlayer materials for bulk heterojunction organic solar cells

Conjugated polyelectrolyte–surfactant cathodic interface layers lead to improved power conversion efficiencies in organic solar cells.</p

Controlled Oxyanionic Polymerization of Propylene Oxide: Unlocking the Molecular-Weight Limitation by a Soft Nucleophilic Catalysis

The oxyanionic ring-opening polymerization of propylene oxide (PO) from an exogenous alcohol activated with benign (complexed) metal-alkali carboxylates is described. The equimolar mixture of potassium acetate (KOAc) and 18-crown-6 ether (18C6) is demonstrated to be the complex of choice for preparing poly(propylene oxide) (PPO) in a controlled manner. In the presence of 18C6/KOAc, hydrogen-bonded alcohols act as soft nucleophiles promoting the PO SN2 process at room temperature and in solvent-free conditions while drastically limiting the occurrence of parasitic hydrogen abstraction generally observed during the anionic ROP of PO. The resulting PPO displays predictable and unprecedented molar masses (up to 20 kg mol−1) with low dispersities (ĐM < 1.1), rendering the 18C6/KOAc complex the most performing activator for the oxyanionic polymerization of PO reported to date. Preliminary studies on the preparation of block and statistical copolyethers are also reported

Organocatalysis applied to the ring-opening polymerization of beta-lactones A brief overview

International audienceOrganocatalysis offers a number of prospects in the polymer community and presents advantages over metal based and bio-organic methods. The use of organic molecules for performing chemical reactions is not a new concept, and any research into organocatalytic reactions builds on a respected history. Compared to the organocatalysis of large lactones, which began in the early 2000s, the examples presented here will demonstrate that few metal-free initiating systems had been applied to beta-lactones well before the beginning of the current millennium. These metal-free initiating systems present indisputable advantages over metal-based processes. In the following paper, ring-opening polymerizations (ROPs) of various beta-lactones for the preparation of poly(hydroxyalkanoate)s will be presented, as will the types of mechanisms involved, that is, zwitterionic and anionic, and cationic or supramolecular-based ROPs. The advantages and drawbacks of the different technics will be discussed in the domain, which, for us, is important in the overall production of bioplastics. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A Polym. Chem. 2019, 57, 657-67

Preparation of a mimetic and degradable poly(ethylene glycol) by a non-eutectic mixture of organocatalysts (NEMO) Via a one-pot two-step process

International audienceA one-pot, two-step method for the preparation of degradable PEG is here presented. The full process addresses the requirements imposed by green chemistry and involves the use of a single and nontoxic non-eutectic mixture of organocatalysts. The strategy relies on the polycondensation of PEG800 after its functionalization by bio-derived 5-membered γ-butyrolactone

Cumulated advantages of enzymatic and carbene chemistry for the non-organometallics synthesis of (co)polyesters

Enzymatic and carbene catalysed ring opening polymerisation can be combined in a one-pot reaction for the metal-free synthesis of degradable block copolymers

Scope and limitations of ring-opening copolymerization of trimethylene carbonate with substituted γ-thiolactones

International audienc

Preparation of highly pure cyclo-polylactides by optimization of the copper-catalyzed azide-alkyne cycloaddition reaction

This work reports on the preparation of highly pure cyclo-polylactides (Mn ≈ 4 000 g • mol-1) by the optimization of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction applied on α-azide-ω-alkyne linear polylactide (PLA) precursors. By adjusting parameters such as the rate of reactant addition and the catalyst loading, monocyclic PLA's with a degree of purity of 93 % are obtained in few minutes. Highly pure monocycles (purity as high as 99.9 %) are also possibly prepared in few hours.Opisano optymalizację syntezy cyklopolilaktydów w katalizowanej miedzią(I) reakcji cykloaddycji azydku do alkinu (CuAAC), której celem było uzyskanie polimerów o wysokiej czystości iśrednim ciężarze cząsteczkowym Mn ≈ 4 000 g • mol-1. Do reakcji użyto prekursorów, którymi były liniowe α-azydo-ω-alkinowe polilaktydy (PLA). Dobrano warunki syntezy, takie jak szybkość dodawania reagenta oraz ilość używanego katalizatora, które pozwalają na otrzymanie w ciągu kilku minut monocyklicznego PLA o stopniu czystości 93 %. Prowadząc syntezę w ciągu kilku godzin można otrzymać monocykliczny polimer o czystości do 99,9 %

Otrzymywanie cyklopolilaktydów o wysokiej czystości poprzez optymalizację katalizowanej miedzią cykloaddycji azydek-alkin

This work reports on the preparation of highly pure cyclo-polylactides (Mn ≈ 4 000 g • mol-1) by the optimization of the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction applied on α-azide-ω-alkyne linear polylactide (PLA) precursors. By adjusting parameters such as the rate of reactant addition and the catalyst loading, monocyclic PLA's with a degree of purity of 93 % are obtained in few minutes. Highly pure monocycles (purity as high as 99.9 %) are also possibly prepared in few hours.Opisano optymalizację syntezy cyklopolilaktydów w katalizowanej miedzią(I) reakcji cykloaddycji azydku do alkinu (CuAAC), której celem było uzyskanie polimerów o wysokiej czystości iśrednim ciężarze cząsteczkowym Mn ≈ 4 000 g • mol-1. Do reakcji użyto prekursorów, którymi były liniowe α-azydo-ω-alkinowe polilaktydy (PLA). Dobrano warunki syntezy, takie jak szybkość dodawania reagenta oraz ilość używanego katalizatora, które pozwalają na otrzymanie w ciągu kilku minut monocyklicznego PLA o stopniu czystości 93 %. Prowadząc syntezę w ciągu kilku godzin można otrzymać monocykliczny polimer o czystości do 99,9 %