Search

Conventional synthetic routes to polythioether usually involve either high energy consumption or potential environmental and health impacts, often accomplished under rigorous conditions. Herein, the oxygen–sulfur exchange reaction (O–S ER) of epoxide and thiocyanate has been successfully combined with aqueous anionic ring-opening polymerization (AAROP) of the in situ generated episulfide, and an unprecedented approach referred to as "cascade O–S ER/AAROP" was established to obtain a well-defined hydroxyl-containing linear polythioether having high molecular weight of 58.6 kDa in an open system at 40 °C. Uniquely, thiocyanate can mediate the O–S ER of epoxide to supply an alkaline circumstance for enhancing the nucleophilicity of sulfanion, and also initiate AAROP of episulfide. The reaction mechanism is revealed by real-time monitoring of the reaction process and tracking pH value of aqueous medium, and further verified by capping and extending the living chain end. Organic ammonium salt can dramatically improve the yield and molecular weight of polythioether with narrow dispersity. This work presents a green strategy where AROP efficiently occurs in water, thereby paving a way to achieving linear poly(hydroxyl thioether) direct from epoxide under mild conditions. [ABSTRACT FROM AUTHOR]

Conjugated polyacetylene-based monocyclic and bicyclic polymers were synthesized by blocking-cyclization metathesis polymerization using short ladderphanes as the initial motif and multi-cyclizing unit, and fully characterized to elucidate the cyclic characteristics and good photoelectric properties. Importantly, the molecular topology of rationally designed cyclic polymers was directly observed without a tedious post-modification treatment. [ABSTRACT FROM AUTHOR]

Linear polymers containing pillar[5]arenes as the pendant groups were designed and synthesized via a ring-opening metathesis polymerization. Such polymers could form supramolecular brush polymers and exhibited tunable fluorescence properties based on the host–guest interactions. [ABSTRACT FROM AUTHOR]

A new type of insulating–conductive block copolymer was synthesized by metathesis polymerization. The copolymer can self-assemble into unique nanostructures of micelles or hollow spheres. It exhibits a high dielectric constant, low dielectric loss, and high stored/released energy density due to the strong dipolar and nano-interfacial polarization contributions. [ABSTRACT FROM AUTHOR]