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The ring opening copolymerization (ROCOP) of epoxides and cyclic anhydrides is one of the most important ways to synthesize polyesters both in industrial and academic fields. Herein, the zeolitic imidazolate framework‐67 (ZIF‐67) was used as a heterogeneous catalyst for the ROCOP of epoxides and cyclic anhydrides without co‐catalyst and initiator. Notably, the obtained polyesters with alternate structures were proved by the 1H NMR spectrum and FTIR spectrum, which indicate the ROCOP is alternatively copolymerized. Kinetic study of the ROCOP of cyclohexene oxide (CHO) and phthalic anhydride (PA) shows that the polymerization reaction is first‐order kinetics. The apparent activation energy (Ea) of the ROCOP of CHO and PA catalyzed by ZIF‐67 was found to be about 104.4 KJ/mol. A possible mechanism of ROCOP of CHO and PA is that the metal Co coordinates with the oxygen atom on the monomer to weaken the C‐O bond thereby opening the ring structure and initiating the copolymerization reaction. In this study, a new system for the copolymerization of epoxide and anhydride catalyzed by heterogeneous catalysts was discovered, which has important guiding significance. [ABSTRACT FROM AUTHOR]

Photo‐induced reversible complexation‐mediated polymerization (RCMP) is a green and economical method to prepare polymers with precise molecular weights, narrow molecular weight distributions and functionally active chain ends. Covalent organic frameworks (COFs) are a promising heterogeneous photocatalyst for mediating RCMP due to their adjustable structure, band gap, and porosity. In this work, 1,3,5‐triformylphloroglucinol (Tp) and p‐azoaniline (Azo) were selected to construct 2D β‐ketoenamine linked Tp‐Azo‐COF as a heterogeneous photocatalyst to trigger RCMP under white light irradiation. A series of polymers with controllable molecular weight and narrow molecular weight distribution were successfully prepared by using Tp‐Azo‐COF as photocatalysis. On/off light experiments confirmed the good spatiotemporal control feature, and chain expansion experiments demonstrated the high "activity" of polymer chain ends. Furthermore, the mechanistic research elucidated that electron transfer between Tp‐Azo‐COF and initiator occurred, allowing the formation of reactive radicals to mediate RCMP. Density functional theory calculations revealed that the coordination of iodine on the initiator to catalyst obviously reduced the bond dissociation energy, leading to enhance in the polymerization rate. This work provides a platform for constructing heterogeneous photocatalysts with more efficient and stable to mediate RCMP. [ABSTRACT FROM AUTHOR]

Surfactants play an important role in the domain of metal anticorrosion. Gemini surfactants, as corrosion inhibitors, have the advantages of strong practicality, high safety, convenient operation and fast response. In this study, a new Schiff‐base cationic Gemini surfactant (named TMPA) was designed, synthesized and characterized. The mechanism of metal anticorrosion of surfactant was studied by electrochemistry and static weightlessness method. And the adsorption isotherm of TMPA shows that the behavior follows Langmuir adsorption isotherm. The anticorrosion efficiency of printed circuit board (PCB) was 92.88% and Q235 carbon steel (Q235 CS) was 97.78% with the addition of only 5 mM TMPA. The surface appearance of the PCB and Q235 CS was scrutinized by x‐ray photoelectron spectroscopy and scanning electron microscopy, proving that samples have few corrosion marks in the presence of TMPA and oxidants. These results show that TMPA provides an attractive application in terms of metal corrosion inhibition. [ABSTRACT FROM AUTHOR]