Design and properties of polyarylene ether nitrile copolymers with improved elongation at break

Advancements and Perspectives toward Lignin Valorization via O-Demethylation

Lignin represents the largest aromatic carbon resource in plants, holding significant promise as a renewable feedstock for bioaromatics and other cyclic hydrocarbons in the context of the circular bioeconomy. However, the methoxy groups of aryl methyl ethers, abundantly found in technical lignins and lignin-derived chemicals, limit their pertinent chemical reactivity and broader applicability. Unlocking the phenolic hydroxyl functionality through O-demethylation (ODM) has emerged as a valuable approach to mitigate this need and enables further applications. In this review, we provide a comprehensive summary of the progress in the valorization of technical lignin and lignin-derived chemicals via ODM, both catalytic and non-catalytic reactions. Furthermore, a detailed analysis of the properties and potential applications of the O-demethylated products is presented, accompanied by a systematic overview of available ODM reactions. This review primarily focuses on enhancing the phenolic hydroxyl content in lignin-derived species through ODM, showcasing its potential in the catalytic funneling of lignin and value-added applications. A comprehensive synopsis and future outlook are included in the concluding section of this review.

Synthesis and properties of polyarylene ether nitrile random copolymer containing naphthalene and biphenyl structure

A novel series of polyarylene ether nitrile (PEN) random copolymers with a higher Tg and better mechanical and electrical properties were synthesized through nucleophilic substitution polycondensation. In the means of adjusting mole ratio of 4,4′-dihydroxybiphenyl (BP) to 2,7-naphthalenediol (ND), the performance of PEN random copolymer could be controlled. The FTIR, SEM, DSC, TGA, AR, intrinsic viscosity, and electrical and mechanical properties were performed on the samples. All the samples exhibited excellent thermal performance with Tg over 210°C, Td5% over 520°C, and heat conduction higher than 0.4 W/m·k. The PEN copolymers when the molar ratio of ND was 15% had the best comprehensive performances, whose Tg was 215°C, Td5% was up to 554.31°C, thermal conductivity was 0.4430 W/m·k, tensile strength was 113.27 MPa, and stable dielectric constant (at frequency from 103 Hz to 106 Hz) was lower than 4. As a result, this PEN copolymer obtained in this paper could provide practical value and possibility in further application in the filed including machine manufacture industry, electronic materials, and automotive industry.