Ultralow Coefficient of Thermal Expansion and a High Colorless Transparent Polyimide Film Realized Through a Reinforced Hydrogen-Bond Network by In Situ Polymerization of Aromatic Polyamide in Colorless Polyimide.

Colorless polyimides (CPIs) are a key substrate material for flexible organic light-emitting diode (OLED) displays and have attracted worldwide attention. Here, in this paper, the dispersion and interfacial interaction of aromatic polyamide (PA) in CPI (synthesized from 4,4'-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 2,2'-bis(trifluoromethyl)benzidine (TFMB)) were significantly improved by in situ polymerization, and colorless transparent macromolecular polyimide composites (CPI-PA) were successfully prepared by PA and CPI. By adjusting the ratio of PA to CPI, a high-performance engineering plastic with excellent film-forming properties was obtained.

Copolymerization of Natural Camphor-Derived Rigid Diol with Various Dicarboxylic Acids: Access to Biobased Polyesters with Various Properties.

In this work, alicyclic (1,3)-1,2,2-trimethylcyclopentane-1,3-dimethanol (TCDM), derived from natural camphor, was copolymerized with linear α,ω-diacids, terephthalic acid (TPA), and 2,5-furandicarboxylic acid (FDCA), affording a series of polyesters with functional properties. 2D NMR spectroscopy revealed that the stereoconfiguration of TCDM was preserved after polymerization. The TCDM polyester based on TPA showed high thermostability, high value (115 °C), high modulus (1.

Copolycarbonates Based on a Bicyclic Diol Derived from Citric Acid and Flexible 1,4-Cyclohexanedimethanol: From Synthesis to Properties.

Octahydro-2,5-pentalenediol (OPD), is a compelling citric acid-based bicyclic diol with excellent rigidity and thermal stability. Herein, a series of copolycarbonates (co-PCs) were synthesized, starting from OPD, 1,4-cyclohexanedimethanol (CHDM), and diphenyl carbonate (DPC). All polycarbonates are amorphous with glass transition temperatures increased when increasing the content in OPD units.