Visible Light Inspires a Truly “Green” Material with Adjustable Fluorescence

The pollution caused by plastics is becoming increasingly serious. Poly(ethylene furanoate) (PEF), which is synthesized from agricultural and forestry wastes, is the most promising sustainable plastic to replace PET. Here, the copolyester PEFA of linear dicarboxylic acid and PEF is synthesized, and rare green fluorescence was obtained at 530 nm. The aggregation of ester clusters and the aggregation of furan and other electron-rich groups as two fluorescent emission centers undergo fluorescence resonance energy transfer exhibit excitation-dependent fluorescence. The carbon chain length of linear dibasic acid and the ratio of copolymerization have been proved to be two means to effectively regulate the emission wavelength and intensity of copolyester fluorescence. Such a copolyester, synthesized from an already industrialized fully biobased platform, is a truly "green" material. The synthesized copolyester has a maximum tensile strength of 90.9 MPa and a maximum thermal decomposition temperature of 362 °C, showing great potential in the fields of textile, plastic industry, metal ion recognition, biomedicine, and other fields. At the same time, it provides a new platform for a deep understanding of the photoluminescence mechanism of nontraditional intrinsic luminescence polymers and further molecular design.