Rasterized Infrared Curing of Aromatic Polyester Vitrimers for Additive Manufacturing and Thin Films Enabled by Dynamic Bond Exchange

ABSTRACT

This work presents a rasterized infrared (IR) curing method for Aromatic Thermosetting Copolyester (ATSP) vitrimers driven by dynamic polymer network evolution. ATSP is formed from paired oligomer precursors with acetoxy and carboxyl end groups. Their cure reaction produces acetic acid, which can freely participate in transesterification. To drive this system to cure completion, the precursor is heated with localized IR, which is repeatedly rastered across a target surface. Each IR pulse is a small partial cure event, allowing for a highly tunable process. Quantification of the cure kinetics using thermogravimetric analyses (TGA) establishes a relationship between raster pass count and cure progression. This allows precise determination of a 75% completion threshold for advancing the target temperature of each cure pulse. Dynamic mechanical analysis (DMA) of the optimized cured material finds an enhanced glass transition temperature. Nanoindentation and freestanding film tension tests show no apparent reduction in bulk modulus, hardness, or tensile elastic modulus. Compared to conventional oven curing, the IR raster process reduces cure time from 180 to 33 min. These results demonstrate flexible processing of vitrimers with dynamic covalent networks, offering a path for the integration of high‐performance, self‐healing materials into advanced manufacturing techniques.