High-Performance Biobased Electronic Packaging Coatings Enabled by Unlocking the Photo-Cross-Linking Capacity of Lignin-Derived Epoxy Resin

Substantial interest in producing thermosets and photoresponsive chemicals from bioresources is garnering, yet moderate performance drastically confines their applicability in electronic packaging material. Herein, several thermosetting epoxy building blocks from lignin-derived monomers (vanillyl alcohol and eugenol) were constructed, and a range of lignin-based enhanced photocurable resins were further developed using acrylic acid and tetrahydrophthalic anhydride as modifiers by an one-pot synthesis method. The comprehensive performance of lignin-based functionalized photocurable resins was systematically investigated, such as their photopolymerization behavior, thermal–mechanical properties, and electrical breakdown properties. As a result, the biobased thermosetting resin stemming from vanillyl alcohol monomers fulfilled fascinating heat resistance (Tg ≈ 103.9 °C) and tensile strength (28.89 ± 4.39 MPa). Additionally, inspired by a tunable chain-extending tactic, the toughness and electrical breakdown strength of the biobased photo-cross-linked films were further intensified by the insertion of flexible alkyl chain segments between cross-linked sites. As proof of concept, the formulated EAAT green ink, consisting of photocurable resin and inorganic, demonstrated a superior patterning ability after alkali development. The rationally designed lignin-derived photo-cross-linked network strengthening mechanism reported here offers an important and universal strategy for significantly enhancing the comprehensive properties of biobased photocurable materials.