A universal strategy to design recyclable photocrosslinked networks via architecting lignin-derived spiro diacetal...

Precise transformation of renewable resources into high-performance photo-crosslinked resins with degradability remains a daunting challenge. In this work, we employed a renewable bioresource, lignin-derived vanillin, to construct a rigid spiro diacetal trigger, which was further coupled with thermosetting epoxy segments to develop three high-performance functionalized polymers. Several high-performance photosensitive materials with alkali-dissolving patterning and recyclable were innovatively engineered based on these polymers. The introduction of rigid spiro diacetal triggers, which function through a unique degradable mechanism under mildly acidic conditions, is expected to address the "seesaw" issue between high performance and degradability in photo-crosslinked networks. More importantly, the effect of spiro diacetal trigger on the thermo-mechanical properties and photopolymerization kinetics of thus-obtained photosensitive resins was systematically investigated. Consequently, the glass transition temperature and mechanical properties of the spiro diacetal-tailored naphthalene-type photosensitive resin (P-VPNE) are comparable to, or even exceed, those of competing materials. This work provides a universal strategy and valuable insights for the design and synthesis of high-performance degradable electronic packaging coatings, which are essential for a wide range of revolutionary technologies based on lignin derivatives.