Facile synthesis of “digestible”, rigid-and-flexible, and bio-based building block for high-performance degradable thermosetting plastics
Plastics are indispensable in modern society, but non-sustainable sources, releasing hazards during service life, and post-disposal issues put the traditional plastics at risk. Here, we report a “digestible”, rigid-and-flexible and bio-sourced building block for high-performance degradable plastics. The building block was synthesized from bioresources vanillin (lignin derivative) and glycerol through solvent-free acetalization with high conversion rate and high selectivity. It could be extremely rapidly degraded into non-toxic vanillin and glycerol under mild acidic conditions even at similar pH and temperature of gastric juice in human stomach (“digested”), resulting in the outstanding chemical degradability of its corresponding epoxy thermosets, which is beneficial to the recycle. In virtue of the benzene ring, heterocycle, and methoxyl group-related hydrogen bond, the degradable thermosetting plastic showed much higher mechanical properties (stronger and tougher) and comparable thermal properties relative to a commercial high-performance counterpart based on bisphenol A (BPA). Such a favorable performance combination has never been reported for plastics. This bio-derived building block exhibits great potential to be as a sustainable and upgraded alternative to petroleum-sourced aromatic chemicals such as BPA for high-performance plastics.