A recyclable, biodegradable and UV-shielding PCL/vanillin-based thermoset fabricated via Knoevenagel condensation

The extensive using of non-degradable plastics has caused serious environmental pollution. To address this issue, this study uses degradable polycaprolactone (PCL) as a raw material,and combines with natural biomass vanillin, it prepare a multi-component biocomposite.This achieving efficient degradation of the material. Meanwhile, the dynamic exchange of C=C bonds, constructed Knoevenagel reaction, enables the recyclable reprocessing of the material. The C=C bonds also expand the conjugate domain of vanillin’s aromatic ring in vanillin, endowing the material with excellent ultraviolet (UV) shielding function..Additionally by adjusting the content of the flexible segment CA-PCL-CA, the mechanical properties of the material are regulated, expanding its application scope. This study is expected to provide new ideas for solving the problems of non-recyclability and heavy environmental burden of traditional thermosetting materials.