Fluoro-containing Polysiloxane Thermoset with Good Thermostability and Acid Resistance Based on the Renewable Multifunctional Vanillin

Vanillin, the only available aromatic biomass in industrial scale derived from lignin, has been transformed to a fluoro-containing polysiloxane thermoset for the first time based on its multifunctional nature. Conventionally, the methoxy groups in vanillin are always ignored in the preparation of polymers, whereas in this work the groups are efficiently utilized to polymerize with a commercially available disiloxane through the Piers-Rubinsztajn reaction in the presence of B(C6F5)(3) (0.1%) at room temperature. Furthermore, the incorporation of thermally polymerizable trifluorovinyl ethers (TFVE)s into the polysiloxane main chain imparts good thermostability and acid resistance to it. In addition, the cross-linked fluoro-containing polysiloxane also exhibits low dielectric constant and good transmittance. Considering the widespread existence of methoxy groups in natural feedstocks and the good performance of the new fluoro-polysiloxane thermoset, the strategy we developed may provide a new method for the application of biomass in the near future.