Preparation of Poly(guaiacol methacrylate-methyl methacrylate) Dielectric Films through Biobased Origin Guaiacol

Film capacitors make extensive use of polymer dielectrics. However, most of the currently studied dielectric film substrate feedstocks are from fossil energy sources. Herein, a series of biobased dielectric copolymers poly(guaiacol methacrylate-methyl methacrylate) [P(GEMA-MMA)] originating from the biobased origin guaiacol have been reported. P(GEMA-MMA) was produced by copolymerizing GEMA and MMA. Anew type of dielectric film with excellent comprehensive performance was obtained. The guaiacol structure in the copolymer has higher HOMO levels that could take charge traps and capture free charge carriers in the polymer, thus endowing the polymer with excellent energy storage performance. P(GEMA-MMA)-1:7 possess a high breakdown strength Eb of 710.5 MV/m at room temperature, which was 32.5% higher than that of pure PMMA. The charge–discharge efficiency was 87.0% at 500 MV/m, which was much higher than that of pure PMMA (70% under 500 MV/m). Even at 100 °C, the energy storage efficiency of P(GEMA-MMA)-1:7 still can be maintained at a high level of 84.7%. This work offers a practical method for producing biobased dielectric films with outstanding all-round performance.