Fig. 2: Influence of chemically uncrosslinked chains on dielectric and mechanical properties.

a Schematic comparison of the polarization process of acrylic elastomer without uncrosslinked chains (ai, aii) and BAC2 sample with a considerable amount of uncrosslinked chains (aiii, aiv). b Gel fraction and swelling ratio of VHB^TM4910 and synthesized elastomers. The insets show the optical images of BAC2 sample before and after swollen. c Elemental analysis comparison between CN9021NS and free chains of BAC2 after swollen. At least three samples were tested for the calculation of average value and standard deviation. d Molecular weight distribution of CN9021NS and free chains of BAC2 after swollen. e Frequency dependence of dielectric constant and dissipation factor (Tan δ_e) of VHB^TM4910 and BAC2 before and after swollen in the range of 10²–10⁶ Hz. f, g Storage modulus (f) and mechanical loss (Tan δ_m) (g) as a function of temperature of VHB^TM4910 and BAC2 before and after swollen. h The cyclic stress–strain curves of VHB^TM4910 and BAC2 at a stretch rate of 100 mm min⁻¹. The area encircled by the curve indicates the dissipated mechanical energy.