Enhancing the electro-mechanical properties of polydimethylsiloxane elastomers through blending with poly(dimethylsiloxane-co-methylphenylsiloxane) copolymers

Abstract

In this work, improved electro-mechanical properties of silicone-based dielectric elastomers are achieved by means of adding so-called "voltage-stabilisers" prepared from phenyl-functional copolymers prepared using oxyanionic ring-opening polymerisation of octamethylcyclotetrasiloxane (D4) and either tetramethyltetraphenylcyclotetrasiloxane (T4) or octaphenylcyclotetrasiloxane (O4). The concentration of the voltage stabiliser was varied both by changing the molar ratio between methyl and phenyl groups in the copolymer and also by varying the amount of copolymer mixed into a PDMS-based elastomer. The phenyl-functional copolymers were generally found to disperse homogeneously in the PDMS matrix and this resulted in networks with improved mechanical and electrical properties. The developed elastomers were inherently extensible with enhanced tensile and tear strengths, due to phenyl-rich microphases acting as reinforcing domains. Furthermore, addition of phenyl-functional copolymers resulted in elastomers with increased relative permittivity and electrical breakdown strength compared to control elastomers while retaining a low dielectric loss. This demonstrates their efficiency as voltage stabilisers.a Phenyl content based on the added phenyl copolymer. b Residual mass fraction of the lm aer extraction and drying. c Mass fraction of the added phenyl copolymer. d Mass fraction of the phenyl copolymer in the extract, calculated from 1 H NMR. e Peak molecular weight of the early eluting peak. f Peak molecular weight relative to the late eluting peak.

Remarkable improvement of the electro-mechanical properties of polydimethylsiloxane elastomers through the combined usage of glycerol and pyridinium-based ionic liquids

“…Thereby, the increased dielectric permittivity is ascribed to the combined usage of ILB and glycerol. [36][37] According to Equation (2), the 100% increase in dielectric permittivity of S184-gly-ILB-5% is beneficial, in that it increases the Fom(DEA) of transducers. Variations in dielectric losses are presented in Figure 5.…”

Octakis(phenyl)‐T8‐silsesquioxane‐filled silicone elastomers with enhanced electromechanical capability

“…resulting in increased relative permittivity and electrical breakdown strength compared to control elastomers, while retaining a low dielectric loss, thus evidencing their efficiency as voltage stabilizers. 29 In a previous work, we used trialkoxysilanes having different organic groups attached to the silicon atom (methyl, phenyl, aminopropyl, chloropropyl and cyanopropyl) in excess as crosslinking agents for polydimethylsiloxane-α,ω-diols and precursors for in situ formation of silsesquioxane (SSQ) domains. It was found that the elastomers crosslinked with the phenyl derivative had significant lower values for dielectric losses compared to similar elastomers with cyan groups.…”

Influence of Surface Modified Nanodiamonds on Dielectric and Mechanical Properties of Silicone Composites

“…Dielectric energy harvesters can provide sustainable energy from the ambient sources, such as ocean waves [8,9,10,11,12] and human motion [13,14], but their efficiency and economic profitability is dependent, among others, on the material-related losses of the elastomeric membrane. Silicone rubber is often used for dielectric energy harvesting, as it possesses low dielectric losses, low mechanical hysteresis, dynamic damping and stress relaxation [15,16]. However, a modification of the material is needed in order to increase the economic profitability of elastomer-based energy harvesters [17].…”

“…However, a modification of the material is needed in order to increase the economic profitability of elastomer-based energy harvesters [17]. A modification of the silicone matrix by covalent attachment of various molecules can not only improve mechanical properties of the material, but also result in lower dielectric losses and better electrical breakdown resistance in dielectric elastomer transducers [16]. Therefore, it is expected that the introduction of NDs into a silicone matrix improves the physical and chemical interactions within the matrix.…”