Dipolar cross-linkers for PDMS networks with enhanced dielectric permittivity and low dielectric loss

• Published in: Smart materials and structures Vol. 22; no. 10; pp. 104002 - 1-11
• Main Authors: Madsen, Frederikke Bahrt, Daugaard, Anders Egede, Hvilsted, Søren, Benslimane, Mohamed Yahia, Skov, Anne Ladegaard
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.10.2013
• Subjects: Crosslinking
• ISSN: 0964-1726; 1361-665X
• DOI: 10.1088/0964-1726/22/10/104002

Dipole grafted cross-linkers were utilized to prepare polydimethylsiloxane (PDMS) elastomers with various chain lengths and with various concentrations of functional cross-linker. The grafted cross-linkers were prepared by reaction of two alkyne-functional dipoles, 1-ethynyl-4-nitrobenzene and 3-(4-((4-nitrophenyl)diazenyl)phenoxy)-prop-1-yn-1-ylium, with a synthesized silicone compatible azide-functional cross-linker by click chemistry. The thermal, mechanical and electromechanical properties were investigated for PDMS films with 0 to 3.6 wt% of dipole-cross-linker. The relative dielectric permittivity was found to increase by ∼20% at only 0.46 wt% of incorporated dipole without significant changes in the mechanical properties. Furthermore, the dielectric losses were proved to be remarkably low while the electrical breakdown strengths were high.