Dielectric Elastomers UV-Cured from Poly(dimethylsiloxane) Solution in Vinyl Acetate

Area of Science:

• Materials Science
• Polymer Chemistry
• Electroactive Polymers

Background:

• Poly(dimethylsiloxane) (PDMS) is a versatile electroactive polymer known for moldability and mechanical strength.
• Its non-polar molecular structure results in low dielectric permittivity, limiting certain electroactive applications.
• Improving dielectric properties is crucial for expanding PDMS utility in advanced materials.

Purpose of the Study:

• To enhance the dielectric permittivity and electroactive properties of PDMS.
• To introduce polar groups into PDMS elastomers using vinyl acetate (VAc) as a crosslinker.
• To evaluate the impact of VAc incorporation and subsequent saponification on PDMS film performance.

Main Methods:

• Synthesis of a high-molecular weight PDMS copolymer with vinyl groups (VPDMS).
• Preparation of VPDMS solutions in VAc and UV curing to form transparent PDMS films.
• Saponification of the UV-cured films to modify their chemical structure and properties.

Main Results:

• UV-cured PDMS films exhibited electromechanical properties comparable or superior to traditional platinum-catalyzed films.
• Saponification significantly boosted electrical and mechanical properties, achieving a dielectric permittivity (ɛ') of ~44.1 pF/m at 10 kHz.
• The modified PDMS films demonstrated a Young's modulus (E) of ~350 kPa and strain (ɛ) of ~320% after saponification.

Conclusions:

• Chemical incorporation of VAc into PDMS main chains is an effective strategy to enhance electroactive properties.
• Saponification of VAc-crosslinked PDMS offers a facile route to significantly improve dielectric and mechanical performance.
• This approach provides a promising method for developing high-performance PDMS-based electroactive materials.