Extracting uncrosslinked material from low modulus sylgard 184 and the effect on mechanical properties

Justin D. Glover, Colbi E. McLaughlin, Mary K. McFarland, Jonathan T. Pham

Research output: Contribution to journalArticlepeer-review

44 Scopus citations


Commercial silicone elastomers are commonly used in soft materials research due to their easily tunable mechanical properties. However, conventional polydimethylsiloxane (PDMS) elastomers with moduli below ∼100 kPa contain uncrosslinked free molecules, which play a significant role in their behavior. To utilize these materials, it is important to quantify what role these free molecules play in the mechanical response before and after their removal. We present a simple and inexpensive extraction method that enables the removal of free molecules from a lightly crosslinked sheet of Sylgard 184, a commercially available PDMS elastomer. The materials can contain a majority of free molecules yet maintain a thin and flat geometry without fractures after extraction. Subsequently, we compare the modulus, maximum stretchability, and hysteresis behavior with mixing ratios ranging from 60:1 to 30:1, before and after extraction. We show that the modulus, maximum stretchability, and dissipation increase upon extraction. Moreover, our approach offers a route to prepare crosslinked silicone elastomers with a modulus as low as ∼20 kPa without free molecules from a commercially available kit.

Original languageEnglish
Pages (from-to)343-351
Number of pages9
JournalJournal of Polymer Science
Issue number2
StatePublished - Jan 15 2020

Bibliographical note

Publisher Copyright:
© 2019 Wiley Periodicals, Inc.


  • Young's modulus
  • elastomers
  • free chains
  • interfacial extraction
  • modulus
  • polydimethylsiloxane (PDMS)
  • silicones

ASJC Scopus subject areas

  • Materials Chemistry
  • Polymers and Plastics
  • Physical and Theoretical Chemistry


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