Modeling polysiloxane volume and viscosity variations with molecular structure and thermodynamic state

Thomas J. Zolper, Manfred Jungk, Tobin J. Marks, Yip Wah Chung, Qian Wang

Research output: Contribution to journalArticle

6 Citations (Scopus)


Siloxane-based polymers (polysiloxanes) exhibit a range of volume, viscosity, and pressure-viscosity behaviors that are strongly influenced by the macromolecular structure. In this report, a combination of extant rheological models is applied to develop a molecular-rheological modeling formalism that predicts polysiloxane rheological properties, such as specific volume, which means density, viscosity, and pressure-viscosity index variations with macromolecular structure, pressure, and temperature. Polysiloxane molecular features are described in terms of alkyl branch length L, pendant type J, density of branch functional monomers Q, and degree of polymerization DP. Both new and published data are used for model parameter determination and validation. Several siloxane-based polymers with alkyl, aryl, alkyl-aryl, cycloalkyl, and halogenated branches were synthesized to examine the modeled relationship between their molecular structures and rheological behaviors.

Original languageEnglish
Article number011801
JournalJournal of Tribology
Issue number1
Publication statusPublished - Jan 1 2014



  • Elastohydrodynamic lubrication
  • Lubricants
  • Rheology
  • Viscosity

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films

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