Sub-θ Hydrodynamic Behavior of Poly(α-methylstyrene) in Cyclohexane

Nikolaos Hadjichristidis, J. S. Lindner*, J. W. Mays, W. W. Wilson

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

The hydrodynamic properties of poly(α-methylstyrene) (PaMS) in cyclohexane from 16 °C below the θ temperature to 10 °C above θ have been investigated by dilute-solution viscometry and photon correlation spectroscopy. Seven near-monodisperse samples covering the range 5.9 × 104 ≤ Mw ≤ 3.41 × 106 were used. These data have been analyzed with regard to chain contraction below θ (the so-called “coil-globule” transition). No evidence for the existence of a globular state was found. It is found that the temperature dependencies of chain contraction parameters, based on the intrinsic viscosity [η] and the hydrodynamic radius Rh, can be expressed in terms of master curves of α3∣τM1/2 versus ∣τIM1/2, where α is the chain expansion or contraction factor (from [η] or RH), τ is the reduced temperature (τ = (T - θ)/θ), and M is molecular weight. An asymptotic region (plateau), generally associated with the collapsed state, is reached with the Rh data and approached with the [η] data. Attainment of the plateau occurs at higher values of αη3∣M1/2 than for αh3|τ|M1/2, where αη, and αH are, respectively, [η]- and Rh-based contraction factors. For polystyrene the reverse order has been observed. These results suggest a strong dependence of polymer contraction on chemical structure.

Original languageEnglish (US)
Pages (from-to)6725-6729
Number of pages5
JournalMacromolecules
Volume24
Issue number25
DOIs
StatePublished - Dec 1 1991

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint

Dive into the research topics of 'Sub-θ Hydrodynamic Behavior of Poly(α-methylstyrene) in Cyclohexane'. Together they form a unique fingerprint.

Cite this