Diffusion and equilibrium swelling of macromolecular networks by their linear homologs

✍ Scribed by Gent, A. N. ;Tobias, R. H.

• Book ID: 105334248
• Publisher: Wiley (John Wiley & Sons)
• Year: 1982
• Tongue: English
• Weight: 611 KB
• Volume: 20
• Category: Article
• ISSN: 0098-1273
• DOI: 10.1002/pol.1982.180201212

✦ Synopsis

Abstract

Polydimethylsiloxane (PDMS) networks having strands of molecular weight in the range 11,000–36,000 have been prepared by endlinking linear PDMS molecules of these molecular weights with a tetrafunctional linking agent. Absorption of a series of homologous linear PDMS molecules by the resulting PDMS networks has been investigated. The diffusion coefficients at 70°C were found to be rather large, 1 × 10^−12^–6 × 10^−12^ m^2^/s, and approximately inversely proportional to the molecular weight of the diffusing liquid, over the range 5000–38,000. The amount of liquid absorbed at equilibrium was relatively small, 10–80%, in good agreement in all cases with an especially simple version of the Flory–Huggins theory when the heat of mixing is made vanishingly small and only entropic terms are retained.