Accession Number:

ADA282872

Title:

Surface Composition of a Series of Dimethylsiloxane Urea, Urethane Segmented Copolymers Studied by Electron Spectroscopy for Chemical Analysis

Descriptive Note:

Technical rept.

Corporate Author:

STATE UNIV OF NEW YORK AT BUFFALO DEPT OF CHEMISTRY

Report Date:

1994-03-01

Pagination or Media Count:

63.0

Abstract:

Surface composition of a series of segmented polysiloxane urea urethanes have been determined by angle- and energy-dependent ESCA. The polymers are based on aminopropyl end-capped dimethylsiloxane oligomers, isophorone diisocyanate and 1,4-benzene dimethanol. Effects of segmental length and annealing on the surface composition were investigated. It was found that when the average molecular weight of the siloxane segments reaches 27K, the topmost surface region within 18 A of the free surface of a film cast from tetrahydrofuran solution is nearly siloxane phase. To achieve a comparable degree of surface phase enrichment in films of copolymers with siloxane segmental molecular weight of 10K, annealing at 120 deg C for 15 minutes was required. Depth profiles based on these data showed that in as-cast films a siloxane deficient phase several nanometers thick occurs beneath the siloxane surface layer. Annealing increases the thickness of both surface phases

Subject Categories:

  • Polymer Chemistry
  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE