Accession Number:

ADA242570

Title:

Mechanism of DNP-Enhanced Polarization Transfer Across the Interface of Polycarbonate/Polystyrene Heterogeneous Blends

Descriptive Note:

Technical rept.,

Corporate Author:

WASHINGTON UNIV ST LOUIS MO DEPT OF CHEMISTRY

Personal Author(s):

Report Date:

1991-11-14

Pagination or Media Count:

31.0

Abstract:

The same integrated intensity is observed for the interface-PC signal in PC13CPS12C and PC13CPS2D thin film blends in a DNP-difference experiment. This result proves that the dominant mechanism of polarization transfer from the electrons in the PS phase to the protons in the PC phase is by direct polarization transfer. The interface-PC signal intensity arises from a 60-A region which is 2 of the PC film thickness. Minor polarization transfer from the DNP-enhanced protons of PS to the PC protons across the PCPS interface via H-H spin diffusion in PC13CPS12C may also occur. Even in BDPA-doped homopolymers, the enhancement mechanism is mainly via direct solid-effect polarization transfer, a conclusion based on the similarity of the time dependence of the electron-proton polarization transfers for PS and PS2D.

Subject Categories:

  • Plastics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE