Hi,

A propos of our earlier discussion, this just came across the wire from the
Society for Appl. Spectroscopy:

TOUR SPEAKER (Society for Applied Spectroscopy) - 4/12/2000 Meeting in
Mountain View

"RAMAN SPECTROSCOPY AS A PROBE OF STRUCTURE/ORIENTATION IN POLYMERIC
FIBERS"

by DR. BRUCE CHASE (DuPont Central Research, Wilmington DE)

at Michaels at Shoreline, Mountain View (Directions to follow)

Register        6:45 PM
Dinner  7:30 PM
Talk    8:30 PM

Cost:  $30 for dinner ($10 students and teachers), free for talk.

Dinner Choices:  (Indicate Choice when RSVP'ing)

Breast of Chicken, Piccata
Chilean Sea Bass, Ginger Shallot Sauce
Grilled Vegetable Brochette with Wild Rice

Reserve by April 10 to Steve Rabin, 650-564-5315 or [log in to unmask]




Also, see our web site at www.sas-ncss.org

ABSTRACT
Polymeric macroscopic properties such as tenacity, modulus, elasticity,
etc. are determined by molecular level effects such as conformational state
populations, orientation, and intermolecular interactions.  Significant
changes occur at the molecular level as a molten or solution phase polymer
is spun into fiber form.  The polymer goes from an unoriented, amorphous
state to an oriented, semi-crystalline material via the deformations
imposed by spinning and drawing.  Raman spectroscopy can potentially
provide information on both structure and orientation.   Changes in band
intensities can be related to conformational populations and to formation
of crystalline regions.  Changes in relative intensities as a function of
incident and scattered polarization yields information on chain
orientation. The use of polarized Raman scattering done in both 90 and 180
degree scattering geometries has been used to determine the second and
fourth order orientation functions for both polyethylene and PET fibers.
Raman measurements have been made in both the laboratory frame and on-line
for  66 nylon and PET fibers. For both PET and 66 nylon, crystallinity
levels and a qualitative measure of orientation can be obtained.