The Use of Small-Angle Light-Scattering (SALS) to Examine the Structure of Fibers 1

Abstract

The small-angle light-scattering (SALS) patterns of a wide range of polypropylene, nylon 6, and polyethylene ter ephthalate (PET) fibers have been examined so as to investigate the level of superstructural (>500 nm) ordering present within them. Many samples that were highly-disordered at a microstructural level, as evidenced by their wide-angle x-ray scattering (WAXS) patterns, showed evidence of extensive superstructural ordering. For example, a rapidly- quenched polypropylene fiber, which exhibited a "smectic" WAXS pattern, had a SALS pattern characteristic of spheru lites about 6 μm in diameter. Brief annealing of this sample produced the conventional monoclinic polypropylene WAXS pattern but did not noticeably change the size or shape of the SALS pattern. The usefulness and limitations of SALS for examining sheath-core effects and for demonstrating the existence of distorted spherulites is also discussed.

References

Carlsson, D.J. , Garton, A. , and Wiles, D.M. , The Weatherability of Polypropylene Monofilaments. Effects of Fiber Production Conditions, J. Appl. Polym. Sci. 21, 2963-2978 (1977 ).

Garton, A. , Stepaniak, R.F. , Carlsson, D.J. and Wiles, D.M. , Some Effects of Melt-Induced Orientation on the Drawing of Polypropylene Monofilaments, J. Polym. Sci., Polym. Phys. Ed. 16, 599-612 (1978).

Gezovich, D.M. and Geil, P.H. , Morphology of Quenched Polypropylene , Polym. Eng. and Sci. 8, 202-209 (1968).

Keller, A. and Mackley, M.R. , Chain Orientation and Crystallization, Pure and Appl. Chem. 39, 195-224 (1974).

Konda, A. , Nose, K. , and Ishikawa, H. , Changes in Light Scattering from Poly(Ethylene Terephthalate) and Nylon 6 Films on Stretching in Relation to Their Deformation Mechanism J. Polym. Sci., Polym. Phys. Ed. 14 , 1495-1512 (1976).

Miles, M. , Petermann, J. , and Gleiter, H. , Structure and Deformation of Polyethylene Hard Elastic Fibers, J. Macromol. Sci. Phys. B12 , 523-534 (1976).

Rhodes, M.B. and Stein, R.S. , Light-Scattering Studies of the Internal Structure of Films and Fibers, ASTM Spec. Tech. Pub. 348, 59-78 (1963).

Samuels, R.J. , "Structured Polymer Properties," J. Wiley, N. Y., 1974.

Stein, R.S. , Misra, A. , Yuasa T. , and Khambatta, F. , Recent Studies of Light Scattering from Polymer Films, Pure and Appl. Chem. 49, 915-928 (1977).

10.

Stein, R.S. , Optical Studies of the Morphology of Polymer Films, Polym. Sci. and Tech. 11, 1-23 (1973).

11.

Stepaniak, R.F. , Garton, A. , Carlsson , D.J. , and Wiles, D.M. , The Characterization of Nylon 6 Filaments by X-Ray Diffraction J. Appl. Polym. Sci. , in press.

12.

Wilkes, G.L. , Rheo-Optical Methods and Their Application to Polymeric Solids J. Macromol. Sci., Rev. Macromol. Chem. C10, 149-255(1974).