Accession Number:

ADA237331

Title:

Morphology of Bulk Nylon 6 Subjected to Plane Strain Compression

Descriptive Note:

Interim technical rept. no. 28, 1990-1991,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s):

Report Date:

1991-05-31

Pagination or Media Count:

36.0

Abstract:

The mechanics of deformation of nylon 6 is plane strain compression were elucidated by density measurements, differential scanning calorimetry, polarized light microscopy, x ray diffraction and x ray diffraction pole figures. A deconvolution procedure for separating overlapping x ray diffraction peaks and the amorphous halo was used to generate pole figures for the various alpha and gamma phase reflections exhibited by nylon 6. At compression ratios above 1.6, specimens experienced intense shear stresses at -45 deg and 45 deg with respect to the flow direction. Shear bands were formed most frequently at interspherulitic boundaries. This shearing produced a small volume fraction of gamma phase crystals in samples which originally contained only alpha crystallinity. The x ray diffraction studies showed that gamma phase crystals were oriented with their macromolecular chains along the directions of shear bands. The alpha crystals of nylon 6 underwent extensive deterioration in compression by a chain slip mechanism along the 0 0 2 planes containing hydrogen bonds. Slip also caused the rotation of fragmented lamellae that lead, at high compression ratios, to a peculiar bifurcated orientation state resembling a twinned monocrystal.

Subject Categories:

  • Textiles
  • Crystallography
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE