Direct Imaging of Deformation and Disorder in Extended-Chain Polymer Fibers
Abstract
The rigid rod polymers (paraphenylene benzobisthiazole) (PBZT) and poly (paraphenylene benzobisoxazole) (PBZO) can be spun from lyotropic liquid crystalline solutions into solid fibers with extraordinary mechanical properties. However, these fibers are comparatively weak in compression, with deformation occuring by strain localization into kink bands. This report examines the ultrastructure of PBZT and PBZO fibers as a function of processing condition. In particular, High Resolution Electron Microscopy (HREM)is used to directly image structural features such as grain boundaries, dislocations, and the molecular level details of deformation processes. HREM images of PBZT and PBZO enable the quantitative determination of crystallite size, shape, orientation, and internal perfection as a function of processing condition. The nature of the disorder present within and between PBZT and PBZO crystallites is analyzed, modeled, and compared to experimental Wide Angle X-ray Scattering (WAXS) and Selected Area Electron Diffraction (SAED) data. Both PBZT and PBZO exhibit high degrees of orientation on a local scale, yet measurable misorientation does exist.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1991
- Accession Number
- ADA240651
Entities
People
- David C. Martin
Organizations
- University of Massachusetts Amherst