Article
Development of Crystallinity in a Polyurethane Containing Mesogenic Units. 1. Morphology and Mechanism
Macromolecules
(1990)
Abstract
This work extends prior studies of a polyurethane containing mesogenic moieties. Optical
and thermal methods reveal that this polyurethane exhibits monotropic mesomorphic behavior. Two distinct
crystallization mechanisms and crystal morphologies are identified, one arising from the isotropic
melt and producing a spherulitic texture and the other arising from the mesophase and producing a threaded
texture. A combination of thermal analysis, X-ray diffraction, and dynamic rheological studies reveals that
crystals grown from the mesophase are readily perfected to a higher melting form by annealing whereas
spherulitic crystals are less amenable to perfection. The development and perfection of the crystalline
state were also found to be dependent on polyurethane molecular weight.
Keywords
- Development,
- Crystallinity,
- Polyurethane,
- Mesogenic Units,
- Morphology,
- Mechanism
Disciplines
Publication Date
1990
Citation Information
William MacKnight, G. Smyth, E. M. Valles, S. K. Pollack, et al.. "Development of Crystallinity in a Polyurethane Containing Mesogenic Units. 1. Morphology and Mechanism" Macromolecules Iss. 23 (1990) p. 3389 - 3398 Available at: http://works.bepress.com/william_macknight/266/