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No abstract provided.

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 …

No abstract provided.

By following the copolymerization of a model polyurethane system, HTP B D /2,6 (or 2.4 )-TD I /B DO, by

optical microscopy, it was found that initial reactant incompatibility was the key factor in determining the

final morphology of bulk sample. Based on this finding and the esults from the previous paper, models

are proposed to describe the morphology during polymerization of this particular polyurethane system

for several hard segment compositions where both macro-phase separation and micro-phase separation

of reactants can occur during polymerization. The copolymerization of one seemingly compatible

system, PPO-EO/MDl/BDO, which has been previously studied and commercially produced, …

No abstract provided.

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