COMPUTATIONAL MODELING OF PROCESSINGFLOWS OF CARBONACEOUS MESOPHASES

摘要

Carbonaceous mesophases are liquid crystalline precursor materials that can be spun into high performance carbon fibersrnusing the conventional melt spinning process. The melt spinning process can be considered as a flow cascade consisting ofrnpressure driven flow-converging die flow-free surface extensional spinline flow, that modifies the precursor molecularrnorientation structure at several length scales. Carbon fiber property optimization requires a better understanding of thernprinciples that control the structure development during the fiber formation processes and the rheological processingrnproperties. This paper presents the elastic and continuum theory of liquid crystals and computer simulations of structurernformation for pressure-driven flow of carbonaceous liquid crystalline precursors used in the industrial carbon fiber spinningrnprocess. The simulations results capture successfully the formation of characteristic fiber macro-textures and its non-rnNewtonian rheology.