| Popis: |
When referred to polymers, the word morphology is adopted to indicate: crystallinity, which is the relative volume occupied by each of the crystalline phases, including mesophases; dimensions, shape, distribution, and orientation of the crystallites. In this chapter, we describe the morphology of isotactic polypropylene in function of the main variables: temperature, pressure, and flow. This description is carried out not only under the phenomenological point of view but also considering the models which describe the effects of these variables. The chapter describes then the morphology development during injection molding, which is taken as an example of a complex process in which fast cooling rates, high pressures and strong flow fields are involved. A case study in which the simulation of the behavior of polypropylene during injection molding tests is eventually reported. |
