Engineers at DSM Research, Geleen, The Netherlands, have developed models to show the process of disintegration of an array of parallel, closely spaced molten polymer threads in a matrix of another molten polymer. This has been difficult in the past because thermoplastic polymer blends often exhibit different microstructures as they have different melting points and different viscosity levels.
According to the researchers, P.H. M. Elemans, J.M. van Wunnik, and R.A. van Ram, understanding this process has an important, practical implication in any given blend system that consists of immiscible polymers. Their experiments revealed that the simultaneous breakup processes of liquid cylinders, which are surrounded by others, are slightly different from the breakup process of a single, liquid cylinder of comparable diameter. They observed that the beginning of the large-amplitude distortions is delayed in the presence of neighboring threads. For the threads to exhibit sinusoidal distortions, however, the surrounding liquid has to be deformed, but periodic distortions along neighboring threads have to be initiated as well. Once this "accommodation stage" has been completed, the growth rate of the distortions is the same for all threads, regardless of their position inside or outside the array.
More information about their work appears in the June issue of the AIChE Journal.
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