Next: Rheological Measurement Up:
Experimental
Previous: Experimental
Materials.
Two polymers are used in this study. Polyamide-6 (PA-6) was purchased from Polysciences Inc. (Mn =
16 000).17 Polystyrene (PS) was donated from Dow Chemicals
(Styron 666D) . The reason for choosing the nylon/PS system
is that the nylon thread can be embedding into the PS phase
without deforming (or flattening) it. If we had chosen a system
such as PS/PMMA or PS/PP, it would be very difficult to embed
the thread into the matrix without deforming it because the
threads would be soft at the temperature at which PS can flow
and vice versa. However, at just below melting temperature
of nylon (for example, 200 
C), PS can flow easily and nylon is
still hard, allowing the embedding process. Degradation of
nylon is not serious because it is fully covered with PS and
nylon does not contact oxygen direction; also, the instability
process is normally completed within 30 min.