M. Sikka et al., MELT INTERCALATION OF POLYSTYRENE IN LAYERED SILICATES, Journal of polymer science. Part B, Polymer physics, 34(8), 1996, pp. 1443-1449
We have studied the melt intercalation of polystyrene into organically
modified sodium bentonite, a layered, mica-type silicate, using a var
iety of techniques. Wide-angle X-ray scattering experiments on polymer
/silicate hybrid samples demonstrate that intercalation of polymer cha
ins leads to an similar to 25% increase in the spacing between silicat
e layers. The magnitude of this increase, compared with the radius of
gyration of the melt polymer, implies a flattened conformation of chai
ns in the galleries. Low voltage scanning electron microscopy reveals
voids in the intercalated hybrid matrix that correspond to regions whe
re pristine polymer was present in the physical mixture of polymer and
silicate before intercalation. Differential scanning calorimetry show
s that only unintercalated polymer contributes to the measured glass t
ransition trace, so that the magnitude of the trace is diminished upon
intercalation. (C) 1996 John Wiley & Sons, Inc.