PHASE-BEHAVIOR OF SYNDIOTACTIC POLYSTYRENE DECALIN

The phase behaviour of syndiotactic polystyrene-decalin is studied by differential scanning calorimetry, wide-angle X-ray scattering and the rmogravimetric analysis. Both the trans and cis isomers of the solvent have been used. The polymer chain can adopt a helix or a zigzag confo rmation. The formation of these conformations and their relative contr ibution to the crystalline structure depend on the initial concentrati on, the scanning rate and the thermal history of the samples. High coo ling rates and low polymer concentrations tend to favour the formation of the helix structure. The conformational transition from the helix to the zigzag conformation can take place on heating. This depends on the experimental conditions.