Analysis of the modes of packing of the .alpha. and .beta. forms of syndiotactic polystyrene

Abstract

Packing energy calculations have been performed on the α and β forms of syndiotactic polystyrene by using three different sets of potential functions. In the case of the α form the modes of packing of the chains in the R3, P3, R3, and P3 space groups have been considered. In the case of the β form the P2 1 2 1 2 1 and Cmcm space groups have been considered. The results indicate that the energy of the β form is lower than that of the a form for all the space groups considered, while the energies corresponding to the space groups of the a form are very similar. A statistical positioning of the chains can be realised at a low energy cost for both crystalline forms