ON THE CLATHRATE FORMS OF SYNDIOTACTIC POLY(P-METHYLSTYRENE)

A classification for clathrate structures of syndiotactic poly(p-methy lstyrene) in two classes (alpha and beta), on the basis of X-ray diffr action analyses as well as of the different observed behavior with res pect to the thermal and acetone treatment, is presented. A structural correlation between alpha and beta class clathrates and forms I and II , respectively, is evidenced. it is also suggested that form I and for m II could be the ''emptied forms'' of the alpha and beta class clathr ates, respectively. Similar steric hindrance of the molecules inducing clathrate structures, within each class has been observed.