The growth of alpha and beta crystals for melt-crystallized syndiotactic po
lystyrene (sPS) has been studied by the morphological observations of trans
mission electron microscopy and the structural analysis of electron diffrac
tion (ED). The crystallographic textures of alpha and beta single crystals
were identified by the results of ED and polyethylene decorated experiments
. Phase transformation from the alpha" phase to the beta' phase for bulk an
d thin film samples was observed during isothermal crystallization. The tra
nsition was found to occur in the later stage of crystallization as evidenc
ed by the structural analysis of Fourier transform infrared spectroscopy ex
periments combined with the enthalpic measurements of differential scanning
calorimetry experiments. The coexistent alpha " and beta' crystals exhibit
three specific crystallographic correspondences as identified by the appea
rance of three different [00l] zonal ED patterns. The corresponding diffrac
tion results indicate that the alpha" and beta' crystals are both grown as
flat-on type and possess a common c-axis in these structures so as to form
dual-layer lamellar texture. The rearrangement of molecular chains during t
he transition was thus proposed. The initial growth of the metastable alpha
" crystals is attributed to the kinetic effect of crystallization while the
later formation of the beta' crystals results from the tendency to reach a
thermodynamically more stable state. We suggest that the occurrence of the
isothermal transformation is the results of floating chain behavior for sP
S crystalline superstructure.