Anomalies of glass transition. Manifestation in fullerene core polystyrenestars

Segmental dynamics around T-g in the 4- and 6-arm fullerene (C-60) core sta r-like polystyrenes with different preset arm lengths was studied by DSC as compared to that in the linear PS and PS/C-60 blend. The 'anomalies' in gl ass transition behavior were found for the stars including both suppression and facilitation of segmental motion, and pronounced dynamic heterogeneity within a transition range. The results are interpreted in terms of breakdo wn of intermolecular cooperativity of segmental motions and PS-C-60 interac tions.