Unique thermal behaviors of collective single and few-chain compact globules of isotactic polystyrene

Collective single- and few-chain compact globules of isotactic polystyrene (i-PS) were prepared from very dilute solution via the freeze-drying technique. A small exothermic peak was found in the differential scanning calorimetry (DSC) traces of freeze-dried samples. This is a manifestation of the existence of ‘cohesional entanglements’.