Glass transition and dynamics of single and stacked thin films of poly(2-chlorostyrene)

Abstract

The glass transition temperature and the dynamics of the α-process have been investigated using dielectric relaxation spectroscopy for single and stacked thin films of poly(2-chlorostyrene) (P2CS). The stacked film consists of 10 layers of single thin films with thickness of 12 nm or 18 nm. The glass transition temperature T g of the single thin films of P2CS is found to decrease with decreasing film thickness in a similar way as observed for polystyrene thin films. The magnitude of the depression of T g for the stacked thin films is larger than that of the single thin films with corresponding thickness. The depression of the temperature at which the dielectric loss shows a peak due to the α-process at a given frequency, T α, is larger than that of the single thin films, although the magnitude is smaller than that of T g . Annealing at a high temperature could cause the T g and T α of the stacked thin films to approach the values of the bulk system.