Me. Godard et al., ENTHALPY RELAXATION IN POLYMETHYL(ALPHA-N-ALKYL)ACRYLATES - EFFECT OFLENGTH OF ALKYL CHAIN, Journal of polymer science. Part B, Polymer physics, 36(4), 1998, pp. 583-593
In this work, we have investigated by DSC the structural relaxation of
amorphous polymethyl(alpha-n-alkyl) acrylates in which it is possible
to change the length of the alkyl chain. We have evaluated the Naraya
naswamy parameter, x, which controls the relative contribution of temp
erature and of structure to the relaxation time, the apparent activati
on energy, Delta h, and the nonexponentiality parameter, beta, of the
stretched exponential response function. The results suggest that x i
ncreases while Delta h decreases and beta remains constant as the len
gth of the side chain increases. This allows us to comment on the effe
ct of chemical modification on the relaxation kinetics. (C) 1998 John
Wiley & Sons, Inc.