The practical applicability of TMDSC to polymeric systems

The practical applicability and the relevance of a classification of proces ses into three different regimes is examined based on some typical TMDSC ex periments. It is demonstrated that this classification, simply based on the presence and temperature susceptibility of an excess process, is very usef ul to identify and understand phenomena observed with TMDSC. The ability to separate the base-line heat capacity from excess phenomena i s undoubtedly the most valuable feature of TMDSC. Nonetheless, one has to r ealize that this feature is restricted to excess processes that are not sus ceptible to the temperature modulation such as for instance curing and enth alpy recovery. Crystallization and melting processes, on the other hand, ar e susceptible to the temperature modulation and thus the complex heat capac ity is in that case not uniquely determined by the base-line heat capacity. In addition, the strong temperature dependence of the kinetics in combinat ion with the generally large heat flow, imply that the conditions applied a re very critical to obtain a reliable complex heat capacity. In spite of th ese serious limitations it is demonstrated that TMDSC can provide additiona l insight in the crystallization and melting behaviour using (step-wise) qu asi-isothermal measurements (i.e. beta(0)=0) (C) 1994 Published by Elsevier Science B.V. All rights reserved.