Thermal prehistory influence

The thermal prehistory of such cryogenically gelling systems also influences the process dynamics. The kinetic data in Fig. 10b were obtained by conventional freezing of the feeds, i.e., without low-temperature quenching, as mentioned in Sect. 2.2. When the same reaction solutions are subjected to the low-temperature quenching technique to freeze the feeds quickly, one obtains the plots illustrated in Fig.lOc. Here, the decrease in the thiol group content of the polymer is shown during the course of the first 2 h of the reaction. Note that the zero time in these plots... 

The present contribution has shown that the creep behavior of amorphous polymers under the influence of progressing aging can be well described and predicted under any thermal prehistory applying the multiparameter model based on free volume. The only condition necessary is the knowledge of any measured equilibrium creep curve. For each material the multiparameter model with the given set of parameters allows the prediction of the behavior in volume under any complicated thermal history as well. Introducing some additional postulations, the free volume model is adapted to work at low temperatures, i.e., at temperatures below T. Next, the theory should be extended to measurements at still lower temperatures as well as to some other amorphous polymers. 

Voinov, I.D., Influence of thermal and chemical prehistory on the substructure and catalytic activity of cobalt ferrite, PhD dissertation, Moscow State University, Moscow, 1976. 

It has been established that the process of enzymatic destmction of chitosan (CHT) film specimens obtained from acetic acid solution experiences the influence of the prehistory of film formation, including the concentration of acetic acid used for films preparation and the thermal film modification. 

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