Crystallization of polymers in variable external conditions. III: Experimental determination of kinetic characteristics

In two recent papers 1,?2] a new model of non-isothermal crystallization kinetics has been proposed. We are discussing now the possibility of experimental determi-nation of material characteristics appearing in the model. These include relaxation time, τ, and athermal nucleation function, B_ath. Two kinds of experiments are discussed: isothermal and non-isothermal, with constant cooling or heating rate. The following approach should be valid for polymers characterized by not too high crystallization rates, like polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT, Corterra^®), polypropylene and others. Preliminary experiments on isotactic polypropylene and polyvinylidene fluoride will illustrate possibilities of the suggested experimental procedures.