Nonisothermal crystallization kinetics of PA6 and PA6/SEBS-g-MA blends

The non-isothermal crystallization kinetics of neat PA6 and binary blends of PA6/SEBS-g-MA were investigated by means of differential scanning calorimetry at four different coolings rates. Three macro kinetic models, viz. Avrami, Jeziorny and Tobin, were used to describe the non-isothermal crystallization kinetics. Primary and secondary crystallization were analyzed by Avrami equation. The results obtained by Avrami equation suggested that under non-isothermal condition, the mechanism of primary crystallization is more complex, while secondary crystallization showed one to three dimensional crystal growths. Tobin model described the overall crystallization kinetics and results were almost similar to those of Avrami model. The results obtained by Dobreva and Gutzowa method suggested that SEBS-g-MA did not act as a nucleating agent for PA6. Three isokinetic models (Augis-Bennet, Kissinger and Takhore) have been used for the evaluation of the activation energy of non-isothermal crystallization kinetics process. The value of activation energy Delta E slightly increases in the presence of 5, 10, 20 phr content of SEBS-g-MA and then decreases with at 35 and 50 phr contents of SEBS-g-MA. These results showed that up to 20 phr SEBS-g-MA hinder the mobility of PA6 chain segments and at 35 and 50 phr SEBS-g-MA eases the mobility of PA6 chain segments.