Isothermal crystallization kinetics and melting behavior of in situ compatibilized polyamide 6/Polyethylene-octene blends

We developed in situ compatibilization technology to improve the compatibility between polyamide 6 (PA 6) and polyethylene-octene (POE). In the present work, we investigated the isothermal crystallization and melting behavior of PA 6/POE blends using differential scanning calorimetry (DSC). All specimens exhibited double melting peaks at lower temperature and single melting peaks at higher temperature. The Avrami exponent and equilibrium melting temperature were obtained by analysis of DSC experimental data using the Avrami equation and Hoffman-Weeks theory, respectively. It has demonstrated that the crystallization model of PA 6 for all specimens might be a mixture with two-dimensional, circular, three-dimensional growth with thermal nucleation. We further calculated the nucleation parameter (K _g ) from the obtained crystallization kinetics data using Lauritzen-Hoffmann equation. It was found that the K _g values of the compatibilized PA 6 were lower than that of pure PA 6 whereas increased with the increase of POE content, which was related to the better dispersion of POE and the interaction between PA 6 and the in situ formed POE-g-MAH. Additionally, the spherulite morphology was observed by polarized optical microscopy (POM).