The Effect of Molecular Mass Distribution on Time-Dependent Behavior of Polyamides

Abstract

Abstract In this paper we show that the time-dependent properties of polyamides may be significantly modified by altering the “initial kinetics” of the material through the modification of the molecular mass distribution. In our investigations we have used polyamide 6 (PA6) as a testing material. We have shown that the molecular weight distribution determines the time scale of material structure formation and, hence, its time-dependent properties. The melting temperature of the bimodal molecular mass distribution of polyamide 6 material is shifted for about 30°C towards higher temperatures in comparison to the conventional monomodal molecular mass distribution of PA6. Modification of the molecular mass distribution also improves the time and temperature dependence of the mechanical properties of PA6. It seems that understanding the effect of the molecular weight distribution on the process of material structure formation may well become a new approach in development of new generation polymeric materials.