Thermal studies on melting and crystallization of polyamide fibres

Abstract

Effect of heating rate on melting and crystallization of polyamide fibres has been examined using differential scanning calorimetric (DSC) technique. Peak temperature for melting (T_m) and crystallization (T_k) get suppressed with the increase in the heating rate which has been explained on the basis of chain orientation. Heat of melting (ΔH_m) and crystallization (ΔH_k) have been measured. ΔH_m vs. T_m shows a nonlinear dependence which has been explained on the basis of entropy change. Quantitative difference in ΔH_m and ΔH_k values has been explained on the basis of orientation and degradation of the polymer.