TPE behavior of segmented copolymers with crystallizable esteramide units of uniform length

Segmented polyesteramides are synthesized from N,N'-bis(p-carbomethoxybenzoy)diamine as crystalline segments and poly(tetramethylene oxide) as soft segments. As diamine is mainly taken tetramethylene diamine, but also studied are C6 - C12 diamines. The crystalline segments are uniform in length. The poly tetramethylene oxide segments ranged in molecular weight from 250 - 2900. Also used are tetramethylene oxides with amine endgroups. As extender is sometimes used pentadiol. The polymerization is carried out in the melt at 250 degrees C for 1 hour while vacuum is applied. The melting behavior of the copolymers is studied by differential scanning calorimetry. The mechanical properties are investigated on injection molded bars using dynamic mechanical analysis. The melting temperatures decrease with PTMO length and the length of the diamine. The glass transition temperatures were, for the polytetramethylene oxides of molecular weight of 650 and higher, little affected by the composition. The modulus decreased with PTMO length and the segmented copolymers have very high elongation's at break.