POLYESTERAMIDES WITH MIXTURES OF POLY(TETRAMETHYLENE OXIDE) AND 1,5-PENTANEDIOL

Segmented polyesteramides have been synthesized from N,N'-bis(p-carbom ethoxybenzoy)butanediamine as crystalline segments and mixtures of pol y(tetramethylene oxide) (mel, wt. 1000) and 1,5-pentanediol as soft se gments. The polymerization was carried out in the melt at 250 degrees C for Ih while Vacuum was applied. The melting behaviour of the copoly mers was studied by differential scanning calorimetry. The mechanical properties were investigated on injection moulded bars, using dynamic mechanical analysis. It was found that the copolymers with more than 5 0% molar ratio pentanediol showed two glass transition temperatures an d two melting temperatures. The glass transition temperatures were not affected by the composition. The melting temperatures increased with pentanediol content. The pentanediol seems in part to be present as ad jacent re-entry groups. The under-cooling for these copolymers was ver y small, which means that these segmented copolymers crystallize very fast. (C) 1997 Elsevier Science Ltd.