Relaxation processes and phase structure of ester-etheramide copolymers

The results of investigations by DSC and DMTA methods as well as dielectric properties of ester-etheramide copolymers - poly [ester-block-(ether-amide)] (PEEA) built of hard oligoester blocks (PBT) and soft oligoetheramide ones (OEA). Three series of PEEA differing in weight parts and polymerization degrees of hard and soft blocks were evaluated (Table 1). The effects of these variables on the following values were determined: phase transition temperatures (Fig. 1), dynamic mechanical properties (storage modulus, loss modulus and loss tangent - Fig. 2) and on the courses of dielectric relaxation processes (Fig. 3-6). An increase in phase separation has been found with elongation of oligoetheramide chain. The results of all our investigations show that PEEA type materials discussed show the properties typical for multiblock thermoplastic elastomers.