Thermal properties of ester-amide copolymers with cyclic groups in oligoamide soft segment
Polimery 2002, No 10, 730
Thermoplastic poly(ester-block-amide) elastomers (PEAs) comprising hard blocks of oligoester [oligo(butylene terephthalate), PBT] and oligoamide soft segments [reaction product of l,4-cyclohexanediamine (CHDA) with dimerized fatty acid (DFA)] were synthesized and analyzed by differential scanning calorimetry (DSC). The influence of segments content (ws:wh) and oligoamide block length (DPs) on the glass transition temperature (Tg), melting temperature (Tm) and crystallization temperature (Tc) were examined. Increasing the soft segment molecular weight by reacting DFA with diamine resulted in a decreasing ability of forming a homogenous mixture with the amorphous PBT phase, thus, affecting elastomer properties. PEA containing cyclic group (from CHDA) in oligoamide soft segment exhibits higher temperature transitions contrary to PEA based on l,6-hexamethylenediamine.
Keywords: poly(ester-block-amide), thermoplastic elastomers, soft oligoamide segments, phase transition temperatures, oligoamide cyclic groups