Micromechanical properties of polyether block amide copolymers

A series of polyether block amide copolymers based on poly(tetramethylene oxide) of molecular weight 1000 or 2000 and polyamide 12 of molecular weight between 600 and 4000 with varying PE/PA weight ratio (from 80 to 20%) were studied by using dynamic mechanical spectroscopy and differential scanning calorimetry. Dynamic mechanical experiments showed three main relaxation peaks related to, the subglass transition of the soft segments, the glass transition of the soft segments, and the glass transition of the hard segments. A quench, carried out on a 70% PA copolymer from 110 to 15°C, leads to a decrease in the storage modulus. This result should be related to the destruction of physical ties.