Synthesis and properties of thermoplastic elastomers based on PTMO and tetra-amide

Segmented copolymers based on T6T6T-dimethyl (two-and-a-half repeating unit of nylon-6,T) and PTMO or extended PTMO1000/DMT that are thermoplastic elastomers were made via polycondensation. The materials have a good solvent resistance, are melt-processable and transparent. The polymers all have a low glass transition temperature (−60 to −0 °C). The rubbery plateau is wide and extremely flat and the melting temperature is sharp and high. The shear modulus of the rubbery plateau (3.3–14.5 MPa) and the flow temperature (183–220 °C) increase with increasing T6T6T content (5–16 wt%), corresponding to increasing crystallinity. The undercooling, as measured by DSC, is 20–30 °C. The compression set at room temperature is low (6–7%) and decreases slightly with decreasing T6T6T content. With AFM it was shown that the crystalline T6T6T units form long threads or ribbon like structures with a high aspect ratio in the amorphous PTMO matrix.