MULTIBLOCK POLY(ETHER-ESTER-AMIDE)S BASED ON POLYAMIDE-6 AND POLY(ETHYLENE GLYCOL) .2. EFFECT OF COMPOSITION AND SOFT-SEGMENT LENGTH ON THESTRUCTURE OF POLY(ETHER-ESTER-AMIDE)S AS REVEALED BY X-RAY-SCATTERING

Isotropic unannealed and annealed melt-pressed and quenched samples of segmented multiblock poly(ether-ester-amide)s based on polyamide-6 an d poly(ethylene glycol)s (PEGs) of molecular weights 400 and 1000 with various hard/soft segment weight ratios were investigated. The effect of composition, segment length and annealing temperature on the cryst al structure was studied by differential scanning calorimetry, wide-an gle and small-angle X-ray scattering. In addition to the gamma-phase, one of the unannealed samples having relatively long hard and soft seg ments exhibits a high amount of alpha-phase. This is assumed to be due to the high flexibility of the PEG segments, linking the polyamide bl ocks thus enhancing their mobility. The lack of hydrogen bonds between the PEG segments facilitates crystallization of the polyamide segment s in the more perfect alpha-modification, which is the most pronounced in the above mentioned sample. Part of the gamma-phase transforms int o the alpha-phase upon annealing in all copolymer samples studied, sim ilarly to polyamide-6.