Study on the synthesis of poly(ether-block-amide) copolymer based on nylon6 and poly(ethylene oxide) with various block lengths

摘要

Various segmented block copolyetheramides based on nylon6 (N6) and poly(ethylene oxide) (PEO) with different compositions and block length of the hard and soft segments were synthesized. The effect of composition of the hard and soft segments was studied via FTIR spectroscopy based on the characteristic peak of ester group at wave number of 1730 cm~(-1). The average block length of the hard and soft segments in block copolymers was determined from H-NMR analysis. Differential thermal analysis thermograms confirmed a microphase separated morphology over a broad range of temperature, leading to two separated crystalline domains. An increase in the interconnectivity of the polyamidesegments controlled by chain extension, greatly improved the formation of polyamide lamellae crystals determined by X-ray diffractometry. Atomic force microscopy images indicated different morphologies of dispersed phase in the dominant phase, which plays an important role in their performance for membrane processes.