Synthesis and Characterization of N -Substituted Polyether- Block -Amide Copolymers

• Published in: Materials Vol. 14; no. 4; p. 773
• Main Authors: Ye, Jyun-Yan, Peng, Kuo-Fu, Zhang, Yu-Ning, Huang, Szu-Yuan, Liang, Mong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 06.02.2021; MDPI AG
• Subjects: crystallinity; N-substituted nylon elastomers; polyamide 6; polyether-block-amide; thermal properties; crystallinity; N-substituted nylon elastomers; thermal properties; polyether-block-amide; polyamide 6
• DOI: 10.3390/ma14040773
• ISSN: 1996-1944

A series of substituted polyether- -amide (PEBA-X%) copolymers were prepared by melt polycondensation of nylon-6 prepolymer and polytetramethylene ether glycol at an elevated temperature using titanium isopropoxide as a catalyst. The structure, thermal properties, and crystallinity of PEBA-X% were investigated using nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, differential scanning calorimetry, wide angle X-ray diffraction, and thermogravimetric analysis. In general, the crystallinity, melting point, and thermal degradation temperature of PEBA-X% decreased as the incorporation of -methyl functionalized groups increased, owing to the disruption caused to the structural regularity of the copolymer. However, in -acetyl functionalized analogues, the crystallinity first dropped and then increased because of a new γ form arrangement that developed in the microstructure. After the cross-linking reaction of the -methyl-substituted derivative, which has electron-donating characteristics, with poly(4,4'-methylenebis(phenyl isocyanate), the decomposition temperature of the resulting polymer significantly increased, whereas no such improvements could be observed in the case of the electro-withdrawing -acetyl-substituted derivative, because of the incompleteness of its cross-linking reaction.