Ye Jyun-Yan, Peng Kuo-Fu, Zhang Yu-Ning, Huang Szu-Yuan, Liang Mong
Department of Applied Chemistry, National Chia-Yi University, Chia-Yi 600, Taiwan.
Department of Footwear Technology, Footwear & Recreation Technology Research Institute, Taichung 407, Taiwan.
Materials (Basel). 2021 Feb 6;14(4):773. doi: 10.3390/ma14040773.
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.
通过在高温下使用异丙醇钛作为催化剂，使尼龙-6预聚物与聚四亚甲基醚二醇进行熔融缩聚反应，制备了一系列取代聚醚-酰胺（PEBA-X%）共聚物。使用核磁共振光谱、傅里叶变换红外光谱、差示扫描量热法、广角X射线衍射和热重分析对PEBA-X%的结构、热性能和结晶度进行了研究。一般来说，随着甲基官能团引入量的增加，PEBA-X%的结晶度、熔点和热降解温度降低，这是由于共聚物结构规整性受到破坏所致。然而，在乙酰官能化类似物中，由于微观结构中形成了新的γ型排列，结晶度先下降后上升。具有供电子特性的甲基取代衍生物与聚（4,4'-亚甲基双（苯基异氰酸酯））发生交联反应后，所得聚合物的分解温度显著提高，而吸电子的乙酰取代衍生物由于交联反应不完全，未观察到这种改善。
