Synthesis and nonisothermal crystallization kinetics of thermoplastic polyamide-6 elastomers

摘要

Three kinds of thermoplastic polyamide-6 elastomers (TPAEs) with varying polytetramethyleneglycol (PTMG) contents of 10, 20, and 30 wt % were prepared via a one-pot polymerization synthetic route and named as TPAE1, TPAE2, and TPAE3, respectively. First, their structures were investigated by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, scanning electron microscope, and X-ray diffraction. The obtained results confirmed that targeted TPAEs were successfully synthesized and the unit cell of crystallization in TPAEs with alpha form was confirmed. Subsequently, the thermal properties of prepared TPAEs were characterized by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) measurements, respectively. DSC curves showed that melting points of synthesized TPAEs were in the range of 209.2-215.9 degrees C. Moreover, TGA results showed TPAEs possess good thermal stability and cannot be decomposed under 300 degrees C. Additionally, the modified Avrami's equation, Ozawa's theory, and Mo's method were employed to investigate the nonisothermal crystallization kinetics of prepared TPAEs. It is found that the Mo's method exhibited great advantages in treating the nonisothermal crystallization kinetics of prepared TPAEs. Meanwhile, the crystallization kinetics and halftime are influenced by the contents of PTMG and follows a nonlinear fashion in agreement with the trend inactivation energies calculated by the Kissinger method. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47388.