Shape Memory Thermoplastic Polyamide Elastomer Based on PA1212

• Published in: Macromolecular materials and engineering Vol. 308; no. 4
• Main Authors: Fu, Peng, Zhang, Jiahui, Zhang, Yuancheng, Zhao, Wei, Zhang, Xiaomeng, Shi, Ge, He, Yanjie, Cui, Zhe, Pang, Xinchang, Liu, Minying
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.04.2023; Wiley-VCH
• Subjects: Domains; Elasticity; Elastomers; Mechanical properties; Molecular chains; PA1212; Polyamide resins; Robotics; Shape memory; shape memory effect; Smart materials; Smart sensors; Thermal stability; thermoplastic polyamide elastomers; China
• ISSN: 1438-7492; 1439-2054
• DOI: 10.1002/mame.202200547

Shape memory polyamide elastomers have attracted large attention owing to a variety of favorable properties (e.g., designable chemical structure, good thermal stability, flexibility, and elasticity, et al). However, the polyamide elastomer reported recently still lack good mechanical property. In the present work, a new type of shape memory thermoplastic polyamide elastomer (TPAE), composed of long carbon chain PA1212 and polytetramethylene ether glycol (PTMEG), is synthesized through two‐step melt polycondensation, which is named as poly(ether‐b‐amide) (PEBA). The chemical structure of PEBA is confirmed by FTIR results and it also shows excellent mechanical properties. PEBA, possessing two melting temperatures, stay in microphase separation among PTMEG soft domains and PA1212 hard domains that are amorphous and α crystal, respectively. Furthermore, PEBA can fix a temporary shape after the heated strip is twisted and cooled down and then recover to the original shape after secondary heating, which is attributed to the fixing force provided by PTMEG domains and entropy elasticity of physically cross‐linked PA1212 domains, respectively. Besides, PEBA elastomer can be reshaped between ≈190 and ≈380 °C and it also has shape memory behavior. This new kind of TPAE proposes a new smart material for sensors and soft robotics. A new type of poly(ether‐b‐amide) (PEBA) elastomer with excellent mechanical properties, consisting of PA1212 hard segments and polytetramethylene ether glycol (PTMEG) soft segments, is successfully synthesized by a two‐step melt polycondensation method. The crystallization/melting behavior of PTMEG and microphase separation among PA1212 and PTMEG domains endows PEBA with outstanding shape memory property. Besides, the PEBA sample can be reshaped between ≈190 and ≈380 °C and it also has shape memory behavior.