Direct visualization of a strain-induced dynamic stress network in a SEBS thermoplastic elastomer with in situ AFM nanomechanics
Direct visualization of a strain-induced dynamic stress network in a SEBS thermoplastic elastomer with in situ AFM nanomechanics
复制标题
DOI：
10.35848/1347-4065/ab948a
复制
发表时间：
2020-08-01
影响因子：
1.5
通讯作者：
Nakajima, Ken
中科院分区：
文献类型：
--
作者：
Liu, Haonan;Liang, Xiaobin;Nakajima, Ken
热塑性弹性体（TPE）在拉伸后可能会产生残余应变，这阻碍了它们在高性能材料中的应用潜力。然而，迄今为止，残余应变形成的机制尚未得到充分阐明。在这里，我们使用基于原子力显微镜的纳米力学测绘来研究由苯乙烯含量为 15 wt% 的聚（苯乙烯-b-乙烯-共聚-丁烯-b-苯乙烯）（SEBS-15）组成的拉伸 TPE 样品。在保持0.5应变的SEBS-15聚合物结构中，由聚苯乙烯链段聚集的硬链段（HS）无定形域变形并平行于拉伸方向取向，而由聚（乙烯-丁烯）链段聚集的软链段橡胶域伸长，使用HS域作为连接点形成应力网络。此外，对拉伸的SEBS-15进行的原位观察表明，受所形成的应力网络的影响，其中的HS域发生了相对位移和部分分离，这与不可逆现象密切相关。 (C)2020 日本应用物理学会
Thermoplastic elastomers (TPEs) may generate a residual strain after being stretched, which hinders their potential for use in high-performance materials. However, the mechanism of the residual strain formation has not been sufficiently elucidated thus far. Here, we used atomic force microscopy-based nanomechanical mapping to investigate a stretched TPE specimen consisting of poly(styrene-b-ethylene-co-butylene-b-styrene) with a content of 15 wt% styrene (SEBS-15). In the SEBS-15 polymer structure that maintained a strain of 0.5, hard-segmental (HS) amorphous domains aggregated by poly(styrene) segments deformed and became oriented parallel to the stretching direction, whereas soft-segmental rubbery domains aggregated by poly(ethylene-co-butylene) segments elongated, formed a stress network using the HS domains as junction points. Moreover, an in situ observation adopted for the stretched SEBS-15 revealed that HS domains therein underwent a relative displacement and partial separation that was influenced by the formed stress network, which was strongly related to the irreversible phenomena. (C) 2020 The Japan Society of Applied Physics