报告题目：Potential of the vitrimers as sustainable materials类玻璃体作为可持续聚合物的潜能
报 告 人：Mikihiro Hayashi (Nagoya Institute of Technology, Japan)名古屋理工学院
报告时间：2022年10月14日上午10:00
线上Zoom 会议号： 839 3114 4370
线下报告地点：bat365中文官方网站五山校区北区科技园2号楼324报告厅
前沿软物质学院
华南软物质科学与技术高等研究院
2022年10月8日
报告摘要：
Usually, polymeric cross-linked materials, so-called thermosets, have been suffered from the lack of recyclability due to the formation of covalent bonded cross-links with permanent life time. This defect is very negative, considering the current international trend to seek realization of sustainable societies. To overcome this issue, incorporation of dynamic covalent bonds into network structures is admitted as a useful option, which provides sustainable functions, such as recyclability and healability, with cross-linked materials. Recently, a new type of dynamic covalent bonds has been developed, in which the associative bond exchange without distinct steps of bond dissociation and reassociation are operated (Fig. 1). Such materials have been termed vitrimers since the pioneering work reported by L. Leibler’s group (Science, 334, 965-968 (2011)). In vitrimer network, the dissociation of original bonds occurs exactly after the formation of new bonds, like in the case of SN2-type reaction. At above a certain activation temperature of the bond-exchange, the network starts to be rearranged with keeping the constant cross-link density. Owing to these unique features of the bond exchange manner, vitrimers can be reprocessed without showing sudden flow at high temperatures, where the temperature dependence of viscosity is much weaker than the thermoplastics and follows Arrhenius-type relationship as shown in the inorganic silica glasses. Except the reprocessability, vitrimers can exhibit various useful functions, such as recyclability, healability.In the presentation, I will demonstrate some unique physics of vitrimers and a route for practical application on the basis of our original studies.
热固性高分子通常使用永久共价键进行交联，因此结构比较稳定，一旦成型便难以再回收。这对于社会和环境的可持续发展是极为不利的。为克服这个缺陷，科学家们在高分子网络结构中嵌入动态共价键，从而赋予了网络结构可逆性，使得材料可以被回收和再加工，并具有自愈合性能。近年来，一类新型的动态共价键被广泛嵌入到高分子网络中，该动态键并不具有明显的解离和结合过程，其解离和重新结合的过程是同时发生的，含这类动态键的材料也叫类玻璃体材料(vitrimer)。在特定温度下，动态键交换反应的发生使得高分子网络会发生拓扑结构重整，但却不会改变网络的交联密度，因此在高温下可实现交联高分子的再加工。因此，在这个报告中，我将着重介绍类玻璃体的一些独特的物理性质以及一些相关的实际应用。
报告人简介：
Mikihiro Hayashi received his Ph.D. degree from Nagoya University (Prof. Yushu Matsushita group) in 2015. During his doctor course, he had been selected as a JSPS research fellow (DC2) and experienced researches in ESPCI Paris-Tech (Prof. Ludwik Leibler) and in Shanghai Jiao Tong University (Prof. Xinyuan Zhu). He then re-joined Ludwik Leibler’s group as a postdoc, and experienced another postdoc in Prof. Masatoshi Tokita in Tokyo institute of technology. In 2017, he became an assistant professor in Prof. Akinori Takasu group (Nagoya institute of technology), and currently manages his own laboratory as a PI. His research interest is the design of functional cross-linked materials
Mikihiro Hayashi教授于2015年从日本名古屋大学获得博士学位。读博期间，他受JSPS的资助分别在法国ESPCI Paris-Tech的Leibler课题组和中国上海交通大学朱新远教授课题组进行短期学术研究。获得博士学位后，他分别同法国Leibler教授及东京理工学院的Tokita教授合作进行博士后研究。2017年，他在名古屋理工学院Takasu教授课题组获得助理教授职位。当前他已经是一位独立PI。他的研究兴趣主要集中在功能性交联高分子材料的设计。