Super Stretched Polymers With A Stretch Ratio Of More Than 104 Times

Good stretchability is essential for polymer applications in flexible electronic devices, actuators and energy storage. Building dual networks, nano hybridization and dynamic chemistry is a common strategy to improve polymer tensile properties. Among them, dynamic polymer networks constructed by dynamic interactions have attracted wide attention. The dynamic crosslinking point can effectively prevent the irreversible failure of polymer materials through reversible fracture or dynamic exchange of dissipated energy, thereby achieving high tensile properties.

Zhao Ning, a research fellow of the Chinese Academy of Sciences Institute of chemistry, proposed a strategy for obtaining super tensile properties by using strong and weak dynamic bonds. They use weak ionic hydrogen bonds and strong imine bonds to crosslink polybutadiene (PB). During stretching, a small amount of imine bonds are used to maintain the network structure and avoid irreversible destruction, while a large number of ionic hydrogen bonds dissipate energy. The synergistic effect of these two mechanisms makes the maximum stretching ratio of cross-linked PB more than 13000 times (limited by the range of instruments and the influence of gravity on tensile properties, and has not yet reached the ultimate stretch ratio). This result is far more than the high tensile polymer reported in the literature (210 times the gel and 180 times the bulk polymer).

　　 Relevant research work has recently been published in advanced materials (Adv. Mater. 2019, 31, 1904029, DOI: 10.1002/adma.201904029). The work was done in collaboration with Professor Cui Shuxun of Southwest Jiao Tong University, researcher Wang Jianping of the Institute of chemistry, Xiang Junfeng and McMaster University professor Shi Anchang.