Broken Chain Self-Reconnection Strategy Enables Radiation Ultraresistance of Polyurethane

Abstract

High-energy radiation could accelerate the deterioration of polymer properties, greatly increase the risk of equipment failure, and reduce the polymer’s service life. Inhibition of macromolecular chemical changes in polymers is the core design concept for conventional radiation resistance. Herein, we report a novel strategy that turns the radiation reaction into a repair effect for the self-reconnection of broken chains, thereby improving the radiation resistance of polyurethane (PU) concretely; the polybutadiene (PB) segments are evenly introduced into the PU with poly(propylene glycol) (PG) to prepare the PU containing PB and PG segments (PBG-PU). During irradiation, the radical addition coupling reactions of PB segments in PBG-PU allow the broken molecular chain of PBG-PU to be reconnected, thus continually repairing the radiation damage on PBG-PU. Therefore, the PBG-PU elastomers still maintain about 70% strength with minimal alterations in creep properties and recovery rates after 300 KGy radiation, while the ordinary PU elastomers have completely lost their original properties. The combination of the self-reconnection strategy and the modification method of the hard segment can even boost radiation resistance of PU to more than three times, showing excellent radiation stability. The self-reconnection strategy can also be used to increase the stability of the ultrastructure in material during high-dose gamma ray irradiation, showing great adjustability. This novel strategy demonstrates enormous potential in achieving the long-term application of polymers in nuclear industry, space mission, and radiation medicine fields.