All-in-one benzophenone structure realizes the simultaneous improvement of flexibility and radiation resistance of polyurethane

In the environment of nuclear industry, space navigation and radiotherapy, a large number of high-energy rays pose a severe challenge to the radiation resistance of polyurethane (PU) elastomer. However, the traditional radiation resistance strategy of linking aromatic hydrocarbons into the molecular chain would severely sacrifice polymer flexibility, not suitable for flexible polymers. In this study, an all-in-one strategy to develop the radiotolerant and flexible PU elastomer is proposed through integrating radiation-resistance function with phase structure regulation. Concretely, the benzophenone (BP) structure is linked into the hard segment of PU to prepare the BP modified PU (BP-PU). In terms of flexibility, benefiting from the hydrogen-bond interaction between carbonyl group of BP and amide group of PU, the BP structure could inhibit the growth of hard phase to achieve the increase of PU flexibility instead of reduction. In terms of radiotolerance, the BP structure in BP-PU elastomer was found to perform dual radiation-resistance function that efficiently dissipates radiation-energy to reduce radical generation and trap the active radical. Under gamma-ray irradiation, BP-PU elastomer exhibited excellent chemical stability and radiotolerance in macro-properties. Notably, after high-dose irradiation, BP-PU elastomer not only shown a slight change in macroscopic color, but also performed twice the mechanical durability of control group. This work achieved the synchronous improvement of radiotolerance and flexibility of PU for the first time, providing an easy and promising avenue for the development of radiotolerant and flexible PU to fill the lack in radiation-related fields.