Research on increasing the resistance of space-use materials to atomic oxygen (AO) has focused on adding Si to the base compound. The Si reacts with AO to form a protective silicon oxide film. Our previous research centered on a siloxane-block polyimide film used in commercial products. We assessed its resistance to AO on the ground and in space. However, there is a risk for future application of this materials because this material contains cyclic siloxane compounds as raw materials. which poses a risk for future applications. Cyclic siloxane compounds have recently been strongly considered for regulation from the viewpoint of environmental and human health hazards. Several prototypes of improved siloxane-modified polyimide film (BSF-NCS) have been that do not contain low-molecular-weight cyclic siloxane. This material also contains no fluorine compounds. The AO and UV resistance of these films was evaluated and found to be excellent. We also evaluate space debris impact on the AO resistance of this type films. Outgassing characteristics were also found to be acceptable for routine space application.

In the final paper, we will report on the status of our research on this new siloxane-modified polyimide films with space demonstration plans. Prototype films will be also displayed on an exhibition area.