Preparation of polysilsesquioxane-urethaneacrylate copolymer film reinforced with chitin nanofibers

► Chitin nanofibers reinforced silsesquioxane films were prepared. ► Chitin nanofibers/silsesquioxane composites were highly transparent. ► Chitin nanofibers drastically increased Young's modulus and tensile strength of the composites. ► Chitin nanofibers drastically decreased the thermal expansion of the composites. ► Polysilsesquioxanes improved heat resistance of chitin nanofibers.