Polystyrene (PS) is one of the most widely used polymeric materials. However, PS is too brittle to utilize for various applications. Additives are typically added into PS to create stronger PS. PS was successfully strengthened by adding cyclodextrin (CD), which could form inclusion complexes with benzene rings. Acetylated CD (AcCD) and PS were dissolved in toluene to obtain casting film with different contents of AcCD. Interestingly, 3–4 wt% of AcCD increased the fracture energy up to four times. In particular, AcγCD showed better molecular recognition than AcβCD, increasing the Young’s modulus by approximately 160%. Since CD has mainly been used to reinforce soft materials, this report expands the understanding host-guest chemistry of CD and suggests new application.
