Strength Enhancement of Aliphatic Polyurethane Film by Solution Annealing

In recent years, aliphatic polyurethane has attracted more and more attention depending on its high adhesion and excellent optical and yellowing resistance properties. Among them, polyurethane-based laminated safety glass relies on the high strength of polyurethane films. In this work, the tensile strength of polyurethane film based on isophorone diisocyanate (IPDI) was increased from 48 to 65 MPa and the elongation at break was increased from 345% to 446% after solvent annealing. The absorbed impact energy of their laminated glass has been increased from 0.49 to 3.43 J, which is attributed to the activation of polyurethane chain segments rearranging by ethanol molecules. The higher hydrogen bonding degree and the regular internal structure are confirmed by FT-IR, SEM, and DMA characterization. On this basis, laminated glass with a high impact strength of Y12 film was successfully constructed.