High-Strength Polyurethane Composite Film Reinforced by Cellulose Nanocrystals

In recent years, safety laminated glasses have been widely used in construction, transportation, military, and other fields owing to their safety, comfort, and concealment. In this work, a cellulose nanocrystal was synthesized and blended in a polyurethane (PU) elastomer. Based on this, an aliphatic PU composite (CPU) film with high transparency and excellent mechanical properties has been achieved by stepwise polymerization. The mechanical properties and impact resistance of CPU composites were improved obviously, attributed to the microphase separation and hydrogen bonding. The tensile strength and bonding strength of the CPU film with glass can reach 53 and 3.4 MPa, which were 150 and 280% higher than those of the PU film, respectively. Extremely strong impact resistance of the laminated glass based on the CPU film has been confirmed by the falling ball impact test, which was 2.3 times that of polyvinyl butyral and 3.5 times that of PU. It will be an excellent candidate for safety laminated glass, which can be used in the aerospace, defense, and automotive fields.