Functionalization of Polyurethane-Based Adhesives with UV Additives for LTA Applications

The high interlaminar strength in the multilayered structure is one of the crucial parameters of lighter-than-air (LTA) envelope material. In this work, different polyurethane (PU)-based adhesives were functionalized and their synergistic effect of adhesion with fabric has been studied. Three types of PU-based adhesives were used which were based on two-component systems that was further functionalized with carbon black and UV additives, and the peel strength was determined. PU-based adhesives were applied on a substrate, and laminates were prepared, and the gram per square meter (gsm) of the adhesives was optimized. The tensile strength, UV resistance property of the functionalized adhesives were improved and the UPF of the adhesives film was measured. Thermal properties and stability of the functionalized adhesives films were analyzed through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The crosslinking and the interaction between the carbon black and PU-based thermoset adhesives was analyzed through Fourier transform infrared spectroscopy (FTIR). Also, the prepared adhesive films were exposed to artificial weathering for 200 h. Functionalized PU adhesives films show excellent weather resistance behavior as compared to neat adhesive films due to better UV resistance property of carbon black.