Abstract

In this study, the effects of crosslinker concentration on the physical and mechanical properties of polyurethane (PU), an underwater sound-absorbing material, were investigated. Trimethylolpropane (TMP) was employed as a crosslinker, and its concentration was adjusted to examine its impact on the material properties. Dynamic mechanical analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and tensile testing were performed to analyze the material characteristics. As the TMP content increased from 25% to 100%, the elastic modulus increased by approximately 103.8%, corresponding to a nearly 300% change in TMP concentration. The loss factor, which is closely related to sound-absorption performance, increased by up to 27.19% with increasing TMP content. Additionally, the loss factor was found to increase by up to 13.68% as the temperature decreased from 30 to 10°C. These findings indicate that the mechanical properties and loss factor of PU improved at lower temperatures and higher TMP concentrations, thereby providing insights into the effective design of sound-absorbing materials.

Keywords: polyurethane;crosslinking;young’s modulus;loss factor;glass transition temperature