Viscoelastic macromolecular materials are widely used in underwater acoustic fields because of their favorable acoustic performance. Dynamical mechanical properties of viscoelastic materials, such as Young's modulus, shear modulus, and relevant loss factors, are important in the forecast of acoustic properties, which connect acoustical design of underwater coating with materials prescription design. Dynamic Young's modulus of some macromolecular materials is measured with dynamic mechanical apparatus (DMA), and then the basic acoustic parameters are expanded from a narrow band to a broad band by using principles of time-temperature superposition (TTS). When applying the basic parameters to calculating characteristics of the uniform layer sample by using the finite element method, a reasonable agreement of sound absorption coefficients is obtained between the calculations and measurements in the acoustic pipe. Furthermore, the underwater acoustic absorption properties of the coating with a local resonant structure are discussed. Finally, some suggestions are given about how to improve the underwater absorption performance at low frequencies.