Characterization and simulation of composite films synthesized by Eucommia rubber and epoxy resin

The present work aims to characterize Eucommia rubber (ER)/epoxy resin (Epr) composite films with respect to morphological, mechanical and hydrophilic properties which may allow potential application of such materials for sound insulation. Molecular dynamics (MD) simulation is performed to estimate the homogeneity of the cross-linked ER/Epr compounds. Based on simulation results, the most suitable ER/Epr blending ratio (5/5) and critical point (420 K) are predicted for preparing the ER/Epr films. Radial distribution function analysis is conducted to provide insight into the nature and type of the interactions occurring between the ER and Epr molecules. The surface chemistry of the ER/Epr films is characterized by using scanning electron microscopy (SEM), atomic force microscope (AFM), and fourier transform infra-red (FT-IR) spectroscopy, which proves that the addition of Epr (50%) can significantly improve the homogeneity and surface smoothness of the composite films. The composite films also show a strong stress strength (10.8 MPa) and tensile strain (1.56%) at an ER/Epr ratio of 8/2, and excellent hydrophobicity at an ER/Epr ratio of 4/6. Based on selection of the above optimal parameters, the composite films with an ER/Epr ratio of 4/6, 6/4 and 10/0 and thickness of 0.5 mm were prepared, and their sound insulation performance was characterized. The films showed wide sound insulation ranging across the low (<400 Hz), medium (400–2000 Hz) and high frequency ranges (>2000 Hz), which is promising for potential industrial application of ER-based films.