Molecular Insights Into Chain Length Effects of Hindered Phenol on the Molecular Interactions and Damping Properties of Polymer‐Based Hybrid Materials

Abstract

For hindered phenol (HP)/polymer‐based hybrid damping materials, the unclear relationship between the structure of HP and the damping properties limits the application of such promising materials. Herein, three kinds of HPs with different chain lengths were synthesized to explore the mechanism. The structures of the HPs were confirmed by nuclear magnetic resonance spectrum, the Fourier Transform Infrared Spectroscopy (FT‐IR), and X‐ray Diffraction (XRD). For further prepared HP/polyurethane hybrids, FT‐IR and XRD were adopted to confirm the hydrogen bonding interactions and micromorphologies. Moreover, molecular dynamics simulation was used to characterize the effects of chain length variation on the inter‐ and intramolecular hydrogen bonds (HBs) and the chain packing of the hybrids in a quantitative manner. Subsequently, combined with the dynamic mechanical analysis, the relationship between the chain length variation and the damping properties was established. The results showed that with the increasing of chain length, the intramolecular HBs between HPs can be prevented, and the loose HP chain within tight polymer matrix can be achieved, which results in a maximum increase of loss factor. While the homogeneity of the chain packing increases with the chain length increasing, which results in a decrease of the temperature range of loss factor ≥ 0.3. POLYM. ENG. SCI., 60:446–454, 2020. © 2019 Society of Plastics Engineers