YUAN Xinhua1, HU Zhenguo1, CHEN Zeyu2, MENG Fuliang3, JIA Yufei1, ZHENG Shaoqiu1, ZHOU Kewu1, FEI Hongwei2, HE Kun4
To address the shortcomings of butyl rubber (IIR) with low damping factor and unstable damping performance at temperatures above room temperature, the lignin-based phenolic formaldehyde resin (LPF) was incorporated into the IIR matrix to prepare LPF/butyl rubber damping composite materials. The three-dimensional network structure formed between LPF and IIR was utilized to broaden the damping temperature range of the material and enhance the damping coefficient. The experimental results show that LPF exhibits favorable compatibility with IIR at the LPF content of 12 phr, whereas excessive LPF addition tends to trigger particle agglomeration and degrade composite properties. LPF contributes to improved mechanical properties of the damping composites. At 12 phr LPF content, the maximum torque reaches 6.8 dN·m with the elongation at break of 1 706%, and the tensile strength attains 7.1 MPa. Benefiting from the constructed three-dimensional network between LPF and IIR, the damping capacity of composites is remarkably enhanced with the damping factor remaining as high as 0.32 at 70 ℃. The thermal stability of LPF/IIR composites is significantly improved, delivering the char residue of 26.4% at 800 ℃, which is substantially superior to the 3.3% of pure IIR.