Strategic moderation of thermal stability and curing time of lignin-based phenolic resin by incorporating nanoparticles

In order to solve the problem of poor thermal stability of lignin-based phenolic resin (LPF), nanoparticles such as nano-SiO2, nano-Al2O3 and nano-TiO2 were used as modifiers to modify LPF. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) results showed that nano-SiO2, nano-Al2O3 and nano-TiO2 can be chemically cross-linked with LPF to form Si-O-Si, Al-O and Ti-O, respectively. Scanning electronic microscopy (SEM) results showed that after modifying by nano-SiO2 (SLPF), nano-Al2O3 (ALPF) and nano-TiO2 (TLPF), the small copolymers were significantly reduced and the surface become flat and smooth. Thermogravimetric analysis (TGA) showed that at 800 °C, the thermal stability of SLPF, ALPF and TLPF increased by 4.28, 5.38 and 4.74%, respectively, compared with LPF, the reason was that the introduction of nanoparticles required more energy to be absorbed during thermal degradation. Differential scanning calorimetry (DSC) results showed that the curing temperature of the modified LPF remained basically unchanged, and the curing time was reduced.