The use of low-cost agricultural and forestry waste for the preparation of modified phenolic foam (MPF) has attracted widespread attention and has shown promising prospects. This study proposes a novel method for producing MPF using pine sawdust. The full components of pine wood powder and its liquefied products were used as raw materials, and the resin was modified with a silane coupling agent (KH560), triethylene glycol (TEG), and nylon 66 (PA66). Subsequently, three novel MPFs were successfully fabricated using a transplanted core foaming technique, and their material properties were subsequently investigated. The results showed that all three MPFs exhibited excellent compressive strength and flame retardancy, with compressive strength ranging from 5.93 MPa to 12.22 MPa and oxygen index values between 36.2% and 41.5%. In terms of water resistance, the MPFs significantly outperformed traditional phenolic foam (PF); in particular, the addition of 4% KH560 and PA66 reduced the water absorption rate to as low as 2.5%. Furthermore, the powdering rate and thermal conductivity of all MPFs were significantly reduced, with chalking rates decreasing by 28.57% to 50%. This research presents a novel method for preparing MPF using agroforestry waste as a partial replacement for phenol. This approach achieves high-value utilization of pine sawdust while maintaining the performance of the MPF, thus broadening the avenues for MPF production.

Biomass carbon foams are extensively utilized across various fields due to their favorable properties and cost-effectiveness. In this study, triethylene glycol (TEG), nylon 66 (PA66), and 3-glycidyl-oxypropyl-trimethoxy-silane (KH560) were incorporated into pine wood liquefaction resin to successfully prepare three novel modified carbon foams (MCFs), and their characteristics were investigated. The results indicate that the compressive strength and specific surface area of the three MCFs were significantly enhanced. Specifically, the compressive strength increased by 37%, 46%, and 89% following modification with TEG, PA66, and KH560, respectively, while the specific surface areas ranged from 383.4 to 499.3 m²/g. Additionally, the cell structures of the three MCFs exhibited greater uniformity, with larger average pore sizes, thinner ligament thicknesses, and increased opening porosities. Notably, the opening porosity of KH560-modified carbon foam (KH560-PLP-PF-CF) reached its maximum value at 87.95%. XPS analysis confirmed the successful introduction of Si-containing molecular bonds, including Si-OH-Si, Si-OH, and Si-CH, into KH560-PLP-PF-CF. Furthermore, FT-IR analysis revealed characteristic Si-O vibration peaks, PA66 amide peaks, and TEG ether bond absorption peaks in the three MCFs. The incorporation of flexible functional groups effectively enhanced their compressive properties. The findings of this study expand the potential for utilizing biomass waste to partially replace phenol in the development of novel carbon foams.