TY  - EJOU
AU  - Li, Jinxing 
AU  - Zor, Mustafa 
AU  - Zhou, Xiaojian 
AU  - Du, Guanben 
AU  - Rodrigue, Denis 
AU  - Wang, Xiaodong (Alice) 

TI  - Environmentally Friendly Tannic Acid-Furfuryl Alcohol-Soybean Isolate/Casein Composite Foams Reinforced with Wood Fibers
T2  - Journal of Renewable Materials

PY  - 2025
VL  - 13
IS  - 2
SN  - 2164-6341

AB  - In this study, two series of foams based on tannic acid (TA), furfuryl alcohol (FA), soybean protein isolate (SPI), and casein (CA), namely TA–FA–SPI (TS series) and TA–FA–CA (TC series) were developed, and their properties were enhanced by adding poplar fibers (WF). From the samples produced, a complete set of characterization was performed including possible crosslinking reactions, morphology, mechanical properties, flame retardancy, thermal insulation and thermal stability. Fourier-transform infrared spectroscopy (FTIR) revealed possible covalent crosslinking among the components and hydrogen bonding between WF and the matrix. Viscosity results indicated that lower prepolymer viscosity led to lower apparent density, while WF addition reduced even more the density. Mechanical tests showed that the maximum compressive strengths were good, while WF improved the compressive strength by up to 56%. Scanning electron microscopy (SEM) showed uniform cell structures, but small open pores were observed. Two-dimensional (2D) CT scan images confirmed the good compatibility between WF and the matrix, with low anisotropy in the material. Friability tests indicated that WF decreased the pulverization ratio of the materials by up to 42%. Thermogravimetric analysis (TGA) showed good thermal stability of the materials up to 328°C. Vertical burning tests showed that the materials were self-extinguishing without residue (dripping). The lowest thermal conductivity was 0.04 W/m·K. These results suggest that these novel formaldehyde-free, high biomass content (95%–96%) foams and composite foams have high potential to replace traditional phenolic foams (PF) in applications such as construction, transportation, packaging, and thermal insulation.
KW  - Foam composite; tannic acid; soybean isolate protein; casein; poplar fiber; compressive strength; flame retardancy; thermal insulation

DO  - 10.32604/jrm.2024.056795