Hydrophobic and Flame-Retardant Foam Based on Cellulose

A study aimed to prepare cellulose-based hydrophobic, lightweight, and flame retardant foam composites. Cellulose was activated by phosphoric acid followed by blending with dolomite clay of different loading ratios. Gelatin/tannin as an adhesive system was used as a binder. A solution of the environmentally friendly silicone rubber (RTV) was applied onto foam samples via spray-coating to improve their water repealing performance, which was explored by investigating both of water contacting angle and wettability time of the coated foam samples. Flammability characteristics, thermal decomposition, surface morphology, and chemical structure of treated and untreated foams were investigated by flammability test, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The fire retardancy of foam composites was optimized at low and medium loading of dolomite. Also, the addition of RTV improved the hydrophobicity of composites maintained the fire retardancy of composites with medium loading.