Natural fiber reinforced inorganic foam composites from short hemp bast fibers obtained by mechanical decortation of unretted stems from the wastes of hemp cultivations

The wettability of hemp fibers, to be applied in fiber-reinforced foams, can be improved with several chemical treatments. In this paper, a innovative treatment with sodium ascorbate was evaluated. Untreated and treated fibers have been characterized using FTIR spectroscopy and TGA measurements. Furthermore, the feasibility of treated fibers was evaluated preparing diatomite-based fiber-reinforced foams. These materials were finally characterized by mechanical compressive strength and thermal properties (thermal conductivity). The fiber-reinforced foams have been produced using a diatomite natural source as a matrix. A suitable amount of Si powder and vegetable surfactant were used as chemical and physical foaming agents while a polysilicate solution was used as reactive crosslinker. The foams highlight low density, around 350 kg/m3, and low thermal conductivity (0.06 W/mK).