Reinforcement of plant fiberbased ultra low density material with sodium silicate

Inorganic materials such as sodium silicate and aluminum sulfate can be used as additives to improve mechanical and fire resistance performances of plant fiberbased ultra low density material (ULDM) during its making process using the liquid frothing approach. Following process was used to make sample mats: after fiberization in a refiner, adding resin and surface active agent in the pulp solution, then adding sodium silicate and aluminum sulfate, well mixing the solution; after solution frothing, mat forming and drying, a plant fiberbased ultra low density mat was made. Compared with 0 inorganic additive, using 40% sodium silicate and corresponding amount of aluminum sulfate could increase internal bonding strength of the ULDM from 0.1 MPa to 10 MPa, MOE from 12.4 MPa to 87.3 MPa; MOR from 0.2 MPa to 7.3 MPa and compressive strength (at 10% strain) was ranging from 0.2 MPa to 3.7 MPa. This also can reinforce fire resistance performance and oxygen index reach a higher level of 42%. No significant weight loss and exothermic decomposition could be observed below 700 ℃.