Nanocomposites membranes from cellulose nanofibers, SiO₂ and carboxymethyl cellulose with improved properties

The binary nanocomposites blended by carboxymethyl cellulose (CMC) and SiO₂ nanoparticles were constructed to prepare the films with superior thermal stability and flame retardant properties. The incorporation of cellulose nanofibers(CNFs) and SiO₂ nanoparticles were followed to prepare ternary nanocomposite films exhibiting excellent mechanical properties. The mechanism and chemical reaction of the thermal decomposition for the CMC/SiO₂ composite membrane were proposed, which showed that the mass residuals were Na₂CO₃, SiO₂ and Na₂SiO₃, Na₂CO₃ when the content of the SiO₂ nanoparticles was lowered and higher than 9.6 %, respectively. Compared with the pure CMC, micro combustion calorimeter (MCC) showed that the total heat release (THR) and the peak heat release rate (PHRR) both decreased from 6.4 kJ/g to 5.8 kJ/g, 134 w/g to 27 w/g, respectively. Moreover, mechanical properties of CMC/CNFs/SiO₂ membrane showed that the toughness and rigidity of the nanocomposites increased by 56.0 % and 63.0 % on the basis of CMC, respectively.