Mechanical and thermal properties of Posidonia oceanica cellulose nanocrystal reinforced polymer

In the present study, cellulose nanocrystals (CNC) were isolated from Posidonia oceanica balls and leaves. CNC was prepared from this marine biomass by sulfuric acid hydrolysis (H2SO4) treatment. The raw fibers were firstly isolated by a delignification-bleaching process then the acid hydrolysis treatment was performed at 55 °C during 40 min under mechanical stirring. The ensuing CNCs were characterized by their morphological and thermal properties using transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA), respectively. Nanocomposite materials using the CNC extracted from marine biomass were obtained by casting and evaporating a mixture of this suspension with poly(styrene-co-butyl acrylate). The effect of CNC loading on mechanical and thermal properties was studied. Dynamic mechanical analysis (DMA) results showed a strong reinforcing effect of CNC that depends on their origin (balls or leaves). The difference was attributed not only to differences in the aspect ratio of CNC but also to the stiffness of the percolating network of nanoparticles.