Advanced Nanocomposites of Cellulose Nanowhiskers and Cellulose Acetate Butyrate Prepared by Sol-Gel Processing Method

摘要

Dispersion of cellulose nanoparticles and their chemical compatibility with polymer matrix are important issues for the final properties. Homogeneous dispersion of cellulose nanoparticles in polymers, by using traditional process techniques, is very difficult due to their strong tendency of self-association (Capadona et al. 2007, Capadona et al. 2009). In order to improve the dispersion of cellulose nanowhiskers in non-aqueous polymers, several strategies have been adopted. It includes the use of surfactants (Bondeson and Oksman 2007) and chemical modification via reaction of the hydroxyl groups (Habibi et al. 2008, Nair et al. 2003). It is also reported the preparation of stable cellulose nanowhiskers suspensions, after freeze-drying step, in different organic solvents, such as dunethylformamide (DMF) (Marcovich et al. 2006, Samir et al. 2004, Viet et al. 2007), dimethyl sulfoxide (DMSO) (van den Berg et al. 2007, Viet et al. 2007) and N-methylpyrrolidine (NMP) (van den Berg et al. 2007) without either addition of a surfactant or any chemical modification. This study, describes the production of cellulose nanowhisker organogels in ethanol medium, and investigates their ability to be dispersed and distributed into cellulose acetate butyrate (CAB) solutions. The sol-gel process is adopted with the objective to efficiently eliminate the water from the nanowhiskers suspension. Conventional mechanical properties, thermal properties and optical transparency of the nanomaterials were studied as a function of nanowhisker content in the matrix.