Cellulose-nanofiber-reinforced poly(lactic acid) composites prepared by a water-based approach.

The difficulty of dispersing cellulose nanofibers (CNFs) in hydrophobic polymers such as poly(lactic acid) (PLA) remains a major obstacle to the expansion of cellulose nanocomposite applications. In this work, we employed the solvent evaporation technique commonly used for drug microencapsulation to suspend PLA in water as microparticles. The suspension of the microparticles was easily mixed with the CNFs prepared by high-pressure homogenization. Water removal by membrane filtration produced CNF sheets filled with the particles. Compression molding of the stacked sheets resulted in nanocomposites with good CNF dispersions. Increases in the modulus and strength (up to 58% and 210%, respectively) demonstrated the load-bearing capability of the CNF network in the composites.