Poly(lactic acid)/cellulose nanocrystal composites via the Pickering emulsion approach: Rheological, thermal and mechanical properties.

The use of nanocellulose is an attractive method to improve the characteristics of biodegradable polymers, but its effects are often affected by uneven dispersion. In this work, cellulose nanocrystals (CNCs) were evenly dispersed into poly(lactic acid) (PLA) via the Pickering emulsion approach. The PLA/CNC composites prepared were studied by rheological, thermal as well as mechanical measurements. Changes in the rheological characteristics of the composites showed that CNC promoted the transition of the composites from fluid to solid-like behavior at high temperatures. The introduction of 5 wt% CNC improved the crystallinity of PLA considerably and increased the onset temperature of crystallization by about 10 °C. The storage modulus of the composites increased throughout the entire temperature range of testing. Flexural modulus was improved considerably. All the results indicated that the Pickering emulsion approach improved the dispersion of CNC in the PLA matrix and CNC improved efficiently most properties of PLA.