A comparative study of the thermo-mechanical properties of polylactide/cellulose nanocrystal nanocomposites obtained by two surface compatibilization strategies

Nanocomposites of poly(lactide) (PLA) and cellulose nanocrystal (CNC) were fabricated using two different types covalently grafted surface compatibilizers, namely fatty acids (lauric or stearic acid) poly(glycidyl methacrylate) (PGMA) bearing reactive epoxy end-groups. Temperature-Modulated DSC analysis informed on weak attractive interaction PLA CNC-g-lauric acid plasticizing CNC-g-stearic acid. Despite that a homogenous dispersion up to 50 wt% CNC in was obtained the rubbery elastic moduli increased 150-fold as compared PLA. CNC-g-PGMA phase-separated but partially it at interface. It yielded 40-fold increase plateau moduli. The data with Ouali model for percolated systems Halpin-Tsai composites short fibers showed However effective modulus network smaller than unmodified CNC. Reactive compatibilization prevented percolation lead high filler/matrix coupling. In case, could be described model. conclusion, compatibilizing even if developing only interactions polymer matrix helps obtain nanocomposites, strength is lowered because weakens also CNC/CNC interactions. polymers can an interesting alternative, needs optimized take advantage coupling avoid phase separation.