Non-isothermal crystallization behavior of PLA/acetylated cellulose nanocrystal/silica nanocomposites

Abstract

Poly(lactide) (PLA)/acetylated cellulose nanocrystals (ACN)/silica nanocomposites were prepared by solution casting. Surface modification of cellulose nanocrystal (CNC) was performed to prepare the ACN. The ACN and silica were expected to act as a mechanical reinforcement of PLA and a nucleation agent, respectively, to increase the crystallization rate. Introduction of acetyl groups on the surface of the cellulose nanocrystals was confirmed by Fourier transform infrared spectroscopy. A combined Avrami-Ozawa analysis described the non-isothermal crystallization effectively. The activation energy for the crystallization was calculated from the Kissinger and the Takhor equations. Spherulite growth behavior was observed by polarizing optical microscopeandspherulitegrowthrate, thenumberof spherulite versus crystallization timehave investigated. Thedevelopment of PLA crystals and the thermal stability had a tendency to improvewith increasing silica content. Increased tensile strengthwas observed due to the reinforcement effect of ACN and themorphology of the nanocomposites was investigated.