Non-isothermal Crystallization Behavior and Kinetics of Polylactide/Acetylated Cellulose Nanocrystals/Silica Nanocomposites

Abstract

Polylactide (PLA)/acetylated cellulose nanocrystals (ACN)/silica composites were prepared by solution casting method and processed by compression molding. ACN was synthesized by surface modification of cellulose nanocrystals. All samples include 0.5wt% of ACN and 0, 1, 3, and 5 % of silica was added, respectively. ACN was used as reinforcement of polymer matrix, silica play a role as nucleation agent to increase crystallization rate. FT-IR was measured to confirm that acetyl group was substituted to cellulose nanocrystals. Non-isothermal crystallization behavior was studied with the cooling rate of 2.5, 5, 10, and 15oC/min. Avrami equation and Ozawa equation failed to interpret non-isothermal crystallization behavior of composite on the other hand Avrami-Ozawa equation performed perfect prediction. Activation energy calculated by Kissinger and Takhor equations. As silica content increases, activation energy decreases due to nucleating effect of silica.