Effect of low loadings of cellulose nanocrystals on the significantly enhanced crystallization of biodegradable poly(butylene succinate-co-butylene adipate).

Biodegradable poly(butylene succinate-co-butylene adipate) (PBSA)/cellulose nanocrystals (CNC) nanocomposites were successfully prepared via a solution and casting method at low CNC loadings. The nonisothermal and isothermal melt crystallization behaviors of PBSA/CNC nanocomposites were significantly enhanced by low loading of CNC. The nonisothermal melt crystallization peak temperature obviously increased from 56 °C for neat PBSA to 63.6 °C for PBSA/CNC1 (the nanocomposite containing 1 wt% CNC) at 10 °C/min. Crystallization half-time at 80 °C significantly decreased from 31 min for neat PBSA to 8.4 min for PBSA/CNC1. CNC apparently increased the crystallization rate of PBSA; however, the crystallization mechanism remained unchanged. The crystalline morphology study verified the enhanced nucleation density of PBSA spherulites, indicating the role of CNC as an efficient nucleating agent. In addition, low loadings of CNC did not modify the crystal structure of PBSA.