Nonisothermal Melt Crystallization Study of Poly(ethylene succinate)/Cellulose Nanocrystals Composites

The nonisothermal melt crystallization behavior of fully biodegradable poly(ethylene succinate)/cellulose nanocrystals (PES/CNC) composites with low loadings of CNC from 0.25 to 1 wt% was studied in detail in this research at different cooling rates with differential scanning calorimetry. As an efficient heterogeneous nucleating agent, CNC remarkably enhanced the melt crystallization of PES, thereby obviously increasing the crystallization rate coefficient parameters of the composites. The Ozawa method failed to analyze the melt crystallization kinetics of both neat PES and its composites. Through the methods proposed by Dobreva and Ortega, the nucleation activity of CNC and crystallization activation energy of the composites were calculated, respectively, showing the CNC loading dependence. When CNC loading was 0.5 wt%, the composite showed the highest melt crystallization peak temperature at the same cooling rate, greatest crystallization rate coefficient, strongest nucleation activity, and highest absolute crystallization activation energy at the same extent of conversion. The nucleation mechanism of PES on CNC surface was proposed; moreover, the CNC loading dependence of the crystallization of PES was further discussed through the dispersion of CNC in PES matrix study.