Enhancing the crystallization of biodegradable poly(ε-caprolactone) using a polyvinyl alcohol fiber favoring nucleation

In this study, biodegradable poly(epsilon-caprolactone) (PCL)/polyvinyl alcohol (PVA) fiber composites were prepared using melt processing techniques with different PVA fiber contents. The effect of PVA fiber on the non-isothermal and isothermal melt crystallization kinetics of PCL/PVA fiber composites was studied by using differential scanning calorimetry. Non-isothermal crystallization peak temperatures were enhanced significantly, as exemplified by about 20 K increase for the composite loaded with 5 wt% PVA fiber at a cooling rate of 20 K/min compared to that of neat PCL. The crystallization half-time decreased from 1.67 min for neat PCL to 0.80 min for composite with 5 wt% PVA fiber at a cooling rate of 5 K/min. PVA fiber was also found to dramatically accelerate the isothermal crystallization rate of PCL/PVA fiber composites. The crystallization half-time of composite containing 5 wt% PVA fiber was reduced by more than 10 times compared with neat PCL. Moreover, dynamic mechanical analysis results showed that PVA fiber had a strengthening effect on the PCL.