Transcrystallization behavior at the poly(lactic acid)/sisal fibre biocomposite interface

The focus of this work was to evaluate the transcrystalline effects at poly(lactic acid) (PLA) matrix caused by various sisal fibres, which were untreated (U-sisal), or treated with alkali (A-sisal) and silane (S-sisal). Isothermal crystallization was performed at temperatures between 123 and 130 degrees C using polarized optical microscopy. Results showed that the sisal fibres untreated or treated all had a nucleating ability to transcrystallize in PIA matrix. Based on the theory of heterogeneous nucleation, the interfacial free energy difference functions Delta sigma were determined to be 0.68, 0.65, and 0.65 erg/cm(2) for PLA/U-sisal, PLA/A-sisal and PLA/S-sisal, respectively. This suggests that the fibre surface modification by using alkali or silane has little or no influence to the nucleation ability of sisal fibre in PLA matrix. (C) 2010 Elsevier Ltd. All rights reserved.