Double-Melting Behavior of Bamboo Fiber/Talc/Poly (Lactic Acid) Composites

The melting and crystallization behavior of pure poly (lactic acid) (PLA) and PLA composites (1% Bamboo Fiber (BF)/PLA, 1% Talc/PLA, 1% BF/1% Talc/PLA) were studied with differential scanning calorimetry (DSC). DSC curves for PLA composites were obtained at various cooling rates, the crystallization temperature and heat of crystallization of PLA composites decreased almost linearly with increasing of log (cooling rate). Moreover, BF has minor effect and talc has the great effect on the crystallization temperature in the PLA composites. With increasing of cooling rate, the main melting temperature of PLA composites decreased. In pure PLA and 1% BF/PLA, the double-melting behavior appeared in the heating curves after slow rate of cooling, and there was the opposite phenomenon of double-melting behavior in other two PLA composites. BF promotes forming the imperfect crystal in the PLA composites during heating process. With increasing of heating rate, the main melting temperature of PLA composites increased except the 1% BF/PLA. At various heating rates, the defects of BF structure promoted the melt-recrystallization and talc promoted forming the small crystals. At last, the recrystallization model was given.