Miscibility and Thermal and Mechanical Properties of Melt-Mixed Poly(lactic acid)/Poly(trimethylene terephthalate)/(Methyl Methacrylate)-Butadiene-Styrene Copolymer Blends

This study examined the miscibility and mechanical properties of melt-mixed poly(lactic acid) (PLA), poly (trimethylene terephthalate) (PTT), and PLA/PTT blend with 5-10 phr of methyl methacrylate-butadiene-styrene copolymer (MBS). The isothermal crystallization kinetics of the PTT blends were analyzed by using the Avrami equation. The Differential Scanning Calorimetry (DSc) and scanning electron microscope results indicated that the miscibility of the PLA/PTT blends was improved by adding 5-10 phr of MBS. Although PLA, with the addition of 10 phr of MBS, had lower tensile strength at yield and higher breaking elongation and impact strength than pure PLA, no improvement in these mechanical properties could be observed in PLA/PTT blends. This result is explained by assuming that the crystallization of PTT at the interface favors the disentanglement of MBS from the PTT domain. J. VINYL ADDIT. TECHNOL., 17:70-76, 2011. (C) 2011 Society of Plastics Engineers