Improvement of Microstructure and Fractured Property of Poly(L-lactic acid) and Poly(butylene succinate-co-e-caprolactone) Blend Compatibilized with Lysine Triisocyanate

Blends of poly(L-lactic acid) (PLLA) and poly(butylene succinate-co-e-caprolactone) (PBSC) with and without addition of lysine triisocyanate (LTI) were prepared by using a conventional melt-mixer. The effect of LTI on the microstructures and fractured property of the blends was characterized by Fourier transform infrared (FT-IR) analysis and field emission scanning electron microscopy (FE-SEM). J-integral at crack initiation, Jin, and the total fracture energy, Jf, were measured as mode I fracture properties to assess the effect of LTI addition on these properties. Fracture morphologies were also examined by FE-SEM to characterize the effect of structural change due to LTI addition on the fracture micromechanism. It was found that LTI addition dramatically improves the compatibility between PLLA and PBSC and results in the improvement of the fractured energy, Jf of ACI value was about 17 times larger than that of neat PLLA. FE-SEM also showed that the reduction of the phase-separation increases local ductile deformation in the crack-tip region.