Synthesis and Characterization of Poly(L-lactide)/Montmorillonite Nanocomposites

초록

Polylactide-Montmorillonite(PLLA/MMT)nanocomposites were prepared by simple esterification of PLLA and MMT modified with. 11-aminoundecanoic acid(ADA). The structural characterization confirmed the existence of characteristic ester linkage and the formation of intercalated nanocomposites. In particular, the XRD patterns of the modified clays showed 001 basal spacing enlargement as much as 1.40~1.80nm depending on the amount of ADA. PLLA/MMT nanocomposite showed the different aspect according to the amount of clay. Tensile modulus of composite were marginally enhanced as a result of intercalation of clay. However the increment of tensile strength, elongation at break grow less. It is another evidence of intercalation that IR spectra of the product extracted with hot THF (at >5wt% clay content) showed the absorption bands of PLLA. The glass transition temperature(Tg) of the composites appeared the similar trace. Whereas melting peak temperature(Tm) decreased and crystallization peak temperature(Tc) increased indicating that the crystallization PLLA was retarded due to the presence of MMT.