Preparation and Properties of Poly(L-Lactid Acid)/Organo-Montmorillonite Composites by Solution Casting Method

PLLA / OMMT composite films were prepared through solution casting method, in which chloroform was used as solvent. Mechanical, thermal and crystallization properties of neat PLLA and PLLA / OMMT composites films were investigated as well as morphology through scanning electron microscope. It was shown that tensile strength of PLLA / OMMT composite films gradually increased with increasing OMMT content, but reduced when more filler were added. Loading of 2wt% of OMMT seemed to benifit PLLA in tensile strength most. With the increase of montmorillonite content, the elongation at break of PLLA decreased first and then reached to a steady level. When compared with pure PLLA, the composite system showed decreased spherulite size, lower degree of order and an increase in the number of grains. Thermal analysis has proved that the addition of OMMT greatly enhanced crystability and thermal stability of PLLA.