Influence of interfaces on the crystallization behavior and the rigid amorphous phase of poly(L-lactide)-based nanocomposites with different layered doubled hydroxides as nanofiller

Based on the three-phase model of semi-crystalline polymers, we determined all phase fractions of the NiAl-LDH/PLLA nanocomposite in dependence on the concentration of the nanofiller. Moreover, the rigid amorphous fraction (RAF) was separated into the RAF(crystal) and the RAF(filler) unbiasedly. A detailed comparison to the related nanocomposite system MgAl-LDH/PLLA was made considering that Mg and Ni have different atomic weights. As a first result is was found that NiAl-LDH/PLLA displays a higher crystallization rate compared to MgAl-LDH/PLLA, which is related to the different morphologies of the two nanocomposite systems. For both systems RAF(crystal) devided by the degree of crystallization increases with increasing concentration of the nanofiller. This means in the case of the nanocomposites investigated here not each crystal produces the same amount of RAF, as often assumed. Also, RAF(filler) increases with the concentration for both systems but in a different way. This is discussed considering again the different morphologies of both nanocomposites.