Abstract Cobalt/aluminum and nickel/aluminum layered double hydroxide (LDH - M+2:Al molar ratio of 3:1) were intercalated with dodecylsulphate (DDS), laurate (LAU), stearate (STE) and palmitate (PAL) and used as filler in low-density polyethylene (LDPE) in percentages between 0.2 and 7.0wt%. After injection molding, the samples were submitted to morphological characterization by scanning electron microscopy (SEM), analysis of thermal behavior by differential scanning calorimetry (DSC) and investigation of rheological properties. All Co/Al-LDPE samples showed the formation of a high temperature polymer crystal domain, induced by the LDH filler. The rheological properties indicated in general a reduction of shear modulus due to incompatibility between some regions of LDH and LDPE, which promoted phase separation. However, interaction with the LDH surface indicated higher affinity of the Ni/Al-LDH for the LDPE compared to Co/Al-LDH, forming permanent networks.

Green (Ni2+/Al+3) and pink (Co2+/Al+3) layered double hydroxides (LDH) (molar ratio of 3:1) were intercalated with several organic anions and used as functional colored fillers into low density polyethylene (LDPE) by melt mixing in amounts of 0.2 to 7 wt.%. Scanning electron microscopic (SEM) results of LDPE nanocomposites indicated that with low percentage of filler, all the LDH samples showed efficient delamination/exfoliation in the polymer matrix. Fillers added to LDPE with concentrations of 0.2, 0.5, 2 and 5% presented, in general, maintenance of Young's modulus and tensile strength, tending to the reduction with a loading of 7%. Most of the nanocomposites presented similar elongations, although NiUS stood out, with an elongation increase of 300%. Differential scanning calorimetry (DSC) indicated the effect of the Co/Al-LDH in inducing the formation of LDPE crystalline domains, especially at higher temperature than neat LDPE.