LDH as a multifunctional additive in EVA/TPU blends: Influence on mechanical, thermal, rheological and flame retardancy properties

Highlights: • Development of high performance EVA/TPU/LDH nanocomposite. • LDH incorporation results steady increase in LOI value. • Nanocomposites show superior mechanical properties and flame retardance. • TGA analysis also reveals higher thermal stability of the nanocomposite. - Abstract: Ethylene vinyl acetate/Thermoplastic polyurethane/Layered double hydroxide (EVA/TPU/LDH) nanocomposites were prepared with varying LDH content via melt mixing technique. The nanocomposites show significant improvement in tensile strength and modulus and the optimum improvement was obtained for E70L3 containing 3 wt% LDH. X-ray diffraction study (XRD) suggested the possible crystal disordering and partial exfoliation of LDH layers in the matrix and this exfoliation is also supported by transmission electron microscopy (TEM) study. Dynamic mechanical thermal analysis shows that the storage moduli of the nanocomposites are higher as compared to the unfilled blend. FTIR study also depicts the interaction between the polymer matrix and nanofiller. Thermogravimetric analysis indicates the better thermal stability and higher char residue for the exfoliated nanocomposites. The presence of the LDH positively affects the flame retardance characteristics with a steady increase in limiting oxygen index (LOI) value. Melt rheological analysis exhibits significant changes in the value of relaxation exponent and shear thinning exponent for the nanocomposites as compared to the neat blend. Thus, LDH turn out to be an excellent multifunctional additive for this blend system.