Microcellular Foaming Process of PLA-TPU/cellulose Nano-fiber Nanocomposites

This study has been dedicated to the foaming of biocompatible blends of biodegradable poly-lactic acid (PLA) and thermoplastic polyurethane reinforced by bio-degradable cellulose nano fiber. The fabricated nanocomposites were examined via microstructural, mechanical and diffractometry in order to evaluate formation of percolated nanocomposites with promising characteristics. Foaming was then performed on the nanocomposites in a batch process with CO2 as a blowing agent. Experimental analysis of bulk density, cell density indicated that depending on the foaming parameters, foams with a microcellular structure were achievable. The results demonstrated that the high saturation pressure and time participate in high cell density (up to 1.3 × 109 cell/cm3) due to the grown degree of crystallinity or promoted PLA and TPU miscibility. Accordingly, adding TPU and CNF to the PLA enhanced the chance of creating high crystalline PLA foamed samples decorated with low bulk density. B