Morphological and mechanical properties of Poly (lactic Acid) /zinc oxide nanocomposite films

Abstract

Objective(s): Nowadays, tendency to use green materials can reduce environmental pollution and plastic waste. Poly (lactic Acid) PLA is one of the natural biodegradable polymers mainly used in the production of bioplastics for packaging which is made of non-toxic compounds and is easily biodegradable. In this research, the effect of 1, 3 and 5% nanocomposite zinc oxide on the morphological, mechanical properties and chemicals interaction of poly-lactic acid films was investigated.<br />Methods: To study morphological structure of nanocomposites, scanning electron microscope (SEM) was used. For evaluating the mechanical properties of films, tensile strength, elongation at break and young's modulus were measured by the ASTM D882 standard. Also, The Fourier-transform infrared spectroscopy (FT-IR) spectrum of films with PERKIN ELMER 1650, FT-IR spectrophotometer was recorded.<br />Results: Morphological shows that zinc oxide nanoparticles are well distributed in polymer matrix in all nanocomposite samples. It is clear from the result of mechanical properties that the Young's modulus was increased significantly (p<0.05) when the percentage of zinc oxide in the poly-lactic acid film increased from 1% to 5%. The tensile strength values of films zinc oxide nanocomposites were significantly (p <0.05) less than the control film. Also, elongation at break was no statistically significant. In the investigation of FTIR spectra, the percentage of created bonds between nanozinc oxide and poly lactic acid are increased by enhancing the percentage of nanozinc oxide.<br />Conclusions: Due to the good functional mechanical and morphological properties of PLA-nanozinc oxide films, they can be employed for various packaging.