Effect of lysozyme and glucose oxidase on the physical-mechanical and barrier properties of linear low-density polyethylene

Abstract

Bio-composite from linear low-density polyethylene (LLDPE) with lysozyme, mixed lysosome and glucose oxidase enzymes was synthesized through the melt extrusion system, respectively. The aim of this work was evaluation and characterization of the effect of lysosome, mixed lysosome and glucose oxidase enzymes on the mechanical, water vapor transfer rate, and structural appearance of the Bio based LLDPE composite films. Along this line, 50 g of LLDPE pellets incorporated with 1%, 5%, and 10% (w/w) of lysozyme alone, mixed lysosome and glucose oxidase were examined, apparently. Pure LLDPE was used as a control. Over all, biocomposite with 5 and 10%(w/w) of mixed lysosome and glucose oxidase enzymes did not result in good outcome and not even enough for characterization. The surface structure of biocomposites was examined through the digital microscopy for identify dispersion of enzymes inside the LLDPE matrix and at higher concentration (10w/w%) dense and large surface are formed. However, good dispersion and reinforcing activity of enzymes in the LLDPE matrix was noticed with small concentration of lysosome (1, and 5w/w%) enzymes. The mechanical strength and elongation at break of biocomposite composite films were found to increase with small concentration (1 and 5 w/w%), but decrease with increasing of enzyme concentration. Averagely, the WVTR showed increase as the enzyme concentration increased. Besides, the Fourier-transform infrared spectroscopy (FTIR) was used to determine structural configuration of the enzymes in LDPE matrix; single sharp stretching breaks at 570 cm-1 with 1, 5 and 10 wt.% was corresponded to the existence of enzyme bands. All in one, the addition of lysozomes and glucose oxidase in small concentration has high potential in development of biocomposite relative to the traditional plastic composites.

Keywords

• linear low-density polyethylene
• lysosome and glucose oxidase enzymes
• water vapor permeability
• mechanical and barrier properties
• ftir spectroscopy