Effects of PE-g-MA on tensile, thermal, surface, barrier properties, and morphology of plasticized LDPE/chitosan films

In this work, low-density polyethylene (LDPE)/chitosan (CH) blend films were prepared using polyethylene-graft-maleic-anhydride (PE- g -MA) as a compatibilizing agent for improving the interfacial adhesion. The effects of PE- g -MA concentration on the plasticized LDPE/CH blend films were investigated. The films were characterized by mechanical, thermal, hydrophobicity, structural, and permeability analyses. The results showed that CH and PEG (P) addition into PE had a reducing effect on tensile strength but, addition of the compatibilizer improved this property. Tensile strength value increased by about 16% in PE/CH/PE- g -MA film with only 5 wt% MA addition compared to pure PE film. Flexibility was sharply affected by the incorporation of CH while it increased with the use of PEG and PE- g -MA. Thermal stability recovered with the use of PE- g -MA compared to the plasticized PE/CH film. The crystallinity increased with the incorporation of CH. Contact angle and water permeability increased with CH and PEG addition to PE and reduced with the addition of PE- g -MA. Oxygen permeability decreased by about 50% with the addition of CH into PE. FTIR analysis indicated that there is an interaction between amino groups of CH and maleic anhydride groups. The use of PEG and PE- g -MA improved the compatibility of the PE/CH blends as showed by scanning electron microscopy (SEM). This study revealed that PE- g -MA had obvious positive effects on the mechanical, thermal, barrier, and structural properties of PE/CH blend films. The blend films can be a good candidate in the packaging industry due to biodegradable and non-toxic properties of chitosan. Graphical abstract