Tensile and antimicrobial properties of linear low density polyethylene (LLDPE) and chitosan blend

Abstract

Plastic film for food packaging which are in great demand in many countries needs protection upon transportation and storage. Shelf life of food product can be prolong if added criteria such as antimould and antimicrobial (AM) properties are introduced to plastics film packaging itself. Polyethylene which is a popular commodity resin are among films used for packing but there is a need to incorporate bio fillers or polymer as blends. Hence, LLDPE with chitosan is an alternative blend to impart biodegradability. Chitosan exist as a naturally available polymer, its antimicrobial properties and biodegradability is exploited in this study. Blend films were prepared by blending linear low density polyethylene (LLDPE) and chitosan at different formulation via twin screw compounder. Film of thickness 50-60 micron were fabricated via compression molding process. Effect of incorporating chitosan and additiveonto LLDPE was tested by using Tensile, Antimicrobial and Mould and Spore count test. The tensile test showed that, AM (antimicrobial agent) added can improve the strength and flexibility of the LLDPE / Chitosan. For antimicrobial properties, all blend samples did not show the effect against Escherichia Coli (E.coli) neither Staphylococcus Aureus (S.aureus) since there are no inhibition zones around the sample; this could be due to the high temperature processing could have reduced the antimicrobial activities. However, for Mould and Spore Count test result, it showed that LLDPE and Chitosan film did exhibit anti mould characteristics compared to LLDPE film. The test was carried out for 7 days to allow the growth of mould and spore on bread wrapped in plastic LLDPE and Chitosan film.