Abstract:
The aim of this study was to examine the use of polylactic acid (PLA)/shellac (SH) polymer-blend for food packaging films. PLA is a biodegradable plastic that can decompose in suitable conditions. Shellac is a natural resin from Laccifer insect.
To study the effect of the amount of shellac on PLA/SH polymer-blend films, shellacs physical and mechanical properties, and bacteria inhibition, PLA/SH polymer-blend films were prepared with an extruder film casting technique at various PLA: SH ratios of 1000:0, 97:3, 95:5, 93:7, 91:9, 90:10, 85:15, and 80:20 with the following code names: PLA, PLA/SH3, PLA/SH5, PLA/SH7, PLA/SH9, PLA/SH10, PLA/SH15 and PLA/SH20, respectively.
The findings showed that the polymer-blend film formed was brown-yellow and more transparent when compared to neat PLA. The modulus of PLA/SH polymer-blend films increased with increasing amounts of SH because SH molecules interpenetrated PLA molecules. PLA/SH polymer-blend films also showed inhibition properties on S.aureus, B.subtilist, E.coli, and K.pnenomoiae bacteria growth. Therefore, PLA/SH poymer-blend films can be a new class of non-toxic and decomposable films in the appropriate conditions.