The Impact of Aloe Vera Gel Towards the Rheological Properties of Thermoplastic Starch-based Film

Abstract

Thermoplastic starch (TPS) is a biopolymer that has gained recognition as a substitution for petroleum-based plastic. TPS combined with other material manufacturing processes through melt mixing necessitates high temperatures that can impact the product’s degrading qualities. Hence, Aloe vera (AV) gel is added as a cross-linker for the process. This paper focuses on investigating the rheological properties of TPS film based on potato-soluble starch upon the addition of AV gel. Melt mixing and hot-press processes were used to create the films. The melt and dynamic rheology of the material were all measured. The result shows that the melt flow index of the TPS/AV films is reduced with the increase in the AV gel content. The formation of crosslinking between TPS and AV prevents polymer chains from sliding past each other contributing to an increase in the viscosity and reduction in shear rate. A higher value of storage modulus than loss modulus proved that the TPS/AV films behaved more like a solid than a liquid. The complex viscosity of the films decreases as the frequency increases which is caused by the shear-thinning effect. Thus, crosslinked TPS/ AV films with well-understood rheological properties could be suitable for various packaging applications due to their mechanical strength, barrier properties, and potentially biodegradable nature.